Association of Bacterial vaginosis and other Sexually Transmitted Infections with HIV among pregnant women in Nigeria

OBJECTIVES

To determine the association of Bacterial vaginosis (BV) and other sexually transmissible infections (STIs) with HIV prevalence among pregnant women in Jos, Nigeria.

METHODS

This was a cross- sectional study of pregnant women who participated in the Prevention of Mother-to-Child Transmission of HIV program of the AIDS Prevention Initiative in Nigeria, between April 2002 and July 2004, at the Jos University Teaching Hospital in Jos, Nigeria. Blood, high vaginal and endocervical samples were obtained for diagnosis of HIV, BV and other STIs. Data were analyzed for prevalence of HIV, BV and other STIs. Univariate and multivariate logistic regression models generated unadjusted and adjusted odds ratios (OR) as well as 95% confidence intervals (CI) of the association of BV and other STIs with HIV prevalence. P value <0.05 was considered statistically significant.

RESULTS

A total of 4,046 pregnant women were studied and 97.6% (3,950/4,046) had complete laboratory records for analysis. The prevalence of HIV was 8.2% (CI: 7.4-9.1); BV 11.9% (CI: 10.9-12.9); Candida 10.7% (CI: 9.7-11.7); mixed infection of BV and Candida 2.8% (CI: 2.3-3.4); Trichomonads 0.6% (CI: 0.3-0.8) and syphilis 0.35% (0.16-0.54). BV, Candida, mixed BV and Candida; and Trichomonads were independently associated with HIV infection [adjusted OR (95% CI), 2.9 (CI: 2.2-3.9); 2.0 (CI: 1.5-2.9); 3.4 (CI: 2.0-5.6), and 3.3 (CI: 1.1-9.7) respectively].

CONCLUSION

HIV prevalence is higher among pregnant women who have BV, Candida and Trichomonads vaginal infections compared with women who have no evidence of infection. The practice of routine screening for BV and other STIs among pregnant women as a strategy for identifying women at risk for prevalent HIV infection should be sustained/ encouraged and the syndromic management of STIs should be integrated into all antenatal care management protocols in antenatal clinics in order to curb the epidemic of heterosexual HIV transmission.

Short communication: Transmitted HIV drug resistance in antiretroviral-naive pregnant women in north central Nigeria

The World Health Organization (WHO) recommends periodic surveillance of transmitted drug resistance (TDR) in communities in which antiretroviral therapy (ART) has been scaled-up for greater than 3 years. We conducted a survey of TDR mutations among newly detected HIV-infected antiretroviral (ARV)-naive pregnant women. From May 2010 to March 2012, 38 ARV-naive pregnant women were recruited in three hospitals in Jos, Plateau state, north central Nigeria. Eligible subjects were recruited using a modified version of the binomial sequential sampling technique recommended by WHO. HIV-1 genotyping was performed and HIV-1 drug resistance mutations were characterized according to the WHO 2009 surveillance drug resistance mutation (SDRM) list. HIV subtypes were determined by phylogenetic analysis. The women's median age was 25.5 years; the median CD4(+) cell count was 317 cells/μl and the median viral load of 16 was 261 copies/ml. Of the 38 samples tested, 34 (89%) were successfully genotyped. The SDRM rate was <5% for all ART drug classes, with 1/34 (2.9%) for NRTIs/NNRTIs and none for protease inhibitors 0/31 (0%). The specific SDRMs detected were M41L for nucleoside reverse transcriptase inhibitors (NRTIs) and G190A for nonnucleoside reverse transcriptase inhibitors (NNRTIs). HIV-1 subtypes detected were CRF02_AG (38.2%), G' (41.2%), G (14.7%), CRF06-CPX (2.9%), and a unique AG recombinant form (2.9%). The single ARV-native pregnant woman with SDRMs was infected with HIV-1 subtype G'. Access to ART has been available in the Jos area for over 8 years. The prevalence of TDR lower than 5% suggests proper ART administration, although continued surveillance is warranted.

The level of APOBEC3G (hA3G)-related G-to-A mutations does not correlate with viral load in HIV type 1-infected individuals

The APOBEC family of mammalian cytidine deaminases, such as APOBEC3G (hA3G), has been demonstrated to function as a host viral restriction factor against HIV-1. hA3G has been shown to cause extensive G-to-A mutations in the HIV-1 genome, which may play a role in viral restriction. To investigate the role of G-to-A mutations in HIV-1 pathogenesis, we isolated, amplified, and sequenced HIV-1 sequences (vif, gag, and env) from 29 therapy-naive HIV-1-infected individuals. The levels of G-to-A mutations correlated with the expression levels of hA3G in the vif (rho = 0.438, p = 0.041) and the env regions (rho = 0.392, p = 0.038), but not in the gag region (rho = 0.131, p = 0.582). There is no correlation between viral load and the level of G-to-A mutations in the vif (rho = 0.144, p = 0.522), env (rho = 0.168, p = 0.391), or gag regions (rho = -0.254, p = 0.279). Taken together, these findings suggest that the hA3G-induced G-to-A mutations may not be the mechanism by which hA3G restricts or controls viral replication. Thus, hA3G might be restricting viral growth in infected individuals through a mechanism that is independent of the cytidine deaminase activities of hA3G.

