Objective: To evaluate the risk of late postnatal HIV-1 infection in nonbreastfed children enrolled in the French ANRS Cohort CO01 (EPF).
Methods: The EPF cohort has prospectively enrolled HIV-infected mother/child pairs with a low proportion of known breastfeeding (<0.2%). Children were followed until they were 24 months old, with HIV-1 DNA/RNA PCR tests performed at birth, M1, M3 and M6 and a late serology at 18-24 months. This substudy included 4539 children who were uninfected at the age of 6 months in 1984-2005.
Results: Five children were late diagnosed with HIV-1 infection despite negative PCR tests until 6 months. In three cases, the infection was diagnosed between 14 and 18 months. The other infections were diagnosed at 10 and 12 years of age because of AIDS-defining symptoms; their last (negative) serologies were performed at 19 and 9 months, respectively. A phylogenetic study performed in the latest case revealed a strong homology between the mother and child strains. No known mode of viral transmission (including breastfeeding or use of premasticated food) could be found. However, we observed previously reported risk factors for intrafamilial HIV-1 transmission: poor socioeconomic backgrounds and sustained HIV-1 viremia in the mothers during the follow-up of their children.
Conclusion: Late postnatal HIV-1 infection can rarely be diagnosed in the absence of known breastfeeding in high-income countries. Our results highlight the need for a maintained close follow-up of the noninfected children even after 6 months, especially when there are risk factors for intrafamilial viral transmission.