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48 Cards in this Set
- Front
- Back
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Enteric Amebiasis
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caused by pseudopod, nonflagellate protozoan Entamoeba Histolytica
- live in LI (mostly), blood and liver (not common), or brain (rare) Fecal - Oral route of transmission Entamoeba dispar is morph. identical, but in noninvasive. - must do PCR to differentiate (also differentiate E. moshkovski) |
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Epidemiology of Enteric Amebiasis
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commonly found in poorer countries
in US common in immigrants from poor countries and travelers often encountered in mental hospitals also present in the gay community (E. dispar> E. Histolytica) |
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Life Cycle of E. Histolytica
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CYSTS - infective (withstand gastric acid)
-from contaminated food handlers - also from the feet of flies - by water - gay sexual intercourse divides into trophozoites - multiply by fision - these invade LI (cysts cannot) - form flask shaped ulcers in colon - can move to liver via portal vein |
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Clinical Manifestations of E. Histolytica
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E. dispar - assymptomatic colonization. does not even invade AIDS patients
E. Histolytica - assymptomatic for months - then invade and cause symptoms Dysentary - abdominal cramping and diarrhea w/ mucus - diarrhea and constipation alternate - can cause fever, chills, and bloody still - tenesmus Also: -necrotizing colitis - Ameboma - cutaneous symptoms - rectovaginal fistula |
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Amebic Liver Abscesses
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liver is most common site for abscesses, but also present in brain, lungs and spleen
severe URQ pain elevated WBC elevated serum transaminases elevated alkaline phosphatase elevated hemidiaphragm 10 times more common in men in women particularly in pregnancy usually dont have bowel symptoms may recal bloody diarrhea within last year - but goes away -ALSO NOT FOUND IN STOOL |
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Amebic Pulmonary disease
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occurs when liver abscesses rupture through the diaphragm
- pleuritic pain - RUQ pain - cough - red sputum |
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Diagnosis of Amebiasis
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usually on top of list for third world diarrhea but should be towards the bottom (overdiagnosed)
microscopy - 3 stool samples - look for "gliding" organisms with pseudopods. - examine stool within 30 mins of harvest - flask shaped ulcerations - has a single nucleus, charcot-leyden crystals present in stools |
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E. histolytica vs. E. Coli (the parasite not the bacteria)
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E. coli is not a pathogen and doesnt require treatment, but looks similar
same size chromatin is dispersed in E. Histolytica and clumped in E. coli karysome is sharp and central in E. Histolytica, and course and peripheral BIG CLUE E. Histolytica usually has ingested RBCs, E coli doesnt do this. E. coli has up to 8 nuclei, E. histolytica has less than 4 |
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Antigen/antibody Detection for E. histolytica
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stool antigen tests are available
high sensitivity and better than microscopy for diagnosis of E histolytica use ELISA for extra-intestinal detection |
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Colonoscopy for E. histolytica
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scrape ulcers and use microscope, also test for antigen
take specimens from edge of ulcer |
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Imaging for Liver abscesses in Amebiasis
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ultrasound
MRI CT |
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Treatment of Amebiasis
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assymptomatic - luminal agent (lodoquinolol, paromycin)
- do not use Metrondiazole or Tinidazole mild intestinal - metronidazole or tinidazole - follow with a luminal agent severe intestinal - metronidazole or tinidazole followed by a luminal agent |
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Prevention and Control of Amebiasis
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avoid raw, unpeeled, uncooked vegetables
drink carbonated bottled water, boiled water, or use iodine tablets |
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Blastocystis Hominis
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very common in tropics, but everywhere
found in pigs, monkeys, rodents, poultry transmitted in gay sexual intercourse causes diarrhea, pain, nausea, vomiting, malaise can treat with metronidazole or bactrim (not required usually though) |
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Giardia Lamblia
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one of the most commonly encoutered intestinal parasitic diseases
very common in WV and Colorado water borne infection or person to person, or in food also gay sexual intercourse can also occur in a number of animals (watch for beavers on boards) |
