Blood and Tissue Helminths Clinical Microbiology Review 265
ORGANISM CLASSIFICATION TRANSMISSION DIAGNOSIS OTHER
Toxocara
Trichinella spiralis
Wuchereria bancrofti
Brugia malayi
Loa loa
Onchocerca volvulus
Echinococcus granulosus
Humans are accidental hosts.
Larvae in tissues. Visceral & ocu-
lar larva migrans (toxocariasis).
Eosinophilia, edema of upper
eyelids, fever, myalgia.
Elephantiasis (lymphatic
filariasis).
Elephantiasis. Nocturnal
periodicity.
Loiasis. Nocturnal periodicity.
River blindness.
Humans are accidental interme-
diate host. Cysts develop in liver
or lungs.
Nematode
(in dogs/cats)
Nematode
Nematode
Nematode
Nematode
Nematode
Cestode
Ingestion of eggs
from dog/cat feces
Undercooked pork,
walrus, bear
Mosquitoes
Mosquitoes
Mango fly (Chrysops)
Black fly
Ingestion of fecal
material from
infected dog
Serological tests.
Larvae encysted in muscle.
Serological tests.
Microfilariae in blood. Giemsa-
stained thick & thin smears.
Microfilariae in blood. Giemsa-
stained thick & thin smears.
Microfilariae in blood. Giemsa-
stained thick & thin smears.
Microfilariae from skin snips or
aspirates of nodules
Radiologic ID of cysts or ID of
scoleces in needle biopsy mate-
rial from cyst (hydatid sand).
Serological methods available.