Search

BACKGROUND: Some but not all observational studieshave suggested an increase in risk of HIV acquisition for women using injectable hormonal contraception (IHC). METHODS: We used country-level data to explore the effects of reducing IHC use on the number of HIV infections the number of live births and the resulting net consequenceson AIDS deaths and maternal mortality for each country. RESULTS: High IHC use coincides with high HIV incidence primarily in southern and eastern Africa. If IHC does increase the risk of HIV acquisition this could generate 27 000-130 000 infections per year globally 87-88% of which occur in this region. Reducing IHC use could result in fewer HIV infections but also a substantial increase in live births and maternal mortality in countries with high IHC use high birth rates and high maternal mortality: mainly southern and eastern Africa South-East Asia and Central and South America. For most countries the net impactof reducing IHC use on maternal and AIDS-related deaths is dependent on the magnitude of the assumed IHC-HIV interaction. CONCLUSIONS: If IHC use increases HIV acquisition risk reducing IHC could reduce new HIV infections; however this must be balanced against other important consequences including unintended pregnancy which impacts maternal and infant mortality. Unless the true effect size approaches a relative risk of 2.19 it is unlikely that reductions in IHC could result in public health benefit with the possible exception of those countries in southern Africa with the largest HIV epidemics.

New HIV-1 infections are increasing in older American women largely through heterosexual transmission. Activated CD4+ T cells and CCR5 expression are linked to HIV-1 susceptibility, but whether these parameters are altered in the cervix of older women is unknown.Whole blood and in some instances endocervical brush samples were collected from healthy premenopausal (n = 22) and postmenopausal women (n = 24). Percentages of HLA-DR(DR)+CD38(38)+CD4+ T cells and HIV-1 chemokine coreceptor expression were determined by flow cytometry.Percentages of DR+38+CD4+ T cells were 6 times greater in cervix (median: 6.4%) than blood (median: 1.1%; P0.001) but did not differ within each compartment between premenopausal and postmenopausal women (P = 0.2). Postmenopausal women had greater percentages of CCR5+CD4+ and CCR5+DR+38+CD4+ T cells compared with premenopausal women in cervix (median: 70% vs. 42%, P = 0.005; and 80% vs. 57%; P = 0.05, respectively) and blood (medians: 22% vs. 13%, and 76% vs. 62%, respectively; P0.001). Postmenopausal women had more CCR5 molecules on cervical DR+38+CD4+ T cells (median: 3176) than premenopausal women (median: 1776; P = 0.02). Age and percent CCR5+CD4+ and CCR5+DR+38+CD4+ cells were linearly related in cervix (r(2) = 0.47, P0.001 and r(2) = 0.25, P = 0.01, respectively) and blood (r(2) = 0.20, P = 0.001 and r(2) = 0.31, P0.001; respectively), but confounding of age with menopause could not be excluded. Cervical CXCR4 expression did not differ substantially between premenopausal and postmenopausal women.Elevated cervical CCR5 expression in postmenopausal women may increase their risk for HIV-1 acquisition. Studies are needed to confirm whether elevated CCR5 expression confers increased HIV-1 susceptibility in postmenopausal women, and if it is related to hormonal or nonhormonal effects of aging.

International audience; OBJECTIVES: A synergy between HIV and herpes simplex virus type 2 (HSV-2) infections has been reported in observational studies. The objectives of this study were to estimate the per-sex-act female-to-male transmission probabilities (FtoMTPs) of HIV and HSV-2, the effect of each infection on the FtoMTP of the other and the effect of male circumcision on these FtoMTPs. DESIGN: We used longitudinal data collected during the male circumcision trial conducted in Orange Farm (South Africa). METHODS: Results were obtained by specific mathematical modeling of HIV and HSV-2 statuses of the men as functions of their sexual behavior and male circumcision status. The model took into account an estimation of the HIV and HSV-2 statuses of each of their female partners. Confidence intervals (CI) were estimated using a bootstrap resampling method. RESULTS: The HIV and HSV-2 FtoMTPs, during an unprotected sexual contact for an uncircumcised male in the absence of the other virus in both partners, were 0.0047 (95% CI: 0.0014-0.017) and 0.0067 (95% CI: 0.0028-0.014), respectively. HSV-2 in either partner increased HIV FtoMTP with a relative risk (RR) of 3.0 (95% CI: 1.01-7.3). Conversely, HIV in either partner increased HSV-2 FtoMTP (RR= 2.5; 95% CI: 1.1- 6.3). Male circumcision significantly decreased these probabilities with RRs of 0.24 (95% CI: 0.11-0.44) and 0.59 (95% CI: 0.36-0.91), respectively. CONCLUSION: This study gave the first estimates of HSV-2 per-sex-act FtoMTPs in Africa. It demonstrated a synergy between HIV and HSV-2 infections and a protective effect of male circumcision on HSV-2 acquisition by males.

