blood,bone marrow,spleen parasites (171)

BLOOD, BONE MARROW,

SPLEEN PARASITES

BLOOD, BONE MARROW,

SPLEEN PARASITES

BLOOD NEMATODABLOOD NEMATODA Order:Order: FilariataFilariata

BRUGIA MALAYI / BRUGIA MALAYI / WUCHERERIA BANCROFTI WUCHERERIA BANCROFTI

Brugia malayi /Wuchereria bancroftiBrugia malayi /Wuchereria bancrofti: : B.malayi B.malayi is is transmitted by mosquitoes of the genus transmitted by mosquitoes of the genus MansoniaMansonia, , AnophelesAnopheles and and AedesAedes..W.bancroftiW.bancrofti is transmitted by mosquitoes of the is transmitted by mosquitoes of the genus genus CulexCulex, , AnophelesAnopheles and and AedesAedes. . Close-up of mosquitoes on human skin. Close-up of mosquitoes on human skin.

Lymphatic filariases have a wide geographic Lymphatic filariases have a wide geographic distribution.distribution.W.bancroftiW.bancrofti and and B.malayiB.malayi infect some infect some 128 milion people,and about 43 milion have 128 milion people,and about 43 milion have symptoms.Lymphatic filariases have a wide symptoms.Lymphatic filariases have a wide geographic distribution.geographic distribution.B.malayiB.malayi infection is infection is endemic in Asia(China, Corea, India, Indonesia, endemic in Asia(China, Corea, India, Indonesia, Malaysia, Philippines, Sri Lanka).Malaysia, Philippines, Sri Lanka).B.timoriB.timori infection infection occurs in Indonesia (islands of Alor, Flores, Timor). occurs in Indonesia (islands of Alor, Flores, Timor). W.bancroftiW.bancrofti has a larger distribution : Asia has a larger distribution : Asia (China, India, Indonesia, Japan, Malaysia, (China, India, Indonesia, Japan, Malaysia, Philippines, South-East Asia,Sri Lanka, Tropical Philippines, South-East Asia,Sri Lanka, Tropical Africa, Central and South America, Pacific Islands.Africa, Central and South America, Pacific Islands.

Brugia malayi:Brugia malayi: microfilariae measure 270 by 8 microfilariae measure 270 by 8 µm, have a sheathµm, have a sheath and a tail with terminal and a tail with terminal constriction,elongated nuclei and absence of constriction,elongated nuclei and absence of nuclei in the cephalic space.They have nocturnal nuclei in the cephalic space.They have nocturnal periodicity.(Wet mount preparation).periodicity.(Wet mount preparation).

Brugia malayi: Brugia malayi: The microfilariae are sheathed The microfilariae are sheathed and can be distinguishedand can be distinguished from from W.bancroftiW.bancrofti for for size (275-320x7,5-10), location of nuclei and tail size (275-320x7,5-10), location of nuclei and tail nuclei.(Fresh examination, particular of the nuclei.(Fresh examination, particular of the caudal space).caudal space).

Brugia malayi: detail of the cephalic space. Microfilariae are usually nocturnally periodic but sub-periodic strains of B.malayi and W.bancrofti are observed.(wet mount, detail of the cephalic space of B.malayi microfilaria).

Brugia malayi:Brugia malayi: identification of microfilariae identification of microfilariae in in stained smear is possible by observation of the stained smear is possible by observation of the stained sheath (stained sheath (W.bancroftiW.bancrofti sheath does not sheath does not stain). stain).

Microfilaria of Microfilaria of Wuchereria bancrofti Wuchereria bancrofti (Giemsa stain, x 400) (Giemsa stain, x 400)

Brugia malayi:Brugia malayi: the tail is tapered and present a the tail is tapered and present a constriction.The last two nuclei are divided by the constriction.The last two nuclei are divided by the constriction. The sheath stains pink. constriction. The sheath stains pink. (Caudal space of (Caudal space of B.malayiB.malayi, Giemsa stain). , Giemsa stain).

Brugia malayi:Brugia malayi: the cephalic space is longer than the cephalic space is longer than broad(in broad(in W.bancroftiW.bancrofti is as long as broad). is as long as broad). (Detail of the cephalic space of (Detail of the cephalic space of B.malayiB.malayi microfilaria, microfilaria, Giemsa stain). Giemsa stain).

Lymphatic filariasis:Lymphatic filariasis: adults of adults of B.malayiB.malayi and and W.bancroftiW.bancrofti live live in the lymphatic vessels and in the lymphatic vessels and lymphnodes where they cause dilatation, lymphnodes where they cause dilatation, inflammatory infiltrates and, at last, blockage of inflammatory infiltrates and, at last, blockage of the lymphatic circulation.Adenolymphangitis, the lymphatic circulation.Adenolymphangitis, orchitis, epididimitis associated with fever areorchitis, epididimitis associated with fever are the the commonest manifestation of the acute stage of the commonest manifestation of the acute stage of the infection;eosinophilia is frequent at this stage. infection;eosinophilia is frequent at this stage. Lymphoedema particularly of the legs and scrotum, Lymphoedema particularly of the legs and scrotum,

hydrocoeles and chyluria are the result of the hydrocoeles and chyluria are the result of the progression of the disease;genital manifestations progression of the disease;genital manifestations are frequent in are frequent in W.bancroftiW.bancrofti infections infections while they while they are rare during are rare during B.malayiB.malayi infections. infections. --Lymphatic filariasis: elephantiasis of scrotum.Lymphatic filariasis: elephantiasis of scrotum.--Tanzanian with elephantiasis due to Tanzanian with elephantiasis due to W.bancrofti.W.bancrofti.--Another Tanzanian patient with elephantiasis due Another Tanzanian patient with elephantiasis due to to W.bancrofti.W.bancrofti.--Early hydrocoel in a Tanzanian man withEarly hydrocoel in a Tanzanian man with W.bancrofti infectionW.bancrofti infection

Lymphatic filariasis: elephantiasis is the last Lymphatic filariasis: elephantiasis is the last consequenceconsequence of the swelling of limbs and scrotum. of the swelling of limbs and scrotum. Diethylcarbamazine (DEC), ivermectine and Diethylcarbamazine (DEC), ivermectine and albendazole usedalbendazole used alone or in combination are the alone or in combination are the drugs of choice.drugs of choice.--Elephantiasis of the limbs. Elephantiasis of the limbs. --Thai patient with elephantiasis of leg due to Thai patient with elephantiasis of leg due to W.bancroftiW.bancrofti or or Brugia malayi. Brugia malayi. --Second Thai patient with elephantiasis due to Second Thai patient with elephantiasis due to lymphatic filariasis.lymphatic filariasis.

LOA LOA LOA LOA

Loa loa: Loa loa: the infection is endemic in West and the infection is endemic in West and Central Africa,especially in Angola, Cameroun, Central Africa,especially in Angola, Cameroun, Congo, Eq. Guinea, Gabon, Nigeria, RCA, Zaire.Congo, Eq. Guinea, Gabon, Nigeria, RCA, Zaire.

Loa loa:Loa loa: after injection larvae develop into adults after injection larvae develop into adults in 6 monthsin 6 months and may live for 17 years in the and may live for 17 years in the organism.Microfilariae measure 275 by 5-6 µm organism.Microfilariae measure 275 by 5-6 µm and are present in blood without periodicity. and are present in blood without periodicity. Count is mandatory before therapy. Count is mandatory before therapy.

Loa loa:Loa loa: microfilariae measure with the sheath microfilariae measure with the sheath 240-300 by 5-6 µm.The sheath doesn't stain with 240-300 by 5-6 µm.The sheath doesn't stain with Giemsa. The nuclei extendGiemsa. The nuclei extend from the small cephalic from the small cephalic space to the tip of the tail.(Giemsa stain).space to the tip of the tail.(Giemsa stain).

Loa loa:Loa loa: the sheath does not stain and appears the sheath does not stain and appears as a virtual space around the larva. as a virtual space around the larva. (Giemsa stain).(Giemsa stain).

Loa loa:Loa loa: the nuclei form a continuous row to the the nuclei form a continuous row to the tip of tail.The unstained sheath is well visible. tip of tail.The unstained sheath is well visible. (Detail of the caudal space, Giemsa stain).(Detail of the caudal space, Giemsa stain).

Loa loa: Loa loa: large nuclei extend from the little large nuclei extend from the little cephalic space. cephalic space. (Detail of the cephalic space, Giemsa stain).(Detail of the cephalic space, Giemsa stain).

Loa loa:Loa loa: the presence of the unstainded sheath is the presence of the unstainded sheath is clearly visibleclearly visible as a space around the larva. as a space around the larva. (Detail of cephalic space with a polymorphonuclear (Detail of cephalic space with a polymorphonuclear cell, Giemsa stain). cell, Giemsa stain).

Loa loa:Loa loa: microfilaria. microfilaria. Thick film, Mayer's haematoxylin (400 X).Thick film, Mayer's haematoxylin (400 X).

Loa loa:Loa loa: microfilaria, tail area. microfilaria, tail area. Thick film, Mayer's haematoxylin (1.000 X).Thick film, Mayer's haematoxylin (1.000 X).

Loa loa:Loa loa: microfilariae can be demonstrated in blood microfilariae can be demonstrated in blood with fluorochromes with fluorochromes (Acridine orange stain). (Acridine orange stain).

Loa loa: Loa loa: although direct diagnosis by observation although direct diagnosis by observation of microfilariaeof microfilariae in blood is the reference method, in blood is the reference method, indirect diagnostic tests such asindirect diagnostic tests such as IF may allow IF may allow diagnosis when direct observation is negative, diagnosis when direct observation is negative, especially in subjects who are not resident in especially in subjects who are not resident in endemic areas. endemic areas. The frequent cross-reaction with other nematode The frequent cross-reaction with other nematode infections limitsinfections limits the usefulness of serology in the usefulness of serology in these patients. these patients. Immunodiagnosis by indirect immunofluorescence. Immunodiagnosis by indirect immunofluorescence.

