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101 Cards in this Set
- Front
- Back
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Amastigotes in a macrophage makes the diagnosis of what?
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Visceral leishmaniasis
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Visceral leishmaniasis often enlarges which organs?
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Liver and spleen
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How many cases of malaria worldwide each year?
How many deaths? |
300 million cases
1-3 million deaths - 75% under age 5 |
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Name 4 species of malaria
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Plasmodium
- falciparum - vivax - ovale - malariae |
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Which species of mosquito transmits malaria?
Which sex transmits What else can it transmit? |
Female anopheles only; no other species transmit malaria.
Anopheles gambiae most important Also transmits filariasis and some arboviruses |
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When do anopheles feed?
What do they feed on? |
At night; humans and animals.
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Multiple rings per cell, multinucleated rings are all characteristic features of which malaria on microscopy?
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Falciparum
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Schuffner's dots throughout RBC, large RBCs and abundant schizonts are all features of which malaria on microscopy?
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Vivax
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Fused zygotes become ___ and migrate to the mosquito stomach wall to become ____
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Ookinetes; oocysts
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Enlarged RBCs which become oval in shape, Schuffner's dots are and smaller schizonts are seen in which malaria?
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Ovale
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Crescent shaped gametocytes and Maurer's dots are characteristic of which malaria?
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Falciparum
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Normal sized RBCs and accole forms (linear ring forms) are characterisitic of which malaria?
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Falciparum
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What is airport malaria?
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Local residents living near airports get malaria in non-endemic areas from international flights carrying mosquitos
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What changes occur in the RBC upon malarial infection?
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surface expression of strain-specific antigens
cytokine release hemoglobin digestion get 'stickier' |
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Minimum incubation for malaria
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7 days
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Key symptoms malaria
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Remitting fever (tertian, quartan)
Mild jaundice Tender hepatosplenomegaly Flu-like symptoms |
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Name 5 serious complications of malaria
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cerebral infarction, anemia, hypoglycemia, metabolic acidosis, renal failure, pulmonary edema, DIC, hyperpyrexia
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Signs of cerebral malaria
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1. abnormal eye movements
2. jaw closure/tooth grinding 3. mild neck stiffness 4. decorticate/decerebrate rigidity 5. CSF protein and lactic acid up 6. abdominal reflexes absent |
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Malaria neurologic sequelae in children (name 3)
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hemiparesis, cerebellar ataxia, cortical blindness, mental retardation
- less than 1% have permanent damage |
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What happens to serum Fe and ferritin in malarial anemia?
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serum Fe down
serum ferritin up |
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What are the two causes of hypoglycemia in malaria?
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quinine/quinidine induced hyperinsulinemia (seen in severe disease or pregnancy)
non-hyperinsulinemic - children, pregnancy, high parasite load |
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Deep breathing may indicate ____ in malaria due to ____
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respiratory distress due to metabolic acidosis, often lactic
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In a well-seeming patient, the presence of this feature is an indication of serious disease and need to iv antibiotics
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retinal hemorrhage
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What drug should be used to prevent relapses of vivax/ovale malaria?
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Primaquine
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Name three cardinal features of leprosy.
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Anesthetic skin lesions
Peripheral neuropathy Peripheral nerve thickening |
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What are the two main clinical types of leprosy (Hansen's disease)?
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Tuberculoid (pauci-bacilary)- effective cell mediated clearance
Lepromatous (multibacillary) - ineffective, poor cell-mediated response, failed clearance Also borerline and indeterminate types |
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How many skin lesions are required for a classification of multibacillary leprosy?
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5 lesions
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What skin lesions are seen in paucibacillary Hansens (tuberculoid leprosy)?
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hypopigmented macules with clear borders and hairless
may see nerve thickening, esp ulnar |
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What skin findings are seen in multibacillary Hansens (lepromatous leprosy)?
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often symmetrical lesions, nodules, plaques;
also get epistaxis due to involvment of nasal mucosa |
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Facial changes in leprosy?
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thinning of eyebrows (as in hypothyroidism), thickening of ears, leonine facies; commonly affecting nose and eyes
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What type of organism causes leprosy?
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Mycobacterium - intracellular aerobic gram+ rod; acid fast; only occurs in man; very durable - persist for months in environment; difficult to culture - mouse foot pads
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What role do antibodies play in leprosy?
