zoonoses of nonhuman primates metazoan...

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ZoonosesZoonoses of Nonhuman Primatesof Nonhuman PrimatesMetazoan ParasitesMetazoan Parasites

ZoonoticZoonotic Metazoan ParasitesMetazoan ParasitesCestodesCestodes

HymenolepisHymenolepis nanananaTrematodesTrematodes

ParagonimusParagonimus westermaniwestermaniSchistosomaSchistosoma sppspp..

NematodesNematodesStrongyloidesStrongyloides stercoralisstercoralisStrongyloidesStrongyloides fullebornifulleborniOesophagostomumOesophagostomum sppspp..

ZoonosesZoonoses of Nonhuman Primatesof Nonhuman PrimatesParagonimiasisParagonimiasis

Agent: Agent: ParagonimusParagonimus westermaniwestermani (Asian lung fluke)(Asian lung fluke)

Range: Southeast AsiaRange: Southeast Asia

Primate Hosts: Primate Hosts: Humans Humans CrabCrab--eating macaque eating macaque (M. (M. fascicularisfascicularis))Taiwanese rock macaque Taiwanese rock macaque (M. (M. cyclopiscyclopis))

“Shared Pathogen” “Shared Pathogen” –– both humans and NHP infected from both humans and NHP infected from environmental source. environmental source.

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ParagonimiasisParagonimiasis

Egg

Adult fluke

Miracidia

Embryonated egg

SporocystsRediae

Cercaria

Infection by ingestion of encysted metacercariae

Encysted metacercariaein crustacean 2nd

intermediate host

Aquatic snail 1st

intermediate host

Paragonimus westermani: Life Cycle

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Clinical signsClinical signsPrimates: Mild Primates: Mild dyspneadyspnea, nonproductive cough, nonproductive cough

occasional occasional cavitarycavitary lung lesionslung lesionsHumans:Humans:

Pulmonary formPulmonary formPleuritisPleuritis, , pneumothoraxpneumothorax, cough, , cough, hemoptysishemoptysis

Cerebral form Cerebral form EpilepsyEpilepsy--like diseaselike disease


PathogenesisPathogenesisMigration through tissuesMigration through tissues

Liver, brainLiver, brainEncapsulation in lungsEncapsulation in lungs

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DiagnosisDiagnosisEggs in fecal samplesEggs in fecal samples

TreatmentTreatmentPraziquantelPraziquantel

ZoonosesZoonoses of Nonhuman Primatesof Nonhuman PrimatesCestodiasisCestodiasis

Agent: Agent: HymenolepisHymenolepis nana (nana (Dwarf tapeworm)Dwarf tapeworm)Only cestode with direct life

cycle

Hosts: Humans; Chimps, tarsier, macaques, squirrelmonkey, others

Low prevalence (1-4%)

Distribution: Worldwide

Clinical signs: Lowly pathogenic, except heavyinfestation

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Life Cycle: Life Cycle: HymenolepisHymenolepis nananana

CestodiasisCestodiasis: : HymenolepisHymenolepis nananana

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ZoonosesZoonoses of Nonhuman Primatesof Nonhuman PrimatesSchistosomiasisSchistosomiasis

Agents and NHP Hosts Agents and NHP Hosts S. S. mansonimansoni –– SubSub--saharansaharan Africa, Arabia, Africa, Arabia, NeotropicsNeotropics

Baboon, African green monkeyBaboon, African green monkey

S. japonica S. japonica –– Southeast Asia, JapanSoutheast Asia, JapanCrabCrab--eating macaqueeating macaque

S. S. haematobiumhaematobium -- Africa, Middle EastAfrica, Middle EastChimpanzee, Chimpanzee, HamadryasHamadryas baboonbaboon

S. mansoni

SchistosomiasisSchistosomiasis

Prevalence in NHPPrevalence in NHPPapioPapio hamadryashamadryas Saudi ArabiaSaudi Arabia 5%5%PapioPapio hamadryashamadryas EthiopiaEthiopia 2%2%PapioPapio anubisanubis TanzaniaTanzania 1616--47%47%PapioPapio anubisanubis KenyaKenya 2%2%PapioPapio cynocephalus cynocephalus KenyaKenya 33--21%21%

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miracidiasporocyst

cercaria

Schistosoma mansoni

Eggs in feces

Infection by cercaria penetrating skin


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SchistosomiasisSchistosomiasisClinical SignsClinical Signs

Nonhuman Primates Nonhuman Primates Anorexia, bloody stool, Anorexia, bloody stool, hepatomegalyhepatomegaly, , ascitesascites

