Download presentation
Presentation is loading. Please wait.
Published byGregory Bruno Craig Modified over 9 years ago
1
ACHA 2009 Name That Bug
2
Malaria-A Major World Disease 300-500 million cases annually 2.7 million deaths annually About 1500 US cases annually Prevalence increasing –Rising resistance –Anopheles vector spreading –Climate change –Increasing travel
4
Malaria A major cause of fever in the returning traveler A complicated disease –But resources are available
5
Fever in the Returning Traveler The Geosentinel Study –Malaria is #1 –Then Dengue –Mononucleosis –Rickettsial infection –Enteric fever (Typhoid or paratyphoid fever)
6
Malaria Etiology Caused by Plasmodium, a parasite Four important species –P. falciparum –P. vivax –P. ovale –P. malariae
7
The four species are not the same Falciparum –Often severe –High parasite burden –Organ damage common Non-falciparum –Generally not severe –Low parasite burden –Rare end organ damage
8
Malaria Transmission Predominantly due to the bite of a female Anopheles mosquito In US, there is rare transfusion spread –Also some “airport” infection
10
Malaria Pathogenesis The parasite digests red blood cell proteins, hemoglobin and deform the cell membrane Hemolysis occurs –Cytokines released Diseased cells filtered out by spleen and liver –Results in sequestration and enlargement
13
Malaria Signs and Symptoms FeverSweatsChillsHeadacheMyalgiasFatigue Abdominal pain
14
Malaria Diagnosis Light microscopy –Look at blood with Giemsa stain (or Wright’s stain) Look for ring forms in red cells, measure percent of red cells infected, look for “banana” forms
17
This is not vivax
18
CDC Assistance Call 770 488 7788 during normal business hours Call 770 488 7100 for emergencies
19
Next Case
20
The Salmonellae Motile gram negative bacilli Some cause gastroenteritis Some cause enteric fever Some cause bacteremia or endovascular infection Some cause osteomyelitis or abscess Some cause asymptomatic carrier state
23
This case was an example of enteric fever This case was an example of enteric fever Typhoid –Salmonella typhi –Salmonella paratyphi –Both are highly specific for human, not animal, infection –Always means that there was contact with an infected individual, a chronic carrier or contaminated food or water –21.6 million cases worldwide in one year, with 216,000 deaths
24
Typhoid in the USA Between 1994-1999 there were 1393 cases –30% had traveled to India –Strongly consider the typhoid vaccine
26
The Clinical Picture of Typhoid A febrile illness –Occurs 5-21 days after ingestion of the bacteria –Fever builds, is often sustained –May have abdominal pain, rose spots, liver or spleen enlargement –If untreated, has 15% mortality –Other symptoms may include headache, cough, relative bradycardia
28
The Diagnosis Established by blood culture
29
Sensitivity to Antibiotics Cipro often considered first choice But beware: resistance is growing –Lab testing may miss Cipro resistance, so specifically ask about sensitivity to nalidixic acid
31
Cipro
32
Next Case
33
Tuberculosis Tuberculosis Koch’s disease Received the Nobel prize for establishing that TB was caused by Mycobacteria tuberculosis in 1882
34
Tuberculosis A disease of antiquity –Mummies have had TB A disease of poverty A large fraction of cases in US are imported An indolent infection A disease of the “artiste” –For example the opera La Boheme
35
TB Epidemiology 14.6 million cases of active TB worldwide each year –1.6 million deaths per year 25,000 new US cases per year –About 50% are in foreign born
38
TB Presentation Symptoms are insidious Fever present in 50% Cough, weight loss or fatigue present in 66% X-ray often shows upper lobe infiltrate
41
A Critical Lab Test for Suspected Active Disease Collect multiple sputum specimens for “AFB smear and culture with sensitivity” –New tests are emerging to aid in diagnosis
43
TB Transmission and Prevention Generally by inhalation of droplet particles –One sneeze can create 40,000 droplets Screening high prevalence populations is helpful
44
TB Screening Focus is to detect both active disease and latent disease ACHA has guidelines Traditional test for latent TB is the Tuberculin skin test Newer tests utilize interferon assay –These tests are now recognized by CDC as equivalent to skin testing
45
TB Screening Tests Skin Testing –An acquired skill –Requires two visits –Well established Much data on sensitivity Cost stable –BCG may cause false positive Interferon Tests –Only needs phlebotomy skills and lab –One visit for result –Cost high, but coming down –Not prone to BCG influence Less data on sensitivity
46
TB Treatment Needs multiple effective drugs for long period of time ATS has established guidelines
47
Next Case
48
Fish Tapeworm Infection Diphyllobothrium Latum, the broad tapeworm Endemic wherever raw or undercooked fish is ingested Full grown worm lives in the human intestine, may reach 40 feet in length, may cause vitamin B12 deficiency with megaloblastic anemia
52
The Worm Itself A sucker head –Adheres to jejunum A neck A body –May consist of 4000 segments called proglottids The proglottids are hermaphroditic, produce up to a million eggs daily
57
American “outbreaks” Due to increased popularity of sushi from raw, unfrozen salmon –Especially farm raised
58
Tapeworm Symptoms Often asymptomatic When symptoms are present they are often vague –Diarrhea, cramping, fatigue –Occasional patient feels the worm segment hanging outside the anus or sees a partial segment in the toilet bowl
59
If complicated by B12 deficiency The patient may have anemia symptoms The patient may have anemia symptoms –Pallor, breathlessness Plus glossitis Plus findings of posterior column spinal cord disease –Loss of vibratory sense, proprioreception, poor coordination
60
Diagnosis Look in the stool for eggs, or sometimes segments of adult worms
63
Treatment Praziquantel is the drug of choice It kills the adult worm, so it will come out in the stool (warn patient) Low toxicity Dose is 5-10 mg/Kg as a single dose
65
Thank You!
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.