Objectives: To develop and implement a method to identify and characterize places where people meet new sexual partners and to assess HIV prevention program coverage in those places. Methods: In three townships (populations 60 000-100 000 each) and one business district (population < 20 000) in South Africa, interviewers asked over 250 informants per area to identify public sites where people meet new sexual partners. All reported sites were visited and mapped. A knowledgeable person onsite was interviewed about the site and its patrons. Individuals socializing at sites were interviewed about their sexual behavior. Results: More than 200 sites in each township and 64 sites in the central business district were identified and visited. The male to female ratio among site patrons was approximately 2:1. In each area, men and women socializing at sites reported high rates of new sexual partner acquisition and low condom use. Almost half of the 3085 men and 1564 women interviewed while socializing reported having a new sexual partner in the last 4 weeks. A third reported meeting a new partner at the site of the interview. Commercial sex was rare in the townships but available at 31% of central business district sites. Fewer than 15% of township and only 20% of business district sites had condoms. Conclusion: The PLACE method successfully identified sites where people with high rates of new sexual partnerships can be reached for prevention programs. Sexual networks in these areas are extensive, diffuse, and characterized by high rates of new partnership formation and concurrency with little acknowledged commercial sex.

Study of the heterosexual transmission of HIV has shifted focus from the behavioral and demographic risk factors associated with HIV to the biological and molecular factors. Although factors such as genetic predisposition may be immutable, others such as co-infection with sexually transmitted diseases are modifiable by the use of treatment. The effect of antiretroviral treatment is also promising but deserves more study, as does the use of contraception and microbicides (chemical barriers meant for intravaginal use).

Statistical modelling is applied to routine AIDS surveillance data to assess recent trends and to provide a range of short-term predictions. Several alternative functions have been fitted to half-yearly incidence data reported by the countries of the European Community by 31 December 1989 and adjusted for reporting delays. Among homosexual/bisexual men, recent trends in AIDS incidence are more nearly linear than exponential. Higher though less than exponential rates of growth are observed among intravenous drug users and among those presumed infected by heterosexual contact. Extrapolations to the end of 1991 using each of five functions provide a range of forecasts. Projections of total cumulated cases to the end of 1991 lie in the range 60,000-78,000, with 24,000-30,000 projected cases among homosexual/bisexual men, 23,000-33,000 among intravenous drug users, and 6000-8000 in the heterosexual transmission group. With the possible exception of the latter group, the lower parts of these ranges appear more probable.

In order to assess the potential role of intravenous drug users (IVDUs) in Amsterdam in the heterosexual transmission of HIV, we studied the sexual behaviour of 243 male and female IVDUs with regard to their private ('steady' and 'casual') and commercial partners. The majority of the study group appear heterosexually active, especially female IVDUs, who often have commercial as well as one or more private partners. Vaginal contact is the most frequent method of sexual contact; condoms are used infrequently with private partners but much more frequently with commercial partners. A history of sexually transmitted disease is common, not only among IVDU prostitutes but also among IVDUs without a history of prostitution. IVDUs who know that they are HIV-infected reported fewer commercial partners and more frequent condom use with private partners than IVDUs who are negative or do not know their test result. We conclude that IVDUs may form an important source for heterosexual transmission of HIV. Voluntary testing of IVDUs on a large scale, together with intensive counselling, may slow down the further spread of HIV from infected IVDUs to their private and commercial partners, but is unlikely to stop heterosexual transmission completely.

For the past decade HIV prevention efforts in most African countries have been predicated on the assumption that heterosexual intercourse is the predominant mode of HIV transmission among adults whereas mother-to-child transmission predominates in children. UNAIDS documents have routinely stated that 90% of adult infections are the result of heterosexual transmission and national AIDS control programs have emphasized behavioral risk reduction as the key to prevention. During the past 3 years however a small group of scientists led by David Gisselquist has questioned these assumptions publishing a series of articles--mostly in the International Journal of STD and AIDS postulating that unsafe medical injections may be responsible for the majority of HIV infections in sub-Saharan Africa. If true this would clearly have major implications for HIV control policies in Africa and beyond. (excerpt)

Evidence indicates that most HIV-infected women in northern Thailand acquired infection through heterosexual transmission not from medical injection using unsterile needles as was asserted by the author of a previously published article. Although unsafe injections may have been common in the 1970s in Thailand such practices have become unacceptable to the medical community and general public since the first HIV infection was identified in the country in 1988.