THE INCIDENCE OF HERPES-ZOSTER

Background: There are few population-based studies of the natural hist ory and epidemiology of herpes zoster. Although a relatively common ca use of morbidity, especially among the elderly, contemporary estimates of herpes tester incidence are lacking. Herein we describe a populati on-based investigation of incident and recurrent herpes tester from 19 90 through 1992 in a health maintenance organization. Methods: The hea lth maintenance organization's automated medical records contain clini cal and administrative information about care rendered to patients in ambulatory settings, emergency departments, and hospitals. Cases of he rpes tester were ascertained by screening the medical. record for code d diagnoses. The predictive value of a herpes tester diagnosis code wa s determined by review of a sample of patient records. Records from al l patients with potential recurrences were also reviewed. Results: The overall incidence, based on 1075 cases in 500 408 person-years, was 2 15 per 100 000 person-years (95% confidence interval, 192 to 240 per 1 00 000) and did not vary by gender. Although the rate increased sharpl y with age, approximately 5% of the cases occurred among children youn ger than 15 years. Infection with human immunodeficiency virus was doc umented in 5% of the persons with incident herpes tester and cancer in 6%. Four persons had confirmed recurrences of herpes tester (744 per 100 000 person-years; 95% confidence interval, 203 to 1907); three of these persons were infected with the human immunodeficiency virus. Con clusions: The recorded incidence of herpes tester was 64% higher than that reported 30 years ago; the age-standardized rate was more than tw ofold higher. Immunosuppressive conditions had little impact on overal l incidence, although they were strongly associated with early recurre nces.