Genetic Epidemiology of HIV-1 Infected Maternity Patients and their Sexual Partners in Buenos Aires, Argentina.

AVILA MM; PANDO MA; SALOMON H; MARTINEZ PERALTA L; NEGRETE M; CARR JK; RUSSELL KL

Durban

Conferencia; XIII International AIDS Conference; 2000

IAS

Background: Genetic and antigenic variation among HIV-1 has presented a major concern regarding the strategies needed to develop vaccines for AIDS. These findings imply that there is likely a need to prepare vaccines based on endemic strains.  In addition, molecular epidemiology can be a useful tool in tracking the emerging epidemics in defined populations.  Past work in genetic genotyping of HIV-1 in Argentina has shown that genotype B is the most common genotype circulating.  Recently, the F genotype and B/F recombinant were identified. These studies reflect the evolving complexity of the epidemic in Argentina.  This study was designed to determine the genotypes of HIV found in heterosexual HIV+ maternity patients and their partners from Buenos Aires, Argentina.  Methods:  HIV+ maternity patients 18 years of age and older were surveyed while attending routine follow-up at the National HIV Reference Laboratory between the months of May to August 1999.  Consent was requested from the maternity patients to interview their male partners.  HIV status of the male partners was determined, and a sample of blood obtained from both maternity patients and their partners for peripheral blood mononuclear cell isolation, PCR, and genotyping.  Genotypes were determined with the heteroduplex mobility assay (HMA).  Restriction fragment length polymorphisms and sequencing are being utilized to confirm these observations.  Results:  One hundred and thirty HIV + maternity patients (49 currently pregnant and 81 post-partum mothers delivered in the last 12 months) and 51 current male partners were included in the study.  HMA analysis has been completed for 99 of the 130 maternity patients.  Genotype F was found by HMA analysis in 81% (80/99), genotype B in 18% (18/99) and genotype C in 1% (1/99) of the maternity patients.  72.5% (37/51) of the male partners were found to be HIV infected.  Of the male partners processed for genotype determination (n=37), all shared the same genotype as their maternity partner. Discussion:  It is quite remarkable that such a high percentage of this heterosexual population appears to genotype F.  Further research in the molecular epidemiology of HIV-1 in the heterosexual population of Argentina is clearly warranted to determine whether the emergence of genotype F in this population is a marker for a change in the epidemic.