Diverse genetic subtypes of HIV-1 among female sex workers in Ibadan, Nigeria

Genetic diversity is the hallmark of HIV-1 infection. It differs among geographical regions throughout the world. This study was undertaken to identify the predominant HIV-1 subtypes among infected female sex workers (FSWs) in Nigeria. Methods: Two hundred and fifty FSWs from brothels in Ibadan Nigeria were screened for HIV antibody using ELISA. All reactive samples were further tested by the Western Blot Techniques. Peripheral Blood Mononuclear Cells (PBMCs) were separated from the blood samples of each subject. Fragments of HIV Proviral DNA was amplified and genetic subtypes of HIV-1 was determined by direct sequencing of the env and gag genes of the viral genome followed by phylogenetic analysis . Results: The age of the FSWs ranged from 15 to 55 years old (Mean = 25.8years, SD =3.74). Majority were Nigerians while others (1.6 %) were from neighboring West Africa countries. Four ( 1.6% ) of the FSWs were active for less than one year as sex workers, and the mean length of sex work was 2.80 years ( Range = 1.0 – 15.0 years ). Sixty-four (25.6%) of the 250 CSWs were positive for HIV-1 while 7 (2-8%) had dual infections to HIV-1 / HIV-2. Among the 34 HIV-1 strains  characterized by sequencing, 19 (55-9%) were subtype G, 9 (26.5%) CRF02_A/G, 3 (8.8%) CRF06_cpx while 1 (2.9%) each were identified as subtype C, CRF01_A/E and CRF09_cpx respectively. Nineteen (55.9%) of the FSWs with subtype G had been active in the sex work for between one to five years. The youngest of the HIV -1 infected FSWs with sexual activity of less than a year had subtype G strain. There is a significant probability that infection with this subtype occurred with a short incubation period (p< 0.05). Conclusion: This study showed a wide range of HIV- 1 subtypes among FSWs in Nigeria. The situation poses serious challenge for the design of HIV vaccine candidate for use in Nigeria.Keywords: Diverse, HIV, subtypes, Female Sex workers and Vaccin

Rapid HIV testing and counselling in labour in a northern Nigerian setting.

Between April and August 2004, all pregnant women in labour at JUTH, were offered rapid HIV testing and counselling with opportunity to decline testing. HIV positive women were offered the standard nevirapine mono-therapy prophylaxis regimen (HIVNET 012). Four hundred and thirty (99.8%) of the 431 pregnant women who were offered rapid HIV testing and counselling, agreed to test. A sero-conversion rate of 2.1% (5 of 235) was found among women who had previously tested negative for HIV during the index pregnancy. A seroprevalence rate of 9.6% (16 of 166) was found among women with unknown HIV status. One patient who had an indeterminate HIV status prior to labour tested positive in labour. Rapid HIV testing and counselling in labour is a useful practice in high prevalence settings since it detects a substantial number of HIV-infected women and HIV-exposed babies that would otherwise have missed interventions to prevent MTCT

Impact of HIV Type 1 Subtype on Drug Resistance Mutations in Nigerian Patients Failing First-Line Therapy

A diverse array of non-subtype B HIV-1 viruses circulates in Africa and dominates the global pandemic. It is important to understand how drug resistance mutations in non-B subtypes may develop differently from the patterns described in subtype B. HIV-1 reverse transcriptase and protease sequences from 338 patients with treatment failure to first-line ART regimens were evaluated. Multivariate logistic regression was used to examine the effect of subtype on each mutation controlling for regimen, time on therapy, and total mutations. The distribution of HIV-1 subtypes included CRF02_AG (45.0%), G (37.9%), CRF06_cpx (4.4%), A (3.6%), and other subtypes or recombinant sequences (9.2%). The most common NRTI mutations were M184V (89.1%) and thymidine analog mutations (TAMs). The most common NNRTI mutations were Y181C (49.7%), K103N (36.4%), G190A (26.3%), and A98G (19.5%). Multivariate analysis showed that CRF02_AG was less likely to have the M41L mutation compared to other subtypes [adjusted odds ratio (AOR) = 0.35; p = 0.022]. Subtype A patients showed a 42.5-fold increased risk (AOR = 42.5, p = 0.001) for the L210W mutation. Among NNRTI mutations, subtype G patients had an increased risk for A98G (AOR = 2.40, p = 0.036) and V106I (AOR = 6.15, p = 0.010), whereas subtype CRF02_AG patients had an increased risk for V90I (AOR = 3.16; p = 0.003) and a decreased risk for A98G (AOR = 0.48, p = 0.019). Five RT mutations were found to vary significantly between different non-B West African subtypes. Further study to understand the clinical impact of subtype-specific diversity on drug resistance will be critically important to the continued success of ART scale-up in resource-limited settings

Changes in the Distribution of HIV Type 1 Subtypes D and A in Rakai District, Uganda Between 1994 and 2002

HIV-1 subtype D (HIV-1D) progresses to disease faster and has lower transmissibility than subtype A (HIV-1A). We examined whether these differences could lead to a population level change in the distribution of these subtypes over time. HIV-1 viral RNA was extracted from stored serum samples from HIV-positive subjects participating in a population-based cohort study in Rakai, Uganda in 1994 and 2002. Portions of the viral proteins gag and gp41 were sequenced and subtyped. HIV-1 subtype assignments were generated for 773 subjects in 1994 and 812 subjects in 2002. The change in subtype distribution of the population as a whole as well as quartile age groups were examined for significant changes using a linear model. There was a significant decrease in the proportion of subjects infected with HIV-1D from 70.2% to 62.4% and a significant increase in subjects infected with HIV-1A from 16.7% to 23.3% over the 8-year period (p = 0.005). The most marked changes in proportion of HIV-1D and A were seen in the younger individuals (<25 and 25–30 years; p < 0.05). The percentages of subjects infected with HIV-1C and recombinant subtypes did not change significantly. Over this 8-year period, the overall viral population in this region evolved toward the less virulent HIV-1A strain, most likely as a consequence of the faster disease progression and lower transmissibility of HIV-1D