ABSTRACT
Cystic fluid, which has antigenic properties of whole Taenia solium cysticerci, was used to discriminate neurocysticercosis cases and other parasitic infections, especially helminthiases. Twenty-one neurocysticercosis and several kinds of 22 different parasitic infections, including HIV cases (n=234) evaluated a 90.48% sensitivity and 86.32% specificity of indirect ELISA as follows: a low antigen concentration of 5 microg/ml. serum dilution of 1:400, conjugate dilution of 1:2,000 and a cut-off value of 0.349. Eight different helminthic infections (n = 25); echinococcosis (8/10), gnathostomiasis (6/8), strongyloidiasis (5/14), hookworm infection (1/18), angiostrongyliasis (2/25), opisthorchiasis (1/18), onchocercosis (1/3) and toxocariasis (1/6) were cross-reactive with this antigen. No serum antibody from other brain infections in the study gave a reaction with the antigen. In this study, the cystic fluid antigen gave high sensitivity of the test. However, the antigen contains various antigenic molecules able to bind with antibodies from several of the above helminthic sera, especially echinococcosis and gnathostomiasis. In Thailand, gnathostomiasis is one of the more famous tropical diseases but echinococcosis is quite rare. Cystic fluid antigen should be further investigated for its specific finding in diagnosis.
Subject(s)
Animals , Antigens, Helminth/therapeutic use , Cestode Infections/diagnosis , Diagnosis, Differential , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin G/immunology , Nematode Infections/diagnosis , Neurocysticercosis/diagnosis , Sensitivity and Specificity , Taenia/immunology , Trematode Infections/diagnosisABSTRACT
Four batches of crude somatic antigens from: (1) Opisthorchis viverrini adult worms, (2) Bithynia funiculata-whole body, (3) B. funiculata-head-foot, and (4) B. funiculata-visceral mass were assayed against sera from 81 opisthorchiasis patients, 30 parasite-free healthy individuals, and 50 individuals infected with other helminthic infections, and their antibody levels determined. By IgG-ELISA, the antigenic reactive proteins were found in both the head-foot and the visceral mass of B. funiculata snails, but the whole snail antigens gave the best results. Furthermore, it was as good as when O. viverini antigens were used. Antibody levels of sera from patients with opisthorchiasis assayed against antigens from whole B. funiculata snails were significantly higher than those of the other two groups. The cut-off value for positivity at 0.228 gave 80.2% sensitivity and 81.2% specificity. Cross reactions were observed with sera from patients with paragonimiasis and strongyloidiasis. No cross reactions were found to occur with sera from healthy individuals.