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!