Risk compensation: the Achilles' heel of innovations in HIV prevention?

Risk compensation after COVID-19 vaccination: Evidence from vaccine rollout by exact birth date in South Korea

We utilize the phased rollout of COVID-19 vaccines by exact birth date in South Korea as a natural experiment for testing risk compensation. People may resume face-to-face social activities following vaccination because they perceive lower risk of infection. Applying a regression discontinuity design based on birth date cutoffs for vaccine eligibility, we find no evidence of risk-compensating behaviors, as measured by large, high-frequency data from credit card and airline companies as well as survey data. We find some evidence of self-selection into vaccine take-up based on perception toward vaccine effectiveness and side effects, but the treatment effects do not differ between compliers and never-takers.

Risk Compensation After Initiation of Daily Oral Pre-exposure Prophylaxis Among Sexual and Gender Minorities in Nigeria

Pre-exposure prophylaxis (PrEP) use may be associated with risk compensation. We enrolled and provided PreP to sexual and gender minorities (SGM) in Abuja, Nigeria between April 2018 and May 2019. Behavioral information and samples for urogenital and anorectal Chlamydia trachomatis and Neisseria gonorrhoeae sexually transmitted infections (STIs) were collected at baseline. Blood samples for PrEP assay and self-reported adherence were collected at three-monthly follow-up visits. STIs were detected using Aptima Combo2 assay. We estimated the odds ratios (ORs) of PCR-diagnosed bacterial STIs and self-reported behavioral outcomes (condomless anal intercourse [CAI] and concurrent sexual relationships) with conditional logistic regression. Of 400 SGM who initiated PrEP, 206 were eligible for analysis, and had a median age of 24 years (IQR 22-27). In multivariable analysis, participants in the PrEP period had decreased odds of CAI (adjusted OR: 0.49, 95% CI 0.28, 0.84). PrEP use was not associated with risk compensation.

Understanding the impact of women's correct risk perception on human immunodeficiency virus diagnosis: Insights from South Africa

BACKGROUND

South African women have the highest burden of HIV infections globally. We investigated the temporal trends and the impact of key factors associated with HIV diagnosis among a nationally representative cohort of South African women.

METHODS

Total of 24,657 women who participated in the National HIV, Behaviour and Health Surveys conducted from 2002-to-2017.

RESULTS

Despite decades-long prevention efforts, we observed a significant increase in HIV prevalence over time (22% in 2002 to 21% in 2005-2008 and 29% in 2012-2017). Overall, 46% of the women living with HIV were not aware of their risk of HIV with age-specific disparities. Our findings revealed compelling evidence between HIV seropositivity and high HIV risk-perception (adjusted Odds Ratio (aOR):1.47 to 3.29) which increased overtime and exceeded the other factors. At a population-level, 45% of the HIV diagnoses were exclusively associated with women who believed they were at risk of HIV in 2012-2017. Women who reported using condoms at last sexual act were also at increased risk of HIV infection, with a population attributable risk of 18% (2002) to 21% (2012-2017).

CONCLUSION

There is an urgent need for culturally, socially, and linguistically appropriate prevention and awareness campaigns with realistic, non-confrontational messages.

COVID-19 vaccination, risk-compensatory behaviours, and contacts in the UK

The physiological effects of vaccination against SARS-CoV-2 (COVID-19) are well documented, yet the behavioural effects not well known. Risk compensation suggests that gains in personal safety, as a result of vaccination, are offset by increases in risky behaviour, such as socialising, commuting and working outside the home. This is potentially important because transmission of SARS-CoV-2 is driven by contacts, which could be amplified by vaccine-related risk compensation. Here, we show that behaviours were overall unrelated to personal vaccination, but-adjusting for variation in mitigation policies-were responsive to the level of vaccination in the wider population: individuals in the UK were risk compensating when rates of vaccination were rising. This effect was observed across four nations of the UK, each of which varied policies autonomously.

Physical interventions to interrupt or reduce the spread of respiratory viruses

BACKGROUND

Viral epidemics or pandemics of acute respiratory infections (ARIs) pose a global threat. Examples are influenza (H1N1) caused by the H1N1pdm09 virus in 2009, severe acute respiratory syndrome (SARS) in 2003, and coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 in 2019. Antiviral drugs and vaccines may be insufficient to prevent their spread. This is an update of a Cochrane Review last published in 2020. We include results from studies from the current COVID-19 pandemic.

OBJECTIVES

To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, CINAHL, and two trials registers in October 2022, with backwards and forwards citation analysis on the new studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs investigating physical interventions (screening at entry ports, isolation, quarantine, physical distancing, personal protection, hand hygiene, face masks, glasses, and gargling) to prevent respiratory virus transmission.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures.

MAIN RESULTS

We included 11 new RCTs and cluster-RCTs (610,872 participants) in this update, bringing the total number of RCTs to 78. Six of the new trials were conducted during the COVID-19 pandemic; two from Mexico, and one each from Denmark, Bangladesh, England, and Norway. We identified four ongoing studies, of which one is completed, but unreported, evaluating masks concurrent with the COVID-19 pandemic. Many studies were conducted during non-epidemic influenza periods. Several were conducted during the 2009 H1N1 influenza pandemic, and others in epidemic influenza seasons up to 2016. Therefore, many studies were conducted in the context of lower respiratory viral circulation and transmission compared to COVID-19. The included studies were conducted in heterogeneous settings, ranging from suburban schools to hospital wards in high-income countries; crowded inner city settings in low-income countries; and an immigrant neighbourhood in a high-income country. Adherence with interventions was low in many studies. The risk of bias for the RCTs and cluster-RCTs was mostly high or unclear. Medical/surgical masks compared to no masks We included 12 trials (10 cluster-RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and 10 in the community). Wearing masks in the community probably makes little or no difference to the outcome of influenza-like illness (ILI)/COVID-19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants; moderate-certainty evidence. Wearing masks in the community probably makes little or no difference to the outcome of laboratory-confirmed influenza/SARS-CoV-2 compared to not wearing masks (RR 1.01, 95% CI 0.72 to 1.42; 6 trials, 13,919 participants; moderate-certainty evidence). Harms were rarely measured and poorly reported (very low-certainty evidence). N95/P2 respirators compared to medical/surgical masks We pooled trials comparing N95/P2 respirators with medical/surgical masks (four in healthcare settings and one in a household setting). We are very uncertain on the effects of N95/P2 respirators compared with medical/surgical masks on the outcome of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; 3 trials, 7779 participants; very low-certainty evidence). N95/P2 respirators compared with medical/surgical masks may be effective for ILI (RR 0.82, 95% CI 0.66 to 1.03; 5 trials, 8407 participants; low-certainty evidence). Evidence is limited by imprecision and heterogeneity for these subjective outcomes. The use of a N95/P2 respirators compared to medical/surgical masks probably makes little or no difference for the objective and more precise outcome of laboratory-confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; 5 trials, 8407 participants; moderate-certainty evidence). Restricting pooling to healthcare workers made no difference to the overall findings. Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies (very low-certainty evidence).  One previously reported ongoing RCT has now been published and observed that medical/surgical masks were non-inferior to N95 respirators in a large study of 1009 healthcare workers in four countries providing direct care to COVID-19 patients.  Hand hygiene compared to control Nineteen trials compared hand hygiene interventions with controls with sufficient data to include in meta-analyses. Settings included schools, childcare centres and homes. Comparing hand hygiene interventions with controls (i.e. no intervention), there was a 14% relative reduction in the number of people with ARIs in the hand hygiene group (RR 0.86, 95% CI 0.81 to 0.90; 9 trials, 52,105 participants; moderate-certainty evidence), suggesting a probable benefit. In absolute terms this benefit would result in a reduction from 380 events per 1000 people to 327 per 1000 people (95% CI 308 to 342). When considering the more strictly defined outcomes of ILI and laboratory-confirmed influenza, the estimates of effect for ILI (RR 0.94, 95% CI 0.81 to 1.09; 11 trials, 34,503 participants; low-certainty evidence), and laboratory-confirmed influenza (RR 0.91, 95% CI 0.63 to 1.30; 8 trials, 8332 participants; low-certainty evidence), suggest the intervention made little or no difference. We pooled 19 trials (71, 210 participants) for the composite outcome of ARI or ILI or influenza, with each study only contributing once and the most comprehensive outcome reported. Pooled data showed that hand hygiene may be beneficial with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.83 to 0.94; low-certainty evidence), but with high heterogeneity. In absolute terms this benefit would result in a reduction from 200 events per 1000 people to 178 per 1000 people (95% CI 166 to 188). Few trials measured and reported harms (very low-certainty evidence). We found no RCTs on gowns and gloves, face shields, or screening at entry ports.