HumansHumansCercarialCercarial dermatitisdermatitisAcute phase Acute phase –– lymphadenopathylymphadenopathy, , hepatohepato--splenomegalysplenomegalyChronic phase Chronic phase –– portal fibrosis, portal fibrosis, hepatomegalyhepatomegaly

Colonic hemorrhage and ulcerationColonic hemorrhage and ulcerationPulmonary Pulmonary granulomasgranulomas

SchistosomiasisSchistosomiasisPathogenesisPathogenesis

Eggs secrete soluble antigens (DHR)Eggs secrete soluble antigens (DHR)Eggs secrete Eggs secrete proteolyticproteolytic enzymes (tissue damage, enzymes (tissue damage,

inflammation, hemorrhage)inflammation, hemorrhage)Blockage of smaller veins and arteriolesBlockage of smaller veins and arteriolesChronic inflammation and scarringChronic inflammation and scarring

Hepatic “pipeHepatic “pipe--stem” fibrosisstem” fibrosis

S. mansoni egg

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Lung granulomas

Egg in liver

Eggs in bladder

SchistosomiasisSchistosomiasisDiagnosisDiagnosis

Distinctive eggs in fecal sampleDistinctive eggs in fecal sample

TreatmentTreatmentPraziquantelPraziquantel S. mansoni egg

S. hematobium egg

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ZoonosesZoonoses of Nonhuman Primatesof Nonhuman PrimatesStrongyloidiasisStrongyloidiasis

Agent: Agent: StrongyloidesStrongyloides stercoralisstercoralis –– HumanHumanStrongyloidesStrongyloides fullebornifulleborni –– Asian and African NHPAsian and African NHP

One of the most serious nematode infections of One of the most serious nematode infections of humans and humans and NHPsNHPs

StrongyloidesStrongyloides stercoralisstercoralis

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Complex EcologyComplex EcologyDirect cycle: Direct cycle:

RhabditiformRhabditiform larvae in stoollarvae in stoolFilariformFilariform larvae in soillarvae in soilFilariformFilariform larvae penetrate intact skinlarvae penetrate intact skin

Indirect cycle:Indirect cycle:RhabditiformRhabditiform larvae in stoollarvae in stoolFreeFree--living adults in soilliving adults in soilEggs in soil Eggs in soil –– freefree--living or living or filariformfilariform

larvaelarvaeFilariformFilariform larvae penetrate intact skinlarvae penetrate intact skin

Strongyloides egg


Complex Ecology (cont.)Complex Ecology (cont.)Autoinfection Autoinfection

FilariformFilariform larvae in GI tractlarvae in GI tractExternal External –– filariformfilariform larvae penetrate larvae penetrate

perianalperianal tissuestissuesInternal Internal –– filariformfilariform larvae penetrate larvae penetrate

mucosa of colon and rectummucosa of colon and rectum

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Life Cycle: Strongyloides

StrongyloidesStrongyloides stercoralisstercoralisAutoinfection Autoinfection –– increase worm burden (increase worm burden (superinfectionsuperinfection))All cycles All cycles

Larval migration via Larval migration via lymphaticslymphatics and capillaries to and capillaries to pulmonary capillaries and alveolipulmonary capillaries and alveoli

Up respiratory tract, swallowed, relocate to stomach and Up respiratory tract, swallowed, relocate to stomach and small small intestineintestine

Mating in small intestine, fertile females embed in mucosaMating in small intestine, fertile females embed in mucosaEggs hatch in intestine, Eggs hatch in intestine, rhabditiformrhabditiform larvae in feceslarvae in feces

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Clinical SignsClinical SignsVariable Variable –– asymptomatic to severe g.i.diseaseasymptomatic to severe g.i.diseaseDuodenitisDuodenitis: abdominal pain, nausea, vomiting: abdominal pain, nausea, vomiting

diarrhea, anorexia, wt loss, weaknessdiarrhea, anorexia, wt loss, weaknessperipheral blood peripheral blood eosinophiliaeosinophilia

Exacerbations at irregular intervalsExacerbations at irregular intervalsStrongyloidiasisStrongyloidiasis is a chronic diseaseis a chronic disease

StrongyloidesStrongyloides stercoralisstercoralisPathologyPathology

Lesions of adult and Lesions of adult and rhabditiformrhabditiform larvae in mucosalarvae in mucosaerosive and ulcerative enteritiserosive and ulcerative enteritis

