Echinococcus Granulosus IgG ELISA
The Echinococcus IgG ELISA is for the qualitative and semi-quantitative determination of IgG-class antibodies to Echinococcus in human serum and (EDTA-, heparin-, or citrate-) plasma. For in vitro diagnostic use in the United States. For Research Use Only outside of the United States.
Echinococci are microscopic cestodes (tapeworms) ranging in length from 1.4 to 6 mm, dependent on their genus. They are found:
- In dogs or other canids (E. granulosus)
- In foxes, coyotes, and wolves (E. multilocularis)
Sources of infection are final hosts (i.e., dogs for E. granulosus and mainly foxes for E. multilocularis) and food contaminated with parasite eggs. After ingestion of a suitable intermediate host, the egg hatches in the small bowel and releases an oncosphere that penetrates the intestinal wall and travels through the circulatory system into various organs where it develops into a cyst. Echinococcus infections remain silent for years before the enlarging cysts cause symptoms in the affected organs.
E. granulosus larvae (oncospheres) begin to vesiculate mainly in the liver but also in the lungs and other organs (20%). The parasites form spherical, unilocular, fluid-filled cysts and can achieve diameters between 1 cm and 15 cm. In contrast to cystic echinococcosis, E. multilocularis larvae are found almost exclusively (98%) in the liver, though secondary lesions can spread metastatically to other organs (lungs, kidneys, CNS, and others). The parasites grow infiltratively and tumor-like in the host tissue.
E. granulosus occurs worldwide, while E. multilocularis is found in the northern hemisphere, including central Europe and the northern parts of Europe, Asia, and North America.
Detectable immune responses have been associated with the location, integrity, and vitality of the larval cyst. Cysts in the liver are more likely to elicit an antibody response than cysts in the lungs. Regardless of localization, antibody detection tests are less sensitive in patients with intact hyaline cysts. Cysts in the lungs, brain, and spleen are associated with lowered serodiagnostic reactivity, whereas those in bone appear to more regularly stimulate detectable antibodies. Fissuration or rupture of a cyst is followed by an abrupt stimulation of antibodies.
Differentiation between both species of Echinococcus is not possible.
