Increasing incidence of varicella hospitalizations in United States Army and Navy personnel: are today's teenagers more susceptible? Should recruits be vaccinated?

Hospital records for 10,687 United States Army and Navy adult varicella (chickenpox) admissions were reviewed. Annual hospital admission rates for varicella increased more than fourfold in the active-duty army during 1980 to 1988 and more than 18-fold among active-duty navy enlisted personnel during 1975 to 1988. Fifty-seven percent of varicella admissions occurred in the most junior military members, aged 17 to 20. More than half of the total varicella admissions occurred in personnel with less than a year of military service. Multivariate analysis of the navy data confirmed increasing time-related trends of risk, suggesting a national temporal trend of increased varicella susceptibility in US teenagers and young adults. Administering a safe and effective varicella vaccine to army and navy recruits could prevent more than 7260 hospital-bed days during the first year of use.