acha 2009 name that bug. malaria-a major world disease 300-500 million cases annually 2.7 million...
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ACHA 2009ACHA 2009
Name That BugName That Bug
Malaria-A Major World DiseaseMalaria-A Major World Disease
300-500 million cases annually300-500 million cases annually
2.7 million deaths annually2.7 million deaths annually
About 1500 US cases annuallyAbout 1500 US cases annually
Prevalence increasingPrevalence increasing– Rising resistanceRising resistance– Anopheles vector spreadingAnopheles vector spreading– Climate changeClimate change– Increasing travelIncreasing travel
MalariaMalaria
A major cause of fever in the returning A major cause of fever in the returning travelertraveler
A complicated diseaseA complicated disease– But resources are availableBut resources are available
Fever in the Returning TravelerFever in the Returning Traveler
The Geosentinel StudyThe Geosentinel Study– Malaria is #1Malaria is #1– Then DengueThen Dengue– MononucleosisMononucleosis– Rickettsial infectionRickettsial infection– Enteric fever (Typhoid or paratyphoid fever)Enteric fever (Typhoid or paratyphoid fever)
Malaria EtiologyMalaria Etiology
Caused by Plasmodium, a parasiteCaused by Plasmodium, a parasite
Four important speciesFour important species– P. falciparumP. falciparum– P. vivaxP. vivax– P. ovaleP. ovale– P. malariaeP. malariae
The four species are not the The four species are not the samesame
FalciparumFalciparum– Often severeOften severe– High parasite burdenHigh parasite burden– Organ damage Organ damage
commoncommon
Non-falciparumNon-falciparum– Generally not severeGenerally not severe– Low parasite burdenLow parasite burden– Rare end organ Rare end organ
damagedamage
Malaria TransmissionMalaria Transmission
Predominantly due to the bite of a female Predominantly due to the bite of a female Anopheles mosquitoAnopheles mosquito
In US, there is rare transfusion spreadIn US, there is rare transfusion spread– Also some “airport” infectionAlso some “airport” infection
Malaria PathogenesisMalaria Pathogenesis
The parasite digests red blood cell The parasite digests red blood cell proteins, hemoglobin and deform the cell proteins, hemoglobin and deform the cell membranemembrane
Hemolysis occursHemolysis occurs– Cytokines releasedCytokines released
Diseased cells filtered out by spleen and Diseased cells filtered out by spleen and liverliver– Results in sequestration and enlargementResults in sequestration and enlargement
Malaria Signs and SymptomsMalaria Signs and Symptoms
FeverFever
SweatsSweats
ChillsChills
HeadacheHeadache
MyalgiasMyalgias
FatigueFatigue
Abdominal painAbdominal pain
Malaria DiagnosisMalaria Diagnosis
Light microscopyLight microscopy– Look at blood with Giemsa stain (or Wright’s Look at blood with Giemsa stain (or Wright’s
stain)stain)Look for ring forms in red cells, measure percent of Look for ring forms in red cells, measure percent of red cells infected, look for “banana” formsred cells infected, look for “banana” forms
This is not vivaxThis is not vivax
CDC AssistanceCDC Assistance
Call 770 488 7788 during normal business Call 770 488 7788 during normal business hourshours
Call 770 488 7100 for emergenciesCall 770 488 7100 for emergencies
Next CaseNext Case
The SalmonellaeThe Salmonellae
Motile gram negative bacilliMotile gram negative bacilli
Some cause gastroenteritisSome cause gastroenteritis
Some cause enteric feverSome cause enteric fever
Some cause bacteremia or endovascular Some cause bacteremia or endovascular infectioninfection
Some cause osteomyelitis or abscessSome cause osteomyelitis or abscess
Some cause asymptomatic carrier stateSome cause asymptomatic carrier state
This case was an example of This case was an example of enteric feverenteric fever
TyphoidTyphoid– Salmonella typhiSalmonella typhi– Salmonella paratyphiSalmonella paratyphi– Both are highly specific for human, not animal, Both are highly specific for human, not animal,
infectioninfection– Always means that there was contact with an Always means that there was contact with an
infected individual, a chronic carrier or infected individual, a chronic carrier or contaminated food or watercontaminated food or water
– 21.6 million cases worldwide in one year, with 21.6 million cases worldwide in one year, with 216,000 deaths216,000 deaths
Typhoid in the USATyphoid in the USA
Between 1994-1999 there were 1393 Between 1994-1999 there were 1393 casescases– 30% had traveled to India30% had traveled to India– Strongly consider the typhoid vaccineStrongly consider the typhoid vaccine
The Clinical Picture of TyphoidThe Clinical Picture of Typhoid
A febrile illnessA febrile illness– Occurs 5-21 days after ingestion of the Occurs 5-21 days after ingestion of the
bacteriabacteria– Fever builds, is often sustainedFever builds, is often sustained– May have abdominal pain, rose spots, liver or May have abdominal pain, rose spots, liver or
spleen enlargementspleen enlargement– If untreated, has 15% mortalityIf untreated, has 15% mortality– Other symptoms may include headache, Other symptoms may include headache,
cough, relative bradycardiacough, relative bradycardia
The DiagnosisThe Diagnosis
Established by blood cultureEstablished by blood culture
Sensitivity to AntibioticsSensitivity to Antibiotics
Cipro often considered first choiceCipro often considered first choice
But beware: resistance is growingBut beware: resistance is growing– Lab testing may miss Cipro resistance, so Lab testing may miss Cipro resistance, so
specifically ask about sensitivity to nalidixic specifically ask about sensitivity to nalidixic acidacid
CiproCipro
Next CaseNext Case
