HIV-1 subtypes in Nairobi Kenya [letter]

Sequences of the env and gag genes have been used to classify HIV-1 into a major (M) group consisting of 10 subtypes A through J and an outlying (O) group of sequences. The diversity of HIV-1 is most likely greatest in Africa. Monitoring changes in the distribution of subtypes in Africa may offer insight into the course of the HIV/AIDS pandemic. 15 blood samples were randomly selected from stored samples from a cohort of 684 HIV-1-infected adults from Nairobi and the lymphocytes were separated. The samples came from 6 men and 9 women thought to have acquired HIV infection through heterosexual intercourse. Genomic DNA was isolated using a Nucleon I Nucleic Acid Extraction Kit. Portions of the HIV-1 env and gag genes were amplified by polymerase chain reaction methods subtyped by heteroduplex mobility analysis (HMA) and subsequently sequenced. One sample failed to amplify with the env or gag primer. HIV-1 subtypes identified were 12 subtype A 1 subtype C and 1 subtype D.