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 seroprevalence studies, which seldom include medical residents or students. The 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 questionnaire was used to obtain the information. Serum samples were tested for antibodies by commercial immunoenzymatic assays. Statistical analysis was descriptive; history of exposure was evaluated as a diagnostic test and sensitivity, specificity, and predictive values were calculated according to 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 serology for rubella was negative in 12 residents (10 women). Three residents had anti-core against HBV, with negative surface antigen. One positive case for HCV was confirmed by Western blot. All were negative for HIV. A history 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 vaccination against HBV support the implementation of vaccination programs in medical schools in Mexico.