We did a systematic review and meta-analysis of observational studies of the risk of HIV-1 transmission per heterosexual contact. 43 publications comprising 25 different study populations were identified. Pooled female-to-male (0.04% per act [95% CI 0.01-0.14]) and male-to-female (0.08% per act [95% CI 0.06-0.11]) transmission estimates in high-income countries indicated a low risk of infection in the absence of antiretrovirals. Low-income country female-to-male (0.38% per act [95% CI 0.13-1.10]) and male-to-female (0.30% per act [95% CI 0.14-0.63]) estimates in the absence of commercial sex exposure (CSE) were higher. In meta-regression analysis, the infectivity across estimates in the absence of CSE was significantly associated with sex, setting, the interaction between setting and sex, and antenatal HIV prevalence. The pooled receptive anal intercourse estimate was much higher (1.7% per act [95% CI 0.3-8.9]). Estimates for the early and late phases of HIV infection were 9.2 (95% CI 4.5-18.8) and 7.3 (95% CI 4.5-11.9) times larger, respectively, than for the asymptomatic phase. After adjusting for CSE, presence or history of genital ulcers in either couple member increased per-act infectivity 5.3 (95% CI 1.4-19.5) times versus no sexually transmitted infection. Study estimates among non-circumcised men were at least twice those among circumcised men. Low-income country estimates were more heterogeneous than high-income country estimates, which indicates poorer study quality, greater heterogeneity of risk factors, or under-reporting of high-risk behaviour. Efforts are needed to better understand these differences and to quantify infectivity in low-income countries.

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Heterosexual Risk of HIV-1 Infection Per Sexual Act: Systematic Review and Meta-Analysis of Observational Studies

OBJECTIVES: This study examined whether HIV counseling and testing leads to reductions in sexual risk behavior METHODS: The meta-analysis included 27 published studies that provided sexual behavior outcome data, assessed behavior before and after counseling and testing, and provided details sufficient for the calculation of effect sizes The studies involved 19,597 participants RESULTS: After counseling and testing, HIV-positive participants and HIV-serodiscordant couples reduced unprotected intercourse and increased condom use more than HIV-negative and untested participants HIV-negative participants did not modify their behavior more than untested participants Participants' age, volition for testing, and injection drug use treatment status, as well as the sample seroprevalence and length of the follow-up, explained the variance in results CONCLUSIONS: HIV counseling and testing appears to provide an effective means of secondary prevention for HIV-positive individuals but, as conducted in the review

Effects of HIV counseling and testing on sexual risk behavior: a meta-analytic review of published research, 1985-1997

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(08)60886-7.pdf

Behavioural strategies to reduce HIV transmission: how to make them work better

This meta-analysis tested the major theoretical assumptions about behavior change by examining the outcomes and mediating mechanisms of different preventive strategies in a sample of 354 HIV-prevention interventions and 99 control groups, spanning the past 17 years. There were 2 main conclusions from this extensive review. First, the most effective interventions were those that contained attitudinal arguments, educational information, behavioral skills arguments, and behavioral skills training, whereas the least effective ones were those that attempted to induce fear of HIV. Second, the impact of the interventions and the different strategies behind them was contingent on the gender, age, ethnicity, risk group, and past condom use of the target audience in ways that illuminate the direction of future preventive efforts.

/pdf/a-test-of-major-assumptions-about-behavior-change-a-58nhe5pof8.pdf

A Test of Major Assumptions About Behavior Change: A Comprehensive Look at the Effects of Passive and Active HIV-Prevention Interventions Since the Beginning of the Epidemic