AUTHORS' CONCLUSIONS

The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions. There were additional RCTs during the pandemic related to physical interventions but a relative paucity given the importance of the question of masking and its relative effectiveness and the concomitant measures of mask adherence which would be highly relevant to the measurement of effectiveness, especially in the elderly and in young children. There is uncertainty about the effects of face masks. The low to moderate certainty of evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect. The pooled results of RCTs did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection. Hand hygiene is likely to modestly reduce the burden of respiratory illness, and although this effect was also present when ILI and laboratory-confirmed influenza were analysed separately, it was not found to be a significant difference for the latter two outcomes. Harms associated with physical interventions were under-investigated. There is a need for large, well-designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk of ARIs.

The risk of acute and early HIV (AEH) infection among MSM with different behaviour trajectories: an open cohort study in Tianjin, China, 2011-2019

BACKGROUND

Acute and early HIV (AEH) infection is characterized by a high viral load and infectivity. Approximately 50% of cases of HIV-1 transmission occur during AEH. Understanding sexual behaviour trajectories would be useful for predicting changes in the risk of HIV acquisition. However, few studies have investigated sexual behaviour trajectories and their association with AEH acquisition. This study identified behaviour trajectories among men who have sex with men (MSM), determined the risk of AEH infection, and compared risk factors between different behaviour trajectories.

METHODS

The study was based on an ongoing prospective open cohort of voluntary HIV counselling and testing (VHCT) among MSM in Tianjin, China. From 2011 to 2019, 1974 MSM were recruited. Group-based trajectory modelling (GBTM) was used to identify behaviour trajectories by constructing a sexual risk behaviour score. Logistic regression and generalized estimating equation (GEE) were used to compare the risk of AEH infection and risk factors for different behaviour trajectories. All data analyses were performed using SAS 9.4.

RESULTS

The incidence of AEH infection was 1.76/100 person-years, with 64 AEH infections documented in 3633 person-years of follow-up. Three sexual behaviour trajectories were identified: CL (consistently low risk, 35.46%), CH (consistently high risk, 42.71%) and HTL (high to low risk, 21.83%). MSM in the HTL and CH groups had higher AEH infection rates than MSM in the CL group (6.73%, 3.08% and 1.28%, respectively), with ORs of 5.54 (2.60, 11.82) and 2.44 (1.14, 5.25), respectively. MSM aged 30-50 years old and MSM who underwent HIV testing in the last year were more likely to be in the CH group and HTL group. In addition, the HTL group was characterized by a lower likelihood of local registration and a higher likelihood of working as a MSW.

CONCLUSION

MSM in the CH group and the HTL group had a higher risk of AEH infection. In the future, VHCT should be performed more often among younger MSM, and HIV counselling should be given the same priority as HIV testing. In addition, VHCT combined with PrEP may have a better preventive impact on MSM with a high risk of AEH infection.

Risk Compensation in Voluntary Medical Male Circumcision Programs

PURPOSE OF REVIEW

Evidence from clinical trials identified the effectiveness of voluntary medical male circumcision (VMMC) as an additional strategy to reduce the risk of HIV transmission from women to men. However, concerns about post-circumcision sexual risk compensation may hinder the scale-up of VMMC programs. We reviewed the evidence of changes in risky sexual behaviors after circumcision, including condomless sex, multiple sex partners, and early resumption of sex after surgery.

RECENT FINDINGS

Most clinical trial data indicate that condomless sex and multiple partners did not increase for men after circumcision, and early resumption of sex is rare. Only one post-trial surveillance reports that some circumcised men had more sex partners after surgery, but this did not offset the effect of VMMC. Conversely, qualitative studies report that a small number of circumcised men had increased risky sexual behaviors, and community-based research reports that more men resumed sex early after surgery. With the large-scale promotion and expansion of VMMC services, it may be challenging to maintain effective sexual health educations due to various restrictions. Misunderstandings of the effect of VMMC in preventing HIV infection are the main reason for increasing risky sexual behaviors after surgery. Systematic and practical sexual health counseling services should be in place on an ongoing basis to maximize the effect of VMMC.

Impact of universal testing and treatment on sexual risk behaviour and herpes simplex virus type 2: a prespecified secondary outcomes analysis of the HPTN 071 (PopART) community-randomised trial

BACKGROUND

Comprehensive HIV prevention strategies have raised concerns that knowledge of interventions to reduce risk of HIV infection might mitigate an individual's perception of risk, resulting in riskier sexual behaviour. We investigated the prespecified secondary outcomes of the HPTN 071 (PopART) trial to determine whether a combination HIV prevention strategy, including universal HIV testing and treatment, changed sexual behaviour; specifically, we investigated whether there was evidence of sexual risk compensation.

METHODS

HPTN 071 (PopART) was a cluster-randomised trial conducted during 2013-18, in which we randomly assigned 21 communities with high HIV prevalence in Zambia and South Africa (total population, approximately 1 million) to combination prevention intervention with universal antiretroviral therapy (ART; arm A), prevention intervention with ART provided according to local guidelines (universal since 2016; arm B), or standard of care (arm C). The trial included a population cohort of approximately 2000 randomly selected adults (aged 18-44 years) in each community (N=38 474 at baseline) who were followed up for 36 months. A prespecified secondary objective was to evaluate the impact of the PopART intervention compared with standard of care on herpes simplex virus type 2 (HSV-2) and sexual behaviour (N=20 422 completed final visit). Secondary endpoints included differences in sexual risk behaviour measures at 36 months and were assessed using a two-stage method for matched cluster-randomised trials. This trial is registered with ClinicalTrials. gov, number NCT01900977.

FINDINGS

The PopART intervention did not substantially change probability of self-reported multiple sex partners, sexual debut, or pregnancy in women at 36 months. Adjusted for baseline community prevalence, reported condomless sex was significantly lower in arm A versus arm C (adjusted prevalence ratio 0·80 [95% CI 0·64-0·99]; p=0·04) but not in arm B versus arm C (0·94 [0·76-1·17]; p=0·55). 3-year HSV-2 incidence was reduced in arm B versus arm C (adjusted risk ratio 0·76 [95% CI 0·63-0·92]; p=0·010); no significant change was shown between arm A versus arm C (0·89 [0·73-1·08]; p=0·199).

INTERPRETATION

We found little evidence of any change in sexual behaviour owing to the PopART interventions, and reassuringly for public health, we saw no evidence of sexual risk compensation. The findings do not help to explain the differences between the two intervention groups of the HPTN 071 (PopART) trial.

FUNDING

National Institute of Allergy and Infectious Diseases, the National Institutes of Health, the International Initiative for Impact Evaluation (3ie), the Bill & Melinda Gates Foundation, the US President's Emergency Plan for AIDS Relief, and the Medical Research Council UK.

Sexual Behavior Transition and Acute and Early HIV Infection Among Men Who Have Sex With Men: Evidence from an Open Cohort in China, 2011-2019

The present study examined how sexual behaviors transit over time among men who have sex with men (MSM) and whether these transitions were associated with acute and early HIV (AEH) infection. An open cohort study was conducted using snowball sampling to recruit MSM via physical venues and Internet venues from 2011 to 2019, in China. Cox models were used to estimate the correlates of risk factors and AEH infection. We used Latent Transition Analysis (LTA) to describe behavioral profile and explore latent behavioral "trans-phenotypes," then examined the effect between different "trans-phenotypes" and AEH infection risk and explored the effect of characteristics as possible predictors of sexual behavior transition. Of 6502 MSM, a total of 1974 individuals with negative human immunodeficiency virus (HIV) tests at baseline and at least 2 visit records were included in the final analysis from 2011 to 2019. During an average 1.84 years of follow-up, 64 AEH infections were documented. In the multivariable Cox model, the association between condom use in last anal sex (HR: 0.095, 0.038-0.205), fewer sexual partners (HR: 0.375, 0.205-0.712), low frequency of condom use (HR: 3.592, 1.186-11.272), and AEH acquisition were found. The percentage of MSM with "maintain/develop safety-profile," "consistent risky-profile," and "safety-profile to risky-profile" were 52.48, 40.17, and 7.35%, respectively. Compared with "maintain\develop safety-profile," "consistent or develop risky-profile" had an increasing likelihood of AEH infection. Meanwhile, male sex workers (MSWs) or older MSM were more likely to consist or transit in "risky-profile." Having middle education is a risk factor to transit in "risky-profile" for MSM with "safety-profile" at baseline. In addition, MSM who accept health services in the past year engaged in higher proportion of developing safety-profile. Approximately half of MSM maintain or develop risky behavior with the increasing likelihood of AEH acquisition in China, which suggested that targeted and intensive interventions should be prioritized to maintain safety-profile. Clinical Trial Number: ChiCTR2000039500.

