Short-Term and Long-Term Effects of Highly Active Antiretroviral Therapyon the Incidence of Herpes Zoster in HIV-Infected Children

Background: Highly active antiretroviral therapy (HAART) has reduced herpes zoster (HZ) incidence in HIV-infected children, yet it remains common. Methods: We evaluated perinatally HIV-infected youth with varicella infection enrolled between 1993 and 2006 in a prospective cohort study. Incidence rates (IRs) and 95% confidence intervals of HZ were estimated by calendar year, age group, and HAART use. The effect of initiating HAART was also evaluated by fitting Cox survival models adjusted for potential confounders, Results: Among 536 perinatally infected children with documented prior varicella (median follow-up = 6.8 years), 116 (22%) developed HZ (IR = 3.2 events/100 person-years, confidence interval: 2.6 to 3.8). IRs increased from 1993 to 1996 and then declined significantly through 2006 (P < 0.001). However, an IR of 1.4-3.1 HZ episodes per 100 person-years persisted from 2001 to 2006. The risk of HZ was higher for those with lower CD4% or in Centers for Disease Control and Prevention clinical class C. The IR of HZ was similar in the 90 days before or after initiation of HAART but declined significantly after more than 90 days of HAART. Conclusions: Although HAART has markedly reduced the IR of HZ, it remains a frequent complication in HIV-infected children. The risk of HZ is similar in the 90 days before and after initiating HAART.