Term
| What are the two major groups of parasites? |
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Definition
|
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Term
| What percentage of the world's population has amebiasis? |
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Definition
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Term
| What are examples of sporozoa? |
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Definition
| cryptosporidium hominis, toxoplasma gondii (plasmodium species) |
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Term
| What are examples of Rhizopods? |
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Definition
| naeglaria and acanthamoeba (entamoeba histolytica) |
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Term
| What are examples of the flagellates? |
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Definition
| trichomonas vaginalis, giardia lamblia, leishmania, trypanosoma |
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Term
| What are the diferent types of protozoa? |
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Definition
| sporozoa, rhizopods and flagellates |
|
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Term
| Where are the oocysts of crptosporidium hominis found? |
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Definition
| worldside in poop of domestic animals and people. Can enter drinking water supply, causing outbreaks |
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Term
| Cryptosporidium hominis is resistent to.... |
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Definition
| chlorine treatment and freezing |
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Term
| What do the infective oocysts of cryptosporidium hominis do once they are ingested? |
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Definition
| land in microvilli and sporozoites excyst and invade epithelial cells |
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Term
| What are the symptoms of cryptosporidium hominis? |
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Definition
| week of watery, profuse diarrhea with mild malabsorption/weight loss |
|
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Term
| how do you treat cryptosporidium hominis? |
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Definition
| self-limiting in immunocompetent. Fluid and electrolytes in immunocompromised patients |
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Term
| Where is toxoplasma gondii found? |
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Definition
|
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Term
| What is the prevalence of toxoplasma gondii? |
|
Definition
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Term
| What are the symptoms of toxoplasma gondii? |
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Definition
self-limiting febrile adenopathy; usually chronic, assymptomatic
can mimic infectious mononucleosis. Can be highly lethal: AIDS patients develop encephalitis |
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Term
| What does toxoplasma gondii do to fetuses? |
|
Definition
| malformations, chorioretinitis, stillbirths |
|
|
Term
| How do you diagnose toxoplasma gondii? |
|
Definition
primary method: agglutination IFA with antibodies to toxoplasma
PCR in congenital or AIDS pts
histopathology via lymph node biopsy |
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Term
| What is the treatment for toxoplasma gondii? |
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Definition
| no treatment for normal people. For immunocompromised/pregnant you use pryimthamine and sulfonamides (Pryimethmamine is teratogenic and spiramycin should be used in place of pyrimethmamine in the first trimester |
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Term
| What organism causes malaria? |
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Definition
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Term
| In what form does plasmodium enter a liver cell? leave a liver cell? after it enters the RBC? |
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Definition
| sporozoite; merozoite; trophozoite |
|
|
Term
| What are the symptoms of plasmodium infection? |
|
Definition
| fevers, h/a, sweats, dark urine (hemoglobinuria) |
|
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Term
| What might you find on physical exam of a person with malaria? |
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Definition
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Term
| Which is the most dangerous type of plasmodium and what are the mechanism by which it causes morbidity/mortality? |
|
Definition
| P. falciparum; anemia depressed bone marrow function, capilliary blockage in the brain and reduced blood flow to vital organs |
|
|
Term
| How do you diagnose plasmodium? |
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Definition
parasitized RBCs usually visualized by microscopic examination of blood smears stained with Wright's or Giemsa stain
ALSO, card-based antigen detection test: OptiMAL |
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|
Term
| How do you treat plasmodium infection? |
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Definition
| chloroquine, antifolate-sulfonamide combinations, mefloquine, halofantrine, artemisinin-based combination therapy (ACT) with mefloquine |
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Term
| How do the Negleria and Acanthamoeba cause disease? |
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Definition
| enters nasal mucosa, cribiform plate into central nervous system, severe hemorrhagic inflammation |
|
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Term
| What are the symptoms of naegleria and acanthamoeba infection? |
|
Definition
| high fever, bi-frontal h/a, stiff neck, smell/taste anomalies, seizures, coma, death |
|
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Term
| What does the CSF look like in Naegleria infection? |
|
Definition
| bloody with neutrophils and Naegleria trophozoites |
|
|
Term
| How do you treat naegleria and acanthamoeba infections? |