Antigen: frozen sections ofAntigen: frozen sections of Dirofilaria immitis. Dirofilaria immitis.

MANSONELLA OZZARDIMANSONELLA OZZARDIMANSONELLA PERSTANS MANSONELLA PERSTANS

M. ozzardi is endemic in Central and South M. ozzardi is endemic in Central and South America. America. The adults live in subcutaneous tissues. The adults live in subcutaneous tissues. Unsheathed microfilariae (200x4-5 µm) released in Unsheathed microfilariae (200x4-5 µm) released in blood without periodicity,have a small cephalic blood without periodicity,have a small cephalic space, a long and slender tail without nuclei to the space, a long and slender tail without nuclei to the end.end.

M. perstans is endemic in Africa and South M. perstans is endemic in Africa and South America. The adult lives in body cavities. America. The adult lives in body cavities. Unsheathed microfilariae (200x4-5 µm) released Unsheathed microfilariae (200x4-5 µm) released in blood without periodicityin blood without periodicity have a small cephalic have a small cephalic space and nuclei to the end of tail. space and nuclei to the end of tail.

Mansonella perstans: Mansonella perstans: microfilaria. microfilaria. Thick film, (400 X).Thick film, (400 X).

BLOOD SPOROZOEABLOOD SPOROZOEA

Order: Order: Eucoccidiida Eucoccidiida Plasmodium falciparum Plasmodium falciparum Plasmodium malariae Plasmodium malariae Plasmodium ovale Plasmodium ovale Plasmodium vivax Plasmodium vivax Toxoplasma gondii Toxoplasma gondii

PLASMODIUM FALCIPARUM PLASMODIUM FALCIPARUM

Plasmodium sp.:Plasmodium sp.: geographic distribution. geographic distribution.

PlasmodiumPlasmodium sp.: the genus Anopheles includes sp.: the genus Anopheles includes more than 400 species of mosquitoes.Many more than 400 species of mosquitoes.Many may act as vectors of human diseases such as may act as vectors of human diseases such as malaria,filariasis and some arbovirus. malaria,filariasis and some arbovirus. Eggs present a pair of lateral floats and are Eggs present a pair of lateral floats and are laid singly on the water surface,while larvae laid singly on the water surface,while larvae lay in a horizontal position under the water lay in a horizontal position under the water surface.surface.

Plasmodium Plasmodium sp.: the resting position of the adult is sp.: the resting position of the adult is characteristiccharacteristic with the proboscid, head and with the proboscid, head and abdomen in a straight line at an angle of about 45° abdomen in a straight line at an angle of about 45° with the surface on which they rest.Only about 60 with the surface on which they rest.Only about 60 species can transmit malaria and they greatly species can transmit malaria and they greatly differ in their efficiency as vectors according to differ in their efficiency as vectors according to man biting behaviour, survival, fertility, adaptation man biting behaviour, survival, fertility, adaptation to different breeding place.The most efficient to different breeding place.The most efficient vectors belong to the vectors belong to the A.gambiaeA.gambiae complex,widely complex,widely distributed in tropical Africa, where also important distributed in tropical Africa, where also important is is A.funestusA.funestus.In Asia important vectors are .In Asia important vectors are A.culicifaciensA.culicifaciens, , A.dirus, A.sinensisA.dirus, A.sinensis and and A.miminusA.miminus; ; in the Pacific area in the Pacific area A.farautiA.farauti and and A.maculatusA.maculatus play a play a predominant rolepredominant role in malaria transmission. The in malaria transmission. The main vector in South America in main vector in South America in A.albimanus.A.albimanus.

P.falciparum:P.falciparum: species identification is possible on species identification is possible on the basisthe basis of the appearance of parasites of each of of the appearance of parasites of each of the four malaria species.Shape and size of asexual the four malaria species.Shape and size of asexual parasites and of macro- and microgametocytes, parasites and of macro- and microgametocytes, developmental stages in peripheral blood, developmental stages in peripheral blood, modifications of infected erythrocytes,presence of modifications of infected erythrocytes,presence of dots or clefts on the red blood cells are the main dots or clefts on the red blood cells are the main differential characteristics.differential characteristics.

Malaria diagnosis relies on observation of Malaria diagnosis relies on observation of parasites in Giemsa-stained thin or thick smears parasites in Giemsa-stained thin or thick smears (G-TS). (G-TS). Alternative techniques for identification of malaria Alternative techniques for identification of malaria parasites are based on fluorochromes such as parasites are based on fluorochromes such as Acridine Orange (AO), DAPI-PI or BCP. Acridine Orange (AO), DAPI-PI or BCP. With these dyes malaria parasites are easily With these dyes malaria parasites are easily recognized under UV light, reducing the time recognized under UV light, reducing the time spent reading the slides.Another method, based spent reading the slides.Another method, based on fluorochromes, the quantitative buffy coat on fluorochromes, the quantitative buffy coat (QBC) (QBC) (Becton-Dickinson) analysis wich uses AO staining (Becton-Dickinson) analysis wich uses AO staining of centrifuged parasitesof centrifuged parasites in a capillary tube in a capillary tube containing a float, has been shown to be rapid and containing a float, has been shown to be rapid and accurate.accurate.

P.falciparum:P.falciparum: gametocytes of gametocytes of P.falciparumP.falciparum. . QBC technique (60X).QBC technique (60X).

Recently different immunochromatographic Recently different immunochromatographic tests such as the tests such as the ParaParaSight F(Becton Sight F(Becton Dickinson) and the Malaquick (ICT) wich Dickinson) and the Malaquick (ICT) wich capturecapture and detect the histidine rich protein 2 and detect the histidine rich protein 2 (HRP-2) antigen,and the OPTIMAL wich detects (HRP-2) antigen,and the OPTIMAL wich detects PlasmodiumPlasmodium lactate dehydrogenase(pLDH) lactate dehydrogenase(pLDH) have been developed and distributed. have been developed and distributed. The tests are highly sensitive and specific and The tests are highly sensitive and specific and are now ableare now able to distinguish to distinguish P.falciparumP.falciparum infections from non-falciparum infections.infections from non-falciparum infections. P.falciparumP.falciparum trophozoites, thin smear, Giemsa trophozoites, thin smear, Giemsa stain.stain.

Malaria diagnosis:whereas thin film gives more Malaria diagnosis:whereas thin film gives more informations on parasite morphologyinformations on parasite morphology and and permits an easier morphologic differentiation,G-permits an easier morphologic differentiation,G-TS is more sensitive allowing a concentration of TS is more sensitive allowing a concentration of plasmodia (10-15 folds)plasmodia (10-15 folds) and it is the standard and it is the standard reference diagnostic test.reference diagnostic test.

Malaria diagnosis: Malaria diagnosis: G-TS needs careful stain (2% Giemsa) and experience in G-TS needs careful stain (2% Giemsa) and experience in examining slides;reasonable sensitivity is reached by examining slides;reasonable sensitivity is reached by observing at least 500-1.000 White Blood Cells observing at least 500-1.000 White Blood Cells (WBC).Quantification of baseline parasitemia is necessary(WBC).Quantification of baseline parasitemia is necessary for monitoring the response to therapy. Parasites must be for monitoring the response to therapy. Parasites must be counted in parallel with leucocytecounted in parallel with leucocyte and parasitemia and parasitemia expressed as parasites/µl. expressed as parasites/µl.

N. of parasites counted x N. of WBC/µlN. of parasites counted x N. of WBC/µl

N. of WBC countedN. of WBC counted

= N. of = N. of parasites/µlparasites/µl

P.falciparum trophozoites, thick smear, Giemsa stain.P.falciparum trophozoites, thick smear, Giemsa stain.

P. falciparum:P. falciparum: trophozoites are small rings with trophozoites are small rings with single or double smallsingle or double small chromatin dots, and chromatin dots, and regular cytoplasm; multiple infection and regular cytoplasm; multiple infection and high parasitemia (>5%) are common. high parasitemia (>5%) are common. Dots or cleft (Maurer's) can be observed on the Dots or cleft (Maurer's) can be observed on the infected RBCs. infected RBCs. P.falciparumP.falciparum trophozoites, thin smear, Giemsa trophozoites, thin smear, Giemsa stain.stain.

P. falciparum:P. falciparum: sometimes trophozoites appear sometimes trophozoites appear at the edgeat the edge of the red blood cell (applique form) of the red blood cell (applique form) left.Erythrocytes maintain regular shape and left.Erythrocytes maintain regular shape and size. size. P.falciparumP.falciparum trophozoites, thin smear, Giemsa trophozoites, thin smear, Giemsa stain.stain.

P. falciparum: P. falciparum: late trophozoites and schizonts late trophozoites and schizonts usually are not observedusually are not observed in peripheral blood in peripheral blood unless in severe infections. unless in severe infections. Cerebral malaria: late trophozoites with a Cerebral malaria: late trophozoites with a coarse granule of pigment in peripheral blood. coarse granule of pigment in peripheral blood. P.falciparumP.falciparum, thin smear, Giemsa stain., thin smear, Giemsa stain.

P.falciparum:P.falciparum: micro- and macrogametocytes are micro- and macrogametocytes are easily recognized by their crescentic, cigar- or easily recognized by their crescentic, cigar- or banana-like shape.Microgametocytes have a banana-like shape.Microgametocytes have a diffuse chromatin,while macrogametocytes have diffuse chromatin,while macrogametocytes have thickened chromatin. thickened chromatin. Microgametocyte, Giemsa thin smear. Microgametocyte, Giemsa thin smear.

P.falciparum:P.falciparum: in thick films red blood cells are not in thick films red blood cells are not visible and leucocytesvisible and leucocytes and parasites appear and parasites appear smaller than in thin smears.Trophozoites have a smaller than in thin smears.Trophozoites have a ring or comma shape, with one or two dots of ring or comma shape, with one or two dots of chromatin.The pigment, when present, is chromatin.The pigment, when present, is compact.compact.