HIV Pre-Exposure Prophylaxis (PrEP) in a Brazilian Clinical Setting: Adherence, Adverse Events, Sexual Behavior, and Sexually Transmitted Infections

Tenofovir/emtricitabine (TDF/FTC) has been used as pre-exposure prophylaxis (PrEP) in preventing HIV infection. PrEP is an effective prevention tool as demonstrated in clinical trials and studies in clinical practice and was incorporated into the Brazilian public health system in December 2017. The present study was a prospective cohort that included 219 PrEP users monitored over a 10 month follow-up period in a capital city in Northeastern Brazil. Data were collected from the PrEP users' electronic medical records platform made available by the Brazilian Health Ministry. During the observation period, there was good user retention to the prevention program (84%) and there was high adherence to medication (90%). Almost half the users (49%) presented an adverse event, although these were mild and transient, 30 days after starting prophylaxis. There was a significant reduction in creatinine clearance (p < .001), from 104.9 to 83.5 mL/min; however, there was no need for drug discontinuation. Throughout the cohort, there was no significant change in the number of sexual partners, but the use of condoms during sexual intercourse decreased (p < .001). There was a non-significant increase in the incidence of syphilis (p = .08), and there was a 50% decrease in reporting signs and symptoms of sexually transmitted infections. No cases of HIV infection were observed. PrEP proved to be an effective tool in HIV prevention, presenting few complications of adverse events.

Is There Risk Compensation among HIV Infected Youth and Adults 15 Years and Older on Antiretroviral Treatment in South Africa? Findings from the 2017 National HIV Prevalence, Incidence, Behaviour and Communication Survey

In this paper, risk compensation among individuals on antiretroviral therapy (ART), using the 2017 South African national survey on HIV, is explored. A multi-stage stratified cluster random sampling approach was used to realize 11,130 participants 15 years and older. Logistic regression analysis assessed the association between multiple sexual partners, condom use at last sexual encounter, consistency of condom usage and potential explanatory variables using HIV status and ART exposure as a mediator variable. HIV positive participants who were aware and on ART were less likely to have multiple sexual partners, and less likely not to use a condom at last sex compared to HIV positive participants who were aware but not on ART. The odds of reporting multiple sexual partners were significantly lower among older age groups, females, non-Black Africans, and rural settings, and higher among those with tertiary level education, and risky alcohol users. The odds of no condom use at last sexual encounter were more likely among older age groups, females, other race groups, and less likely among those with secondary level education. The odds of inconsistent condom use were more likely among older age groups, females, and other race groups, and less likely among those with tertiary level education, high risk and hazardous alcohol users. Risk compensation is not apparent among HIV infected adults who are on ART. Risk groups that should receive tailored interventions to reduced risky sexual behaviours were identified.

Increased condom use among key populations using oral PrEP in Kenya: results from large scale programmatic surveillance

Background

Female sex workers (FSW) and men having sex with men (MSM) in Kenya have high rates of HIV infection. Following a 2015 WHO recommendation, Kenya initiated national scale-up of pre-exposure prophylaxis (PrEP) for all persons at high-risk. Concerns have been raised about PrEP users' potential changes in sexual behaviors such adopting condomless sex and multiple partners as a result of perceived reduction in HIV risk, a phenomenon known as risk compensation. Increased condomless sex may lead to unintended pregnancies and sexually transmitted infections and has been described in research contexts but not in the programmatic setting. This study looks at changes in condom use among FSW and MSM on PrEP through a national a scale-up program.

Methods

Routine program data collected between February 2017 and December 2019 were used to assess changes in condom use during the first three months of PrEP in 80 health facilities supported by a scale-up project, Jilinde. The primary outcome was self-reported condom use. Analyses were conducted separately for FSW and for MSM. Log-Binomial Regression with Generalized Estimating Equations was used to compare the incidence proportion (“risk”) of consistent condom use at the month 1, and month 3 visits relative to the initiation visit.

Results

At initiation, 69% of FSW and 65% of MSM reported consistent condom use. At month 3, this rose to 87% for FSW and 91% for MSM. MSM were 24% more likely to report consistent condom use at month 1 (Relative Risk [RR], 1.24, 95% Confidence Interval [CI], 1.18–1.30) and 40% more likely at month 3 (RR, 1.40, 95% CI, 1.33–1.47) compared to at initiation. FSW were 15% more likely to report consistent condom use at the month one visit (RR, 1.15, 95% CI, 1.13–1.17) and 27% more likely to report condom use on the month 3 visit (RR 1.27, 95% CI, 1.24–1.29).

Conclusion

Condom use increased substantially among both FSW and MSM. This may be because oral PrEP was provided as part of a combination prevention strategy that included counseling and condoms but could also be due to the low retention rates among those who initiated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12639-6.

Waning of BNT162b2 Vaccine Protection against SARS-CoV-2 Infection in Qatar

BACKGROUND

Waning of vaccine protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (Covid-19) is a concern. The persistence of BNT162b2 (Pfizer-BioNTech) vaccine effectiveness against infection and disease in Qatar, where the B.1.351 (or beta) and B.1.617.2 (or delta) variants have dominated incidence and polymerase-chain-reaction testing is done on a mass scale, is unclear.

METHODS

We used a matched test-negative, case-control study design to estimate vaccine effectiveness against any SARS-CoV-2 infection and against any severe, critical, or fatal case of Covid-19, from January 1 to September 5, 2021.

RESULTS

Estimated BNT162b2 effectiveness against any SARS-CoV-2 infection was negligible in the first 2 weeks after the first dose. It increased to 36.8% (95% confidence interval [CI], 33.2 to 40.2) in the third week after the first dose and reached its peak at 77.5% (95% CI, 76.4 to 78.6) in the first month after the second dose. Effectiveness declined gradually thereafter, with the decline accelerating after the fourth month to reach approximately 20% in months 5 through 7 after the second dose. Effectiveness against symptomatic infection was higher than effectiveness against asymptomatic infection but waned similarly. Variant-specific effectiveness waned in the same pattern. Effectiveness against any severe, critical, or fatal case of Covid-19 increased rapidly to 66.1% (95% CI, 56.8 to 73.5) by the third week after the first dose and reached 96% or higher in the first 2 months after the second dose; effectiveness persisted at approximately this level for 6 months.

CONCLUSIONS

BNT162b2-induced protection against SARS-CoV-2 infection appeared to wane rapidly following its peak after the second dose, but protection against hospitalization and death persisted at a robust level for 6 months after the second dose. (Funded by Weill Cornell Medicine-Qatar and others.).

BNT162b2 and mRNA-1273 COVID-19 vaccine effectiveness against the SARS-CoV-2 Delta variant in Qatar

With the global expansion of the highly transmissible SARS-CoV-2 Delta (B.1.617.2) variant, we conducted a matched test-negative case-control study to assess the real-world effectiveness of COVID-19 messenger RNA vaccines against infection with Delta in Qatar's population. BNT162b2 effectiveness against any, symptomatic or asymptomatic, Delta infection was 45.3% (95% CI, 22.0-61.6%) ≥14 d after the first vaccine dose, but only 51.9% (95% CI, 47.0-56.4%) ≥14 d after the second dose, with 50% of fully vaccinated individuals receiving their second dose before 11 May 2021. Corresponding mRNA-1273 effectiveness ≥14 d after the first or second dose was 73.7% (95% CI, 58.1-83.5%) and 73.1% (95% CI, 67.5-77.8%), respectively. Notably, effectiveness against Delta-induced severe, critical or fatal disease was 93.4% (95% CI, 85.4-97.0%) for BNT162b2 and 96.1% (95% CI, 71.6-99.5%) for mRNA-1273 ≥ 14 d after the second dose. Our findings show robust effectiveness for both BNT162b2 and mRNA-1273 in preventing Delta hospitalization and death in Qatar's population, despite lower effectiveness in preventing infection, particularly for the BNT162b2 vaccine.