Long-term intrapatient viral evolution during HIV-2 infection

Background. Disease progression and transmission of human immunodeficiency virus (HIV) type 2 are attenuated, compared with HIV-1, which is consistent with the lower plasma viral loads observed in HIV-2 infection. Although numerous studies have characterized the intrapatient evolution of viral sequences during HIV-1 infection, prospective studies examining intrapatient evolution during HIV-2 infection have been limited.Methods. We examined viral sequence evolution in the C2V3C3 region of the viral env gene in 8 HIV-2-infected individuals from Dakar, Senegal, over the course of approximately 10 years. To compare results with HIV-1 infection, we reanalyzed data from our previous study that prospectively examined intrapatient viral evolution in HIV-1-infected individuals from the same population.Results. HIV-2 sequences from early and late time points were phylogenetically intermixed for all subjects. No distinct trends were observed in terms of increases or decreases in fragment size or the number of N-linked glycosylation sites, and ratios of synonymous substitutions per synonymous site to nonsynonymous substitutions per nonsynonymous site suggested selection to be neutral or negative. In homologous env C2V3 sequences, rates of viral divergence and diversification were slower in individuals infected with HIV-2 than in those infected with HIV-1.Conclusions. Viral evolution occurs slowly in HIV-2 infection, which is consistent with the slow disease progression of HIV-2 and supports the notion that viral evolution may be a relevant correlate for disease progression.

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.

HIV infection among pregnant women in Nigeria

OBJECTIVES

To determine risk factors for HIV among pregnant women (N = 2657) receiving antenatal services in Jos, Plateau state, Nigeria.

METHODS

Information about potential risk factors was obtained at interview. Biological samples were collected for detection of HIV and other sexually transmitted infections (STIs).

RESULTS

The prevalence of HIV was 8.2%. Women aged 20-29 years had more than 4-fold increased risk of HIV. Women of Catholic (adjusted odds ratio (AOR) = 1.72, 95% CI = 1.01-2.95) and Pentecostal (AOR = 2.57, 95% CI = 1.46-4.52) denominations were more likely to be HIV-infected when compared to Moslem women. The risk of HIV was also increased among women with multiple marriages and in women married to a banker/accountant. Other predictors of HIV were having a husband with other partners, perceived risk of HIV, STIs, candidiasis and bacterial vaginosis.

CONCLUSIONS

Development of effective interventions, including behavioral change, expansion of perinatal HIV prevention services and STI control, should be given the highest priority.

Characterization of complete HIV type 1 genomes from non-B subtype infections in U.S. military personnel

Infections with non-B HIV-1 subtypes are rare in the United States, but comprise a significant percentage of infections among U.S. military personnel. Risk behavior while on overseas deployment correlates with non-B infection in this population. Extensive genetic characterization will be required to define HIV-1 diversity, and to effectively evaluate requirements for HIV-1 vaccines and other prevention strategies in this group. From 1997 to 2000, 520 recent seroconverters, identified through routine HIV-1 testing in the U.S. active military force, volunteered for a prospective study. V3 loop serology or partial genome sequencing identified 28 non- B subtype infections; 14 were studied by full genome sequencing and phylogenetic analysis. Five strains were CRF01_AE. Four of these clustered with CM240 from Thailand, and one clustered with African CRF01_AE. Four strains were CRF02_AG, prevalent in West and West Central Africa. Two strains were subtype C. One strain was a unique recombinant between CRF01_AE and subtype B, and another was a complex unique recombinant between subtype A and D. The final strain was a member of a complex circulating recombinant first identified in Senegal, CRF09_cpx, incorporating subtypes A, F, G, and an unclassified genome. This diversity of non-B subtype HIV-1 strains, encompassing three globally prevalent non-B strains and including rare or even possibly unique strains, illustrates the breadth of U.S. military exposure while deployed and sets the bar higher for breadth of cross-subtype protection to be afforded by an HIV-1 vaccine.

Highly Active Antiretroviral Therapy and Viral Response in HIV Type 2 Infection

Human immunodeficiency virus type 2 (HIV-2), the second human retrovirus known to cause AIDS, is endemic to West Africa but is infrequently found outside this region. We present a case series of 10 HIV-2--infected individuals treated in the United States. Physicians applied the principles of highly active antiretroviral therapy (HAART), normally used in treating HIV type 1, with modifications considered appropriate for treating HIV-2. CD4+ cell count, HIV-2 virus load, and clinical status were found to correlate well, providing evidence that HIV-2 virus load is useful in managing treatment of patients with HIV-2 who are receiving therapy. However, HAART regimens with predicted efficacy for treatment of HIV type 1 infection are not as efficacious for treatment of HIV-2. Controlled clinical trials of HIV-2-infected patients receiving various HAART regimens are needed to provide therapeutic guidance to the medical community.