TuberculosisTuberculosis
Koch’s diseaseKoch’s disease
Received the Nobel prize for establishing Received the Nobel prize for establishing that TB was caused by Mycobacteria that TB was caused by Mycobacteria tuberculosis in 1882tuberculosis in 1882
TuberculosisTuberculosis
A disease of antiquityA disease of antiquity– Mummies have had TBMummies have had TB
A disease of povertyA disease of poverty
A large fraction of cases in US are A large fraction of cases in US are importedimported
An indolent infectionAn indolent infection
A disease of the “artiste”A disease of the “artiste”– For example the opera La BohemeFor example the opera La Boheme
TB EpidemiologyTB Epidemiology
14.6 million cases of active TB worldwide 14.6 million cases of active TB worldwide each yeareach year– 1.6 million deaths per year1.6 million deaths per year
25,000 new US cases per year25,000 new US cases per year– About 50% are in foreign bornAbout 50% are in foreign born
TB PresentationTB Presentation
Symptoms are insidiousSymptoms are insidious
Fever present in 50%Fever present in 50%
Cough, weight loss or fatigue present in Cough, weight loss or fatigue present in 66%66%
X-ray often shows upper lobe infiltrateX-ray often shows upper lobe infiltrate
A Critical Lab Test for A Critical Lab Test for Suspected Active DiseaseSuspected Active Disease
Collect multiple sputum specimens for Collect multiple sputum specimens for “AFB smear and culture with sensitivity”“AFB smear and culture with sensitivity”– New tests are emerging to aid in diagnosisNew tests are emerging to aid in diagnosis
TB Transmission and TB Transmission and PreventionPrevention
Generally by inhalation of droplet particlesGenerally by inhalation of droplet particles– One sneeze can create 40,000 dropletsOne sneeze can create 40,000 droplets
Screening high prevalence populations is Screening high prevalence populations is helpfulhelpful
TB ScreeningTB Screening
Focus is to detect both active disease and Focus is to detect both active disease and latent diseaselatent disease
ACHA has guidelinesACHA has guidelines
Traditional test for latent TB is the Traditional test for latent TB is the Tuberculin skin testTuberculin skin test
Newer tests utilize interferon assayNewer tests utilize interferon assay– These tests are now recognized by CDC as These tests are now recognized by CDC as
equivalent to skin testingequivalent to skin testing
TB Screening TestsTB Screening Tests
Skin TestingSkin Testing– An acquired skillAn acquired skill– Requires two visitsRequires two visits– Well establishedWell established
Much data on Much data on sensitivitysensitivity
Cost stableCost stable
– BCG may cause false BCG may cause false positivepositive
Interferon TestsInterferon Tests– Only needs Only needs
phlebotomy skills and phlebotomy skills and lablab
– One visit for resultOne visit for result– Cost high, but coming Cost high, but coming
downdown– Not prone to BCG Not prone to BCG
influenceinfluence
Less data on sensitivityLess data on sensitivity
TB TreatmentTB Treatment
Needs multiple effective drugs for long Needs multiple effective drugs for long period of timeperiod of time
ATS has established guidelinesATS has established guidelines
Next CaseNext Case
Fish Tapeworm InfectionFish Tapeworm Infection
Diphyllobothrium Latum, the broad Diphyllobothrium Latum, the broad tapewormtapeworm
Endemic wherever raw or undercooked Endemic wherever raw or undercooked fish is ingestedfish is ingested
Full grown worm lives in the human Full grown worm lives in the human intestine, may reach 40 feet in length, may intestine, may reach 40 feet in length, may cause vitamin B12 deficiency with cause vitamin B12 deficiency with megaloblastic anemiamegaloblastic anemia
The Worm ItselfThe Worm Itself
A sucker headA sucker head– Adheres to jejunumAdheres to jejunum
A neckA neck
A bodyA body– May consist of 4000 segments called May consist of 4000 segments called
proglottidsproglottidsThe proglottids are hermaphroditic, produce up to The proglottids are hermaphroditic, produce up to a million eggs dailya million eggs daily
American “outbreaks”American “outbreaks”
Due to increased popularity of sushi from Due to increased popularity of sushi from raw, unfrozen salmonraw, unfrozen salmon– Especially farm raisedEspecially farm raised
Tapeworm SymptomsTapeworm Symptoms
Often asymptomaticOften asymptomatic
When symptoms are present they are When symptoms are present they are often vagueoften vague– Diarrhea, cramping, fatigueDiarrhea, cramping, fatigue– Occasional patient feels the worm segment Occasional patient feels the worm segment
hanging outside the anus or sees a partial hanging outside the anus or sees a partial segment in the toilet bowlsegment in the toilet bowl
If complicated by B12 deficiencyIf complicated by B12 deficiency
The patient may have anemia symptomsThe patient may have anemia symptoms– Pallor, breathlessnessPallor, breathlessness
Plus glossitisPlus glossitis
Plus findings of posterior column spinal Plus findings of posterior column spinal cord diseasecord disease– Loss of vibratory sense, proprioreception, Loss of vibratory sense, proprioreception,
poor coordinationpoor coordination
DiagnosisDiagnosis
Look in the stool for eggs, or sometimes Look in the stool for eggs, or sometimes segments of adult wormssegments of adult worms
TreatmentTreatment
Praziquantel is the drug of choicePraziquantel is the drug of choice
It kills the adult worm, so it will come out in It kills the adult worm, so it will come out in the stool (warn patient)the stool (warn patient)
Low toxicityLow toxicity
Dose is 5-10 mg/Kg as a single doseDose is 5-10 mg/Kg as a single dose
Thank You!Thank You!