<prompt> True about toxoplasmosis is all except ?In adults toxoplasmosis is usually asymptomaticIgG antibodies are diagnostic in Congenital toxoplasmosisIs a antroponotic diseaseEncephalitis is uncommon rare in immunocompetent individuals  <response>: Ans. is b i.e., IgG Antibodies are diagnostic in congenital Toxoplasmosis The presence of IgM which does not cross placenta in the infants circulation is diagnostic. Specific IgG in the infants circulation may be of maternal origin or due to infection. Diagnosis of congenital toxoplasmosis ? 1. PCR . PCR of the amniotic fluid to detect the B1 gene of the parasite has replaced fetal blood sampling. 2. Serology . The presence of IgM in infants circulation is diagnostic of congenital infection. . The double - sandwitch IgA - ELISA is more sensitive than the IgM- ELISA for detecting congenital infection in the fetus and newborn - Harrison 16th - 1309 . Specific IgG in infants circulation may be of maternal origin or due to infection. Testing of infants blood at 2 monthly intervals will show whether the IgG antibody level is decreasing. At 6 - 10 months the infants circulation should not contain maternal IgG and therefore persistence of IgG beyond 6 -10 months is indicative of infection in the infant. About other options . In immunocompetant adults, 80-90 infections are asymptomatic. . Toxoplasmosis is an anthropozoonoses ie : infection transmitted to man from veebrate animals. . Encephalitis is a rare complication in immunocompetant patients. 