Social and behavioural research prospects for sexually transmissible infection prevention in the era of advances in biomedical approaches

In the past two decades, major advances in biomedical intervention approaches to prevent HIV and many sexually transmissible infections (STIs) have shown great promise. However, challenges to prevention remain in the area of achieving population-level impact for biomedical prevention approaches. In this paper we address what social and behavioural research approaches can contribute beyond well-known behaviour change and counselling interventions. We organise work into five areas. Adherence and disinhibition research is primarily into individual-level constructs pertaining to maximising intervention effectiveness. Coverage research represents a population-level construct germane to maximising efficient prioritisation for prevention. Research covering social determinants, a second population-level construct, contributes to both prioritisation and effectiveness. Finally, disparities and social inequities need to be incorporated into prevention, given the pervasive and persistent disparities found in rates of HIV and STIs and in their antecedents.

Face Mask Use Conditionally Decreases Compliance With Physical Distancing Rules Against COVID-19: Gender Differences in Risk Compensation Pattern

BACKGROUND

In the context of the COVID-19 emergency, the concern has been raised that people may compensate the reduction in risk ensured by mask use with an increase in risk induced by lower adherence to physical distancing rules.

PURPOSE

The paper investigates if people compensate risk in this manner when their interaction partner wears a face mask, examining if risk compensation further depends on gender, signaled social status and perceived race.

METHODS

An experiment was conducted in two waves (June, n = 1396 and September 2020, n = 1326) in front of the traffic lights of four busy roads in Paris. A confederate asked a randomly selected pedestrian for directions following a script and keeping the recommended distance. Confederates were locally recognizable as Blacks or Whites and alternatively presented themselves with a costume indicative of high or low social status. An observer recorded whether the pedestrian kept the recommended distance.

RESULTS

Both in June and September, men are less likely to comply with the distancing rule when the confederate wears the face mask, and particularly so when the confederate signals high status. When the confederate wears the mask, female pedestrians observe less the one-meter rule in September than in June.

CONCLUSIONS

Men's risk compensatory behavior is constant over time. In contrast, women's depends on the time period.

"Shades of risk": Understanding current PrEP users' sexually transmitted infection perceptions

ABSTRACTPre-exposure prophylaxis (PrEP) is a safe and effective HIV prevention strategy. Given the possibility of increased sexual risk-taking and acquisition of other sexually transmitted infections (STIs) following PrEP initiation, it is important to explore STI risk perceptions both before and after PrEP initiation to understand the extent to which these perceptions inform decisions to engage in condomless sex. Semi-structured qualitative interviews were conducted with men who have sex with men currently using PrEP (n = 30). Prior to analysis, PrEP users were categorized into four subgroups based on condom use behavior post-PrEP initiation: (1) condom continuers (2) condomless sex continuers, (3) condomless sex increasers, and (4) condomless sex decreasers. Thematic analysis revealed two major themes that elucidated differences in (1) the appraisal of HIV risk relative to other STIs and (2) the importance of partner communication in determining STI risk perceptions by subgroup. Most PrEP users demonstrated no behavioral change after PrEP initiation. Those engaging in condomless sex prior to PrEP initiation also continued that behavior while taking PrEP. Results of this study support a tailored approach to PrEP counseling based on individual STI risk appraisal and motivations to initiate and continue PrEP.

Psychological Distress as a Primer for Sexual Risk Taking Among Emerging Adults

Emerging adults experience increased morbidity as a result of psychological distress and risky sexual behavior. This study examines how sexual behaviors (e.g., condom use inconsistency and past year STI history) differ among emerging adults with low, moderate, and high psychological distress. Participants are 251,254 emerging adults attending colleges and universities in the United States who participated in the National College Health Assessment (NCHA). Findings suggest a dose-response relationship between psychological distress, condom use inconsistency, and past STI history, such that an association between greater psychological distress and condom use inconsistency and/or past year history of sexually transmitted infections (STIs).

PrEP Use and PrEP Use Disclosure are Associated with Condom Use During Sex: A Multilevel Analysis of Latino MSM Egocentric Sexual Networks

Pre-exposure prophylaxis (PrEP) is integral to HIV prevention; however, the influence of PrEP use and PrEP use disclosure on condom use is unclear among Latinx men who have sex with men (LMSM). This study explored associations of LMSM PrEP use and use disclosure on consistent dyadic condom use in the past 6 months. Participants were 130 HIV-negative PrEP and non-PrEP using LMSM ages 20-39 years. Two-level logistic regression models assessing individual- and dyadic-level predictors on condom use were fitted using R. Participants reported a mean of four sexual partners (n = 507 dyads). Participants who reported using PrEP or having more sexual partners were more likely to use condoms; however, participants who reported disclosing PrEP use were less likely to use condoms. Future longitudinal studies should characterize approaches to increase informed personal health choices and conversations about PrEP, condom use, and other HIV risk-reduction strategies using network methodologies.

Association between medical male circumcision and HIV risk compensation among heterosexual men: a systematic review and meta-analysis

Background

Medical male circumcision (MMC) reduces HIV infection among heterosexual men. There are concerns MMC might prompt higher-risk sexual behaviours because of lower self-perceived risk of HIV infection. We reviewed the published literature to examine associations between MMC and both condom use and number of sex partners among heterosexual men.

Methods

In this systematic review and meta-analysis, we searched PubMed, Embase, and the Cochrane Library for studies published before Nov 15, 2020. Interventional and observational studies were included if they contained original quantitative data describing the association between MMC and condom use or number of sex partners among heterosexual men. We excluded data from men whose circumcisions were ritual or religious and data from men who have sex with men. We extracted odds ratios (ORs) and 95% CIs for the associations between MMC and condomless sex and MMC and multiple sex partners directly from the publications if available, selecting adjusted ORs when provided; when necessary, we calculated ORs and 95% CIs using original study data provided in the publication. We used the Mantel-Haenszel random effects model to calculate pooled ORs and 95% CIs.

Findings

Our search yielded 3035 results, of which 471 were duplicates and 2537 did not meet the inclusion criteria. From the remaining 27 eligible studies, we identified 99 292 men from 31 independent population samples. 24 studies were done in Africa. We found no statistically significant associations between MMC and condomless sex (OR 0·91, 95% CI 0·80–1·05; k=30; I²=88·7%) or multiple sex partners (1·02, 0·88–1·18; k=27; I²=90·1%). No associations between MMC and condomless sex or multiple sexual partners were found in any subgroup analyses by study design, income of country, age, recruitment setting, circumcision assessment, circumcision prevalence, and risk of publication bias.

Interpretation

The promotion of circumcision as an HIV preventive measure does not appear to increase higher-risk sexual behaviours in heterosexual men. Ongoing sexual health education should be maintained as a vital component of effective MMC programmes.

Associations Between Early Circumcision, Sexual and Protective Practices, and HIV Among a National Sample of Male Adults in Eswatini

To reduce HIV incidence in countries such as Eswatini (Swaziland), UNAIDS has recommended male circumcision as one possible effective strategy. We analyzed the 2016s Swaziland HIV Incidence Measurement Survey to explore the association between early circumcision and HIV history among 2964 sexually active adult males aged 15 to 64 years old. Early circumcision was defined as circumcision practiced at an age of 15 years old or younger. Results from logistic regression and OLS regression found that male adults with early circumcision are more likely to have multiple sexual partners and to use condoms. Multiple partners and condom use at last sex encounter remained associated with a higher odds of being HIV positive after controlling for all factors. Nevertheless, early circumcision is significantly associated with a lower odds of being HIV positive (AOR 0.53, p < 0.01). These findings suggest that HIV prevention may benefit when early male circumcision is carried out.

Modelling the effect of market forces on the impact of introducing human immunodeficiency virus pre-exposure prophylaxis among female sex workers

Pre-exposure prophylaxis (PrEP) to prevent human immunodeficiency virus (HIV) enables female sex workers (FSWs) to protect themselves from HIV without relying on clients using condoms. Yet, because PrEP reduces HIV risk, financial incentives to not use condoms may lead to risk compensation: reductions in condom use and/or increases in commercial sex, and may reduce the price of unprotected sex. In this analysis, we integrate market forces into a dynamic HIV transmission model to assess how risk compensation could change the impact of PrEP among FSWs and clients. We parameterise how sexual behavior may change with PrEP use among FSWs using stated preference data combined with economic theory. Our projections suggest the impact of PrEP is sensitive to risk compensatory behaviors driven by changes in the economics of sex work. Condom substitution could reduce the impact of PrEP on HIV incidence by 55%, while increases in the frequency of commercial sex to counter decreases in the price charged for unprotected sex among PrEP users could entirely mitigate the impact of PrEP. Accounting for competition between PrEP users and nonusers exacerbates this further. Alternative scenarios where increases in unprotected sex among PrEP users are balanced by decreases in non-PrEP users have the opposite effect, resulting in PrEP having much greater impact. Intervention studies need to determine how HIV prevention products may change the economics of sex work and provision of unprotected sex to enable a better understanding of their impact.

