Protozoa Flashcards
Protozoa
free-living, single celled, eukaryotic cells
Intestinal protozoa
Entamoeba histolytica, Giardia lamblia, Cuclospora cayetanensis, Cryptosporidium, Isospora belli
Entamoeba histolytica
found in developing world, often asymptomatic
Trophozoite
motile feeding form of the amoeba
Sxs of trophozoite
asymptomatic BUT if it erodes the intestinal mucosa it will cause loose stools (with blood and mucus) and abdominal pain; if it penetrates the portal blood circulation it may cause abscesses
Giardia lamblia
outbreaks occur when sewage contaminates water; interferes with fat absorption causing greasy diarrhea, gas, abdominal cramps
Cryptosporidium
outbreaks of diarrhea from contaminated water sources; causes diarrhea and abdominal pain, typically found in immunocompromise patients
Isospora and Cyclospora
cause severe diarrhea in immunocompromised patients, transmitted fecal-oral route; acid-fast!
Trichomonas vaginalis
sexually transmitted; itching, burning on urination, copious vaginal secretions, males usually asymptomatic
Diagnosis of Trichomonas
microscopic exam of vaginal discharge and urine
Naegleria fowleri
95% die within a week; fever, HA, stiff neck, nausea, and vomiting after swimming
Acanthamoeba
chronic granulomatous brain infection of immunocomprimised patients; HA, fever, seizers, focal neuro signs
Balamuthia mandrillaris
chronic granulomatous skin lesions, amebic encephalitis, possibly asymptomatic
Toxoplasma gondii
most common in AIDS pts, undercooked meat and cat poop
Toxoplasma gondii presentation
fever, LN, liver, spleen enlargement, pneumonia, encephalitis and eye infection
Pneumocystis carinii
causes pneumonia in immunocompromised patients
Malaria-causing protozoa
Plasmodium falciparum, P. vivax, P. ovale, P. malariae, P. knowlesi
Transmission of malaria protozoa
anopheles mosquito, travels to liver and spreads into RBC where it reproduces
Tertian malaria
P. ovale and P. vivax burst every two days causing chills and fever
Quartan malaria
P. malariae bursts every 72 hours causing three day cycles of chills and fever
Plasmodia sporozoites
thin, motile, spindle-shaped plasmodia; “pre-erythrocytic” stage
Schizont
mass of replicated protozoa; only one cell but divides into merozoites
Exo-erythrocytic cycle
repeating sporozoite formation
Erythrocytic cycle
merozoites infiltrate bloodstream
Hypnozoites
dormant form caused by P. viviax and P. ovale causing relapsing malaria
Babesiosis
transmitted by a tick (carrier from mouse) and results in fever and hemolysis
Leishmaniasis
carried by rodents, dogs, and foxes but transmitted to humans via sandfly; common in south and central america, africa, middle east; skin ulcerations that can progress to strike retroendothelial organs (liver and spleen)
Cutaneous leishmaniasis
skin ulcer develops and heals in about a year; latin America and Texas
Diffuse cutaneous leishmaniasis
Venezuela and Ethiopia, pts with deficient immune systems, nodular skin lesions across the body, nonulcerating
Mucocutaneous leishmaniasis
dermal ulcer arises and heals, progresses to mucous membranes of nose and mouth
Visceral leishmaniasis
abdominal discomfort and distension, low-grade fevers, anorexia, weight loss, massive splenomegaly
African sleeping sickness
Tryapnosma transmitted by tsetse fly; hard, red, painful skin ulcer, fever, HA, dizziness, LN swelling can further develop into drowsiness, behavioral changes, difficulty walking, coma
Chagas’ Disease
Trypanosoma cruzi; Americas; rodents, possums, armadillos via kissing bug
Acute chagas’ disease
chagoma (hardened red area) develops at site of entry, followed with fever, malaise, swollen LN; will usually attack heart and CNS
Chronic Chagas’ disease
arrhythmias, heart failure, poorly functioning esophagus, megacolon
Balantidium coli
pig feces, trophozoites dig into intestinal wall, can be asymptomatic or have diarrhea