P.falciparum:P.falciparum: trophozoites in Giemsa-stained trophozoites in Giemsa-stained thick films have a wide range of shapes. thick films have a wide range of shapes. Maurer's clefts are not visible.Maurer's clefts are not visible.

P.falciparum:P.falciparum: micro- and macrogametocytes have micro- and macrogametocytes have an evident malaric pigment,scattered through in an evident malaric pigment,scattered through in the cytoplasm in the microgametocyte. the cytoplasm in the microgametocyte. Microgametocyte, Giemsa thick smear.Microgametocyte, Giemsa thick smear.

P.falciparum: P.falciparum: staining with fluorochromes is rapid staining with fluorochromes is rapid (less than 1 min)and observation of slides can be (less than 1 min)and observation of slides can be performed at low magnification (400X)performed at low magnification (400X) allowing allowing rapid screening of smears even with low rapid screening of smears even with low parasitemia. parasitemia. P.falciparumP.falciparum (DAPI-PI). (DAPI-PI).

P.falciparumP.falciparum trophozoites. Acridine Orange stain. trophozoites. Acridine Orange stain.

P.falciparum:P.falciparum: the sensitivity of different isolates the sensitivity of different isolates of of P.falciparumP.falciparum to drugs to drugs can be assessed with can be assessed with the WHO "in vitro test". the WHO "in vitro test". The development to mature schizont in presence The development to mature schizont in presence of therapeutic levelsof therapeutic levels of the drug demonstrates of the drug demonstrates resistance of the isolate.resistance of the isolate.

P.falciparum:P.falciparum: severe severe P.falciparumP.falciparum infections are infections are clinical forms characterized by potentially fatal clinical forms characterized by potentially fatal manifestations or complications:cerebramanifestations or complications:cerebral l malaria, malaria, defined by a state of unrousable coma in absence defined by a state of unrousable coma in absence of other causes,is the most common of other causes,is the most common manifestation. manifestation. Celebral malaria: parasitized RBCs in brain vessels Celebral malaria: parasitized RBCs in brain vessels (H&E stain).(H&E stain).

P.falciparum:P.falciparum: rosetting of infected and uninfected rosetting of infected and uninfected red blood cells andred blood cells and cytoadherence of parasitized cytoadherence of parasitized erythrocytes to the vascular endothelium,play a erythrocytes to the vascular endothelium,play a crucial role in sequestration of parasites and crucial role in sequestration of parasites and obstruction of brain vessels. obstruction of brain vessels. Induction of host cytokines and soluble mediators Induction of host cytokines and soluble mediators such as oxygen radicalssuch as oxygen radicals and NO play an important and NO play an important role in the pathogenesis of the infection.role in the pathogenesis of the infection.

P.falciparum:P.falciparum: the brain appears oedematous, the brain appears oedematous, hyperaemic and with pigmenthyperaemic and with pigment deposition; the deposition; the capillaries, expecially of the white matter, capillaries, expecially of the white matter, appear dilated and congested and obstructed by appear dilated and congested and obstructed by parasitized RBCs. parasitized RBCs.

P.falciparum: P.falciparum: renal failure may result from renal failure may result from sequestration of RBCssequestration of RBCs and alteration of the renal and alteration of the renal microcirculation. microcirculation. Glomerulal and interstitial vessels present RBCs Glomerulal and interstitial vessels present RBCs adhering to the endothelium.adhering to the endothelium.

P.falciparum:P.falciparum: renal failure may also result from renal failure may also result from releasing of compounds secondaryreleasing of compounds secondary to to intravascular haemolysis (not haemoglobin itself) intravascular haemolysis (not haemoglobin itself) that can causethat can cause acute tubular necrosis especially in acute tubular necrosis especially in presence of dehydratation and acidosis.presence of dehydratation and acidosis.

P.falciparum: P.falciparum: sequestration and cytoadherence sequestration and cytoadherence of parasitized RBCs in heartof parasitized RBCs in heart microcirculation is microcirculation is frequent but myocardial dysfunctionsfrequent but myocardial dysfunctions and and cardiac arrhythmias are uncommon in severe cardiac arrhythmias are uncommon in severe falciparumfalciparum malaria. malaria.

P.falciparum: P.falciparum: jaundice and abnormalities of liver jaundice and abnormalities of liver function tests are frequent findingsfunction tests are frequent findings in severe in severe falciparumfalciparum malaria but hepatic failure is rare malaria but hepatic failure is rare even in heavily infected individuals.even in heavily infected individuals.

P.falciparum:P.falciparum: histological abnormalities include histological abnormalities include Kuppfer hyperplasia,mononuclear hyperplasia Kuppfer hyperplasia,mononuclear hyperplasia and sinusoid dilatation;swollen hepatocytes and sinusoid dilatation;swollen hepatocytes contain haemosiderin.Kuppfer cells contain a lot contain haemosiderin.Kuppfer cells contain a lot of malaria pigment.of malaria pigment.

A fatal case of A fatal case of P.falciparum P.falciparum malaria (liver): malaria (liver): malarial pigment within Kupffer cells (H&E X 400) malarial pigment within Kupffer cells (H&E X 400)

A fatal case of A fatal case of P.falciparum P.falciparum malaria (liver): malaria (liver): note a parasitized erytrocyte (H&E X1000) note a parasitized erytrocyte (H&E X1000)

P.falciparum:P.falciparum: pulmonary, non specific pulmonary, non specific complications, complications, such as atypical pneumonia, lobar pneumonia or such as atypical pneumonia, lobar pneumonia or bronchopneumonia,frequently occur during malaria bronchopneumonia,frequently occur during malaria infections.Pulmonary oedema is a specific and severe infections.Pulmonary oedema is a specific and severe complication of complication of P.falciparumP.falciparum infection: 3-10% This infection: 3-10% This syndrome, wich resembles the Acute Respiratory syndrome, wich resembles the Acute Respiratory Distress Syndrome (ARDS),has a relative late onset Distress Syndrome (ARDS),has a relative late onset (wich may be abrupt) in the course of the infection(wich may be abrupt) in the course of the infection and and is often associated with other manifestations of the is often associated with other manifestations of the severe falciparum malaria.Different pathogenic severe falciparum malaria.Different pathogenic mechanisms have been suggested: mechanisms have been suggested: -increased capillary membrane permeability[due to -increased capillary membrane permeability[due to microemboli or to Disseminated Intravascular microemboli or to Disseminated Intravascular Coagulation (DIC)] Coagulation (DIC)] -impaired function of the alveolar capillaries; -impaired function of the alveolar capillaries; -severe disfunction of the pulmonary-severe disfunction of the pulmonary microcirculation; microcirculation; -allergic phenomena; -allergic phenomena; -therapeutic fluid overload. -therapeutic fluid overload. The chest radiograph, in severe cases, shows The chest radiograph, in severe cases, shows widespread bilateral,confluent intraalveolar and widespread bilateral,confluent intraalveolar and interstitial infiltrates.interstitial infiltrates.

PLASMODIUM MALARIAE PLASMODIUM MALARIAE

PlasmodiumPlasmodium sp.: the genus Anopheles includes sp.: the genus Anopheles includes more than 400 species of mosquitoes.Many may more than 400 species of mosquitoes.Many may act as vectors of human diseases such as act as vectors of human diseases such as malaria, malaria, filariasis and some arbovirus. filariasis and some arbovirus. Eggs present a pair of lateral floats and are laid Eggs present a pair of lateral floats and are laid singly on the water surface,while larvae lay in a singly on the water surface,while larvae lay in a horizontal position under the water surface.horizontal position under the water surface.

Plasmodium Plasmodium sp.: the resting position of the adult is sp.: the resting position of the adult is characteristiccharacteristic with the proboscid, head and with the proboscid, head and abdomen in a straight lineabdomen in a straight line at an angle of about 45° at an angle of about 45° with the surface on which they rest.Only about 60 with the surface on which they rest.Only about 60 species can transmit malaria and they greatlyspecies can transmit malaria and they greatly differ differ in their efficiency as vectors according to manin their efficiency as vectors according to man biting biting behaviour, survival, fertility, adaptation to different behaviour, survival, fertility, adaptation to different breeding place.The most efficient vectors belong to breeding place.The most efficient vectors belong to the the A.gambiaeA.gambiae complex,widely distributed in complex,widely distributed in tropical Africa, where also important is tropical Africa, where also important is A.funestusA.funestus. . In Asia important vectors are In Asia important vectors are A.culicifaciensA.culicifaciens, , A.dirus, A.sinensisA.dirus, A.sinensis and and A.miminusA.miminus;in the Pacific area ;in the Pacific area A.farautiA.farauti and and A.maculatusA.maculatus play a predominant role play a predominant role in malaria transmission. The main vector in South in malaria transmission. The main vector in South America in America in A.albimanus.A.albimanus.

P.malariae:P.malariae: species identification is possible on species identification is possible on the basis of the appearance of parasites of each of the basis of the appearance of parasites of each of the four malaria species.Shape and size of asexual the four malaria species.Shape and size of asexual parasites and of macro- and microgametocytes, parasites and of macro- and microgametocytes, developmental stages in peripheral blood, developmental stages in peripheral blood, modifications of infected erythrocytes,presence of modifications of infected erythrocytes,presence of dots or clefts on the red blood cells are the main dots or clefts on the red blood cells are the main differential characteristics.differential characteristics.

Malaria diagnosis relies mainly on observation of Malaria diagnosis relies mainly on observation of parasitesparasites in Giemsa-stained thin or thick smears in Giemsa-stained thin or thick smears (G-TS).Alternative techniques for identification of (G-TS).Alternative techniques for identification of malaria parasites are basedmalaria parasites are based on fluorochromes on fluorochromes such as Acridine Orange (AO), DAPI-PI or BCP. such as Acridine Orange (AO), DAPI-PI or BCP. With these dyes malaria parasites are easily With these dyes malaria parasites are easily recognized under UV light,reducing the time recognized under UV light,reducing the time spent reading the slides.Another method, based spent reading the slides.Another method, based on fluorochromes, the quantitative buffy coat on fluorochromes, the quantitative buffy coat (QBC) (QBC) (Becton-Dickinson) analysis wich uses AO staining (Becton-Dickinson) analysis wich uses AO staining of centrifuged parasitesof centrifuged parasites in a capillary tube in a capillary tube containing a float, has been shown to be rapid containing a float, has been shown to be rapid and accurate.and accurate.

