Protozoa and Helminths Flashcards
(15 cards)
Babesiosis: E, C, D, T
E: Eastern seaboard, upper Midwest
C: non-specific febrile illness
D: Giemsa stained blood smear, look for parasites, Maltese cross; antibody assay can be >85-90% sensitive and specific
T: quinine and clindamycin (exchange transfusion of severe)
Trematode pearls (3)
- -trematodes = flukes = flatworms
- -praziquantal treats all of them but Fasciola
- -intermediate hosts are usually snail and clams
Nematode migration patterns
- -nematodes = roundworms
- -hookworms (Ancylostoma, Necator americanus, Toxocara) and strongyloides migrate from skin → lungs → gut
- -Ascaris migrates from gut → lungs → gut
Cutaneous larva migrans causes (3)
Ancylostoma, Necator, Toxocara
Filariae transmission
- -mosquitos (Wucheria and Brugia)
- -Chrysops flies (Loa Loa)
- -black flies (Onchocerca)
Eye worms (6)
- -Loa Loa (usually moves in anterior eye compared to others)
- -Toxocara
- -Onchocerca
- -Baylisascaris
- -Taenia solium (in neurocysticercosis form with ingestion of eggs)
- -Schistosoma (usually japonicum)
Intestinal protozoa (5)
- -Entamoeba histolytica (amoeba):, sometimes bloody invasive disease, visceral abscesses (E. dispar is identical and non-pathogenic); give metronidazole + subsequent paromomycin
- -Giardia (flagellated): tinidazole, nitazoxanide, metronidazole
- -Cryptosporidia (sporozoa): nitazoxanide
- -Cyclospora (sporozoa): TMP-SMX (or cipro)
- -Isosopora (sporozoa): TMP-SMX
Intestinal cestodes = tapeworms (3)
- -Taenia saginata: beef; sometimes into biliary tree, praziquantal
- -Taenia solium: pork with larvae (if you ingest eggs from infected human you can get neurocysticercosis); albendazole or praziquantal
- -Diphyllobothrium latum: freshwater fish; 40% with B12 deficiency; praziquantal
Intestinal nematodes = roundworms (7)
- -Anisakiasis: raw fish; endoscopy removal or albendazole
- -Enterobius (pinworm): anal pruritis; mebendazole or albendazole and tx family members
- -Ascaris: soil to mouth; intestinal, biliary, pulmonary disease; albendazole; often no eggs in stool during lung phase
- -Strongyloides: soil to skin; intestinal, pulmonary sx or hyperinfection syndrome with gram- sepsis; serology better than O&P; ivermectin
- -Ancyclostoma: soil to skin; iron deficiency anemia, abdominal sx; albendazole
- -Necator: soil to skin; iron deficiency anemia, abdominal sx; albendazole
- -Trichuris (whipworm): soil to mouth; bloody diarrhea, rectal prolapse; albendazole
[drug for all of these is albendazole…except ivermectin preferred for strongyloides]
Trypanosomes (2)
These are protozoa
- -T. cruzi (chagas): riduviid bud, “C” form in blood, chagoma acutely w/ LAD then later myocarditis and dilated esophagus or colon, rarely CNS disease; benznidazole (don’t tx everyone)
- -T. gambiense or rhodesiense (sleeping sickness): tse-tse fly bite with ulceratin then LAD and CNS sx
Schistosomiasis: M, C, D, T
M: mansoni, japonicum, haematobium; a trematode (flatworm)
C: three clinical syndromes
1) acute swimmer’s itch
2) Katamaya fever: fever, urticaria, bronchospasm, eosinophilia, elevated LFTs
3) Chronic: egg deposition and disease in number of places - bladder, interstines, liver, CNS/eye
D: serology +/- stool O&P (for chronic disease)
T: praziquantal
Filariae = thread-like nematodes/roundworms that invade the blood (4)
In addition to below can cause tropical pulmonary eosinophilia (paroxysmal nocturnal asthma with infiltrates; can diagnose these diseases by night time blood smear (or noon for Loa Loa)
- -Brugia malayi: mosquitos; lymphatic swelling; DEC + doxy
- -Wucheria bancrofti: mosquitos; lymphatic swelling; DEC + doxy
- -Loa Loa: tabanid flies; calabar swelling, sometimes ocular; surgical extraction before any DEC + doxy
- -Onchocerca volvulus: blackflies, blindness, lymphatic swelling; surgical extraction before any ivermectin + doxy
Tissue invasive trematodes = flatworms = flukes (3)
–Paragonimiasis westermanii: undercooked crabs and crayfish (most in US is in Midwest); lung fluke, praziquantal
Clonorchis sinensis and Opisthorchis viverrini: undercooked freshwater fish in Asia, liver flukes, praziquantal
Fasciola hepatica and buski: aquatic vegetation (chestnuts), intestinal, triclabendazole
Tissue invasive cestodes = tapeworms (2)
Echinococcus granulosis (from dog poop ingestion) and multilocularis (fox/rodents): cysts in lungs (2%, most in RLL), liver (65%), other visceral organs then sx from rupture; dx by ELISA (IgG 85% sensitive for liver, 50% for lung); tx w/ surgery/drainage and albendazole
Taenia solium: from eggs of human feces you get neurocysticercosis, confirmed dx by tissue bx if needed; albendazole (or praziquantal) if active (rule out spinal and ocular disease first)
Tissue invasive nematodes = roundworms (5)
Trichinella: undercooked pork, acute is n/v/d, then next week systemic (eosinophilia, fever, periorbital edema, myositis; bx and serology to dx; albendazole
Dracunculiasis (Guinea worm): from ingestion
Baylisascaris: ingestion of raccoon poop, migrates to eye, sometimes CNS or other organs
Toxocara canis: dog poop ingestion, ocular or visceral disease (visceral larva migrans); cutaneous infection from stepping on dog poop; ELISA IgG (but could be past exposure); albendazole
Angiostrongylus cantonensis: eosinophilic meningitis, most in SE Asia but other tropics as well; ingestion of vegetables or crustaceans with snail/slug contamination; drugs may make it worse, steroids are controversial
