Mortality among HIV-1- and human herpesvirus type 8-affected mother-infant pairs in Zambia

Objective: To determine the respective trends in mortality of Zambian mother-infant pairs based on maternal infection with HIV-1 and human herpesvirus type 8 (HHV-8). Methods: A prospective cohort study was done on Zambian mother-infant pairs, stratified by maternal serologic status and followed from 6 weeks postdelivery for48 months. Statistical analysis of the differences in the calculated mortality rates among the four groups was done using Stata 7.0. Kaplan-Meier analysis and Cox proportional hazard models were used to measure subject survival time. Results: Between September 1998 and March 2002, a total of 1,425 mother-infant pairs were enrolled. The crude mortality rate among children born to dually infected mothers was ∼9 times higher (245.90 deaths per 1,000 live births) when compared with the death ratio of children born to seronegative mothers (24.63 deaths per 1,000 live births). The incidence rate for death was 0.34/1,000 in infants of co-infected mothers in comparison with 0.32/1,000 among HIV-1-infected mothers, 0.0336/1,000 among uninfected mothers, and 0.0403/1,000 among HHV-8-infected mothers (χ² = 154.56; P < 0.01). Infants of co-infected mothers had a comparable risk of death in comparison with infants infected with HIV-1 alone {hazard ratio, 9.91 [95% confidence interval (95% CI), 5.08-19.37] for co-infected versus 9.26 [95% CI, 4.75-18.07] for HIV-1-infected alone}. Infants of mothers infected only with HHV-8 also had comparable survival in comparison with uninfected infants (hazard ratio, 1.21; 95% CI, 0.56-2.61). Conclusion: Infants born to mothers dually infected with both HIV-1 and HHV-8 have comparable survival with infants exposed to HIV-1 alone. Infants born to mothers infected only with HHV-8 have comparable survival with uninfected infants.