Prevalence of serological markers against measles, rubella, varicella, hepatitis B, hepatitis C, and human immunodeficiency virus among medical residents in Mexico

Background. Vaccination programs among health care workers are based on ser oprevalence studies, which seldom include medical residents or students. Th e objective of this study was to determine the seroprevalence of antibodies against measles, rubella, varicella, hepatitis B (HBV), hepatitis C (HCV), and human immunodeficiency virus (HIV) among medical residents. Methods. This study was designed as a prospective survey. A self-reported q uestionnaire was used to obtain the information. Serum samples were tested for antibodies by commercial immunoenzymatic assays, Statistical analysis w as descriptive; history of exposure was evaluated as a diagnostic test and sensitivity, specificity, and predictive values were calculated according t o Bayes theorem, Results. Eighty-nine residents were included, the median age was 27 years, and 58 (65.2%) were female. Seventy-two (79.7%) had been vaccinated against HBV, but vaccination was complete in only 30/72 (41.6%). All were positive for measles and varicella, with the exception of one case for each. The se rology for rubella was negative in 12 residents (10 women). Three residents had anti-core against HBV, with negative surface antigen. One positive cas e for HCV was confirmed by Western blot. Ah were negative for HIV. A histor y of prior varicella had a 100% positive predictive value; in contrast, the negative predictive value was quite low (7%). Conclusions. Negative serology for rubella among women and incomplete vacci nation against HBV support the implementation of vaccination programs in me dical schools in Mexico. (C) 2001 American Health Foundation and Academic P ress.