FIRST CASE OF MOTHER-TO-INFANT HIV TYPE-1 GROUP-O TRANSMISSION AND EVOLUTION OF C2V3 SEQUENCES IN THE INFECTED CHILD

We report the first case of mother-to-infant transmission and follow-u p for an HIV-1 group O virus from Cameroon, Isolates were obtained fro m the mother at delivery and from the child at birth and when 16 and 3 0 months old, We analyzed the viral evolution within mother and child by examining 51 sequences spanning C2V3 regions of the viral envelope gene, The mother carried two genotypes, vl and v2, The genotype vl was dominant in the child at birth, and persisted as a minor genotype at age 30 months, The genotype v2 was absent in the child sequences, The variability of the nucleotide sequences of the isolates from the child increased with age from 0.8 to 6%, and a novel genotype (v3) appeared at age 30 months, The nonsynonymous-to-synonymous mutation ratio incr eased with the age of the child, from 0.75 at birth to 1.86 at 30 mont hs, indicating a high rate of fixation of amino acid changes in the ch ild. The overall pattern was similar to that reported by Ganeshan et a l.(1) (J Virol 1997;71:663-677) for group M viruses infecting child wi th a slow-developing form of the disease.