AEGiS-14IAC: Late breastmilk transmission of HIV-1 and infant disease progression.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

Late breastmilk transmission of HIV-1 and infant disease progression.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. B10210)

Richardson BA, John-Stewart GC, Nduati R, Mbori-Ngacha D, Reiner M, Overbaugh J, Emery S, Kreiss JK
University of Washington, Seattle, United States

BACKGROUND: Previous studies among HIV-infected children have shown more rapid disease progression among infants infected in-utero versus intrapartum. Little is known regarding disease progression in children infected through late postnatal breastmilk transmission.

METHODS: Data are from antiretroviral naïve HIV-infected infants in a randomized trial of breastfeeding versus formula feeding conducted in Nairobi from 1992-98. Infant blood was collected at birth, 6 and 14 weeks, and every 3 months to 24 months for HIV-1 testing. Mortality information was collected throughout the study. Early infection was a positive HIV-1 DNA PCR assay at <2 months of age, and late infection was a negative PCR assay >2 months of age followed by a positive test. Mortality was analyzed using Cox proportional hazards regression of time from infection to death. The Mann-Whitney U-test was used to test for differences in peak HIV-1 RNA plasma viral load and viral setpoint.

RESULTS: Of 80 infected children, 34% were infected late and 66% were infected early. Mortality in the first year after infection was 12 per 100 person years for children infected late versus 71 per 100 person years for children infected early (HR=0.2, p=0.02). Results were similar when analysis was restricted to breastfed children and when analysis excluded in-utero infections. Infants infected late had a lower peak viral load (median of 5.7 versus 6.4 log₁₀ copies/ml, p=0.07), and a lower viral setpoint (median of 5.6 versus 6.2 log₁₀ copies/ml, p=0.03) than those infected early.

CONCLUSIONS: Infants infected through late postnatal breastmilk transmission of HIV-1 have lower mortality in the first year after infection, and lower HIV-1 RNA viral setpoint than infants infected early. This could be due to older infants having a better ability to mount an effective immune response or having more mature epithelium that limits access to key target cells at the time of infection.

Keywords: AEGIS, HIV-1, Disease Progression, Viral Load, HIV Infections, Breast Feeding, HIV Seropositivity, Polymerase Chain Reaction, Infant Mortality, Infant Food, Infant, Child, Human, transmission, Mortality

020707
B10210