Reliability of self-reported history in predicting immunity against measles, rubella, mumps, and varicella among health care workers

Abstract

To determine the immunity of health care workers (HCWs) against measles, rubella, mumps, and varicella infections, and to evaluate the reliability of self-reported history of the disease in predicting immunity. Materials and methods: A self-reported questionnaire was used to obtain the history of the diseases and ELISA to screen specific IgG antibodies. The history of the diseases was compared with serological testing results. Results: Eighty-one HCWs were included in the study. Immunity against measles was 97.5%, rubella 100%, mumps 72.8%, and varicella 96.3%. Positive predictive values of positive histories of the diseases were 100% for measles and rubella, 96.5% for varicella, and 77.4% for mumps. The negative predictive values of the negative/unknown histories were 3.9%, 0%, 3.8%, and 30.0% for measles, rubella, varicella, and mumps, respectively. Conclusion: A positive history of the disease is reliable for predicting the immunity against measles, rubella, and varicella, and vaccination is not required for the HCWs with a positive history. In contrast, a negative/unknown history had no benefit in predicting susceptibility; thus, we consider that these HCWs must be vaccinated according to the serological testing results. For mumps, a decision for vaccination of HCWs can be made by combining the self-reported history and serological testing results.