[Exposure to group B Streptococcus among Mexican women in reproductive age]. / Exposición a Estreptococo del grupo B en mujeres mexicanas en edad reproductiva.

OBJECTIVE: To assess the prevalence of IgG antibodies against Group B streptococci (GBS) among women of reproductive age in Mexico. MATERIAL AND METHODS: Serum specimens were drawn from 15 to 40 year-old women, representative of all regions and socioeconomic levels of the country. The sample was randomly selected from Banco Nacional de Sueros (National Sera Bank); serum samples were collected during a national seroepidemiologic survey conducted in 1987-1988. The assays for standardization and for evaluation of seroprevalence were carried out at the Hospital de Pediatría del Centro Médico Nacional Siglo XXI (Children's Hospital) Instituto Mexicano del Seguro Social (IMSS) (Mexican Institute of Social Security) from January to November 1995. IgG antibodies against group B antigen were studied with an enzyme-linked immunosorbent assay (ELISA) developed in our lab. Group B antigen was produced and purified from the reference strain GBS 110. RESULTS: A total of 2669 serum samples were studied; 2405 were positive to anti-group B antigen IgG antibodies, for a seroprevalence of 90.2%. No differences in prevalence were found among the different age groups or among the different states of the country. CONCLUSIONS: The high seroprevalence of antibodies against GBS suggests that young women in Mexico are commonly exposed to GBS infection.