|
Definition
| amphotericin B, miconazole and rifampin |
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Term
| Entamoeba histolytica cysts can survive ______ treatments used in municipal water supplies. |
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Definition
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Term
| Where in the human body do entamoeba histolytica live? |
|
Definition
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Term
| What do entamoeba histolytica eat? |
|
Definition
| bacteria and tissue cells in colon |
|
|
Term
| What are the symptoms of entamoeba histolytica infection? |
|
Definition
minimal/asymptomatic. Intermittant diarrhea, flatulence
Ameobic dysentary can occur (abdominal cramping, high fever, blood and mucus in stool) |
|
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Term
| Besides inhibiting the colon, what other organs can the entamoeba histolytica infect? |
|
Definition
| -can infect liver, lung, spleen heart and brain |
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Term
| An abscess in the liver that produces "anchovy paste" aspiration is most likely caused by which protozoan? |
|
Definition
| the rhizopod, entomoeba histolytica |
|
|
Term
| What does the entamoeba histolytica rhizopod do to the mucosa? |
|
Definition
| causes flask shaped mucosal ulceration |
|
|
Term
| How do you diagnose Entamoeba histolytica? |
|
Definition
| identify it in stool! (harder to diagnose when disease is extra intestinal) E. histolytica antigen tests and enzyme immunoassays now available to aid diagnosis |
|
|
Term
| What is the treatment for Entamoeba histolytica? |
|
Definition
metronidazole combined with diloxanide
Dehydroemetine for severe extra intestinal infections |
|
|
Term
| What are the symptoms of trichomonas vaginalis in women? |
|
Definition
| discharge, itching/burning, unpleasant odor, painful intercourse/urination, reddening of vagina and endocervical mucosa, petechial hemorrhages (red/purple spots) |
|
|
Term
| What are the symptoms of trichomonas in men? |
|
Definition
| usually asymptomatic, dysuria, nonpurulent d/c, urethra and prostate are involved (soemtimes involves seminal vesicles and epididymis) |
|
|
Term
| How do you diagnose trichomonas vaginalis? |
|
Definition
| unstained wet mounts of vaginal d/c or urethral exudate in men. Could see jerky parasite cell movements. H and E stain, IFA antibody stain, PCR |
|
|
Term
| How do you treat trichomonas vaginalis? |
|
Definition
| metronidazole (flagyl) and tinidazole (but never use that in first trimester of pregnancy--teratogenic) |
|
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Term
| Where in the human body does Giardia lamblia live? |
|
Definition
| duodenum and jejunum. Form infectious cysts in colon |
|
|
Term
| Which protozoa are resistant to chlorine treatment? |
|
Definition
| cryptosporidium hominis, entamoeba histolytica, giardia lamblia |
|
|
Term
| What is the most commonly identified intestinal parasite in the U.S.? |
|
Definition
|
|
Term
| What are the symptoms of giardia lamblia? |
|
Definition
| usually symptomatic: diarrhea lasting up to 4 weeks (foul-smelling, greasy stool), abdominal pain, nausea, and vomiting. Intestinal malabsorption with heavy parasite burden |
|
|
Term
| What does giardia do do the intestines? |
|
Definition
| damages microvilli brush border |
|
|
Term
| How do you diagnose Giardia lamblia? |
|
Definition
identify cysts in stool, intestinal biopsies by iodine or Giemsa stain (sample weekly because organisms might be intermittant in chronic infection)
reliable commercial immunoassays to detect parasites in stool |
|
|
Term
| What are the treatments ofr giardia lamblia? |
|
Definition
quinacrine hydrochloride and metronidazole
less effective: furazolidone (liquid for children) and paromomycin (pregnant women in first trimester) |
|
|
Term
| What are the three different types of leishmania sp. infection? |
|
Definition
| cutaneous (least severe), mucocutaneous, visceral (most severe) |
|
|
Term
| Cutaneous leishmania is characterized by... |
|
Definition
| ulcers; painless craters with raised erythematous edges, usually self-heals |
|
|
Term
| Mucocutaneous leishmania is usually characterized by... |
|
Definition
| painful, destructive, metastatic mucosal lesions of mouth, nose (weeks to years); fever, anemia, weight loss, and secondary bacterial infections |
|
|
Term
| Visceral leishmania is characterized by... |
|
Definition
| delayed onset: fever, enlarged lymph nodes and liver, massively enlarged spleen, edema; usually fata if untreated |
|
|
Term
| How do you diagnose leishmania? |
|
Definition
| microscopic evaulation of parasites. Smears from these samples are stained with Giemsa, H and E oor immunoperoxidase PCR is a sensitive test too. |
|
|
Term
| What is the treatment for Leishmania? |
|
Definition
| pentavalent antimonials (glucantime, pentostam), amphotericin B (liposomal formulation), paromomycin, azoles (fluconazole) for cutaneous leishmanias DRUG TOXICITY TO PT IS PROBLEMATIC |
|
|
Term
| What causes leishmania infection? |
|
Definition
| infection via sandfly bites |
|
|
Term
| How does trypanosoma cruzi get into the human body? |
|
Definition
| triatomine bug bites and defecates. T cruzi parasites in bug feces are inoculated when host scratches bite site |
|
|
Term
| What are the symptoms of Trypanosoma cruzi? |
|
Definition
|
|
Term
| What tissues does trypanosoma cruzi infect? |
|
Definition
| myocarditis, encephalitis, lymphadenopathy |
|
|
Term
| What might you find on physical exame of a patient with Trypanosoma cruzi? |
|
Definition
| spleen and liver enlargement |
|
|
Term
| What are the sequale of a chronic form of trypanosoma cruzi (10-30 yrs)? |
|
Definition
| heart disease, megacolon, megaesophagus |
|
|
Term
| How do you diagnose trypanosoma cruzi? |
|
Definition
| detection of parasites in blood smear, parasite culture, complement fixation test, xenodiagnosis, PCR |
|
|
Term
| How do you treat trypanosoma cruzi? |
|
Definition
nifurtimox, benznidazole, allopurinol
toxic side effects, not always successful |
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