Comparison of two commercial ELISA kits for detection of rubella specific IgM in suspected congenital rubella syndrome cases and rubella IgG antibodies in a serosurvey of pregnant women

Abstract

Enzyme linked immunosorbent assay (ELISA) for antibody identification, is important for laboratory confirmation of rubella infection in different settings. The Enzygnost rubella ELISA, widely used in the World Health Organization (WHO) Global Measles and Rubella Laboratory Network, is expensive and often unavailable. Qualitative and quantitative performance of the Euroimmun ELISA was compared with the Enzygnost ELISA, for detection of rubella specific IgM, using 283 sera collected from suspected congenital rubella syndrome (CRS) patients and IgG antibodies using 435 sera from a serosurvey among pregnant women. Good qualitative agreement was observed for detection of both rubella specific IgM (94.7% agreement and κ of 0.86) and IgG (96.3% agreement and κ of 0.84). Bland-Altman analysis for IgG yielded a mean difference of 0.781 IU/ml with 97.1% values within ±2 SD of the mean difference. Our study findings suggest that Euroimmun ELISA may be considered for detection of rubella specific IgM in suspected CRS cases and rubella specific IgG in surveillance studies.

Keywords: Antibodies; CRS; IgG; IgM; India; Pregnant women; Rubella; Serology.