Prevalence, genetic diversity and antiretroviral drugs resistance-associated mutations among untreated HIV-1-infected pregnant women in Gabon, central Africa
BACKGROUND: In Africa, the wide genetic diversity of HIV has resulted in
emergence of new strains, rapid spread of this virus in sub-Saharan populations
and therefore spread of the HIV epidemic throughout the continent.
METHODS: To determine the prevalence of antibodies to HIV among a high-risk
population in Gabon, 1098 and 2916 samples were collected from pregnant women in
2005 and 2008, respectively. HIV genotypes were evaluated in 107 HIV-1-positive
samples to determine the circulating subtypes of strains and their resistance to
antiretroviral drugs (ARVs).
RESULTS: The seroprevalences were 6.3% in 2005 and 6.0% in 2008. The main subtype
was recombinant CRF02_AG (46.7%), followed by the subtypes A (19.6%), G (10.3%),
F (4.7%), H (1.9%) and D (0.9%) and the complex recombinants CRF06_cpx (1.9%) and
CRF11_cpx (1.9%); 12.1% of subtypes could not be characterized. Analysis of ARVs
resistance to the protease and reverse transcriptase coding regions showed
mutations associated with extensive subtype polymorphism. In the present study,
the HIV strains showed reduced susceptibility to ARVs (2.8%), particularly to
protease inhibitors (1.9%) and nucleoside reverse transcriptase inhibitors
(0.9%).
CONCLUSIONS: The evolving genetic diversity of HIV calls for continuous
monitoring of its molecular epidemiology in Gabon and in other central African
countries