The epidemiology of varicella in staff and students of a hospital in the tropics.

A five-year retrospective survey of the epidemiology of varicella in staff and students at our hospital revealed a high incidence of 0.72 cases per 100 per year. The incidence was highest among 17-24 year-olds, especially among student nurses (3.22 cases per 100 per year). Most cases of varicella occurred in the cooler and more humid months of the year. Among 102 candidate student nurses aged 17-20 years, only 29.7% had complement-fixing antibodies to varicella-zoster virus. Thus our hospital personnel are at high risk of contracting and transmitting nosocomial varicella. These results corroborate existing evidence that the epidemiology of varicella in the tropics is different from that in temperate regions.