P.falciparum:P.falciparum: gametocytes of gametocytes of P.falciparumP.falciparum. QBC technique (60X).. QBC technique (60X).

Recently different immunochromatographic tests Recently different immunochromatographic tests such as the such as the ParaParaSight F(Becton Dickinson) and Sight F(Becton Dickinson) and the Malaquick (ICT) wich capture and detectthe Malaquick (ICT) wich capture and detect the the histidine rich protein 2 (HRP-2) antigen, and the histidine rich protein 2 (HRP-2) antigen, and the OPTIMAL wich detectsOPTIMAL wich detects PlasmodiumPlasmodium lactate lactate dehydrogenase (pLDH) have been developed and dehydrogenase (pLDH) have been developed and distributed. distributed. The tests are highly sensitive and specific and are The tests are highly sensitive and specific and are now able to distinguish now able to distinguish P.falciparumP.falciparum infections infections from non-falciparum infections. from non-falciparum infections. P.malariae P.malariae trophozoites, thin smear, Giemsa trophozoites, thin smear, Giemsa stain. stain.

Malaria diagnosis:Malaria diagnosis:whereas thin film gives more informations on whereas thin film gives more informations on parasite morphology and permits an easier parasite morphology and permits an easier morphologic differentiation, G-TS is more sensitive morphologic differentiation, G-TS is more sensitive allowing a concentration of plasmodia (10-15 folds) allowing a concentration of plasmodia (10-15 folds)

and it is the standard reference diagnostic test. and it is the standard reference diagnostic test.

Malaria diagnosis: Malaria diagnosis: G-TS needs careful stain (2% Giemsa) and experience in G-TS needs careful stain (2% Giemsa) and experience in examining slides; examining slides; reasonable sensitivity is reached by observing at least reasonable sensitivity is reached by observing at least 500-1.000 White Blood Cells (WBC). 500-1.000 White Blood Cells (WBC). Quantification of baseline parasitemia is necessary Quantification of baseline parasitemia is necessary for monitoring the response to therapy. for monitoring the response to therapy. Parasites must be counted in parallel with leucocyte Parasites must be counted in parallel with leucocyte and parasitemia expressed as parasites/µl. and parasitemia expressed as parasites/µl.




trophozoites,trophozoites,thick smear thick smear

SSchizont,chizont,thick smear thick smear

P. malariae: P. malariae: trophozoites are usually small rings trophozoites are usually small rings with a single dot of chromatinwith a single dot of chromatin or have aor have a compact, compact, regular cytoplasm that seems to contain the regular cytoplasm that seems to contain the nucleus. nucleus. The pigment in late trophozoites is scattered. The pigment in late trophozoites is scattered. (Thin smear, Giemsa).(Thin smear, Giemsa).

P. malariae:P. malariae: trophozoites may assume a band form trophozoites may assume a band form typical of the species.Red blood cells are not typical of the species.Red blood cells are not enlarged or rather smaller than normal.Multiple enlarged or rather smaller than normal.Multiple infection is rare. The parasitemia is usually low. No infection is rare. The parasitemia is usually low. No dots or clefts.(Thin smear, Giemsa).dots or clefts.(Thin smear, Giemsa).

P.malariae:P.malariae: schizonts are small and with a low schizonts are small and with a low number of merozoites (<12)number of merozoites (<12) arranged in regular arranged in regular forms (rosettes) with a thickened, often central, forms (rosettes) with a thickened, often central, pigment.The complete erythrocytic cycle takes pigment.The complete erythrocytic cycle takes 72 hours and ends with the releasing72 hours and ends with the releasing of free of free merozoites (c).(Thin smear, Giemsa).merozoites (c).(Thin smear, Giemsa).

P. malariae:P. malariae: micro- and macrogametocytes are micro- and macrogametocytes are round, small with chromatin defined;round, small with chromatin defined; they must they must be differentiated from late trophozoites.During be differentiated from late trophozoites.During P.malariaeP.malariae infection all stages of development infection all stages of development are present in peripheral blood. are present in peripheral blood. (Microgametocyte, Giemsa stain).(Microgametocyte, Giemsa stain).

PLASMODIUM OVALE PLASMODIUM OVALE

P.ovale:P.ovale: species identification is possible on the species identification is possible on the basisbasis of the appearance of parasites of each of of the appearance of parasites of each of the four malaria species.Shape and size of the four malaria species.Shape and size of asexual parasites and of macro- and asexual parasites and of macro- and microgametocytes, microgametocytes, developmental stages in peripheral blood, developmental stages in peripheral blood, modifications of infected erythrocytes,presence of modifications of infected erythrocytes,presence of dots or clefts on the red blood cells are the main dots or clefts on the red blood cells are the main differential characteristics.differential characteristics.

Malaria diagnosis relies on observation of Malaria diagnosis relies on observation of parasites inparasites in Giemsa-stained thin or thick smears Giemsa-stained thin or thick smears (G-TS).Alternative techniques for identification of (G-TS).Alternative techniques for identification of malaria parasitesmalaria parasites are based on fluorochromes are based on fluorochromes such as Acridine Orange (AO), DAPI-PI or BCP. such as Acridine Orange (AO), DAPI-PI or BCP. With these dyes malaria parasites are easily With these dyes malaria parasites are easily recognized under UV light,reducing the time recognized under UV light,reducing the time spent reading the slides.Another method, based spent reading the slides.Another method, based on fluorochromes, the quantitative buffy coat on fluorochromes, the quantitative buffy coat (QBC)(Becton-Dickinson) analysis wich uses AO (QBC)(Becton-Dickinson) analysis wich uses AO staining of centrifuged parasitesstaining of centrifuged parasites in a capillary in a capillary tube containing a float, has been shown to be tube containing a float, has been shown to be rapid and accurate.rapid and accurate.

Recently different immunochromatographic Recently different immunochromatographic tests such as the tests such as the ParaParaSight FSight F (Becton Dickinson) (Becton Dickinson) and the Malaquick (ICT) wich capture and detect and the Malaquick (ICT) wich capture and detect the histidine rich protein 2 (HRP-2) antigen, and the histidine rich protein 2 (HRP-2) antigen, and the OPTIMAL wich detectsthe OPTIMAL wich detects PlasmodiumPlasmodium lactate lactate dehydrogenase (pLDH) have been developed dehydrogenase (pLDH) have been developed and distributed.The tests are highly sensitive and distributed.The tests are highly sensitive and specific and are now able to distinguish and specific and are now able to distinguish P.falciparumP.falciparum infections from non- infections from non-falciparumfalciparum infections. infections. P.ovaleP.ovale, thin smear, Giemsa stain., thin smear, Giemsa stain.

Malaria diagnosis: Malaria diagnosis: whereas thin film gives more informations on whereas thin film gives more informations on parasite morphologyparasite morphology and permits an easier and permits an easier morphologic differentiation, G-TS is more morphologic differentiation, G-TS is more sensitive allowing a concentration of plasmodia sensitive allowing a concentration of plasmodia (10-15 folds)and it is the standard reference (10-15 folds)and it is the standard reference diagnostic test. diagnostic test.

Malaria diagnosis: G-TS needs careful stain Malaria diagnosis: G-TS needs careful stain (2% Giemsa) and experience in examining slides; (2% Giemsa) and experience in examining slides; reasonable sensitivity is reached by observing at least reasonable sensitivity is reached by observing at least 500-1.000 White Blood Cells (WBC). 500-1.000 White Blood Cells (WBC). Quantification of baseline parasitemia is necessary Quantification of baseline parasitemia is necessary for monitoring the response to therapy. for monitoring the response to therapy. Parasites must be counted in parallel with leucocyte Parasites must be counted in parallel with leucocyte and parasitemia expressed as parasites/µl.and parasitemia expressed as parasites/µl.




P.ovaleP.ovale, thick smear, Giemsa stain., thick smear, Giemsa stain.

Plasmodium ovale: trophozoite Plasmodium ovale: trophozoite

AAll stages are seen in blood films; prominent ll stages are seen in blood films; prominent Shuffner'sShuffner's dots are present at all stages. dots are present at all stages. Trophozoites appear as rings with, usually, a Trophozoites appear as rings with, usually, a compact cytoplasm;they do not have ameboid compact cytoplasm;they do not have ameboid cytoplasm.The parasites are smaller than cytoplasm.The parasites are smaller than P.vivaxP.vivax..

P.ovale:P.ovale: red blood cells are enlarged, ovalized red blood cells are enlarged, ovalized and distorted with fimbriae at poles. and distorted with fimbriae at poles. Schizonts have usually 8-10 merozoites.Schizonts have usually 8-10 merozoites.

P.ovale:P.ovale: micro- and macrogametocytes are micro- and macrogametocytes are sometimes difficult to differentiate from late sometimes difficult to differentiate from late trophozoites;they are round and occupy almost trophozoites;they are round and occupy almost the entire erythrocyte.Microgametocytes have a the entire erythrocyte.Microgametocytes have a more scattered chromatin.more scattered chromatin.

PLASMODIUM VIVAX PLASMODIUM VIVAX

P.vivax:P.vivax: species identification is possible on the species identification is possible on the basis of the appearance of parasites of each of basis of the appearance of parasites of each of the four malaria species. Shape and size of the four malaria species. Shape and size of asexual parasites and of macro- and asexual parasites and of macro- and microgametocytes, microgametocytes, developmental stages in peripheral blood, developmental stages in peripheral blood, modifications of infected erythrocytes,presence modifications of infected erythrocytes,presence of dots or clefts on the red blood cells are the of dots or clefts on the red blood cells are the main differential characteristics.main differential characteristics.

