The ELISA with use of
IgG,
IgA, and
IgE,
latex agglutination, indirect hemagglutination (IHA), total
IgE, the radioallergosorbent test (RAST), and immunoelectrophoresis (IEP) were carried out to determine the preoperative diagnosis of
infection due to Echinococcus granulosus in 131 patients. Eighty-nine patients received
follow-up care for 42 +/- 22 months (mean +/- SD); 72 were treated surgically and 17 with
mebendazole only. We analyzed 5 +/- 2 serum samples per patient and analyzed each serum sample using the eight tests.
IgG ELISA was the most sensitive (up to 94%) and specific (up to 99%) test for the majority of
cyst locations in the patient. IEP was positive in only 73% of cases. The combination of
IgG ELISA, IHA, and
IgA ELISA allowed us to achieve a sensitivity of 81% in cases of
pulmonary echinococcosis.
IgE and
IgA were both responsible for most nonspecific reactions, the former in patients with
parasitic diseases other than
echinococcosis and the latter in patients with
cirrhosis of the liver and
malignancies.
IgG ELISA and IHA were the most adequate tests for postsurgical follow-up. In patients with favorable clinical outcome, the specific
IgG level decreased early toward the end of the first year, although serological positivity could persist beyond 6 years. A rise of
IgG level 2 or 3 years
after treatment suggested persistent active
infection. In patients with
mebendazole-associated cure, only tests with total or specific
IgE detection seemed to exhibit a strong association with decreasing levels or with negative results.