Genital ulcer disease control and HIV prevention

The relationship between anogenital HPV types and incident HIV infection among men who have sex with men and transgender women in Lima, Peru: Findings from a prospective cohort study

Although it is known that individuals living with HIV have a higher HPV prevalence, the impact of individual HPV types on HIV acquisition is less clear. In this prospective cohort study we investigated the relationship between HPV types and incident HIV infection among men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. Six hundred HIV-negative Peruvian MSM and TW participated in a 2-year study with biannual visits. At baseline, participants completed a computerized, self-administered questionnaire on sexual behavior and HPV knowledge and underwent a physical exam including anogenital swabs for HPV DNA (37 genotypes via linear array testing) and HIV testing; follow-up visits included the questionnaire and HIV testing. Participant mean age was 25 years (range = 18-40), with 48.9% self-identifying as gay and 86.5% reporting having sex exclusively with men. At baseline, 530 participants had HPV DNA present (61.1% with high-risk HPV, 84.9% with low-risk HPV). Among 571 participants who returned for any study visit, 73 (12.8%) became infected with HIV during the 2-year follow-up (6% HIV incidence). Compared to those without HIV, more participants with HIV had any HPV type present (97.3% vs. 87.6%, respectively, p = .01), more than one HPV type (79.5% vs. 58.2%, p < .01), or high-risk HPV (72.6% vs. 51.4%, p < .01). Some participants lost to follow-up could have been HIV-positive, which would have affected the relationship of HPV and HIV infection. Our prospective study showed that participants with any HPV type, more than one HPV type, or high-risk HPV were more likely to test positive for HIV. Although most studies have shown HPV-HIV coinfection, our findings illustrate the strong relationship between individual HPV types and HIV infection. This further illustrates the potential utility of HPV vaccine for MSM and TW, not only for HPV prevention but also possibly for HIV prevention.

High prevalence of Mycoplasma genitalium among female sex workers in Honduras: implications for the spread of HIV and other sexually transmitted infections

This study describes HIV, sexually transmitted infections (STI) and risk factors associated with Mycoplasma genitalium among female sex workers (FSWs) in four cities in Honduras. In 2006, 795 FSWs from Tegucigalpa, San Pedro Sula, La Ceiba and Comayagua were recruited using respondent-driven sampling (RDS) and tested for HIV prevalence and STI. HIV prevalence ranged from no infections in Comayagua to 5.4% in Tegucigalpa. With the exception of Comayagua, more than 20% of FSWs were infected with M. genitalium. M. genitalium in the aggregated cities was associated with HIV positivity, being aged ≤30 years old, drinking alcohol more than once weekly and always using condoms with regular clients in the past month. In comparison with a 2001 surveillance study we found lower rates of HIV infection. Interventions for HIV control and prevention among FSWs, including promotion of condom use, are needed in Honduras.

The prevalence of sexually transmitted infections in Papua New Guinea: a systematic review and meta-analysis

BACKGROUND

The potential for an expanded HIV epidemic in Papua New Guinea (PNG) demands an effective, evidence-based and locally-appropriate national response. As sexually transmitted infections (STIs) may be important co-factors in HIV transmission nationally, it is timely to conduct a systematic review of STI prevalences to inform national policy on sexual health and HIV/STI prevention.

METHODOLOGY/PRINCIPAL FINDINGS

We undertook a systematic review and meta-analysis of HIV and STI prevalences in PNG, reported in peer-reviewed and non-peer-reviewed publications for the period 1950-2010. Prevalence estimates were stratified by study site (community or clinic-based), geographic area and socio-demographic characteristics. The search strategy identified 105 reports, of which 25 studies (10 community-based; 10 clinic-based; and 5 among self-identified female sex workers) reported STI prevalences and were included in the systematic review. High prevalences of chlamydia, gonorrhoea, syphilis and trichomonas were reported in all settings, particularly among female sex workers, where pooled estimates of 26.1%, 33.6%, 33.1% and 39.3% respectively were observed. Pooled HIV prevalence in community-based studies was 1.8% (95% CI:1.2-2.4) in men; 2.6% (95% CI:1.7-3.5) in women; and 11.8% (95% CI:5.8-17.7) among female sex workers.

CONCLUSIONS/SIGNIFICANCE

The epidemiology of STIs and HIV in PNG shows considerable heterogeneity by geographical setting and sexual risk group. Prevalences from community-based studies in PNG were higher than in many other countries in the Asia-Pacific. A renewed focus on national STI/HIV surveillance priorities and systems for routine and periodic data collection will be essential to building effective culturally-relevant behavioural and biomedical STI/HIV prevention programs in PNG.

An immunogenic, surface-exposed domain of Haemophilus ducreyi outer membrane protein HgbA is involved in hemoglobin binding

HgbA is the sole TonB-dependent receptor for hemoglobin (Hb) acquisition of Haemophilus ducreyi. Binding of Hb to HgbA is the initial step in heme acquisition from Hb. To better understand this step, we mutagenized hgbA by deletion of each of the 11 putative surface-exposed loops and expressed each of the mutant proteins in trans in host strain H. ducreyi FX547 hgbA. All mutant proteins were expressed, exported, and detected on the surface by anti-HgbA immunoglobulin G (IgG). Deletion of sequences in loops 5 and 7 of HgbA abolished Hb binding in two different formats. In contrast, HgbA proteins containing deletions in the other nine loops retained the ability to bind Hb. None of the clones expressing mutant proteins were able to grow on plates containing low concentrations of Hb. Previously we demonstrated in a swine model of chancroid infection that an HgbA vaccine conferred complete protection from a challenge infection. Using anti-HgbA IgG from this study and the above deletion mutants, we show that loops 4, 5, and 7 of HgbA were immunogenic and surface exposed and that IgG directed against loops 4 and 5 blocked Hb binding. Furthermore, loop 6 was cleaved by protease on intact H. ducreyi, suggesting surface exposure. These data implicate a central domain of HgbA (in respect to the primary amino acid sequence) as important in Hb binding and suggest that this region of the molecule might have potential as a subunit vaccine.

Effect of genital ulcer disease on HIV-1 coreceptor expression in the female genital tract

OBJECTIVE

To examine the expression of human immunodeficiency virus type 1 (HIV-1) coreceptors (CCR5 and CXCR4) by monocytic cells within human genital ulcers.

METHODS

Women with primary or secondary syphilis, herpes simplex virus type 1 (HSV-1) or HSV-2 infection, or noninfectious abrasions had a biopsy sample taken from the lesion and contralateral vulva. HIV-1 coreceptor expression on CD3(+) and CD14(+) cells was analyzed by flow cytometry. Real-time reverse-transcriptase polymerase chain reaction was used to assess levels of coreceptor mRNA expression.

RESULTS

Women with primary or secondary syphilis or with HSV-1 or HSV-2 infection had significantly increased numbers of CD14(+) cells expressing CCR5 within the genital ulcer. This increase was also noted in the nonulcerated tissue isolated from women with syphilis and in peripheral blood mononuclear cells from women with secondary syphilis. CCR5 mRNA expression was increased in tissue obtained from syphilis lesions.

CONCLUSIONS

Monocytes recruited to genital ulcer disease (GUD) sites express increased levels of CCR5. This increased expression could account, at least in part, for enhanced HIV-1 transmission in the setting of GUD.