Protozoa (clinical manifestations)

lilyo's version from 2016-06-02 17:10


Question Answer
Giardia lambliaGiardiasis—bloating, flatulence, foul-smelling, fatty diarrhea (often seen in campers/hikers)— think fat-rich Ghirardelli chocolates for fatty stools of Giardia
Entamoeba histolyticaAmebiasis—bloody diarrhea (dysentery), liver abscess (“anchovy paste” exudate), RUQ pain; histology shows flask-shaped ulcer
CryptosporidiumSevere diarrhea in AIDS, mild disease (watery diarrhea) in immunocompetent hosts
Toxoplasma gondiiCongenital toxoplasmosis = classic triad of chorioretinitis, hydrocephalus, and intracranial calcifications; reactivation in AIDS􏰀, brain abscess seen as ring-enhancing lesions on MRI
Naegleria fowleriRapidly fatal meningoencephalitis
Trypanosoma bruceiAfrican sleeping sickness— enlarged lymph nodes, recurring fever (due to antigenic variation), somnolence, coma, two subspecies: Trypanosoma brucei rhodesiense, Trypanosoma brucei gambiense
PlasmodiumMalaria—fever, headache, anemia, splenomegaly
P vivax/ovale48-hr cycle (tertian; includes fever on first day and third day, thus fevers are actually 48 hr apart); dormant form (hypnozoite) in liver
P falciparumsevere; irregular fever patterns; parasitized RBCs occlude capillaries in brain (cerebral malaria), kidneys, lungs
P malariae72-hr cycle (quartan)
BabesiaBabesiosis—fever and hemolytic anemia; predominantly in northeastern United States; asplenia 􏰂risk of severe disease
Trypanosome cruziChagas disease—dilated cardiomyopathy with apical atrophy, megacolon, megaesophagus; predominantly in South America, Unilateral periorbital swelling (Romaña sign) characteristic of acute stage
Leishmania donovanivisceral leishmaniasis - spiking fevers, hepatosplenomegaly, pancytopenia; cutaneous leishmaniasis - skin ulcers
Trichomonas vaginalisVaginitis—foul-smelling, greenish discharge; itching and burning; do not confuse with Gardnerella vaginalis, a gram-variable bacterium associated with bacterial vaginosis
Enterobius vermicularis (pinworm)Intestinal infection causing anal pruritus (diagnosed by seeing egg via the tape test)
Ascaris lumbricoides (giant roundworm)Intestinal infection with possible obstruction at ileocecal valve
Strongyloides stercoralis (threadworm)Intestinal infection causing vomiting, diarrhea, epigastric pain (may mimic peptic ulcer) (roundworm)
Ancylostoma duodenale, Necator americanus (hookworms)Intestinal infection causing anemia by sucking blood from intestinal wall. Cutaneous larva migrans—pruritic, serpiginous rash from walking barefoot on contaminated beach.
Trichinella spiralisIntestinal infection; larvae enter bloodstream and encyst in striated muscle cells􏰀 --> inflammation of muscle. Trichinosis—fever, vomiting, nausea, periorbital edema, myalgia.
Toxocara canisVisceral larva migrans—nematodes migrate to blood through intestinal wall causing inflammation and damage. Organs frequently affected include the heart (myocarditis), liver, and CNS (seizures, coma).
Onchocerca volvulusSkin changes, loss of elastic fibers, and river blindness (black flies, black skin nodules, “black sight”); allergic reaction to microfilaria possible (river blindness)
Loa loaSwelling in skin, worm in conjunctiva
Wuchereria bancroftiElephantiasis—worms invade lymph nodes and cause inflammation, which can block lymphatic vessels, takes 9 mo–1 yr after bite to become symptomatic.
Taenia soliumIntestinal tapeworm, Cysticercosis, neurocysticercosis
Diphyllobothrium latumVitamin B12 deficiency (tapeworm competes for B12 in intestine), 􏰀megaloblastic anemia
Echinococcus granulosusHydatid cysts in liver, causing anaphylaxis if antigens released (hydatid cyst injected with ethanol or hypertonic saline to kill daughter cysts before removal) (tapeworm)
SchistosomaLiver and spleen enlargement (S mansoni, egg with lateral spine), fibrosis, and inflammation, Chronic infection with S haematobium (egg with terminal spine) can lead to squamous cell carcinoma of the bladder (painless hematuria) and pulmonary hypertension
Clonorchis sinensisBiliary tract inflammation 􏰀pigmented gallstones, associated with cholangiocarcinoma