Comparative sensitivity and specificity of the Casoni intradermal and the immunoelectrophoresis tests for the diagnosis of hydatid disease.

The Casoni intradermal (ID) test, using two antigens, was compared with the immunoelectrophoresis (IEP) test for diagnosis in 47 surgically confirmed cases of hydatid disease and 73 non-hydatid persons. An antigen prepared from boiled hydatid cyst fluid (HF) was markedly more sensitive in the ID test than another prepared from whole HF but both produced false-positive reactions in three persons with other disease conditions. The IEP test yielded no false positives and its sensitivity was similar to the ID test using the more sensitive boiled HF antigen.

Application of the immunoelectrophoresis test for hydatidosis in patients with a presumptive diagnosis of the disease.

The Echinococcus granulosus diagnostic arc 5 was detected by the immunoelectrophoresis (IEP) test in 43 of 51 sera from patients with a presumptive clinical diagnosis of hydatid disease when stained slides were examined. In 22 of these, however, the arc 5 was readily recognized in the reading following citrate treatment of the slide. The routine reading of slides after 24 and 48 hours of incubation is recommended in an attempt to provide the clinician with an earlier immunological confirmation of hydatidosis by the IEP test.

Evaluation of the crossed-over electrophoresis test for the immunodiagnosis of human hydatid disease.

The crossed-over electrophoresis (COE) test for hydatidosis was evaluated with sera from preoperative, surgically-confirmed hydatidosis cases, postoperative hydatidosis patients, healthy donors and persons with other parasitic and non-parasitic diseases. The sensitivity and specificity of the test varied with the use of concentrated or unconcentrated serum and when test positivity was based on readings carried out before or after citrate treatment of slides or after their staining. Although the sensitivity of the COE test was higher than that obtained by the immunoelectrophoresis (IEP) test, it was not possible to differentiate hydatid from non-hydatid sera by the former technique.

[Reactivity of a purified antigen of Paracoccidioides brasiliensis with paracoccidioidomycosis and histoplasmosis sera].

The immunoelectrophoretic reactivity of a "crude" and a "purified" antigens of Paracoccidiodes brasiliensis against the sera of confirmed cases of paracoccidioidomycosis and histoplasmosis was evaluated. The "crude" antigen revealed precipitating antibodies in both the homologous and the heterologous human sera; the number of precipitating systems being higher with the former. The "purified" antigen reacted only with the homologous sera.

[Correlation between intradermal reaction and immunoelectrophoresis in human hydatidosis].

The results obtained by the immunoelectrophoresis (IEP) aand Casoni intradermal (IDR) tests in a group of 50 hydatidosis patients in which the presence of cysts was later confirmed at surgery, are analyzed. The sensitivity of the IEP test was 74%; the IDR test was positive in 54% of these patients and there was no correlation between the results of the two tests in 24% of the cases. The low sensitivity observed for the IDR test, its known nonspecificity and its poor correlation with IEP test results do not enable us to recommend its use for the diagnosis of hydatid disease or for the selection of cases in which an immunodiagnostic confirmation is feasible.

Evaluation of three immunodiagnostic tests for human hydatid disease.

The comparative sensitivity and specificity of the immunoelectrophoresis (IEP), latex agglutination (LA) and indirect hemagglutination (IHA) test for hydatidosis were evaluated using a single hydatid cyst fluid pool as antigen and the same hydatid and nonhydatid sera and were found to vary with the type of IHA test, the criterion for IHA test positively and the group of sera selected for study. The sensitivity of the LA and IEP tests was comparable, both tests correlated well and neither gave a positive result in the nonhydatid sera studied. The sensitivity of the IEP test was higher when IHA test positivity was based on diagnostically significant titers but not when all IHA test reactors were considered as positive to this test.

Evaluation of four variants of the indirect hemagglutination test for human hydatidosis.

The comparative sensitivity and specificity of four technical variants of the indirect hemagglutination test (IHA) for hydatidosis with tannic acid, glutaraldehyde, benzidine and formol treated cells, the same pool of hydatid cyst fluid and sera from hydatid and non-hydatid persons was studied. The number of reactors in each group of sera and the degree of reactivity of each serum sample varied with the type of IHA test. The sensitivity and specificity of each technique was related to the criterion on which IHA test positivity was based and to the group of sera examined.