Description of HIV-1 Group M Molecular Epidemiology and Drug Resistance Prevalence in Equatorial Guinea from Migrants in Spain

<div><p>Background</p><p>The HIV epidemic is increasing in Equatorial Guinea (GQ), West Central Africa, but few studies have reported its HIV molecular epidemiology. We aimed to describe the HIV-1 group M (HIV-1M) variants and drug-resistance mutations in GQ using sequences sampled in this country and in Spain, a frequent destination of Equatoguinean migrants.</p><p>Methods</p><p>We collected 195 HIV-1M <i>pol</i> sequences from Equatoguinean subjects attending Spanish clinics during 1997-2011, and 83 additional sequences sampled in GQ in 1997 and 2008 from GenBank. All (n = 278) were re-classified using phylogeny and tested for drug-resistance mutations. To evaluate the origin of CRF02_AG in GQ, we analyzed 2,562 CRF02_AG sequences and applied Bayesian MCMC inference (BEAST program).</p><p>Results</p><p>Most Equatoguinean patients recruited in Spain were women (61.1%) or heterosexuals (87.7%). In the 278 sequences, the variants found were CRF02_AG (47.8%), A (13.7%), B (7.2%), C (5.8%), G (5.4%) and others (20.1%). We found 6 CRF02_AG clusters emerged from 1983.9 to 2002.5 with origin in GQ (5.5 sequences/cluster). Transmitted drug-resistance (TDR) rate among naïve patients attended in Spain (n = 144) was 4.7%: 3.4% for PI (all with M46IL), 1.8% for NRTI (all with M184V) and 0.9% for NNRTI (Y188L). Among pre-treated patients, 9/31 (29%) presented any resistance, mainly affecting NNRTI (27.8%).</p><p>Conclusions</p><p>We report a low (<5%) TDR rate among naïve, with PI as the most affected class. Pre-treated patients also showed a low drug-resistance prevalence (29%) maybe related to the insufficient treatment coverage in GQ. CRF02_AG was the prevalent HIV-1M variant and entered GQ through independent introductions at least since the early 1980s.</p></div

ML phylogenetic tree of the global HIV-1 subtype B <i>pol</i> sequences.

<p>The phylogenetic tree was constructed by the general time-reversible with gamma-distributed rate heterogeneity across sites model of substitution implemented into RAxML. Branches are drawn on scale with the bar at the bottom, which represents 0.03 nucleotide substitution per site and a progressive bootstrap gradient value using FigTree, v. 1.4. The statistically highly supported nodes (bootstrap >70%) and the clusters with five or more related sequences are indicated by an asterisk (*).</p

Prevalence of TDR to each drug class according to the origin of the patients.

<p>TDR, transmitted drug resistance; NRTI, nucleoside reverse transcriptase inhibitors; NNRTI, non-nucleoside reverse transcriptase inhibitors; PI, protease inhibitors; n, number of patients.</p

Distribution of the HIV-1 non-subtype B genetic forms detected in Eastern Andalusia over the 2005–2012 period.

<p>Distribution of the HIV-1 non-subtype B genetic forms detected in Eastern Andalusia over the 2005–2012 period.</p

Comparison of characteristics between patients infected with virus harbouring TDR and patients infected with wild-type virus.

<p>TDR, transmitted drug resistance; OR, odds ratio; CI, confidence interval; n, number of patients; SSA, sub-Saharan Africa; CSA, Central and South America.</p>a<p>Data available for 684 patients.</p>b<p>Data available for 544 patients.</p>c<p>Data available for 541 patients.</p

Temporal trends of TDR prevalence.

<p>The prevalences are detached according to A) drug class; B) HIV-1 variant; C) origin of the patients (as self-reported birth place); D) sex of the patients; and E) risk practice. TDR, transmitted drug resistance; NRTI, nucleoside reverse transcriptase inhibitors; NNRTI, non-nucleoside reverse transcriptase inhibitors; PI, protease inhibitors; SSA, sub-Saharan Africa; CSA, Central and South America; Htsex, heterosexual contact; Homo, homo/bisexual contact; IDU, injection drug use. The <i>p</i>-values shown next to the lines and sharing color code correspond to the chi-square test for trend in each case.</p

Prevalence of individual mutations among the patients infected with HIV-1 variants harbouring any TDR.

<p>SSA, sub-Saharan Africa; CSA, Central and South America; PI, protease inhibitors; NRTI, nucleoside reverse transcriptase inhibitors; NNRTI, non-nucleoside reverse transcriptase inhibitors.</p

Bayesian maximum clade credibility phylogeographic tree of the HIV-1 Subtype B by the Bayesian discrete approach in BEAST v1.7.5.

<p>The upper left bar represents the gradient of location probability. Nodes were drawn using a progressive ancestral probability location value of 0–1. Colours of terminal and internal branches indicate the sampling location for each sequence and the most probable ancestral location for each clade, respectively. The clusters of greatest epidemiological interest (≥5 patients grouped) are indicated by an asterisk (*).</p

Demographic, clinical and virological characteristics of the patients infected with HIV-1 non B variants sampled over the 2005–2012 period.

<p>Demographic, clinical and virological characteristics of the patients infected with HIV-1 non B variants sampled over the 2005–2012 period.</p