Parasitic (F-L) Flashcards
what are the 3 species of filarial nematodes that cause Lymphatic filariasis?
Wuchereria bancrofti;
Brugia malayi;
Brugia timori.
how do you get Lymphatic filariasis?
mosquitoes - Aedes, Anopheles, Coquillettidia, Culex, Mansonia
rural, urban, semiurban settings, day and night
where is Lymphatic filariasis occur?
Africa (Egypt, sub-Saharan Africa); Asia (SE Asia, the Indian subcontinent); some southwestern Pacific Islands;
NE coast of Brazil, Guyana, Dominican Republic, Haiti
why is it low risk for short term travelers get lymphatic filariasis?
multiple exposures over time is required
what are the symptoms of lymphatic filariasis?
adult worms live in human lymphatic and subcutaneous tissues - can be asymptomatic or associated with acute and chronic clinical manifestations involivng moderate to severe lymphedema of the arm, breast, leg, penis, or scrotum;
progression of lymphedema to elephantiasis;
what is tropical pulmonary eosinophilia TPE syndrome?
result from immune hyper-responsiveness to microfilariae (due to lymphatic filariasis) in the pulmonary capillaries;
serious, progressive lung disease characterized by fever and nocturnal cough, wheezing, or both
how to diagnose lymphatic filariasis?
filarial antibody tests that detect elevated IgG and IgG4 can be useful
how to treat lymphatic filariasis?
lymphedema and hydrocele?
DEC (diethylcarbamazine);
4-8 week course of doxycycline (200mg daily) can both serilze adult worms and improve lymphatic pathologic features
what do you need to rule out before initiating DEC (diethylcarbamazine)?
co-infection with Onchocerca volvulus - contraindicated due to potential for causing a sevee allergic response (Mazzotti reaction) that especially affects the eyes and skin
DEC must be used extreme caution with patients with Loa loa infection (Loiasis) - due to possible life-threatening side effects in people with high circulating microfilariae loads
what cause liver flukes?
trematode flatworms, including
Clonorchis sinensis;
Fasciola hepatica and Fasciola gigantica;
Opisthorchis felineus and Opisthorchis viverrini
what is reservoir hosts for Clonorchis and Opisthorchis spp?
cats, dogs, other fish-eating mammals
how do you get liver flukes?
eat raw or undercooked freshwater fish
which species of causing liver fluke found mainly in Asia (China, Korea, eastern Russia, Taiwan, Vietnam, japan)?
Clonorchis sinensis
where is Fasciola gigantica found ?
Africa, Asia
where is Opisthorchis felineus found mainly in?
eastern Europe and through central Asia to Siberia, including the Baltic countries, Belarus, Italy, Germany, Greece, Kazakhstan, Moldova, Poland, Romania, Russia, Ukraine
where is Opisthorchis viverrini found in ?
Burma (Myanmar), NE Cambodia, Laos, Thailand, central and southern Vietnam
what are the symptoms of Clonorchiasis and Opisthorchiasis?
low-intensity infection: asymptomatic/mild symptoms;
high-intensity: nonspecific signs and symptoms - diarrhea, eosinophilia, fatigue, fever, nausea, indigestion, abdominal pain (right upper quadrant), colicky pain-associated with worms obstructing the gallbladder, jaundice, unlarged or tender liver
chronic infection (30 days or more) can complicate - cholelithiasis, cholangitis, cholecystitis, liver abscesses, pancreatitis, cholangiocarcinoma (CCA)
what are the symptoms of fascioliasis - acute and chronic?
acute: migratory, invasive, or hepatic phase can last 3-4 months;
abdominal pain, GI symptoms, marked eosinophilia, fever, respiratory symptoms, urticaria
chronic: biliary phase - begin 6 months after infection when immature worms (larval flukes) reach the bile ducts, mature into adult worms (can live 10 or more years) and start to produce eggs - chronic phase reflect biliary tract disease (biliary tract obstruction, cholangitis, cholecystitis) or pancreatitis
how to diagnose liver flukes?
eggs in stool; duodenal or biliary aspirates;
serologic testing can be useful for fascioliasis diagnosis during the acute phase
how to treat fascioliasis?
triclabendazole - first line
(nitazoxnide can be helpful in some patients)
how to treat clonorchiasis and opisthorchiasis?
praziquantel - first line
(albendazole - alternate)
which parasite cause lung fluke, Paragonimiasis?
Paragonimus westermani
how do you get lung fluke infection?
eat raw or undercooked freshwater crab or crawfish
where are Paragonimus species are found in?
western Africa, the Americas, Asia
what are the symptoms of lung fluke?
acute: occur within 2 days to 2 weeks after ingestion
chronic: symptoms like tuberculosis - shortness of breath, cough, hemoptysis
extrapulmonary infections can occur - CNS involvment is serious;
eosinophilia especially during the larval migration stage
how to diagnose lung fluke?
eggs in stool or sputum;
serologic test is helpful
what parasite cause Giardiasis?
anaerobic protozoan parasite Giardia duodenalis (formerly known as G. lamblia or G. intestnalis)
how do you get Giardiasis?
fecal-oral route;
moderate chlorine tolerance - transmission through drinking and recreational water
what are the symptoms of Giardias?
