Herpes zoster in HIV-1-infected patients in the era of highly active antiretroviral therapy: a prospective observational study.

Between June 1994 and May 2003, 93 of 716 (13.0%) HIV-infected patients with a median baseline cell differentiation CD4+ count of 61 x 10(6) cells/L (range, 1-1206 x 10(6) cells/L) developed 103 episodes of herpes zoster [HZ], with an incidence of 5.67 per 100 person-years (PY). The incidence of HZ in the pre-highly active antiretroviral therapy (HAART) era (17.21 per 100 PY) was significantly higher than that in the post-HAART era (5.05 per 100 PY) (P < 0.0001). In the first six months of enrollment, the incidence of HZ was significantly higher than that between six and 12 months both in the pre-HAART (27.65 per 100 PY versus 8.43 per 100 PY, P = 0.02) and post-HAART era (17.79 per 100 PY versus 3.39 per 100 PY, P < 0.0001). In multivariate analyses, only baseline CD4+ count remained a significant risk factor associated with HZ. HZ did not increase mortality rate either in the pre-HAART or post-HAART era, although the risk for HIV progression was significantly higher in patients with HZ (adjusted odds ratio [OR], 1.747, 95% confidence interval, 1.037-2.943). We conclude that the incidence of HZ was highest in the first six months of enrollment in patients at late stage of HIV infection, which did not increase with the introduction of HAART. Baseline CD4+ lymphocyte count was the most significant risk factor associated with development of HZ. HZ was associated with increased risk for HIV progression, but not mortality.