Seroprevalence of antibodies against varicella zoster virus and rubella virus among newly recruited expatriate healthcare workers: a cross-sectional study

OBJECTIVES To assess the state of immunity to varicella zoster virus (VZV) and rubella virus (RV) among newly recruited healthcare workers (HCWs) in Kuwait before they begin work, and to determine whether there are differences in the prevalence of seronegativity according to nationality, gender, age group and occupation group. SETTING This cross-sectional study involved analysis of blood samples from workers newly recruited to the Kuwaiti healthcare system. PARTICIPANTS All new non- national HCWs recruited during the study period (n=1540). INTERVENTION Enzyme-linked immunoassays for VZV-specific and RV-specific IgG were performed. RESULTS Among HCWs, 81.9% and 93.5% were immune to VZV and RV, respectively. Male seronegativity was higher than that of females for both viruses. Regarding VZV, the majority of seronegative individuals were Indians (23.5%), followed by Somalis (12.5), Filipinos (6.5) and Egyptians (5.4%); the between-group differences were significant for all groups. The age groups 20-30 and 30-40 years were most likely to be seronegative, with prevalences of 18.2% and 18.9%, respectively. VZV seronegativity was most common among nurses (21.1%) and least common among physicians (9.2%), and the difference was significant. In addition, RV seronegativity was most frequent among Somalis (12.5%) and lowest among Indians (5.3%); other nationalities (Egyptian, Filipino and others) ranged between 9.1% and 9.6%. Seronegative individuals were most frequently in the younger age group (<20 years old) (17.5%), followed by the >40 years old group (10.4%). RV seronegativity was highest among nurses (6.9%) and lowest among physicians (5.2%). CONCLUSION The prevalence of seronegativity is highest among Indians for VZV and Somalis for RV, and HCWs aged 20-40 years for VZV and <20 years for RV. For both viruses, the seronegativity rate was highest for male HCWs, and for nurses compared with other HCWs, with physicians having the lowest prevalence of both viruses.