Malaria diagnosis relies mainly on observation of Malaria diagnosis relies mainly on observation of parasitesparasites in Giemsa-stained thin or thick smears in Giemsa-stained thin or thick smears (G-TS).Alternative techniques for identification of (G-TS).Alternative techniques for identification of malaria parasites are based on fluorochromes malaria parasites are based on fluorochromes such as Acridine Orange (AO), such as Acridine Orange (AO), DAPI-PI or BCP. or BCP. With these dyes malaria parasites are easily With these dyes malaria parasites are easily recognized under UV light, reducing the time recognized under UV light, reducing the time spent reading the slides.Another method, based spent reading the slides.Another method, based on fluorochromes, the quantitative buffy coat on fluorochromes, the quantitative buffy coat (QBC) (Becton-Dickinson) analysis wich uses AO (QBC) (Becton-Dickinson) analysis wich uses AO stainingstaining of centrifuged parasites in a capillary of centrifuged parasites in a capillary tube containing a float,has been shown to be tube containing a float,has been shown to be rapid and accurate.rapid and accurate.

Recently different immunochromatographic tests Recently different immunochromatographic tests such as the such as the ParaParaSight F(Becton Dickinson) and Sight F(Becton Dickinson) and the Malaquick (ICT) wich capture and detect the Malaquick (ICT) wich capture and detect the histidine rich protein 2 (HRP-2) antigen, the histidine rich protein 2 (HRP-2) antigen, and the OPTIMAL wich detects and the OPTIMAL wich detects PlasmodiumPlasmodium lactate dehydrogenase (pLDH)have been lactate dehydrogenase (pLDH)have been developed and distributed.The tests are highly developed and distributed.The tests are highly sensitive and specific and are now able to sensitive and specific and are now able to distinguishdistinguish P.falciparumP.falciparum infections from non- infections from non-falciparum infections. falciparum infections. P.vivaxP.vivax trophozoites, GT-s. trophozoites, GT-s.

Malaria diagnosis: Malaria diagnosis: whereas thin film gives more informations on whereas thin film gives more informations on parasite morphology and permits an easier parasite morphology and permits an easier morphologic differentiation,G-TS is more sensitive morphologic differentiation,G-TS is more sensitive allowing a concentration of plasmodia(10-15 folds) allowing a concentration of plasmodia(10-15 folds) and it is the standard reference diagnostic test. and it is the standard reference diagnostic test.

Malaria diagnosis: Malaria diagnosis: G-TS needs careful stain (2% Giemsa) and experience in G-TS needs careful stain (2% Giemsa) and experience in examining slides;reasonable sensitivity is reached by examining slides;reasonable sensitivity is reached by observing at least 500-1.000 White Blood Cells (WBC). observing at least 500-1.000 White Blood Cells (WBC). Quantification of baseline parasitemia is necessary Quantification of baseline parasitemia is necessary for monitoring the response to therapy.Parasites must be for monitoring the response to therapy.Parasites must be counted in parallel with leucocyte and parasitemia counted in parallel with leucocyte and parasitemia expressed as parasites/µl.expressed as parasites/µl.




P. vivax P. vivax trophozoites, thick smear, Giemsa stain.trophozoites, thick smear, Giemsa stain.

P.vivax:P.vivax: young trophozoites are small with single young trophozoites are small with single (rarely double) chromatin,with a loop of thin (rarely double) chromatin,with a loop of thin cytoplasm.The red blood cell is sligthly enlarged cytoplasm.The red blood cell is sligthly enlarged and a few Shuffner's dots are present. and a few Shuffner's dots are present. Parasitemia range form 0.5 to 2%, multiple Parasitemia range form 0.5 to 2%, multiple infection is rare.infection is rare.

P.vivax:P.vivax: the trophozoites increases in size and the the trophozoites increases in size and the cytoplasm becomes ameboid with rapid movements cytoplasm becomes ameboid with rapid movements ("vivax").The red blood cell enlarges and prominet ("vivax").The red blood cell enlarges and prominet Shuffner's dots are present.(Thin smear, Giemsa).Shuffner's dots are present.(Thin smear, Giemsa).

P.vivax:P.vivax: in more advanced stage of development in more advanced stage of development trophozoites occupy most of the RBC, and have a trophozoites occupy most of the RBC, and have a large vacuole and fine rods of pigment.The large vacuole and fine rods of pigment.The nucleus increases in size.nucleus increases in size.

P.vivax:P.vivax: late trophozoites have a more dense late trophozoites have a more dense cytoplasm, and a large vacuole. cytoplasm, and a large vacuole.

P.vivax:P.vivax: in young schizonts the nucleus divides and in young schizonts the nucleus divides and the vacuole disappears; the vacuole disappears; the cytoplasm is dense.the cytoplasm is dense.

P.vivax:P.vivax: in about 48hours schizogony is in about 48hours schizogony is completed.Mature schizont may contain 12-24 completed.Mature schizont may contain 12-24 merozoites. In thick smears schizonts look smaller merozoites. In thick smears schizonts look smaller than in thin smears and the Schuffner's dots are than in thin smears and the Schuffner's dots are not always visible.not always visible.

P.vivax:P.vivax: gametocytes are round or oval without gametocytes are round or oval without vacuole; most of the RBC is occupied by the vacuole; most of the RBC is occupied by the parasite. Macrogametocytes have a compact parasite. Macrogametocytes have a compact chromatin mass while microgametocytes have a chromatin mass while microgametocytes have a more diffuse nucleus stained pink.more diffuse nucleus stained pink.

P.vivax: P.vivax: staining with fluorochromes is rapid (less staining with fluorochromes is rapid (less than 1 min) and observation of slides can be than 1 min) and observation of slides can be performed at low magnification (400X)performed at low magnification (400X) allowing rapid allowing rapid screening of smears even with lowscreening of smears even with low parasitemia.parasitemia.P. vivaxP. vivax (DAPI-PI). (DAPI-PI).

TOXOPLASMA GONDIITOXOPLASMA GONDII

T. gondii:T. gondii: T.gondiiT.gondii encephalitis (TE) is the most encephalitis (TE) is the most common cerebralcommon cerebral opportunistic infection in opportunistic infection in patients with AIDS. patients with AIDS. The typical lesion is an ipodense focal area with The typical lesion is an ipodense focal area with ring contrast-enhancement and edema. ring contrast-enhancement and edema. (CT scan of a toxoplasmic encephalitis).(CT scan of a toxoplasmic encephalitis).

T. gondii:T. gondii: tissue cysts, 100-300 µm, may contain tissue cysts, 100-300 µm, may contain up to 3.000 bradyzoites.The wall of mature up to 3.000 bradyzoites.The wall of mature pseudocysts is believed to represent a pseudocysts is believed to represent a combination of host and parasitic components. combination of host and parasitic components.

T. gondii:T. gondii: diagnosis of TE is usually presumptive, diagnosis of TE is usually presumptive, based on clinical and radiologic findings and on the based on clinical and radiologic findings and on the response to treatment; cerebral biopsy sometimes response to treatment; cerebral biopsy sometimes allows identification of pseudocysts in tissue allows identification of pseudocysts in tissue sections. (H&E stain).sections. (H&E stain).

T. gondii:T. gondii: toxoplasmic pseudocyst within an toxoplasmic pseudocyst within an inflammatory tissue reaction. (H&E stain).inflammatory tissue reaction. (H&E stain).

T. gondii: the pseudocysts of T.gondii can be T. gondii: the pseudocysts of T.gondii can be observed in tissue sections with monoclonal observed in tissue sections with monoclonal antibodies. antibodies.

T. gondii: T. gondii: direct detection of direct detection of T.gondii T.gondii in clinical in clinical specimens is rare;parasites can be isolated from specimens is rare;parasites can be isolated from blood, CSF, amniotic fluid,tissue biopsies on cell lines blood, CSF, amniotic fluid,tissue biopsies on cell lines (THP-1 or MRC-5). (THP-1 or MRC-5). In clinical specimens the presence of parasites can In clinical specimens the presence of parasites can alsoalso be demonstrated by PCR analysis. be demonstrated by PCR analysis.

T. gondii:T. gondii: intracellular trophozoites of intracellular trophozoites of T.gondiiT.gondii in in a cell culture. a cell culture. The trophozoites proliferate within the vacuole The trophozoites proliferate within the vacuole developing a pseudocyst. developing a pseudocyst. (Trophozoites in a THP-1 cell, Giemsa stain).(Trophozoites in a THP-1 cell, Giemsa stain).

T. gondii:T. gondii: in cell cultures in cell cultures T.gondiiT.gondii proliferates to proliferates to form a pseudocyst of 8-20 parasites. form a pseudocyst of 8-20 parasites. (Trophozoites in a THP-1 cell, Giemsa stain).(Trophozoites in a THP-1 cell, Giemsa stain).

T. gondii:T. gondii: lysis of a THP-1 cell with release of lysis of a THP-1 cell with release of tachizoites in culture. tachizoites in culture. (Trophozoites in a THP-1 cell, Giemsa stain). (Trophozoites in a THP-1 cell, Giemsa stain).

T. gondii:T. gondii: microscopical features of tachizoites of microscopical features of tachizoites of Toxoplasma gondiiToxoplasma gondii and peritoneal macrophages and peritoneal macrophages of mouse in peritoneal exudate. (SEM)of mouse in peritoneal exudate. (SEM)

T. gondii:T. gondii: microscopical features of tachizoites of microscopical features of tachizoites of Toxoplasma gondiiToxoplasma gondii and peritoneal macrophages of and peritoneal macrophages of mouse in peritoneal exudate. (SEM)mouse in peritoneal exudate. (SEM)

T. gondii:T. gondii: the anterior pole of an endozoid in the anterior pole of an endozoid in tangential projection.Several subpellicular tangential projection.Several subpellicular fibrils and their insertion onfibrils and their insertion on the anterior polar the anterior polar ring are visible.ring are visible.

T. gondii:T. gondii: transmision electron microscopic picture. transmision electron microscopic picture. Longitudinal section of an endozoid.Longitudinal section of an endozoid.