A high-density admixture map for disease gene discovery in african americans

Admixture mapping (also known as "mapping by admixture linkage disequilibrium," or MALD) provides a way of localizing genes that cause disease, in admixed ethnic groups such as African Americans, with approximately 100 times fewer markers than are required for whole-genome haplotype scans. However, it has not been possible to perform powerful scans with admixture mapping because the method requires a dense map of validated markers known to have large frequency differences between Europeans and Africans. To create such a map, we screened through databases containing approximately 450000 single-nucleotide polymorphisms (SNPs) for which frequencies had been estimated in African and European population samples. We experimentally confirmed the frequencies of the most promising SNPs in a multiethnic panel of unrelated samples and identified 3011 as a MALD map (1.2 cM average spacing). We estimate that this map is approximately 70% informative in differentiating African versus European origins of chromosomal segments. This map provides a practical and powerful tool, which is freely available without restriction, for screening for disease genes in African American patient cohorts. The map is especially appropriate for those diseases that differ in incidence between the parental African and European populations.

In vitro correlates of HIV-2-mediated HIV-1 protection

A prospective study of high-risk commercial sex workers in Senegal has shown that HIV-2 infection may reduce the risk of subsequent HIV-1 infection; these findings have been confirmed and extended, now with 13 years of observation. While exploring the biological mechanisms behind this natural protection, we found that a significant proportion of peripheral blood mononuclear cells obtained from HIV-2-infected subjects resisted in vitro challenge with CCR5-dependent HIV-1 viruses but not CXCR4-dependent viruses. High levels of beta-chemokines, the natural ligands of the CCR5 coreceptor, were correlated with low levels of viral replication, and resistance was abrogated by antibodies to beta-chemokines. Our results suggest that beta-chemokine-mediated resistance may be an important correlate of HIV protection against HIV-1 infection and relevant to HIV vaccine design.

Perinatal transmission of hepatitis B virus in Senegal, west Africa

We studied 152 healthy pregnant women and their 156 newborns for markers of hepatitis B virus (HBV) infection in Dakar, Senegal. Of these, 120 mothers (79%) had antibodies to the hepatitis B core antigen (anti-HBc), 21 (13.8%) were hepatitis B surface antigen (HBs Ag) positive, including 2/21 (9.5%) hepatitis B core-associated antigen (HBe Ag) positive and 1/21 (4.7%) HBV DNA positive. At birth, 11 (7%) infants were HBs Ag positive; 9/11 had an HBs Ag positive mother. Ten of these HBs Ag positive-born infants were investigated at 6-7 months: 5 were strongly HBs Ag positive and developed antibodies to HBs Ag, HBc Ag or HBe Ag; these 5 (3.2% of the total) probably became chronic carriers of HBV. The 5 others were HBs Ag negative and 4/5 did not develop antibodies against HBV Ag; HBs Ag positivity at birth was likely due to contamination of the mother's blood. Thirty-one of the 145 HBs Ag negative-born infants were studied at 6-7 months and remained HBs Ag negative. However, 5 (16%) showed evidence of HBV infection occurring between 0 and 6 months, as shown by the development of antibodies to HBs Ag, HBc Ag, and/or HBe Ag. Despite the low prevalence of HBV DNA and HBe Ag in HBs Ag positive African mothers, this study shows the occurrence of perinatal transmission of HBV in West Africa, in contrast with previous studies. Perinatal HBV transmission could explain the HBV vaccination failure recently reported in children in Senegal.

Field evaluation of alternative HIV testing strategy with a rapid immunobinding assay and an agglutination assay

A rapid immunobinding assay ('HIVCHEK', Ortho) and an agglutination assay ('Serodia-HIV', Fujirebio) were evaluated as an alternative to enzyme-linked immunosorbent assay (ELISA) and western blot under field conditions in Africa for detection of antibody to human immunodeficiency virus (HIV). 7106 specimens were tested at 25 laboratories in Kenya, Ghana, Senegal, and Zaire. HIVCHEK was used as a screening test, and serodia-HIV as a supplemental test to evaluate these assays in an alternative testing strategy to the standard ELISA/western blot testing procedure. In each country, HIVCHEK was more sensitive and specific than ELISA when compared with western blot. The sensitivity of HIVCHEK ranged from 87.0 to 96.3% and the specificity from 99.0 to 100%. The sensitivity and specificity of serodia-HIV ranged from 85 to 98% and from 88 to 98%, respectively. The sensitivity and specificity were affected by the presence of HIV-2 in Ghana and Senegal. Overall, with an HIV-1 prevalence of 14.8% in Kenya and 22.5% in Zaire, the sensitivities of the alternative strategy were 96.4% and 91.4%, the specificities 99.6% and 100%, the positive predictive values 97.6% and 100%, and the negative predictive values 99.3% and 97.9% for Kenya and Zaire, respectively. With this testing format there was an estimated average cost saving of up to 82% over the conventional strategy with ELISA/western blot. This procedure constitutes a reasonable alternative to the standard ELISA/western blot combination.