Protozoa Flashcards
Amebae=
Entamoeba histolytica
Infections of Entamoeba histolytica
Amebiasis= 3rd most common cause of death from parasite
Amebic Dysentery, which can disseminate
Liver abscess (usu develops within 5 mos; responds to metronidazole w/o resection)
only one that can eat RBCs!
Entamoeba histolytica ( Amebae)
diagnosis= Trophozoites in tissue or feces
Gal/GalNAc Antigen detected in stool
Entamoeba histolytica rx
Colitis or Abscess: Tinidazole or Metronidazole
Luminal Infection: Paromomycin, Iodoquinol
3rd most common cause of death from parasite
Amebiasis= Infections of Entamoeba histolytica
Giardia lamblia diagnosis
Cysts/trophozoites in stools
Immunofluor or ELISA for antigen in stool
Giardia lamblia rx
Tinidazole or Metronidazole
Usually sexually transmitted
No cyst forms are found
Trichomonas (Flagellates)
Trichomonas life
No cyst forms are found
Pear-shaped trophozoite with 4 anterior flagella and undulating membrane
Trichomonas s/s
Females: frothy yellow vaginal discharge, inflammation, itching. strawberry cervix
Males: urethra, seminal vesicles and prostate may be infected; usu asymp but can have white urethral discharge
Sleeping Sickness
Flagellates
T. brucei rhodesiense (East Africa) antelope and cattle, acute disease
T. brucei gambiense (West Africa) humans only, chronic disease
Transmitted via Tsetse flies
Trypanosoma diagnosis
IgM Ab in CSF is diagnostic for encephalitic phase of illness
Trypomastigote in blood, CSF, or biopsy
Trypanosoma Rx
Suramin & Melarsoprol
Sleeping Sickness
Chagoma (lesion)
T. cruzi (Flagellates)
at bite
Fever, LAD, HSM, heart damage in 2 weeks –> severe and last for 6 months
painless periorbital edema if conjunctiva=portal of entry)
Chronic disease usu dilated cardiomyopathy, thromboembolism
Romana’s sign= T. cruzi (Flagellates)
“C” shaped trypanosome in blood is diagnostic
T. cruzi (Flagellates)
20 different species cause disease in humans (via 30 types of sandflies)
Leishmania (Flagellates)
Nitrofurtimox treats
chaga
Leishmania amastigote
no flagella; only in humans
Leishmania promastigote
+flagella; only in insects
Sodium stibugluconate treats?
Leishmania (Flagellates)
Major cause of intractable diarrhea in AIDS pts
Self-limited diarrhea in immunocompetent
Cryptosporidium (Coccidia)
can be highly lethal, sx take 3-12 mos; can cause kala azar=black disease where white skin becomes darkly pigmented
Visceral Leishmaniasis
Invade young RBCs
Establish a dormant hepatic phase –> late relapses
Plasmodium P. vivax and P. ovale (Coccidia)
Malaria
Natural immunity is short-lived; continual re-infection is required to maintain it
Malaria affects > _____ and causes 1-3 million deaths/yr
1 billion
Invasde old RBCs
P. malariae (Coccidia)
Malaria
Natural immunity is short-lived; continual re-infection is required to maintain it
Primarily tropics/subtropics
Can invade RBCs of all ages=highest parasitemia and mortality
P. falciparum (Coccidia)
Malaria
Natural immunity is short-lived; continual re-infection is required to maintain it
Malaria s/s
anemia
hemolysis (black water fever)
Jaundice, hypotension, tachycardia hepatosplenomegaly
death from multiorgan failure
Fever paroxysm with periodicity
Vivax and ovale=48hrs
Malariae= 72 hrs
Falciparum=_____
36-48 hrs
Fever paroxyms with periodicity
Vivax and ovale=____
Malariae= 72 hrs
Falciparum=36-48 hrs
48hrs
anemia
hemolysis (black water fever)
Jaundice, hypotension, tachycardia hepatosplenomegaly
death from multiorgan failure
Malaria
Rapid Antibody test for PfHRP2 or LDH antigens
P. falciparum= diagnosis
Fever paroxyms with periodicity
Vivax and ovale=48hrs
Malariae= ____
Falciparum=36-48 hrs
72 hrs
Ring forms and all RBC infected; little to no schizonts in smear (they are in the capillaries, bind ECs , prone to thrombus)
P. falciparum= diagnosis
Malaria Treatment
Chloroquine
Primaquine (latent ovale/vivax)
Quinine, Mefloquine, or Malarone for resistant P. falciparum
Minimize mosquito contact (i.e. mosquito nets, avoid stagnant water, etc)
Vaccines in development, none approved thus far