T. gondii:T. gondii: cross-section through an endozoid cross-section through an endozoid in an advanced stage of endodiogeny. in an advanced stage of endodiogeny. The daugther cells appear to be surrounded. The daugther cells appear to be surrounded. In each of these news cells there are two round In each of these news cells there are two round bodiesbodies that lengthen forming the first that lengthen forming the first rhoptries.rhoptries.

SPOROZOEASPOROZOEA Order :Order :PiroplasmidaPiroplasmida

BABESIA CANISBABESIA CANIS

Babesia spp: babesiosis is a zoonosis that affects Babesia spp: babesiosis is a zoonosis that affects several animals:B.canis (dogs), B.equi (horses), several animals:B.canis (dogs), B.equi (horses), B.bovis (cattle), B.microti (rodents).Some Babesia B.bovis (cattle), B.microti (rodents).Some Babesia spp. are not host specific and can be transmitted to spp. are not host specific and can be transmitted to humans:B. microti and B.bovis/divergens.The humans:B. microti and B.bovis/divergens.The infection is transmitted by the bite of ticks of the infection is transmitted by the bite of ticks of the Family IxodidaeFamily Ixodidae of the genera Dermatocentor, of the genera Dermatocentor, Ixodes and Rhipicephalus.The main vector of Ixodes and Rhipicephalus.The main vector of B.microti is I.dammini, while vector of B.microti is B.microti is I.dammini, while vector of B.microti is I.ricinus I.ricinus B.canisB.canis, , Giemsa stain.Giemsa stain.

Babesia spp.: intraerythrocytic organisms in blood Babesia spp.: intraerythrocytic organisms in blood smears smears

Babesia Babesia spp.: after inoculation by the vector, the spp.: after inoculation by the vector, the trophozoites entertrophozoites enter the bloodstream and multiply inside the bloodstream and multiply inside the erythrocytes by budding, releasing two to fours the erythrocytes by budding, releasing two to fours daughter parasites and causing hemolytic anemia. Ticks daughter parasites and causing hemolytic anemia. Ticks become infected by ingesting blood of parasitized become infected by ingesting blood of parasitized mammals. mammals. Motile "vermicules" develop and multiply in the tick's gut Motile "vermicules" develop and multiply in the tick's gut and then migrate through the body (salivary glands and and then migrate through the body (salivary glands and ovaries).In some species transovarial transmission ovaries).In some species transovarial transmission ((B.bovisB.bovis and and B.caballiB.caballi)or transtadial passage, from larva to )or transtadial passage, from larva to nimph (nimph (B.microtiB.microti) occur.Vermicules of ) occur.Vermicules of BabesiaBabesia spp. spp. ((B.caballiB.caballi ?) obtained from crushed ?) obtained from crushed Rhipicephalus Rhipicephalus turanicusturanicus eggs. Tick collected from horses in a military eggs. Tick collected from horses in a military farm in Turkey where the prevalence of equine babesiosis farm in Turkey where the prevalence of equine babesiosis is high.is high.

Babesia Babesia spp.:spp.: by transovarial transmission "vermicules" by transovarial transmission "vermicules" can infect tick eggs; can infect tick eggs; they multiply in the yolk and in intestinal tissues of the they multiply in the yolk and in intestinal tissues of the larva; larva; pyriform bodies are then observed in the salivary glands pyriform bodies are then observed in the salivary glands of of the haematophage larvae and nimphs.the haematophage larvae and nimphs.Vermicules of Vermicules of Babesia sppBabesia spp. (. (B.caballiB.caballi ?) obtained from ?) obtained from crushed crushed Rhipicephalus turanicusRhipicephalus turanicus eggs. Tick collected from eggs. Tick collected from horses horses in a military farm in Turkey where the prevalence of in a military farm in Turkey where the prevalence of equine babesiosis is high.equine babesiosis is high.

B.canis:B.canis: diagnosis depends on the observation diagnosis depends on the observation of theof the intraerythrocytic organisms in blood intraerythrocytic organisms in blood smears.Pear shaped microorganisms (2-5 µm) smears.Pear shaped microorganisms (2-5 µm) and tetrads are the diagnostic shape of the and tetrads are the diagnostic shape of the parasite. (Giemsa stain).parasite. (Giemsa stain).

B.canis:B.canis: intraerythrocytic parasites can be intraerythrocytic parasites can be confused with confused with P.falciparum P.falciparum or or P.malariae P.malariae trophozoitestrophozoites. . Ring and band forms are sometimes observed. Ring and band forms are sometimes observed. (Giemsa stain).(Giemsa stain).

B.equi: B.equi: trophozoites of trophozoites of B.equi B.equi can mimic can mimic P.falciparumP.falciparum young ring trophozoites. young ring trophozoites.

ZOOMASTIGOPHOREA ZOOMASTIGOPHOREA Order:Order: KinetoplastidaKinetoplastida

TRYPANOSOMA CRUZITRYPANOSOMA CRUZI (Chagas' disease)(Chagas' disease)

T. cruzi: american trypanosomiasis was first T. cruzi: american trypanosomiasis was first described by Carlos Chagas in Brasil in 1909. described by Carlos Chagas in Brasil in 1909. The infection, Chagas' disease, is caused The infection, Chagas' disease, is caused by the haemoflagellate Trypanosoma cruzi. by the haemoflagellate Trypanosoma cruzi. tc1: T.cruzi in blood sample, Giemsa. tc1: T.cruzi in blood sample, Giemsa.

T. cruzi: T. cruzi: the disease is a public health threat in the disease is a public health threat in most Latin American countries,although cases due most Latin American countries,although cases due to blood derivatives or blood transfusionto blood derivatives or blood transfusion has been has been reported in non-endemic regions. reported in non-endemic regions. According to WHO the overall prevalence ofAccording to WHO the overall prevalence of human T.cruzi infectionhuman T.cruzi infection is estimated in 18 million is estimated in 18 million cases and 100 million people are living at risk. cases and 100 million people are living at risk. tc2: T. cruzi:tc2: T. cruzi: geographical distribution. geographical distribution.

T. cruzi: the vectors are reduvidae bugs which are T. cruzi: the vectors are reduvidae bugs which are haematophagushaematophagus and the most important are and the most important are Triatoma infestans(Argentina, Chile, Brazil, Bolivia, Triatoma infestans(Argentina, Chile, Brazil, Bolivia, Paraguay, Uruguay, Peru),T. sordida (Argentina, Paraguay, Uruguay, Peru),T. sordida (Argentina, Bolivia, Brazil, Paraguay),Rhodnius prolixus Bolivia, Brazil, Paraguay),Rhodnius prolixus (Colombia, Venezuela, Mexico, Central America),(Colombia, Venezuela, Mexico, Central America),T. dimidiata (Ecuador, Mexico, Central America),T. dimidiata (Ecuador, Mexico, Central America),and Panstrogylus megistus (northeast Brazil).and Panstrogylus megistus (northeast Brazil).

T. cruzi: the transmission by the vector is faecal. T. cruzi: the transmission by the vector is faecal. T.cruzi infective metacyclic trypomastigotes are shedT.cruzi infective metacyclic trypomastigotes are shed in the faeces of the bug and are inoculated intoin the faeces of the bug and are inoculated into the the human host by scratching infected faeces into skin human host by scratching infected faeces into skin abrasionsabrasions usually caused by the bug in the process of usually caused by the bug in the process of feeding (blood-sucking). feeding (blood-sucking). T.cruzi metacyclic trypomastigote: scanning electron T.cruzi metacyclic trypomastigote: scanning electron microscopymicroscopy showing T.cruzishowing T.cruzi trypomastigotes trypomastigotes recovered from an infectedrecovered from an infected Triatoma spp. in Pedro Triatoma spp. in Pedro Carbo, Ecuador.Carbo, Ecuador.

T. cruzi: infective metacyclic trypomastigotes are T. cruzi: infective metacyclic trypomastigotes are shed in the faecesshed in the faeces of the bug and inoculated into of the bug and inoculated into the vertebrate host not onlythe vertebrate host not only by skin lesions but by skin lesions but also through the mucosa of the mouth and,in also through the mucosa of the mouth and,in humans, through the conjunctiva of the eyes. humans, through the conjunctiva of the eyes.

T. cruzi: trypomastigotes can infect most of the T. cruzi: trypomastigotes can infect most of the vertebrate cells,polymorphonuclear leucocytes and vertebrate cells,polymorphonuclear leucocytes and macrophages are probably amongmacrophages are probably among the first the first vertebrate host cells with which T.cruzi interacts in vertebrate host cells with which T.cruzi interacts in vivo. vivo. tc7a: In vitro T.cruzi infection of macrophages tc7a: In vitro T.cruzi infection of macrophages showing the presence of amastigotes: showing the presence of amastigotes: Wright-Giemsa stain, showing replicating T.cruzi Wright-Giemsa stain, showing replicating T.cruzi amastigotes within host cell. amastigotes within host cell.

T. cruzi: this invasive step is crucial for the life T. cruzi: this invasive step is crucial for the life cycle of the parasitecycle of the parasite since it has to become since it has to become intracellular to multiply. intracellular to multiply. tc7b: In vitro T.cruzi infection of macrophages tc7b: In vitro T.cruzi infection of macrophages showing the presence of amastigotes: showing the presence of amastigotes: immunofluorescence assay showing T.cruzi immunofluorescence assay showing T.cruzi amastigotes after treatmentamastigotes after treatment with anti-T.cruzi with anti-T.cruzi polyclonal mouse sera.polyclonal mouse sera.