Background: The amount of protection that condoms provide for HIV and other sexually transmitted infections is unknown. Cohort studies of sexually active HIV serodiscordant couples with follow-up of the seronegative partner provide a situation in which a seronegative partner has known exposure to the disease and disease incidence can be estimated When some individuals use condoms and some do not namely some individuals use condoms 100% of the time and some never use (0%) condoms condom effectiveness can be estimated by comparing the two incidence rates. Condom effectiveness is the proportionate reduction in disease due to the use of condoms. Objectives: The objective of this review is to estimate condom effectiveness in reducing heterosexual transmission of HIV. Search strategy: Studies were located using electronic databases (AIDSLINE CINAHL Embase and MEDLINE) and handsearched reference lists. Selection criteria: For inclusion studies had to have: (1) data concerning sexually active HIV serodiscordant heterosexual couples (2) a longitudinal study design (3) HIV status determined by serology and (4) contain condom usage information on a cohort of always (100%) or never (0%) condom users. Data collection and analysis: Studies identified through the above search strategy that met the inclusion criteria were reviewed for inclusion in the analysis. Sample sizes number of seroconversions and the person-years of disease-free exposure time were recorded for each cohort. If available the direction of transmission in the cohort (male-to-female female-to-male) date of study enrollment source of infection in the index case and the presence of other STDs was recorded. Duplicate reports on the same cohort and studies with incomplete or nonspecific information were excluded. HIV incidence was estimated from the cohorts of "always" users and for the cohorts of "never" users. Effectiveness was estimated from these two incidence estimates. Main results: Of the 4709 references that were initially identified 14 were included in the final analysis. There were 13 cohorts of "always" users that yielded an homogeneous HIV incidence estimate of 1.14 [95% C.I.: .56 2.04] per 100 person-years. There were 10 cohorts of "never" users that appeared to be heterogeneous. The studies with the longest follow-up time consisting mainly of studies of partners of hemophiliac and transfusion patients yielded an HIV incidence estimate of 5.75 [95% C.I.: 3.16 9.66] per 100 person-years. Overall effectiveness the proportionate reduction in HIV seroconversion with condom use is approximately 80%. Reviewers conclusions: This review indicates that consistent use of condoms results in 80% reduction in HIV incidence. Consistent use is defined as using a condom for all acts of penetrative vaginal intercourse. Because the studies used in this review did not report on the "correctness" of use namely whether condoms were used correctly and perfectly for each and every act of intercourse effectiveness and not efficacy is estimated. Also this estimate refers in general to the male condom and not specifically to the latex condom since studies also tended not to specify the type of condom that was used. Thus condom effectiveness is similar to although lower than that for contraception. (authors)

Condom effectiveness in reducing heterosexual HIV transmission

OBJECTIVE--To determine whether HIV testing and counselling increased condom use and decreased heterosexual transmission of HIV in discordant couples. DESIGN--Prospective study. SETTING--Kigali, the capital of Rwanda. SUBJECTS--Cohabiting couples with discordant HIV serology results. MAIN OUTCOME MEASURES--Condom use in the couple and HIV seroconversion in the negative partners. RESULTS--60 HIV discordant couples were identified, of whom 53 were followed for an average of 2.2 years. The proportion of discordant couples using condoms increased from 4% to 57% after one year of follow up. During follow up two of the 23 HIV negative men and six of the 30 HIV negative women seroconverted (seroconversion rates of 4 and 9 per 100 person years). The rate among women was less than half that estimated for similar women in discordant couples whose partners had not been serotested. Condom use was less common among those who seroconverted (100% v 5%, p = 0.01 in men; 67% v 25%, p = 0.14 in women). CONCLUSIONS--Roughly one in seven cohabiting couples in Kigali have discordant HIV serological results. Confidential HIV serotesting with counselling caused a large increase in condom use and was associated with a lower rate of new HIV infections. HIV testing is a promising intervention for preventing the spread of HIV in African cities.

https://www.bmj.com/content/bmj/304/6842/1605.full.pdf

Effect of serotesting with counselling on condom use and seroconversion among HIV discordant couples in Africa.

Two cases of HIV-associated cryptococcosis due to the variety gattii in Rwanda.

https://www.bmj.com/content/bmj/302/6786/1206.1.full.pdf

Tuberculosis and HIV infection.

To evaluate the latex test, two different retrospective studies were undertaken. A positive culture for Cr. neoformans was used as the golden standard of active cryptococcal infection. 439 sera selected at random sent to the NSP laboratory for screening of HIV antibody were tested as well as--71 CSF from patients with meningeal symptoms sent to the laboratory of the Centre Hospitalier de Kigali. In total, two discrepancies were found: two CSF samples from ancient cases of cryptococcosis under treatment were positive with the latex test and negative by culture. If it stands to reason that the antigen test cannot differentiate between active and inactive cryptococcal diseases, the persistence of small amounts of soluble antigens in a CSF implies that the patient must remain under surveillance, a relapse being very frequent in AIDS patients. As a conclusion, the latex test is a fast, easy to perform and quite reliable test for the diagnosis of cryptococcosis.

P. Van de Perre

Papers

Effect of serotesting with counselling on condom use and seroconversion among HIV discordant couples in Africa.

Two cases of HIV-associated cryptococcosis due to the variety gattii in Rwanda.

Tuberculosis and HIV infection.

Evaluation of the cryptococcal antigen test as a diagnostic tool of AIDS-associated cryptococcosis in Rwanda.