Assessment of risk compensation following use of the dapivirine vaginal ring in southwestern Uganda

Objectives

Participation in HIV prevention trials could trigger risk compensation among participants. We evaluated potential risk compensation following use of a vaginal ring microbicide by women in a phase III trial in southwestern Uganda.

Methods

We used markers of sexual risk behaviour documented on standardised questionnaires, tested for STIs at baseline and quarterly for 2 years. Risk compensation was defined as a significant increase (trend p<0.05) in the proportion of women reporting risky sexual behaviour or a diagnosed STI between baseline and end of follow-up.

Results

Between September 2013 and December 2016, 197 women (active arm: n=132 and placebo: n=65) were enrolled at the Masaka site. There were decreases in all markers of sexual risk behaviour with statistically significant decreases in only the proportion of women reporting ≥2 sexual partners, p=0.026 and those diagnosed with Trichomonas vaginalis p<0.001 and or Neisseria gonorrhoeae p<0.001

Conclusions

No evidence of risk compensation was observed in this trial.

Trial registration number

NCT01539226.

Risk compensation and face mask mandates during the COVID-19 pandemic

Face masks are an important component in controlling COVID-19, and policy orders to wear masks are common. However, behavioral responses are seldom additive, and exchanging one protective behavior for another could undermine the COVID-19 policy response. We use SafeGraph smart device location data and variation in the date that US states and counties issued face mask mandates as a set of natural experiments to investigate risk compensation behavior. We compare time at home and the number of visits to public locations before and after face mask orders conditional on multiple statistical controls. We find that face mask orders lead to risk compensation behavior. Americans subject to the mask orders spend 11-24 fewer minutes at home on average and increase visits to some commercial locations-most notably restaurants, which are a high-risk location. It is unclear if this would lead to a net increase or decrease in transmission. However, it is clear that mask orders would be an important part of an economic recovery if people otherwise overestimate the risk of visiting public places.

An evidence review of face masks against COVID-19

The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people ("source control") with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

An evidence review of face masks against COVID-19

The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people ("source control") with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

An evidence review of face masks against COVID-19

The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people ("source control") with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

Roles of genetics and blood type in clinical responses to COVID-19: ethical and policy concerns

Recently, several genetic variants have been associated with increased or decreased risks of becoming infected and/or seriously ill with COVID-19-not only offering important potential medical benefits but also posing critical ethical questions. These genetic factors, some of which are associated with blood type, may account for variations in observed responses to COVID-19. Hence, assessments of these genetic differences and blood type could provide possible benefits in gauging patients' risks of disease acquisition and prioritising allocation of interventions or vaccines, if supplies are limited. The media has widely reported these findings, and people online are now discussing their blood type and its possible effects on their COVID-19 risks, but several ethical concerns arise. Individuals possessing genetic variants or blood types associated with lower risk may engage in 'risk compensation', erroneously assuming that they can protect themselves less, and hence less frequently wearing masks or washing hands. Given the ongoing COVID-19 pandemic, many physicians, hospitals, patients, policymakers, members of the public, testing companies and others may well consider these factors in making critical prevention/treatment decisions. Researchers, providers and others should thus begin to address these concerns. Increased awareness and education aimed at providers, patients, family members, public health officials, political leaders and the public-at-large are critical. Attitudinal research is vital to examine how providers, patients and the public understand these findings. Ethical frameworks and guidelines are needed, addressing whether such genetic information should be incorporated into decisions regarding allocation of scarce resources-including hospital and ICU beds, ventilators, medications (eg, remdesivir) and vaccines-and if so, how.

Physical interventions to interrupt or reduce the spread of respiratory viruses

BACKGROUND

Viral epidemics or pandemics of acute respiratory infections (ARIs) pose a global threat. Examples are influenza (H1N1) caused by the H1N1pdm09 virus in 2009, severe acute respiratory syndrome (SARS) in 2003, and coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 in 2019. Antiviral drugs and vaccines may be insufficient to prevent their spread. This is an update of a Cochrane Review published in 2007, 2009, 2010, and 2011. The evidence summarised in this review does not include results from studies from the current COVID-19 pandemic.

OBJECTIVES

To assess the effectiveness of physical interventions to interrupt or reduce the spread of acute respiratory viruses.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, CINAHL on 1 April 2020. We searched ClinicalTrials.gov, and the WHO ICTRP on 16 March 2020. We conducted a backwards and forwards citation analysis on the newly included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs of trials investigating physical interventions (screening at entry ports, isolation, quarantine, physical distancing, personal protection, hand hygiene, face masks, and gargling) to prevent respiratory virus transmission. In previous versions of this review we also included observational studies. However, for this update, there were sufficient RCTs to address our study aims.   DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of the evidence. Three pairs of review authors independently extracted data using a standard template applied in previous versions of this review, but which was revised to reflect our focus on RCTs and cluster-RCTs for this update. We did not contact trialists for missing data due to the urgency in completing the review. We extracted data on adverse events (harms) associated with the interventions.

MAIN RESULTS

We included 44 new RCTs and cluster-RCTs in this update, bringing the total number of randomised trials to 67. There were no included studies conducted during the COVID-19 pandemic. Six ongoing studies were identified, of which three evaluating masks are being conducted concurrent with the COVID pandemic, and one is completed. Many studies were conducted during non-epidemic influenza periods, but several studies were conducted during the global H1N1 influenza pandemic in 2009, and others in epidemic influenza seasons up to 2016. Thus, studies were conducted in the context of lower respiratory viral circulation and transmission compared to COVID-19. The included studies were conducted in heterogeneous settings, ranging from suburban schools to hospital wards in high-income countries; crowded inner city settings in low-income countries; and an immigrant neighbourhood in a high-income country. Compliance with interventions was low in many studies. The risk of bias for the RCTs and cluster-RCTs was mostly high or unclear. Medical/surgical masks compared to no masks We included nine trials (of which eight were cluster-RCTs) comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness (two trials with healthcare workers and seven in the community). There is low certainty evidence from nine trials (3507 participants) that wearing a mask may make little or no difference to the outcome of influenza-like illness (ILI) compared to not wearing a mask (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.82 to 1.18. There is moderate certainty evidence that wearing a mask probably makes little or no difference to the outcome of laboratory-confirmed influenza compared to not wearing a mask (RR 0.91, 95% CI 0.66 to 1.26; 6 trials; 3005 participants). Harms were rarely measured and poorly reported. Two studies during COVID-19 plan to recruit a total of 72,000 people. One evaluates medical/surgical masks (N = 6000) (published Annals of Internal Medicine, 18 Nov 2020), and one evaluates cloth masks (N = 66,000). N95/P2 respirators compared to medical/surgical masks We pooled trials comparing N95/P2 respirators with medical/surgical masks (four in healthcare settings and one in a household setting). There is uncertainty over the effects of N95/P2 respirators when compared with medical/surgical masks on the outcomes of clinical respiratory illness (RR 0.70, 95% CI 0.45 to 1.10; very low-certainty evidence; 3 trials; 7779 participants) and ILI (RR 0.82, 95% CI 0.66 to 1.03; low-certainty evidence; 5 trials; 8407 participants). The evidence is limited by imprecision and heterogeneity for these subjective outcomes. The use of a N95/P2 respirator compared to a medical/surgical mask probably makes little or no difference for the objective and more precise outcome of laboratory-confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; moderate-certainty evidence; 5 trials; 8407 participants). Restricting the pooling to healthcare workers made no difference to the overall findings. Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies. One ongoing study recruiting 576 people compares N95/P2 respirators with medical surgical masks for healthcare workers during COVID-19. Hand hygiene compared to control Settings included schools, childcare centres, homes, and offices. In a comparison of hand hygiene interventions with control (no intervention), there was a 16% relative reduction in the number of people with ARIs in the hand hygiene group (RR 0.84, 95% CI 0.82 to 0.86; 7 trials; 44,129 participants; moderate-certainty evidence), suggesting a probable benefit. When considering the more strictly defined outcomes of ILI and laboratory-confirmed influenza, the estimates of effect for ILI (RR 0.98, 95% CI 0.85 to 1.13; 10 trials; 32,641 participants; low-certainty evidence) and laboratory-confirmed influenza (RR 0.91, 95% CI 0.63 to 1.30; 8 trials; 8332 participants; low-certainty evidence) suggest the intervention made little or no difference. We pooled all 16 trials (61,372 participants) for the composite outcome of ARI or ILI or influenza, with each study only contributing once and the most comprehensive outcome reported. The pooled data showed that hand hygiene may offer a benefit with an 11% relative reduction of respiratory illness (RR 0.89, 95% CI 0.84 to 0.95; low-certainty evidence), but with high heterogeneity. Few trials measured and reported harms. There are two ongoing studies of handwashing interventions in 395 children outside of COVID-19. We identified one RCT on quarantine/physical distancing. Company employees in Japan were asked to stay at home if household members had ILI symptoms. Overall fewer people in the intervention group contracted influenza compared with workers in the control group (2.75% versus 3.18%; hazard ratio 0.80, 95% CI 0.66 to 0.97). However, those who stayed at home with their infected family members were 2.17 times more likely to be infected. We found no RCTs on eye protection, gowns and gloves, or screening at entry ports.

