Early spread of HIV-1 B/F recombinant intersubtype in children born to infected mothers in Argentina.

GOMEZ CARRILLO M; AVILA MM; PANDO MA; MARTINEZ PERALTA L; CARR JK

Buenos Aires

Conferencia; The 1st IAS Conference on HIV Pathogenesis and Treatment.; 2001

IAS

Introduction: In Argentina, the first AIDS case was detected in 1982. HIV-1 sequences reported during early ´90 showed a predominance of subtype B. Since 1996 subtype F and recombinants B/F were reported and a high proportion of B/F recombinant was observed in 2000 in different populations. In order to elucidate the possible change in the molecular patterns of HIV-1 epidemic in Argentina, sequences obtained from proviral DNA present in PBMC samples from infected children born before 1995 were compared with sequences of virus obtained in children born in 1998-2000. Methods: A total of 25 PBMCs samples from children born to HIV infected mothers in 1984 to 1989 (14 children) and 1995 to 2000 (11 ch.) were collected. The selected region for sequencing was previously found as a common break-point site for most of B/F recombinants in Argentinean sequences. A nested PCR strategy was performed in order to amplify a 600-bp fragment containing the break point  (position 5967 to 5570 in HXB2 reference sequence). Sequencing was performed in an automated sequencer (Applied Biosystems 3100).  A multiple alignment of the sequences with selected reference sequences of subtype B and subtype F was constructed. Phylogenetic trees were made using Neighbor Joining and Treetool. Results: B/F recombinant sequences were found in 6/14 children born between 1984 and 1989: 1 born in 1986 and 5 born in 1987. The remaining 8 children born in this period showed a B pattern for the 600 bp fragment. Among children born after 1995 4 were B and 7 were B/F recombinants. Two siblings, born in 1985 and 1989, showed the same B pattern and clustered together. Conclusions: A high percentage of B/F recombinants were observed as from 1986/87, when only 90 AIDS cases were reported in Argentina in that same period. Data shown in this population are suggesting that the recombinants had an early spread in Argentina and are probably predominant in the present time.