1-2 weeks after exposure and resolve 2-4 weeks;
abdominal cramps, anorexia, bloating, diarrhea (foul smelling, greasy stools), flatulence, nausea;
2-5 loose stools per day, increasing fatigue;
upper GI symptoms, weight loss,
reactive arthritis, irritable bowel syndrome, other chronic symptoms sometimes occur;
children - severe giardiasis can cause development delay, failure to thrive, malnutrition, stunted growth
how to diagnose Giardia?
exam 3 stool specimens over several days;
new molecular enteric panel assays;
microscopy with direct fluorescent antibody testing;
microscopy with trichrome staining, enzyme immunoassay kits, rapid immunochromatographic cartricge assays, molecular assays;
only Molecular testing (DNA sequencing) can identify the genotypes and subtypes of Giardia
how to treat Giardiasis?
metronidazole, tinidazole, nitazoxanide;
alternative - furozolidone, paromomycin, quinacrine
what is helminths?
parasitic worms
what are helminths that infect the intestine?
Ascaris lumbicoides (Ascaris or roundworm);
Ancylostoma duodenale (hookworm);
Necator americanus (hookworm);
Trichuris trichiura (whipworm)
how do you get Ascaris and whipworm infection?
ingest eggs of Ascaris, whipworm, and some hookworm;
feces deposited in soil - infective larvae of Ascaris and whipworms develop in the fertile eggs and, if ingested by a human host, hatch and develop into adult worms over several months.
what is soil-transmitted helminths (STH) and what are they?
nematode worms that are known to be transmitted through soil;
Ascaris lumbicoides, Ancylostoma duodenale, Necator americanus, Trichuris trichiura, Strongyloides stercoralis (threadworm)
how do you get hookworm infection?
skin transmission;
hookworm eggs are not infective - need larvae to mature in soil before they become infective;
larvae penetrate the skin of people walking barefoot on contaminated soil; Ancylostoma duodenale also can be transmitted when larvae are ingested
what is Ascaris suum? how is this transmitted to human?
pig roundworm - infection occurs when ingestion of infectious eggs shed in pig feces
what are the symptoms of Ascaris infection?
ppulmonary symptoms (Loffler syndrome) - marked eosinophilia and fever - occur in a few patients when larvae pass through the lungs;
what are the symptoms of heavy roundworm infection?
intestinal discomfort, impaired nutritional status, obstruction
what does hookworm infection cause?
lead to anemia due to blood loss and chronic protein deficiency, particularly in children
what does whipworm infection cause?
chronic abdominal pian, blood loss, diarrhea, dysentery, rectal prolapse
how to treat hookworm and Ascaris?
albendazole and mebendazole
how to treat whipworm?
albendazole + ivermectin
which parasite cause Leishmaniasis?
obligate intracellular protozoan parasites;
>20 Leishmania species
what are different Leishmaniasis forms?
visceral leishmaniasis (VL, most severe);
cutaneous leishmaniasis (CL);
mucosal leishmaniasis (ML)
how do you get cutaneous leishmaniasis?
through the bites of infected female phlebotomine sand flies;
occupational (lab) exposures;
where does Cutaneous Leishmaniasis occur?
Afria (tropical region and N. Africa);
Asia (central and SW Asia);
S. Europe (France, Greece, Italy, Portugal, Spain, Mediterranean islands)
The Middle East
Mexico, all in Central America, most S. America; Texas, Oklahoma;
CL not found in Canada, Chile, Uruguay
which times of the day does sand flies bite?
sand flies bite at night; less active during the hottest part of the day - but still bite if they are disturbed
what are the symptoms of Cutaneous Leishmaniasis?
dermatologic - 10% are asymptomatic; closed or open sores, develop on exposed areas of the skin within several weeks or months after infection; sores progress to ulcer; lesions usually painless (but painful if superinfected with bacteria); satellite lesions, regional lymphadenopathy, and nodular lymphangitis can occur
what are the symptoms of Mucosal Leishmaniasis?
parasite spread from skin to mucosal surfaces of the nose or mouth and cause sores in these areas; destruction of the mouth, nose, laryn, pharynx, if advanced.
how to diagnose cutaneous leishmaniasis?
chronic, nonhealing skin lesions;
lab - detect parasite or DNA;
serologic test not useful
how to treat leishmaniasis?
ML - systemic therpy
CL - topical or systemic
oral: miltefosine to treat CL caused by 3 WEstern Hemisphere species - Viannia subgenus: Leishmania braziliensis, L. guyanensis, L. panamensis; ML caused by L. braziliensis - in adults and adolescents 12 and up who weigh 30 kg and up, and not pregnant or breastfeeding
parenteral: liposomal amphotericin B
what is the primary causing parasite of Visceral Leishmaniasis?
Leishmania infantum (=L. chagasi), and L. donovani.
what organs does Visceral Leish affect?
bone marrow, liver, spleen & more
how do you get visceral leish?
infected female sand flies, congenital transmission and parenteral transmission through blood transfusions and needle sharing also reported
where are VL found?
Eastern Hemisphere - Africa (East Africa); Asia (Indian subcontinent and central and southwest Asia);
southern Europe; the Middle East
Western Hemisphere - Brazil mostly, some else where in Latin America
90% occur on the Indian subcontinent, in Bangladesh, India, Nepal, East Africa (Ethiopia, Kenya, Somalia, South Sudan, Sudan), and Brazil
what are the symptoms of VL?
fever, hepatosplenomegaly (especially splenomegaly), night sweats, weight loss;
lymphadenopathy can occur
lab - pancytopenia (anemia, leukopenia, thrombocytopenia), high total protein, low albumin, hypergammaglobulinemia
latent infection can manifest years to decades after exposure
person has unexplained fever illness with pancytopenia and splenomegaly. he has hemophagocytic lymphohistiocytosis. what can you suspect?
VL
how do treat VL?
liposomal amphotericin B;
miltefosine - VL with L. donovani who are 12 years and up, 30 kg up, not pregnant or lactating;
Pentavalent antimonials (e.g. meglumine antimoniate, sodium stibogluconate) are used in endemic areas, except for India