T. cruzi:T. cruzi: trypomastigotes in the host cell transform trypomastigotes in the host cell transform into amastigotes,which multiply intracellularly by into amastigotes,which multiply intracellularly by binary division inducing inflammatorybinary division inducing inflammatory and and immunological responses in vivo, and destroy cells immunological responses in vivo, and destroy cells in vitro. in vitro. Amastigotes are then released into the blood Amastigotes are then released into the blood stream as trypomastigotes.The latter are stream as trypomastigotes.The latter are nondividing forms which are able to infect a wide nondividing forms which are able to infect a wide rangerange of new host cells but muscle and glia seem of new host cells but muscle and glia seem most often parasitized,or they have to be ingested most often parasitized,or they have to be ingested by another reduviid bugby another reduviid bug in order to continue the in order to continue the parasite life cycle in the invertebrate host. parasite life cycle in the invertebrate host. tc8:tc8: Trypomastigotes reach the myocardial cells Trypomastigotes reach the myocardial cells and after penetrationand after penetration they multiply as amastigotes they multiply as amastigotes with formation of a pseudocyst. with formation of a pseudocyst.

T. cruzi:T. cruzi: in the in the ReduvidaeReduvidae bug the bloodstream bug the bloodstream derived trypomastigotederived trypomastigote forms pass along the forms pass along the digestive tract through irreversibledigestive tract through irreversible morphological morphological transformations in sequence;each developmental transformations in sequence;each developmental stage occurs in a specific portion of the insect's gut. stage occurs in a specific portion of the insect's gut. Thus, in the stomach, most blood trypomastigotes Thus, in the stomach, most blood trypomastigotes change intochange into epimastigotes and rounded forms epimastigotes and rounded forms (sphaeromastigotes). (sphaeromastigotes). tc9: T.cruzitc9: T.cruzi epimastigote. Immunofluorescence epimastigote. Immunofluorescence studies usingstudies using antibodies to a antibodies to a T.cruziT.cruzi protein named protein named Tc52(immunosuppressive factor which also express a Tc52(immunosuppressive factor which also express a thiol-transferase activity)and confocal microscopy. thiol-transferase activity)and confocal microscopy. An intense labeling located at the posterior end of An intense labeling located at the posterior end of an epimastigote indicate that Tc52 is targeted to the an epimastigote indicate that Tc52 is targeted to the reservosomes(These organelles are small vesicles reservosomes(These organelles are small vesicles inside multivesicular structuresinside multivesicular structures being formed being formed predominantly at the posterior end of predominantly at the posterior end of epimastigotes). epimastigotes).

T. cruzi: epimastigotes divide actively in the T. cruzi: epimastigotes divide actively in the vector's intestine and reachvector's intestine and reach the rectum where the rectum where a final differentiation results in the infective a final differentiation results in the infective metacyclicmetacyclic trypomastigotes which are trypomastigotes which are eliminated in the bug's faeces.eliminated in the bug's faeces.tc10: T.cruzi epimastigote. Epimastigote tc10: T.cruzi epimastigote. Epimastigote reacting withreacting with a monoclonal antibody against a monoclonal antibody against T.cruzi.T.cruzi.

T. cruzi:T. cruzi: some researchers have postulated that some researchers have postulated that sphaeromastigotessphaeromastigotes may change either into short may change either into short epimastigotes,dividing forms in the intestine, or epimastigotes,dividing forms in the intestine, or into long epimastigotesinto long epimastigotes which are nondividing which are nondividing forms but are able to reach the rectumforms but are able to reach the rectum where they where they transform into the final metacyclic trypomastigote transform into the final metacyclic trypomastigote form.In any case, this hypothesis remains form.In any case, this hypothesis remains controversial.controversial.tc10b: T.cruzi tc10b: T.cruzi epimastigote. Scanning electron epimastigote. Scanning electron microscopyshowing microscopyshowing T.cruziT.cruzi epimastigote. epimastigote.

T. cruzi:T. cruzi: there are three phases of the infection. there are three phases of the infection. The acute phase usually passes unnoticed but The acute phase usually passes unnoticed but there may be an inflamed swelling or chagoma there may be an inflamed swelling or chagoma at the site of entry of the trypanosomes. at the site of entry of the trypanosomes. Romanas'sign is when this swelling involves the Romanas'sign is when this swelling involves the eyelidseyelids but it occurs only in about 1-2% of the but it occurs only in about 1-2% of the cases.In the acute phase, mortality is less than 5% cases.In the acute phase, mortality is less than 5% andand death may result from acute heart failure death may result from acute heart failure or meningoencephalitis in children less than two or meningoencephalitis in children less than two years old.Romana’s sign, clinical manifestation years old.Romana’s sign, clinical manifestation tipically observedtipically observed in the acute phase of some in the acute phase of some Chagas’ disease patients.Chagas’ disease patients.

T. cruzi:T. cruzi: general symptoms in acute Chagas' general symptoms in acute Chagas' diseasediseasemay also include fever, hepatosplenomegaly, may also include fever, hepatosplenomegaly, adenopathies and myocarditis.Electrocardiographic adenopathies and myocarditis.Electrocardiographic changes involve sinus tachycardia, prolongation changes involve sinus tachycardia, prolongation of the P-R interval, primary T-wave changes and of the P-R interval, primary T-wave changes and low QRS voltage.Chest X-ray can reveal low QRS voltage.Chest X-ray can reveal cardiomegaly of different degrees. cardiomegaly of different degrees. The intermediate phase is clinically asymptomatic The intermediate phase is clinically asymptomatic and is detected by the presence of specific and is detected by the presence of specific antibodies.No parasites are found in bloostream antibodies.No parasites are found in bloostream smears butsmears but xenodiagnosis could be positive in some xenodiagnosis could be positive in some cases. cases. Acute Chagas myocarditis (Haematoxylin and Eosin Acute Chagas myocarditis (Haematoxylin and Eosin X 160)X 160)tc12tc12: Posteroanterior chest radiograph : Posteroanterior chest radiograph showing enlargedshowing enlarged heart due to heart due to T.cruziT.cruzi infection. infection.tc12a: tc12a: Acute Chagas' disease myocarditis Acute Chagas' disease myocarditis (Haematoxylin and Eosin X160)(Haematoxylin and Eosin X160)

T.cruzi parasitize mainly the cardiac muscle but T.cruzi parasitize mainly the cardiac muscle but any cell typeany cell type may be parasitized (smooth may be parasitized (smooth muscle cells, hystiocytes): cardiac muscle with muscle cells, hystiocytes): cardiac muscle with amastigotes, H&E stain. amastigotes, H&E stain.

T. cruzi:T. cruzi: the chronic phase of Chagas'disease the chronic phase of Chagas'disease develops 10 - 20 years after infection and affects develops 10 - 20 years after infection and affects internal organs such as the heart,oesophagus and internal organs such as the heart,oesophagus and colon as well as the peripheral nervous system. colon as well as the peripheral nervous system. The lesions of Chagas’ disease are incurable and in The lesions of Chagas’ disease are incurable and in severe casessevere cases patients may die as result of heart patients may die as result of heart failure.failure.

Chagas' disease megacardia Chagas' disease megacardia (slide from the late Prof.Koberle, Brazil) (slide from the late Prof.Koberle, Brazil)

Apical aneurysm in Chagas' disease Apical aneurysm in Chagas' disease (slide from the late Prof.Koberle, Brazil) (slide from the late Prof.Koberle, Brazil)

T. cruzi: T. cruzi: on the other side, megacolon is on the other side, megacolon is associated associated with abnormal constipation (weeks).Faecal with abnormal constipation (weeks).Faecal impaction and sigmoid volvulus are side-effects of impaction and sigmoid volvulus are side-effects of megacolon.Neurological changes in chronic megacolon.Neurological changes in chronic Chagas' disease include changesChagas' disease include changes at the level of at the level of the central, peripheral or autonomic nervous the central, peripheral or autonomic nervous system. system.

Chagasic megacolon with enlargement of the Chagasic megacolon with enlargement of the sigmoid;patient from Morona Santiago sigmoid;patient from Morona Santiago province, southeastern Ecuador province, southeastern Ecuador

X-ray showing megaoesophagus in Chagas' disease X-ray showing megaoesophagus in Chagas' disease

X-ray showing megacolon in Chagas' disease X-ray showing megacolon in Chagas' disease

T. cruzi:T. cruzi: can be observed in the peripheral blood can be observed in the peripheral blood only in the acute case of the disease.Its presence only in the acute case of the disease.Its presence is the best definition of the acute phaseis the best definition of the acute phase as all as all other signs are variable. other signs are variable. --Wright-Giemsa staining of Wright-Giemsa staining of T.cruziT.cruzi trypomastigote trypomastigote in peripheral blood smear from an acute infected in peripheral blood smear from an acute infected patient.patient.--T.cruzi T.cruzi in mouse blood (Giemsa stain) in mouse blood (Giemsa stain)

T. cruzi: T. cruzi: trypomastigotes have a prominent trypomastigotes have a prominent subterminal kinetoplastsubterminal kinetoplast that often distort the that often distort the membrane of the cell,an elongated nucleus and membrane of the cell,an elongated nucleus and an undulating membrane. an undulating membrane. --T.cruziT.cruzi trypomastigote: blood stream trypomastigote: blood stream trypomastigotes are 15-20 µmtrypomastigotes are 15-20 µm in lengin lengthth and and appear with a typical C or S-shaped form.appear with a typical C or S-shaped form.

T. cruzi: multiplication only occurs in the T. cruzi: multiplication only occurs in the amastigote phase, amastigote phase, which grows in a variety of tissue cells especially which grows in a variety of tissue cells especially muscle. muscle. --In vitro infected fibroblast showing a large In vitro infected fibroblast showing a large number of intracellular amastigotes.number of intracellular amastigotes.

T. cruzi: laboratory diagnostic tests based on T. cruzi: laboratory diagnostic tests based on serology (IFA, ELISA) and Polymerase Chain serology (IFA, ELISA) and Polymerase Chain Reaction (PCR) specific for T.cruzi, have been Reaction (PCR) specific for T.cruzi, have been developed. developed. --T.cruzi trypomastigotes reacting with monoclonal T.cruzi trypomastigotes reacting with monoclonal Ab. Ab.

