Rodríguez M

Reliability of four methods for the diagnosis of acute infection by Epstein-Barr virus.

We studied the reliability of new indirect tests in the diagnosis of acute infection by Epstein‐Barr virus (EBV). Studied for all samples were: method 1, the heterophil antibodies (Abs) (Monolatex, Biokit, Germany); method 2, the IgM Abs to EBV with ELISA tests (antigen pools, Enzygnost, Behringwerke, Germany); method 3, EA (Biotest Diagnostics, Germany); and method 4, the IgG avidity test. The reliability of the four tests for the detection of primary infection by EBV was: sensitivity (method 1:89.1%; method 2: 100%; method 3: 79.7%; method 4: 99%); specificity (method 1: 98%; method 2: 100%; method 3:84%; method 4: 100%); positive predictive value (method 1: 97.6%; method 2: 100%; method 3: 73.6%; method 4: 100% method 4: 100%), and negative predictive value (method 1: 90.7%; method 2: 100%; method 3:84%; method 4: 99%). The IgG avidity test (method 4) is simple and automated in the laboratory and is very useful for ascertaining, from a single sample, the time since infection. It is criteria of recent primoinfection higher levels than 55% of IgG with low avidity for the antigen. The investigation of the Abs to antigen pools (method 2) by ELISA of virus had a high reliability, but the investigation of heterophil Abs by latex (method 1) and the Abs IgM to EA (method 2) were lacking in sensibility regarding their use in the diagnosis of the primoinfection. J. Clin. Lab. Anal. 11:78–81.

Behaviour of IgG antibody avidity for the antigen and of IgA antibody in active cytomegalovirus, Epstein-Barr virus, herpes simplex virus and human herpes virus 6 infections. Adaptation of a commercial test

The clinical value of specific IgA and IgG antibody avidity to herpes simplex virus, cytomegalovirus, Epstein-Barr virus and human herpes virus 6 for the detection of active disease and primary infection, respectively, was evaluated. The IgG avidity test, with a break point of 55%, for the detection of primary infection, and of the IgA test for the detection of disease, were associated with a sensitivity of 97% and 64%, respectively; specificity of 100% and 82%; a positive predictive value of 100% and 76%; and a negative predictive value of 96% and 72%, respectively.

A study of IgM antibodies in diagnosis of acute infection by Toxoplasma gondii in Spain

Abstract A study of two ELISA methods (Eti-toxok-M, Sorin; Vidas Toxo IgM, bioMerieux) and one agglutination (Toxo Isaga, bioMerieux) was carried for the detection of specific IgM antibodies to Toxoplasma gondii in Southern Spain in different population groups. For diagnosis of acute toxoplasmosis ELISA methods showed 100% sensitivity, 99.4% specificity, 12% predictive value positive and 100% predictive value negative. Toxo Isaga showed 100% sensitivity, 99.5% specificity, 15% predictive value positive and 100% predictive value negative.