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None!
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Are granulomas a feature of leprosy?
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Yes. Mainatined by TNF release.
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How is leprosy diagnosed?
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Best test is lepromin test - inject antigen into skin - erythema after 24-72 hrs is positive (Fernandez reaction)
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How is leprosy treated?
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Triple therapy - dapsone, rifampicin, clofazamine
- 6 months for tuberculoid - 12 months for lepromatous BCG vaccine maybe useful |
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What causes cutaneous larva migrans?
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Hookworm larvae - serpiginous lesions;
treatment - thiabendazole or ivermectin |
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Which mosquitos transmit dengue?
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Aedes egypti and aedes albopictus
(daytime bites; likes clean water; virus transmits easily; single mosquito may infect many people; mainly an urban diseaese) |
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What type of virus is dengue? How many serotypes are there?
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Flavivirus
4 serotypes: DEN1, DEN2, DEN3, DEN4 |
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Which dengue serotype is ass'd with severe disease?
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DEN3 subtype III
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Which cells does dengue infect?
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Monocytes, T cells, B cells; starts in draining nodes, then disseminates
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When does dengue hemorrhagic fever occur?
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Co-infection with DEN3 and other strains (immune enhancement hypothesis - abs from non-DEN3 infection bind DEN3 but fail to neutralize and actually increase uptake by macros, thereby facilitating more severe infection)
(is possible for DHF to occur with DEN3 alone) |
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Is dengue more severe in children or adults?
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Adults
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Symptoms of dengue
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High fever
Bone pain Myalgia Blanching maculopapular rash |
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What are the consequences of dengue infection?
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DHF or DSS (dengue shock syndrome
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How do we treat dengue?
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Supportive tx only
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Blood test findings in dengue?
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mild thrombocytopenia and eosinophilia; leukopenia; increased ALT
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Diagnosis of dengue?
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serology or RT-PCR;
IgM ELISA check for malaria to rule out |
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Which mosquito carries WNV?
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Culex pipiens
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What percentage of people infected with WNV get symptoms of West Nile fever
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20%
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What viruses is WNV related to?
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Japanese encephalitis and St. Louis encephalitis
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Does immunity develop for dengue?
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Yes. homotypic immunity for life, heterotypic for about 6 months
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Symptoms of DHF?
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usually onset around time fever resolves; severe hemorrhages and possibly shock circulatory collapse, fluid leakage into tissues
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Name some useful antimicrobials for OI prophylaxis
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FACI
fluconazole - cryptococcus and thrush azithromycin if CD4 < 100 co-trimoxazole - PCP isoniazid 300mg if mantoux+ |
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What are the two main serious side effects of the NNRTIs (nevirapine and efavirenz)
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skin rashes including SJS
severe hepatotoxicity and hepatitis |
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List some NRTIs
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lamivudine, stavudine, zidovudine
abacavir, tenofovir |
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Side effects of protease inhibitors?
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fat redistribution, crixi belly, metabolic syndrome
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What drug is useful for pharmacokinetic enhancement of other anti-retrovirals?
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low dose ritonavir
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when should anti-retroviral treament be started?
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CD4 < 200
viral load > 50,000 +CD4 200-350 |
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Which organisms cause leishmaniasis?
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Protozoans
L. donovani spp. donovani, infantum, chagasi - cause visceral L. tropica, major, mexicana, braziliensis - cutaneous Braziliensis - mucocutaneous |
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What is the reservoir for indian kala-azar?
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human only; cutaneous forms have reservoir in dogs or rodents
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Name 4 sites affected by visceral leishmaniasis
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lymph nodes
bone marrow liver spleen |
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Symptoms of visceral leishmaniasis
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Fever
Weight loss Non-tender splenomegaly Non-tender hepatomegaly Pallor |
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What problem can occur after visceral leishmaniasis?
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Post-kala azar dermal leishmaniasis - may occur after successful therapy
- macular form responds to tx - nodular form poor response |
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What form does leishmaniasis take in sandflies
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promastigotes
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Where are Leishman-donovan bodies seen? What are they?
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they are extracellular amastigotes seen commonly in the spleen and bone marrow; also in blood, lymph nodes, liver
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Blood changes in visceral leishmaniasis?