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Life cycle of Giardia Lamblia
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infection by ingesting CYSTS
CYSTS turn into trophozites upon encountering stomach acid - trophozites invade duodenum humans can develop partial immunity no correlation between giardiasis and HIV cysts and trophozoites are passed in the stool |
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Clinical Manifestations
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crampy abdominal pain
bloating yellow, foul smelling frothy, and floats incubation of 1-2 weeks not usually bloody diarrhea reactive arthritis - major joints, not in fingers malabsorption of fat, vit A and B12, protein. may alternate diarrhea and constipation turn people into lactose intolerant |
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Diagnosis
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diarrhea, after traveling for a few days, enterotoxigenic E. Coli is likely
diarrhea (yellow-foul-frothy-floating), a few weeks into a trip or after return - think giardia high index of suspicion for people returning from colorado or WV diagnosis by examination of stool for ova and parasites (x3) duodenal asipiration for trophozites fecal ELISA antigen DNA probes |
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Morphology of Giardia
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flagellate protozoan in SI
trophozoite is described as pear-shiped or teardrop-shaped tumbling or swimming motion, beating of rear flagella multiply by binary fision - form cysts in distal intestine - have 2 (immature) and 4 (mature) nuclei - large clear space around organism |
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Treatment for Giardia
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Tinidazole is drug of choice
Metronidazile used to be standard drug - still pretty good choice - do not drink alcohol - will make you very sick Furazolidone - popular for kids Paromomycin useful in pregnancy |
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Nitazoxanide
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ALINIA
new antiprotozoal approved by the FDA in liquid formation to treat giardia in kids (tablets for adults) effective against a wide variety of parasites and have no real adverse side effects - occasionally cause yellow sclera |
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Prevention and Control of Giardia
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prevention with appropriately safe water and sewage treatment systems
city water treatment does not always kill giardia boil water when camping |
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Trichomoniasis
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T. Vaginalis - flagellate most common pathogenic protozoan - very common STD
Infects vagina, prostate and urethra - NOT an intestinal protozoan |
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clinical Manifestations of Trichomoniasis
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vaginal itching
purulent discharge paiful intercourse symptomatic in women assymptomatic in men increases susceptobility to HIV |
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Diagnosis of Trichomoniasis
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examination of wet mount - motile parasites twirling around slide
use immunofluirescent antibody or culture - more sensitive than wet mounts |
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Dientamoeba Fragilis
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worldwide
uncommon intestinal protozoal ilness flagellate - without flagella only trophozoite observed - no cyst has been observed - transmitted in pinworm eggs and in ascaris eggs diagnosis by microscopy treat with metronidazole, tetracycline |
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Balantidium Coli
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LI protozoan
only CILIATED infection which causes intestinal disease found in pig bowels, mainly in tropics diagnose by finding cysts in stool (OandPx3) trophizoites found in fresh stool crater like ulcers of large intestine treat with tetracycline, iodoquinol or metronidazole |
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Intestinal Coccidial Infections
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almost exclusive to animals until AIDS epidemics
cause severe protracted diarrheain AIDS patients |
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Cryptosporidium Parvum
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fecal oral route of transmision
oocytes can pass through conventional water filters have high chlorine resistance highly contagious outbreak in Milwuakee in 1993 endemic childhood diarrhea in developing nations travelors diarrhea in poor nations protracted diarrhea in AIDS patients water borne outbreak |
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Clinical Manifestations of Cryptosporidium Parvum
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mainly in children
decreased appetite and vomiting profuse watery diarrhea - days to weeks AIDS patients can have a chronic infection |
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Diagnosis of Cryptosporidium Parvum
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find oocysts in stool
modified Kinyoun acid fast stain ELISA kits can also biopsy bowel |
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Treatment of Cryptosporidium
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self limited disease