AUTHORS' CONCLUSIONS

The high risk of bias in the trials, variation in outcome measurement, and relatively low compliance with the interventions during the studies hamper drawing firm conclusions and generalising the findings to the current COVID-19 pandemic. There is uncertainty about the effects of face masks. The low-moderate certainty of the evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect. The pooled results of randomised trials did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks during seasonal influenza. There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection. Hand hygiene is likely to modestly reduce the burden of respiratory illness. Harms associated with physical interventions were under-investigated. There is a need for large, well-designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, especially in those most at risk of ARIs.

Pre-exposure Prophylaxis (PrEP) for HIV Prevention Among Men Who Have Sex with Men (MSM): A Scoping Review on PrEP Service Delivery and Programming

Pre-exposure prophylaxis (PrEP) is an evidence-based new biomedical HIV prevention intervention, which involves the pre-emptive use of daily (or event-based) antiretroviral drugs, to reduce risk of HIV acquisition if exposed. PrEP has recently been positioned as an integral prevention tool to reduce HIV acquisition risk among men who have sex with men (MSM) at country-level and within global prevention strategies. Given this global scale up of PrEP, we conducted a scoping review of extant international literature documenting service related perspectives, models and lessons learnt in PrEP programming for MSM. A systematic search of literature was conducted, and restricted to English language records in the timeframe 2008 to February 2019. Eligibility criteria centered on whether studies broadly described PrEP programming and service delivery for MSM as well as health communication. Following exclusion of ineligible records and removal of duplicates, 84 records were charted and thematically analysed according to scoping review methods. Four themes emerged from the thematic analysis of data; 'PrEP service aspects, settings and staff'; 'PrEP prescriber experiences, therapeutic alliance and care planning'; 'PrEP adherence within formal service structures'; and 'Multi-disciplinary and innovative PrEP care pathways'. The review highlights the complexities in providing optimal PrEP services for MSM by mapping and illustrating the importance of understanding the informal and formal routes to PrEP use among this HIV risk population; the barriers to uptake; the requirement for the presence of a positive therapeutic alliance between patient and prescriber in supporting patient initiation and adherence to PrEP regimes; and the need for availability in different culturally and ethnically sensitive models of PrEP service delivery according to low to high risk groups within the MSM communities.

"It's hard for us men to go to the clinic. We naturally have a fear of hospitals." Men's risk perceptions, experiences and program preferences for PrEP: A mixed methods study in Eswatini

Few studies on HIV Pre-Exposure Prophylaxis (PrEP) have focused on men who have sex with women. We present findings from a mixed-methods study in Eswatini, the country with the highest HIV prevalence in the world (27%). Our findings are based on risk assessments, in-depth interviews and focus-group discussions which describe men’s motivations for taking up or declining PrEP. Quantitatively, men self-reported starting PrEP because they had multiple or sero-discordant partners or did not know the partner’s HIV-status. Men’s self-perception of risk was echoed in the qualitative data, which revealed that the hope of facilitated sexual performance or relations, a preference for pills over condoms and the desire to protect themselves and others also played a role for men to initiate PrEP. Trust and mistrust and being able or unable to speak about PrEP with partner(s) were further considerations for initiating or declining PrEP. Once on PrEP, men’s sexual behavior varied in terms of number of partners and condom use. Men viewed daily pill-taking as an obstacle to starting PrEP. Side-effects were a major reason for men to discontinue PrEP. Men also worried that taking anti-retroviral drugs daily might leave them mistaken for a person living with HIV, and viewed clinic-based PrEP education and initiation processes as a further obstacle. Given that men comprise only 29% of all PrEP users in Eswatini, barriers to men’s uptake of PrEP will need to be addressed, in terms of more male-friendly services as well as trialing community-based PrEP education and service delivery.

A Mobile Gaming Intervention for Persons on Pre-Exposure Prophylaxis: Protocol for Intervention Development and Randomized Controlled Trial

Background

In the United States, young minority men who have sex with men (MSM) are the most likely to become infected with HIV. Pre-exposure prophylaxis (PrEP) is an efficacious and promising prevention strategy. However, PrEP’s safety and effectiveness can be greatly compromised by suboptimal adherence to treatment. To maximize the positive impact of PrEP, it is necessary to combine its prescription with cost-effective behavioral interventions that promote adherence and decrease HIV risk behaviors. In this project, we developed a theoretically informed app/gaming intervention to engage young MSM in learning information, practicing behaviors, and improving motivation for HIV preventative behaviors and PrEP adherence.

Objective

The goal of this project was to develop and test a cutting-edge, engaging, and entertaining app/gaming intervention for improving adherence to PrEP and building HIV prevention knowledge, skills, and behavior.

Methods

This study was conducted in two phases. In the developmental phase, we conducted qualitative interviews with young MSM (n=20) to guide the development of the gaming intervention. In the randomized controlled trial, we tested the preliminary efficacy of the gaming intervention compared to a comparison condition among young MSM. Subjects were recruited from the University of Mississippi Medical Center HIV/STI testing clinics (n=60).

Results

Institutional review board approval was received in February 2015. Research activities began in June 2015 and are still ongoing.

Conclusions

This app/gaming intervention aimed to improve PrEP adherence and HIV preventative behaviors in young MSM. Engaging young MSM in learning information, practicing behaviors, and improving motivation for increased adherence to PrEP has the potential to decrease HIV seroconversion. It is important to develop interventions that are enjoyable, engaging, and easily incorporated into clinical settings.

Trial Registration

ClinicalTrials.gov RCT02611362; https://tinyurl.com/y65gkuwr

International Registered Report Identifier (IRRID)

DERR1-10.2196/18640

The impact of PrEP: results from a multicenter Health Technology Assessment into the Italian setting

INTRODUCTION

The use of oral tenofovir/emtricitabine (FTC/TDF) for pre-exposure prophylaxis (PrEP) among high-risk people without Human Immunodeficiency Virus (HIV), is emerging as an innovative strategy to decrease HIV epidemic. The study aims at evaluating the implications related to PrEP introduction, from a multidimensional point of view, as required by Health Technology Assessment (HTA) approach, with a particular attention on sustainability and social factors, influencing PrEP implementation.

METHODS

An analysis was conducted involving 35 Italian Infectious Disease Departments. The introduction of PrEP (applied both as "add-on" and "substitute" prevention strategy) into the clinical practice was compared with a baseline scenario, consisting of condoms among men who have sex with men, and serodiscordant couples, and the use of Needle Syringe Programme among injection drugs users The above scenarios were analysed by means of a Health Technology Assessment (HTA) approach. The 9 EUnetHTA Core Model domains were assessed through comparative information, retrieved from literature evidence, and collection of qualitative and quantitative information, derived from real-world evidence, in particular from 35 Infectious Disease Departments and potential PrEP' users involved. A final multi-criteria decision analysis approach (MCDA) was implemented to simulate the appraisal phase and providing evidence-based information with regard to the preferable technology.

