A seroepidemiologic survey of the prevalence of varicella-zoster virus in the pediatric population in two university hospitals in Brazil.

BACKGROUND: Varicella-zoster virus (VZV) is an alpha-herpesvirus causing varicella (chickenpox) and herpes zoster (shingles). Varicella results from primary VZV infection, and is a common childhood illness associated with fever and a generalized, pruritic, vesicular eruption. Herpes zoster is caused by VZV reactivation later in life (most cases after the fifth decade), and is characterized by a localized, painful, and vesicular eruption involving one or adjacent dermatomes. The incidence of herpes zoster increases with age and immunosuppression.

OBJECTIVE: To estimate the seroprevalence of VZV in the Brazilian pediatric population by evaluating the prevalence of specific antibodies to VZV in children from two university hospitals in the state of Rio de Janeiro.

METHODS: A population composed of 160 children derived from two university hospitals in the state of Rio de Janeiro was included in the study. All patients completed a questionnaire regarding their socio-epidemiologic characteristics, and a complete physical examination was performed. All blood samples were screened using a commercial enzyme-linked fluorescent assay (ELFA) kit, specific for the detection of immunoglobulin G (IgG) antibodies to VZV.

RESULTS: The seroprevalence of VZV was 58.1% in the overall population, with a statistically significant correlation between seroprevalence and increasing age (P < 0.0001). A previous history of measles infection (P < 0.04), previous history of varicella infection (P < 0.0001), and the presence of skin lesions (P < 0.05) were significantly associated with seropositivity to VZV.

CONCLUSIONS: Further studies should be performed in order to evaluate the endemicity of VZV infections and to establish criteria for the use of the specific vaccine in Brazil.