T. cruzi: serological cross-reactions can occur T. cruzi: serological cross-reactions can occur with infectionswith infections such as leprosy, leishmaniasis, such as leprosy, leishmaniasis, treponematoses, malaria and multiple myeloma.treponematoses, malaria and multiple myeloma.Trypanosoma rangeli is also an important cause Trypanosoma rangeli is also an important cause of false-positive testing, especially in areas of false-positive testing, especially in areas where T.cruzi coexists with T.rangeli. where T.cruzi coexists with T.rangeli. --In vitro T.cruzi infection of macrophages In vitro T.cruzi infection of macrophages showing the presence of amastigotes: showing the presence of amastigotes: confocal microscopy showing T.cruzi amastigotes confocal microscopy showing T.cruzi amastigotes after treatment with anti-Tc24 mouse sera. after treatment with anti-Tc24 mouse sera.

T. cruzi: two drugs are in common use. T. cruzi: two drugs are in common use. Nifurtimox (Lampit, production was discontinued Nifurtimox (Lampit, production was discontinued in 1991)and Benznidazole (Rochagan). in 1991)and Benznidazole (Rochagan). The latter which is now the drug of choice, The latter which is now the drug of choice, is given in an oral dose of 6 mg/kg body weight for is given in an oral dose of 6 mg/kg body weight for 30 or 60 days.Both drugs produce anorexia, weight 30 or 60 days.Both drugs produce anorexia, weight loss, headache and dizziness,gastric irritation, and loss, headache and dizziness,gastric irritation, and sometimes peripheral neuritis.Experimental drugs sometimes peripheral neuritis.Experimental drugs are under evaluation.Treatment of patients in the are under evaluation.Treatment of patients in the intermediate or chronic phase is controversial. intermediate or chronic phase is controversial. Congenital Chagas'disease and transfusion-Congenital Chagas'disease and transfusion-associatedassociated acute disease require Rochagan acute disease require Rochagan therapy.Transfusion infection can be prevented by therapy.Transfusion infection can be prevented by donor screening or,by mixing the blood with donor screening or,by mixing the blood with gentian violet (0,25 gr./L for 24 hours) to kill gentian violet (0,25 gr./L for 24 hours) to kill T.cruzi.Vector control programmes involving T.cruzi.Vector control programmes involving insecticide sprayinginsecticide spraying with modern pyretroids and with modern pyretroids and new tools for delivery in endemicnew tools for delivery in endemic areas is being areas is being carried out in some Latin American countries. carried out in some Latin American countries. tc20: TEM microphotograph of T.cruzi tc20: TEM microphotograph of T.cruzi epimastigote.epimastigote.

ZOOMASTIGOPHOREA ZOOMASTIGOPHOREA Order:Order: KinetoplastidaKinetoplastida

TRYPANOSOMA TRYPANOSOMA BRUCEI RHODESIENSE /BRUCEI RHODESIENSE /

T.B. GAMBIENSE T.B. GAMBIENSE

Sleeping sickness occurs in Africa between the Sleeping sickness occurs in Africa between the 15° North and the 20° South. 15° North and the 20° South. The T.b.rhodesiense form is found in East and The T.b.rhodesiense form is found in East and Central-East Africa whereas theCentral-East Africa whereas the T.b.gambiense T.b.gambiense infection occurs in Central and West Africa.infection occurs in Central and West Africa.

The African The African trypanosomiasis trypanosomiasis is transmitted is transmitted by several by several species of tse-species of tse-tse flies tse flies ((GlossinaGlossina spp.). spp.).

Larva and Larva and pupae of pupae of Glossina Glossina morsitans morsitans

Adult Glossina Adult Glossina tachinoides in tachinoides in West Africa West Africa

T. b. gambiense and rhodesiense:T. b. gambiense and rhodesiense: two forms of two forms of trypomastigotetrypomastigote can be seen in peripheral blood: can be seen in peripheral blood: one is long slender, 30 µm in lengtone is long slender, 30 µm in lengthh,and is ,and is capable of multiplying in the host, the other is capable of multiplying in the host, the other is stumpy, not dividing,18 µm in lengtstumpy, not dividing,18 µm in lengthh..

Trypanosoma brucei gambiense andTrypanosoma brucei gambiense and rhodesiense:rhodesiense: trypanosomes appeartrypanosomes appear in the peripheral blood 5 to in the peripheral blood 5 to 21 days after the infecting bite.21 days after the infecting bite.

Trypanosoma brucei gambiense and Trypanosoma brucei gambiense and rhodesiense: rhodesiense: the terminal stage of the infection the terminal stage of the infection ("sleeping sickness") is the result of a chronic ("sleeping sickness") is the result of a chronic meningoencephalomyelitis. (H&E stain).meningoencephalomyelitis. (H&E stain).

Trypanosoma brucei gambiense and Trypanosoma brucei gambiense and rhodesiense:rhodesiense: the typical pathological lesion the typical pathological lesion of of trypanosomiasis is a perivascular round-cell trypanosomiasis is a perivascular round-cell infiltration (perivascular cuffing)infiltration (perivascular cuffing) due to glial due to glial cells, lymphocytes and plasmocytes (Mott cells). cells, lymphocytes and plasmocytes (Mott cells). (H&E stain). (H&E stain).

LEISHMANIA DONOVANI LEISHMANIA DONOVANI

VisceralVisceral leishmaniasis has a wide geographic leishmaniasis has a wide geographic distribution.North-Eastern China, India, Middle-distribution.North-Eastern China, India, Middle-East, Southern Europe (Mediterranean bassin), East, Southern Europe (Mediterranean bassin), Northern Africa, Central-East Africa and, in foci, Northern Africa, Central-East Africa and, in foci, Central and South America(especially Brazil and Central and South America(especially Brazil and Honduras).Honduras).

The infection is transmitted by various species of The infection is transmitted by various species of Phlebotomus, the sand fly. Phlebotomus, the sand fly.

Leishamnia Leishamnia sppspp.. wich affect humans can be wich affect humans can be differentiated by geographical distribution, differentiated by geographical distribution, clinical spectrum, immunological clinical spectrum, immunological features,isoenzymes and Kinetoplast DNA (kDNA) features,isoenzymes and Kinetoplast DNA (kDNA) characterization. characterization. ((LeishmaniaLeishmania amastigotes, bone marrow aspirate, amastigotes, bone marrow aspirate, Giemsa stain).Giemsa stain).

Visceral leishmaniasis (Kala-azar) is caused by Visceral leishmaniasis (Kala-azar) is caused by parasitesparasites of the genus of the genus LeishmaniaLeishmania, subgenus, subgenus LeishmaniaLeishmania, complex , complex donovani donovani ((donovanidonovani, , infantum, chagasiinfantum, chagasi species).Viscerotropic strains species).Viscerotropic strains of of L.infantumL.infantum and and L.tropicaL.tropica have been described. have been described. (bone marrow aspirate)(bone marrow aspirate)

Diagnosis of the infection depends on Diagnosis of the infection depends on identification of amastigotes in tissues (bone identification of amastigotes in tissues (bone marrow, spleen, liver, limph nodes) or in marrow, spleen, liver, limph nodes) or in blood.Other organs may be affected, expecially in blood.Other organs may be affected, expecially in HIV-1 positive patients HIV-1 positive patients (intestinal and respiratory tract).Amastigotes can (intestinal and respiratory tract).Amastigotes can be found inside and outside the be found inside and outside the reticuloendothelial cells. They measure 2-5 µm, reticuloendothelial cells. They measure 2-5 µm, are oval with a large nucleus (in red), a are oval with a large nucleus (in red), a kinetoplast (usually perpendicular, in red to kinetoplast (usually perpendicular, in red to violet) and a pale blue cytoplasm.(Bone marrowviolet) and a pale blue cytoplasm.(Bone marrow aspirate).aspirate).

Leishamnia Leishamnia sp.: Cultures (on NNN or Tobie media) of sp.: Cultures (on NNN or Tobie media) of blood or tissues samplesblood or tissues samples may permit isolation of the may permit isolation of the parasite, allowing the subsequent characterisation. parasite, allowing the subsequent characterisation. When introduced in culture the amastigotes When introduced in culture the amastigotes transform into promastigotes in 7-21 days. transform into promastigotes in 7-21 days. (Wet mount preparation).(Wet mount preparation).

Leishamnia Leishamnia sp.: Leishmania promastigotes measure sp.: Leishmania promastigotes measure 15-20 by 1.3-3.5 µm and have a single flagellum, 15-20 by 1.3-3.5 µm and have a single flagellum, measuring 15-28 µm.Serologic examination (EIA, measuring 15-28 µm.Serologic examination (EIA, direct Agglutination, IF, WB) is useful in direct Agglutination, IF, WB) is useful in immunocompetent individuals, not ALWAYS in HIV-1 immunocompetent individuals, not ALWAYS in HIV-1 positive patients.positive patients.

Visceral leishmaniasis: liver biopsy can Visceral leishmaniasis: liver biopsy can demonstrate the demonstrate the LeishmaniaLeishmania amastigotes amastigotes inside the reticuloendothelial cells. The hepatic inside the reticuloendothelial cells. The hepatic structure is preserved.structure is preserved.

Visceral leishmaniasis: liver biopsy at higher Visceral leishmaniasis: liver biopsy at higher magnification with intracellular amastigotes.magnification with intracellular amastigotes.

Visceral leishmaniasis: spleen biopsy is a very Visceral leishmaniasis: spleen biopsy is a very high sensitive method of diagnosis but it is not high sensitive method of diagnosis but it is not widely used because of the risk ofwidely used because of the risk of hemorrhage.hemorrhage. Splenic tissue is rich in amastigotes allowing a Splenic tissue is rich in amastigotes allowing a rapid and sensitive diagnosis.rapid and sensitive diagnosis.

Visceral leishmaniasis: spleen biopsy with Visceral leishmaniasis: spleen biopsy with intracellular amastigotes. intracellular amastigotes.

blood,bone marrow,spleen parasites (171)

Health & Medicine

loa loa

malayi microfilaria

bancrofti sheath

malayi infections

malayi andw

cephalic space of b

caudal space of b

bancrofti infections