RESULTS

Despite the improvement in patients' quality of life, PrEP would generate the development of other sexually transmitted and blood-borne diseases, with a consequent decrease of patients' safety in case of PrEP applied as a "substitute" prevention strategy. In addition, PrEP would generate an increase in staff workflow, with investment in medical supplies and training courses. PrEP would lead to significant economic investments both for the NHS (+40%), and for citizens (+2,377%) if used as an add-on strategy, assuming FTC/TDF patent cost. With the off-patent drug, the NHS would benefit from an advantage (37%), and a shrink of the patients' expenditure emerged (+682%). More economic resources are required if PrEP is applied as a substitute strategy, considering both the patent (NHS: 212%; citizens: 3,423%) and the off-patent drug (NHS: 73%; citizens: 1,077%). Conclusions. The most cost-containing strategy would be the use of PrEP, as an add-on strategy, with a consequent improvement in patients' safety, even if drug-related adverse events would be considered. The implementation of the off-patent drug would decrease the economic burden of the innovative prevention strategy. Hence, the organizational aspects related to its adoption would be deeply investigated, with the potential opportunity to create specific ambulatories devoted to PrEP users' especially for medium and big size hospitals.

The Impact of Male Partner Circumcision on Women's Health Outcomes

Medical male circumcision is a proven method of HIV risk reduction in men with no known direct benefit to women. We investigated the benefit of partner circumcision on women's health. We conducted a secondary analysis of 5,029 women enrolled in the Vaginal and Oral Interventions to Control the Epidemic trial across 15 African sites, to look at the impact of partner circumcision status on sexually transmitted infections, pregnancy, frequency of sex, and condom use in women. Of 4,982 participants with a baseline response, 31% had circumcised partners. Women with circumcised partners had a significantly reduced risk of syphilis acquisition, hazard ratio 0.51 (0.26, 1.00), p value = .05. Participants with uncircumcised partners were significantly less likely to have used a condom at the last sex act than the other two groups, adj. relative risk 0.86 (0.80, 0.92), adj. p value < .0001. We found no evidence of sexual risk compensation in women with circumcised partners.

Promoting male circumcision as HIV prevention in sub-Saharan Africa: An evaluation of the ethical and pragmatic considerations of adopting a demand creation approach

Male circumcision for HIV prevention is being promoted in 14 sub-Saharan African countries. Campaigns take a demand creation approach, a strategy based on generating awareness of and demand for an intervention. This article analyzes campaign materials, making the case that a focus on demand per se, at the expense of quality public health information, constitutes an ethical and pragmatic campaign flaw. Clinical trials have demonstrated that circumcision can reduce transmission of HIV from women to men by 53-60%. Since circumcision does not approach 100% prevention efficacy for men and does not directly protect women, behavioural and structural interventions remain necessary, leading international health bodies to position circumcision as an add-on to behavioural interventions. However, in practice, circumcision promotion often lacks information about behavioural prevention. At times, campaigns omit any HIV prevention message. Instead, campaigns variously favour representing circumcision as a route to normative masculinity, to sexual prowess, or to good citizenship, among others. Alongside their targeted outcomes, public health campaigns also contribute to public discourses around sexuality and non-HIV aspects of health, in this case potentially leading to confusion and mistrust. The current public health promotion strategy for circumcision threatens to undermine the social processes needed to support HIV prevention.

Traditional Male Circumcision is Associated with Sexual Risk Behaviors in Sub-Saharan Countries Prioritized for Male Circumcision

To understand the sexual risk behavior of men with traditional male circumcision and medical male circumcision in the context of the World Health Organization's (WHO) campaign for voluntary medical male circumcision (VMMC) scale-up, we investigated ten countries prioritized for the scale-up from the Demographic and Health Surveys. Male respondents aged 15-49 were selected. Ordinal regression was used to analyze the relationship between three sexual risk behaviors-condom use with non-cohabiting partners, number of non-cohabiting partners, and partner type-and circumcision status (traditionally circumcised before and after the VMMC scale-up, medically circumcised before and after the scale-up, and not circumcised), while controlling for social demographic covariates. We found evidence that some sexual risky behavior, specifically lower condom use and higher number of sexual partners, was associated with traditional circumcision. This finding suggests that messages about the protective effect of male circumcision may not have reached men with traditional circumcision. We suggest that WHO's VMMC campaign should include communities where traditional male circumcision is popular. We looked for, but did not find, evidence of differences between groups circumcised at different times, which could have indicated sexual risk compensation.

The Effect of Social Networks and Social Constructions on HIV Risk Perceptions

Roughly 1 in 7 people living with HIV in the United States is unaware of their sero-status, signaling that individuals may be underestimating their risk for HIV. Few studies have examined the effect of socio-structural and socio-cognitive factors on HIV risk perceptions. This analysis identifies individual, interpersonal and network influences on HIV risk perceptions among high-risk heterosexuals. Data come from the Colorado Springs study, a CDC-funded project focused on HIV transmission among high-risk heterosexuals. Using social network data, analyses were first conducted at the individual-level using a partial proportional odds regression to identify predictors of self-perceived HIV risk. Next, multivariate binary logistic regression using GEE was used to examine  predictors of perceptions of network member's  HIV risk. Interpersonal characteristics such as perceptions of network member's HIV risk, racial homophily, and engagement in multiplexity (co-occurrence of drug-use, needle sharing and sex within relationships) were significantly associated with respondents' self-perceived HIV risk. Factors associated with perceptions of network member's HIV risk include self-perceived HIV risk, emotional closeness within relationships, and density of drug ties. Analyses found HIV risk perception is the product of not only individual-level factors, but also interpersonal and social network processes. We also found a reciprocal relationship between individuals' perceptions of their own risk and the risk of their associates/network members. Findings highlight the need for understanding risk perception as a function of interpersonal relationships, social constructions, including socio-cognitive processes.

Sexual behaviour, changes in sexual behaviour and associated factors among women at high risk of HIV participating in feasibility studies for prevention trials in Tanzania

INTRODUCTION

Risk reduction towards safer behaviour is promoted after enrolment in HIV prevention trials. We evaluated sexual behaviour, changes in sexual behaviour and factors associated with risky behaviour after one-year of follow-up among women enrolled in HIV prevention trials in Northern Tanzania.

METHODS

Self-reported information from 1378 HIV-negative women aged 18-44 enrolled in microbicide and vaccine feasibility studies between 2008-2010,was used to assess changes in behaviour during a 12-month follow-up period. Logistic regression with random intercepts was used to estimate odds ratios for trends in each behaviour over time. A behavioural risk score was derived from coefficients of three behavioural variables in a Poisson regression model for HIV incidence and thereafter, dichotomized to risky vs less-risky behaviour. Logistic regression was then used to identify factors associated with risky behaviour at 12 months.

RESULTS

At baseline, 22% reported multiple partners, 28% were involved in transactional sex and only 22% consistently used condoms with non-regular partners. The proportion of women reporting multiple partners, transactional sex and high-risk sex practices reduced at each 3-monthly visit (33%, 43% and 47% reduction in odds per visit respectively, p for linear trend <0.001 for all), however, there was no evidence of a change in the proportion of women consistently using condoms with non-regular partners (p = 0.22). Having riskier behaviours at baseline, being younger than 16 years at sexual debut, having multiple partners, selling sex and excessive alcohol intake at baseline were strongly associated with increased odds of risky sexual behaviour after 12 months (p<0.005 for all).

CONCLUSION

An overall reduction in risky behaviours over time was observed in HIV prevention cohorts. Risk reduction counselling was associated with decreased risk behaviour but was insufficient to change behaviours of all those at highest risk. Biological HIV prevention interventions such as PrEP for individuals at highest risk, should complement risk reduction counselling so as to minimize HIV acquisition risk.

[Care providers' knowledge and willingness to prescribe pre-exposure prophylaxis (PrEP) in Kinshasa, Democratic Republic of Congo (DRC)]

Introduction

la réduction de l'incidence de nouvelles infections liées au VIH est un objectif de santé publique. L’objectif de l’étude était d’évaluer la connaissance et volonté de prescrire la PrEP à Kinshasa.

Méthodes

il s’agit d’une étude transversale à visée analytique auprès des prestataires de soins de 4 structures de prise en charge de VIH/SIDA de la ville de Kinshasa d’avril à octobre 2017. Les analyses univariées et multivariées par régression logistique ont été effectuées pour identifier les facteurs associés à la connaissance et la volonté de prescrire la PrEP.

