Microbiology Parasitology - First Aid Flashcards
Giardia lamblia disease
Giardiasis: bloating, flatulence, foul-smelling, fatty diarrhea (often seen in campers/hikers)
Transmission of Giardia lamblia
cysts in water
Diagnosis of Giardia
trophozoites or cysts in stool
Treatment for Giardia
Metronidazole
Entamoeba histolytica disease
Amebiasis: bloody diarrhea, liver abscess (w/ “anchovy paste” exudate), RUQ pain
Transmission of Entamoeba histolytica
Cysts in the water
Diagonsis of Entamoeba histolytica
serology and trophozoites (w/ RBCs in cytoplasm) or cysts (w/ up to 4 nuclei) in stool
Treatment of Entamoeba histolytica
Metronidazole
Iodoquinol for asymptomatic cyst passers
Cryptosporidium diesease
severe diarrhea in AIDS
mild disease in immunocompromised
Cryptosporidium transmission
oocysts in water
Diagnosis of Cryptosporidium
oocysts on acid-fast stain
Treatment of Cryptosporidium
prevention by filtering city water
Nitazoxanide in immunocompromised hosts
Protozoa that cause GI infections (3)
- Giardia lamblia
- Entamoeba histolytica
- Cryptosporidium
Protozoa that cause CNS infections (3)
- Toxoplasma gondii
- Naegleria fowleri
- Trpanosoma brucei
Toxoplasma gondii disease
brain abcesses in HIV (ring-enhancing lesions on CT/MRI) congenital toxoplasmosis (triad of chorioretinitis, hydrocephalus and intracranial calcifications)
Transmission of Toxoplasma gondii
cysts in meat or oocysts in cat feces; crosses placenta
Diagnosis of Toxoplasma gondii
serology, biopys (tachyzoite)
Treatment for Toxoplasma gondii
Sulfadiazine and pyrimethamine
Naegleria fowleri disease
Rapidly fatal meningoencephalitis
Trasmission of Naegleria fowleri
swimming in freshwater lakes; enters via cribiform plate
Diagnosis of Naegleria fowleri
amoebas in spinal fluid
Treatment of Naegleria fowleri
Amphotericin B
Trypanosoma brucei disease
African sleeping sickness: enlarged LNs, recurring fever, somnolence, coma
Transmission of Trypanosoma brucei
tsetse fly (painful bite)
Diagnosis of Trypanosoma brucei
blood smear
Treatment for Trypanosoma brucei
Suramin for blood-borne disease
Melarsoprol for CNS penetration
Protozoa that cause hematologic infections
- Plasmodium
2. Babesia
Plasmodium Disease
fever, HA, anemia, splenomegaly
P. vivax/ovale
48 hour cycle (fevers on first and third days) dormant form (hypnozoite) in liver
P. falciparum
severe
irregular fever patterns
parasitized RBCs occlude capillaries in brain (cerebral malaria), kidneys and lungs
P. malariae
72 hr cycle (quartan)
Transmission of Plasmodium
mosquito
Diagnosis of Plasmodium
- blood smear, trophozoite ring form within RBC
- schizont containing merozoites
Treatment of Plasmodium
Begin with chloroquine which blocks Plasmodium heme polymerase; if resistant, use mefloquine or atovaquone/proguanil.
If Plasmodium infxn is life-threatening, treat with…
IV quinidine (check for G6PD deficiency).
For vivax/ovale treatment, add…
primaquine for hypnozoites 9test for G6PD deficiency).
Babesia disease
Babesisosis: fever and hemolytic anemia; northeast US; asplenia increases risk of disease
Transmission of Babesia
ixodes tick