Primary infections with HIV-1 of women and their offspring in Rwanda: findings of heterogeneity at seroconversion, coinfection, and recombinants of HIV-1 subtypes A and C

Variation in HIV-1 genomic RNA was studied in seroconversion samples from mother–child pairs from a Rwandan cohort. The mothers ( n = 8) were heterosexually infected and their children ( n = 6) were vertically infected by breast milk. Five of the children seroconverted within the same 3-month period as did their mothers. Highly homogeneous subtype A V3 and p17 gag sequence populations were observed in three mother–child pairs, one of the two nontransmitting mothers, and one child (mean nucleotide distances 0 to 0.9%). Heterogeneous populations of subtype A V3 and p17 gag sequences were found in one mother and a mother–child pair (1.4 to 2.8% for V3, 1.0 to 1.9% for p17). The second nontransmitting mother was infected with a heterogeneous A V1-V3 /C p17-p24 recombinant virus population (3.8% for V3, 2.4% for p17). Finally, in one woman subtype C V3 sequences were observed, in addition to highly homogeneous subtype A V3 and p17 gag sequence populations, also found in the child. Coexistence of subtype A V1-V3 and C V1-V3 env sequences in the mother was confirmed in a follow-up sample. The gag gene of both the maternal and the child's virus population represented an A/C recombinant sequence (A p17 /C p24 ). An infection with subtype C V1-V3/p17-p24 was found upon testing of three additional participants of the mother–child cohort, indicating that subtype C is present in Rwanda. In conclusion, heterogeneity, coinfection, and intersubtype recombinants are not uncommon in primary HIV-1 infections in Rwanda.