no treatment is necessary other than rehydration nitazoxanide (ALINIA) can be used in immunocomprimised |
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Isospora Belli
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mainly infected in the immunocomprimised
patients in institutions practitioners of oral anal sex - acute non bloody diarrhea - Charcot Leyden crystals/eosinophils in stool diagnose with modified acid fast stain stool samples negative - need biopsy treat immunocomprimised patients with TMSM (bactrim) |
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Cyclospora cayentanensis
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increasing frequency in travelers to developing countries
worldwide distribution ingestion of sporulated cysts in food and water excrete unsporulated cysts can contaminate rasberries, msclun lettuce, and basil watery diarrhea, cramps, gas, bloating nausea vomitiing, loss of appetite testing is difficult and not done treat with TMSM(Bactrim) |
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Sarcocystosis
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require 2 hosts for completion (carnivore and herbivore)
RARE but can cause a muscle infection and an intestinal infection treat with TMSM (bactrim) |
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Microsporidia
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obligate intracellular parasites
spores are responsible for infection spore has coiled polar filament effects Gi tracts, lung, eye, diarrhea occular microsporidiosis |
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Echinococcus granulosus
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caused by larvae of tapeworms
-- Hydatid disease -- seen where people use dogs to herd sheep, and where dogs have close contact with humans dogs eat sheep guts (mainly liver) containing the cysts - adult worms develop - eggs passed in dog feces - humans eat eggs contaminated from dog feces - go to liver and lungs common in middle east, Greece, North Africa, New Zealand, South America |
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Echinococcus multilocularis
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dog - rodent cycle
man acquires from eating unwashed fruits or vegetables contaminated with feces occurs in cold climates - Russua, North Japan, West China, Canada, Alaska |
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Diagnosis and treatment of Echinococcus
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history positve for close contact with herd dogs
space occupying lesion of liver should be tested for echinococcus Greece, Middle East, Argentina - who are otherwise healthy - think echinococcus use CT, MRI or ultrasound - will reveal a single, large cyst surgery is required - must be careful 0 can lead to rupture and anaphylaxis use albendazole and praziquantel prophylactically during surgery |
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Taeniasis
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beef/pork tapeworms
worldwide incidence penetrate muscle of farm animals - develop into cysticerci - infect people when eat undercooked meat - adult worms attach to SI - produce proglottids |
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Clinical manifestations of Taeniasis
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usually assymptomatic
can cause a neuro dysfunction mild GI symptoms may pass long segments of worm - freaks people out |
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Diagnosis and treatment of Taeniasis
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up to 15 ft. ribbon tape worm - best clue
microscopic examination for proglottids in feces treat with praziquantel |
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Cysticercosis
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eggs of Taenia solium ARE infective to humans - can cause serious disease - neurocysticercosis
eggs release oncoshperes in SI - migrate to muscle and brain - mental disturbances and seisures |
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Diagnosis and treatment of Cysticercosis
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high index of suspicion
migrant workers with new onset seisures use antibody detection praziquantel or albendazole steroids for inflammation |
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Diphyllobothraiasis (latum)
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fish tapeworm
long tapeworm from fish in cold fresh waters passed in human feces into fresh water - hatch and release motile forms - infect crustaceans - eaten by fish - people eat undercooked fish CAUSES B12 DEFICIENCY - ANEMIA |
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Diagnosis and Treatment of Diphyllobothrium latum
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characteristic eggs
B12 anemia (megaloblastic) treat with praziquantel |
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Hymenolepiasis
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tiny tapeworms
H. Nana - most common eggs are immediately infective once passed in stool - can also infect beetles or fleas - contaminate grain - infect humans patients have abdominal pain diarrhea itching around anus headaches inspect stool for eggs treat with praziquantel |
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Dipylidium caninum
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dog tapeworm
transmit to humans through fleas abdominal pain diarrhea restlessness itching around anus proglottids look like cucumber seeds treat with praziquantel |
