Diversity and resistance of the HIV in seropositive pregnant proceeding from the regions South and Southeastern of Brazil
The first reported case of mother-to-child transmission (MTCT) in Brazil occurred in São Paulo in 1985 and, in spite of the availability of preventive measures in the recent years, the control of MTCT is still a government public health priority. In this study the plasmatic RNA viral load, the CD4+ T cells count, the genetic subtype, and the presence of antiretroviral resistant variants, were determined in a population of pregnant women diagnosed as HIV-1 seropositive at delivery. The influence of these parameters in HIV-1 vertical transmission was also evaluated. Blood samples of 148 pregnant women coming from South (Porto Alegre, PoA; n=98) and Southeast (Rio de Janeiro, RJ; n=50) Brazilian regions were collected between March 2000 and August 2002, and tested for RNA viral load (NASBA) and CD4+ T cells count (flow cytometry). The HIV-1 genetic characterization (genetic subtype and antiretroviral resistance mutations) was performed by HMA based on env region and subsequent nucleotide sequencing of env/pol regions. The babies were diagnosed for HIV-1 infection by PCR DNA (Roche) and confirmed by RNA viral load assay (NASBA).Among the 42 samples analyzed from Rio de Janeiro we observed the following subtype profiles: 36 (86%) Bpol/Benv, 4 (10%) Fpol/Fenv, and 2 (4%) FPR/BRT/Benv. Meanwhile, among 70 samples from Porto Alegre, the following profiles were observed: 15 (22%) Bpol/Benv, 43 (63%) Cpol/Cenv, one (1%) Fpol/Fenv, 4 (6%) Cpol/Benv, 3 (4%) Bpol/Cenv, one (1%) Fpol/Cenv, one (1%) BPR/CRT/Cenv, and one (1%) FPR/BRT/Cenv. A suggestive case of double infection Bpol/B-Cenv was observed. The presence of primary resistance for protease inhibitors (M46I, V82L, and D30N) was found in four out of 112 pregnant women, indicating a primary resistance prevalence of 3.5% in our population. Accessory resistance mutations M36I, L63P and V77I were also detected. The presence of resistance for reverse transcriptase inhibitors was detected in six women, resulting in a prevalence of 5.2%. Seventeen cases of HIV-1 vertical transmission (6 in RJ and 11 in PoA) were detected. No significant difference in CD4+ T cells count, RNA viral load or viral subtype was observed between transmitter and non transmitter mothers. Moreover, the vertical transmission of antiretroviral resistant variants was not verified in our study group.The presence of primary resistance mutations in these treatment-naive pregnant women reveals the transmission of antiretroviral resistant variants in our country, which could represent an important public health problem for the future policies of antiretroviral treatment of HIV/AIDS in Brazil.
Advisor:Mariza Goncalves Morgado
School:Faculdades Oswaldo Cruz
Source Type:Master's Thesis
Keywords:hiv Disease Transmission, Vertical
Date of Publication:10/15/2005