Lesions of Lesions of filariformfilariform larvae (primary and larvae (primary and hyperinfectionhyperinfection))inflammation, multiple organsinflammation, multiple organsnecrotizing, ulcerative or necrotizing, ulcerative or granulomatousgranulomatous enteritisenteritishyperinfectionhyperinfection –– severe colonic lesionssevere colonic lesions

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StrongyloidiasisStrongyloidiasis

DiagnosisDiagnosisRhabditiformRhabditiform larvae in stool sampleslarvae in stool samplesEpigastricEpigastric abdominal pain with abdominal pain with eosinophiliaeosinophilia

high index of suspicionhigh index of suspicion

TreatmentTreatmentThiabendazoleThiabendazole vs. adults (not effective against vs. adults (not effective against

migrating larvae)migrating larvae)Repeat treatment after 1Repeat treatment after 1--2 weeks is necessary2 weeks is necessary

StrongyloidiasisStrongyloidiasisStrongyloidesStrongyloides fullebornifulleborni

Hosts: Old World monkeysHosts: Old World monkeysNot naturally occurring in NW monkeysNot naturally occurring in NW monkeysHuman infections Human infections –– ZambiaZambia

Clinical signsClinical signsNHP NHP –– heavy infections heavy infections –– diarrhea (milder than diarrhea (milder than S. S. stercoralisstercoralis))Humans Humans –– abdominal pain, diarrhea, anemiaabdominal pain, diarrhea, anemia

PathologyPathologySimilar to that for S. Similar to that for S. stercoralisstercoralis

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StrongyloidiasisStrongyloidiasisPrevalence in NHPPrevalence in NHP

222259%59%TanzaniaTanzaniaPanPan

troglodytestroglodytes

12312316.3%16.3%KenyaKenyaChlorocebusChlorocebus

aethiopsaethiops

424276%76%KenyaKenyaPapioPapiocynocephaluscynocephalus

55552%2%KenyaKenyaPapioPapiocynocephaluscynocephalus

12412460.7%60.7%UgandaUgandaPapioPapio anubisanubis

Sample size (n)Sample size (n)Prevalence Prevalence LocationLocationNHP SpeciesNHP Species

ZoonosesZoonoses of Nonhuman Primatesof Nonhuman PrimatesOesophagostomiasisOesophagostomiasis

Agent: Agent: OesophagostomumOesophagostomum sppspp. . (Nodular worm)(Nodular worm)

Most common nematode parasite of Old World NHPMost common nematode parasite of Old World NHP

Life Cycle: Direct, no systemic migrationLife Cycle: Direct, no systemic migrationInfective stage Infective stage –– third stage larvathird stage larvaNodules Nodules –– 44thth stage larvae in intestinal stage larvae in intestinal submucosasubmucosa

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OesophagostomiasisOesophagostomiasisSeveral speciesSeveral species

O. O. apiostomumapiostomum –– AsiaAsiaHosts: humans, macaques, Hosts: humans, macaques, langurslangurs

O. O. aculeatumaculeatum –– AsiaAsiaHosts: macaquesHosts: macaques

O. O. bifurcumbifurcum –– Asia and AfricaAsia and AfricaHosts: Asia Hosts: Asia –– macaquesmacaques

Africa Africa –– baboon, baboon, pataspatas, , geunongeunon, chimp, chimp* most commonly reported human infections* most commonly reported human infections

O. O. stephanostomumstephanostomum –– Africa, South AmericaAfrica, South AmericaHosts: baboon, gorilla, chimpHosts: baboon, gorilla, chimpPathogenic Pathogenic ––apes (diarrhea, anemia, apes (diarrhea, anemia, hypoproteinemiahypoproteinemia

DiphtherioidDiphtherioid enteritisenteritis

OesophagostomiasisOesophagostomiasis

Clinical Clinical PrimatesPrimates

Minor infection Minor infection –– few clinical signsfew clinical signsHeavy infection Heavy infection –– diarrhea, wt loss, diarrhea, wt loss,

anemia, high mortalityanemia, high mortalityHumansHumans

Abdominal pain, tumorAbdominal pain, tumor--like noduleslike nodulesMay mimic appendicitis, colon cancer, May mimic appendicitis, colon cancer, amoebomaamoebomaEctopicEctopic sites commonsites common

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OesophagostomiasisOesophagostomiasis

PathologyPathologyTumorTumor--like nodules (2like nodules (2--4 mm)4 mm)Intestinal Intestinal submucosasubmucosa –– mainly colonmainly colonGranulomatousGranulomatous diseasedisease

TreatmentTreatmentThiabendazoleThiabendazoleMebendazoleMebendazole, , LevamisoleLevamisole less effectiveless effective

zoonoses of nonhuman primates metazoan...

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