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anemia, leukopenia, thrombocytopenia, coag defects, hypergammaglobulinemia, low albumin, leishman-donovan bodies
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Dx of visceral leishmaniasis
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katex: latex agglutination test for leishmanin antigen in urine
or leishmanin skin test |
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treatment of visceral leishmaniasis
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liposomal amphotericin is best
sodium stibogluconate (antimony) miltefosine (only oral tx) pentamidine aminosidine |
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symptoms of cutaneous leishmaniasis
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ulcerating skin lesion a few weeks after exposure - face,ears common
regional lymphadeopathy |
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What transmits leishmaniasis?
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Female sandfly - phlebotomus spp.
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Which species causes mucocutaneous leishmaniasis
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Leishmania braziliensis
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What is the treatment for cutaneous leishmaniasis?
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Stibogluconate - not very safe
meglumine antimoniate allopurinol imiquimod cream - good pentamidine amphotericin azoles eg fluconazole - good miltefosine |
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Name some useful antimicrobials for OI prophylaxis
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FASI
fluconazole - cryptococcus and thrush azithromycin if CD4 < 100 septrin (co-trimoxazole) - PCP isoniazid 300mg if mantoux+ |
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What are the two main serious side effects of the NNRTIs (nevirapine and efavirenz)
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skin rashes including SJS
severe hepatotoxicity and hepatitis |
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What vector spreads onchocerciasis?
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Black fly
- lives near fast flowing rivers |
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How is onchocerciasis diagnosed?
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Skin snip
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What is the treatment for onchocerciasis?
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Ivermectin
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What causes xerophthalmia?
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Vit A deficiency;
- dry eyes, eventually leading to blindness - changes to conjunctiva, and sometimes retina |
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What is a simple treatment for xerophthalmia
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High dose Vit A once/month for first 5 yrs of life
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What is a major source of retinitis ass'd with HIV?
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CMV retinitis - relentlessly progressive necrotizing retinitis which destroys entire retina in 3-6 mos
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What is the treatment for CMV retinitis?
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Ganciclovir
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True of false: eye needs to be fully dilated for appropriate dx of CMV retinitis?
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True; narrow field inappropriate
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What percentage of adults are CMV+
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100% - but latent unless immunosuppressed
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Name the commonest causes of blindness in developing countries
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Cataracts
Trachoma Xerophthalmia Onchocerciasis Serious refractive errors |
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Name some protozoan infections in HIV (opportunistic)
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Cryptosporidium
Isospora Toxoplasma |
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What are the main organs affected by toxoplasma infection?
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Brain - ring-enhancing lesions on CT
Eyes - retinal inflammation on fundoscopy |
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What is the leading cause of blindness in developing countries?
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Cataracts
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What is one severe side effect of ocular trachoma leading to blindness?
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Trichiasis
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What is the treatment for trachoma?
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Single dose azithromycin
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What is the treatment for toxoplasma?
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Sulfadiazine + pyrimethamine
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How do you dx pneumocystis?
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BAL or lung biopsy
CXR can be helpful |
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what histology is ass'd with african trypanosomiasis
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pervicascular cuffing (brain)
morular cell of moth |
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Which environments are rhodesiense and gambiense ass'd with?
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rhodesiense - woodlands
gambiense - waterways |
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Which, rhodesiense or gambiense, has a reservoir outside man?
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rhodesiense - animals
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What sign is first to develop after a tsetse fly bite
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trypanosomal chancre - 2-3 days - 2 weeks
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Which trypansoma species produces a denser parasitemia? (R/G)
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rhodesiense; fever follows with waves of parasitemia
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Which infection is ass'd with posterior triangle lymphadenopahty and a silent expression of grief?
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african trypanosomiasis
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true or false: trypanosomiasis is ass'd with splenomegaly and anemia
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true
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What organs can trypanosomiasis effect?
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Heart - murmurs, hypotension, pericardial effusions, heart failure
Lungs - pulmonary edema, secondary infection CNS - irritability, headache, somnolence, personality change, coma |
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What is Kerandels sign and what is it ass'd with?
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Delayed hyperasthesia; ass'd with trypanosomiasis
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Treatment of trypanosomiasis?
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suramin, melarsoprol
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