ABSTRACT. Objective. To describe survival and signs of human immunodeficiency virus (HIV) infection in perinatally infected children in Thailand.Methods. At 2 large Bangkok hospitals, 295 infants born to HIV-infected mothers were enrolled at birth from November 1992 through September 1994 and followed up with clinical and laboratory evaluations every 1 to 3 months for 18 months. Infected children remained in follow-up thereafter. For the infected children, we used data collected through October 2000 to estimate survival times and compare characteristics among those whose disease progressed at rapid (died within 1 year), intermediate (died at 1-5 years), and slow (survived at least 5 years) rates.Results .

The role of human herpesvirus 6 (HHV-6) infection in 227 children born to human immunodeficiency virus (HIV)-seropositive mothers was investigated. Of 41 HIV-uninfected infants, 3 (7%) were positive for HHV-6 DNA in the first month of life, suggesting possible intrauterine infection. The cumulative infection rates of HHV-6 at 6 and 12 months of age were significantly lower in HIV-infected children (11% and 33%, respectively) than in uninfected children (28% and 78%, respectively; P<.001). There was an association between high CD4+ cell numbers (>15%) before HHV-6 infection and high HHV-6 infection rate. Twenty-two infants with HIV classed as Centers for Disease Control and Prevention stages N1 or N2 were studied for an association of HHV-6 infection with progression of HIV disease. Ten of the infants had HHV-6, and 12 did not. In 5 of the infants without HHV-6 (42%), HIV disease had not progressed by 1 year of age; however, HIV disease had progressed in all 10 children with HHV-6 infection. These results suggest an association of HHV-6 infection and progression of HIV disease in the study children with vertical HIV-1 infection (P<.05).