Abstract:
Samples from infants infected in-utero by the human immunodeficiency virus type 1 (HIV-1) subtypes A, C, D, and recombinants from
Dar es Salaam, Tanzania, were examined for the presence of viral genetic quasispecies. HIV-1 envelope diversity was measured on
peripheral blood mononuclear cells collected within the first 48 h of life from 53 infants. Phylogenetic analysis of C2–C5 envelope
nucleotide sequences was used for HIV-1 subtype classification. Forty-two of 53 samples (79%) showed a heteroduplex mobility assay
(HMA) suggestive of transmission of a single quasispecies, while 21% showed infection with multiple quasispecies. No differences among
HIV-1 subtypes were found in the proportion of single to multiple quasispecies transmitted in-utero (Likelihood ratio test, P 0.83), nor
were differences found among single to multiple quasispecies transmitted and maternal viral load (Mann–Whitney test, P 0.44). This
suggests that differences in perinatal transmission between subtypes we previously observed in this cohort could not be associated with the
likelihood for multiple independent infections during in-utero infections.