Résultats

quatre-vingt-cinq prestataires ont répondu à l’enquête. Moins du quart des prestataires connaissaient la PrEP avant l’enquête et la moitié avait la volonté de la prescrire. La barrière à cet acte évoquée était la résistance (83%). Les facteurs associés à la connaissance de la PrEP étaient la spécialité d’infectiologie et l’expertise en VIH. Les facteurs associés à la volonté de prescrire la PrEP étaient l’âge supérieur à 40 ans, la spécialité d’infectiologie et l’expertise en VIH.

Conclusion

la connaissance de la PrEP à Kinshasa était faible et seule la moitié des prestataires était disposée à la prescrire. Etre médecin infectiologue et expert en VIH était associé à la connaissance et la volonté de prescrire. Les futurs programmes d'éducation devraient renforcer la connaissance sur la PrEP et aborder les préoccupations identifiées dont les barrières à la prescription.

Population uptake and effectiveness of test-and-treat antiretroviral therapy guidelines for preventing the global spread of HIV: an ecological cross-national analysis

OBJECTIVES

Although the benefits of adopting test-and-treat antiretroviral therapy (ART) guidelines that recommend initiation of ART regardless of CD4 cell counts have been demonstrated at the individual level, there is uncertainty about how this translates to the population level. Here, we explored whether adopting ART guidelines recommending earlier treatment initiation improves population ART access and viral suppression and reduces overall disease transmission.

METHODS

Data on ART initiation guidelines and treatment coverage, viral suppression, and HIV incidence from 37 European and Central Asian countries were collected from the European Centre for Disease Prevention and Control and the Global HIV Policy Watch and HIV 90-90-90 Watch databases. We used multivariate linear regression models to quantify the association of ART initiation guidelines with population ART access, viral suppression, and HIV incidence, adjusting for potential confounding factors.

RESULTS

Test-and-treat policies were associated with 15.2 percentage points (pp) [95% confidence interval (CI) 0.8-29.6 pp; P = 0.039] greater treatment coverage (proportion of HIV-positive people on ART) compared with countries with ART initiation at CD4 cell counts ≤ 350 cells/μL. The presence of test-and-treat policies was associated with 15.8 pp (95% CI 2.4-29.1 pp; P = 0.023) higher viral suppression rates (people on ART virally suppressed) compared with countries with treatment initiation at CD4 counts ≤ 350 cells/μL. ART initiation at CD4 counts ≤ 500 cells/μL did not significantly improve ART coverage compared to initiation at CD4 counts ≤ 350 cells/μL but achieved similar degrees of viral suppression as test-and-treat.

CONCLUSIONS

Test-and-treat was found to be associated with substantial improvements in population-level access to ART and viral suppression, further strengthening evidence that rapid initiation of treatment will help curb the spread of HIV.

Personal Genetic Information about HIV: Research Participants' Views of Ethical, Social, and Behavioral Implications

BACKGROUND

Personal genetic information (PGI) about HIV is produced in research and entering the clinic and direct-to-consumer market, but little consideration has been given to ethical and social issues, public perspectives, and potential behavioral implications.

OBJECTIVES

This research queried the views of research participants at risk for or infected with HIV, exploring their perspectives on HIV-related PGI and its ethical, social, and behavioral implications.

METHODS

We used focus groups to collect rich information about participants' perspectives on the ethical, social, and behavioral implications of PGI about HIV and host genetic research. We evaluated their reactions to three different types of genetic variants: those that made them more susceptible to HIV, more protected from or resistant to HIV, or more likely to transmit HIV to others.

RESULTS

Overall, participants wanted PGI about HIV. Their reasons included a mix of personal or family health benefit and benefit to others, which varied in emphasis depending on variant type. While susceptibility variant information was seen primarily in terms of personal or family health benefit, for transmissibility and protective variant information, benefit to others emerged as a major reason for wanting PGI about HIV. Participants thought transmissibility variant information would help them prevent others from becoming infected, and protective variant information would allow them to volunteer for targeted research to help treat, cure, or prevent HIV. Possible harms were raised regarding the tendencies among some individuals to increase risky behavior with modulations in perceived risk. Potential behavioral implications were seen as significant, though complex, reflecting multifaceted risk perceptions.

CONCLUSIONS

Our study adds to the evidence that participants in genetic research, across disease type, have a strong desire for PGI. For participants in research on the genetics of HIV, and potentially other infectious diseases, their desire for PGI is grounded in a perceived duty not to infect others, where they feel a moral responsibility regarding research participation and behavior change. Wider dissemination of HIV-related PGI may well increase research participation, but could have mixed effects on risk behavior. More research is needed on the implications of different variant types of PGI beyond susceptibility factors, especially protective variants or resistance factors.

Give PrEP a chance: moving on from the "risk compensation" concept

INTRODUCTION

While bio-behavioural interventions (BIs) for sexually transmitted infections (STIs) and HIV prevention have shown their effectiveness (e.g. treatment for syphilis, HPV vaccination or pre-exposure prophylaxis [PrEP]), they have also aroused major concerns regarding behavioural changes that could counteract their benefit. Risk compensation (RC) fears concerning BIs in the HIV/STIs prevention field are intimately linked to representations, judgements and social control on sexual behaviour. With an increasing number of PrEP studies describing a rise in STIs due to RC, this paper argues for a shift away from the focus on RC and proposes a more constructive approach to respond to the needs of people living with HIV and populations most at risk.

DISCUSSION

The concept of RC, stemming from road safety and derived from economic theory, relies on rational theoretical models of human behaviour. Although widely applied in several contexts its use has been reasonably questioned. Major methodological issues regarding RC have been raised within HIV/AIDS literature. Although behavioural changes (e.g. condomless sex and number of sexual partners) are often erroneously assimilated with RC, there is no evidence that behavioural changes have undermined the effectiveness of previous and current BIs. Still, PrEP has not escaped RC concerns. Increases in condomless sex within the context of growing uptake of PrEP signals a continued need for integrated and innovative HIV and STI prevention strategies and a comprehensive sexual health approach. Routine HIV/STI testing, peer-led counselling, and identification of sexual health needs within the PrEP model of care could become a gold standard in the sexual health field for all populations.

CONCLUSIONS

RC remains a frequent argument against the availability and provision of prevention methods for vulnerable populations. Individuals should be able to benefit from the full panel of BIs options available, to find and adapt methods according to their needs. Current, past and future PrEP users, with other stakeholders, may provide valuable insight into innovative solutions and programmes to control HIV and other STIs.

Update on HIV Preexposure Prophylaxis: Effectiveness, Drug Resistance, and Risk Compensation

PURPOSE OF REVIEW

In 2019, the US government launched an initiative to decrease new HIV infections by 90% over the next decade. Studies have demonstrated the efficacy of HIV preexposure prophylaxis (PrEP) for high-risk populations, and the United States Preventative Services Task Force has issued a grade A recommendation for PrEP, indicating substantial net benefit. However, questions have been raised about the effectiveness of PrEP in clinical settings and whether PrEP use might promote antiretroviral drug resistance and increased sexual risk behaviors, which could increase transmission of bacterial sexually transmitted infections. In this narrative review, we summarize recent evidence of the effectiveness of PrEP when provided in clinical and community settings, the emergence of antiretroviral drug resistance during PrEP use, and associations between PrEP use and increased sexual risk behaviors. We also review novel PrEP modalities that are being developed to optimize PrEP acceptability, adherence, and effectiveness.

RECENT FINDINGS

Studies suggest that PrEP is effective when provided in clinical settings. However, PrEP uptake and impact have been limited in the USA thus far, and major disparities in access to PrEP exist. In addition, there is evidence that drug resistance can occur with PrEP use, particularly with inadvertent PrEP use during undiagnosed acute HIV infection. Risk compensation can also occur with PrEP use and has been associated with increased sexually transmitted infections. Promising new modalities for PrEP could expand options. PrEP has strong potential to decrease HIV incidence. However, disparities in access must be addressed to ensure equity and impact for PrEP. While drug resistance and risk compensation can occur with PrEP use, these are not valid reasons to withhold PrEP from patients given its substantial protective benefits.

High Prevalence of Anal and Oral High-Risk Human Papillomavirus in Human Immunodeficiency Virus-Uninfected French Men Who Have Sex With Men and Use Preexposure Prophylaxis

Background

We assessed the prevalence and risk factors of anal and oral high-risk (HR) human papillomavirus (HPV) infection in human immunodeficiency virus–uninfected men who have sex with men (MSM) and take preexposure prophylaxis (PrEP) in France.

Methods

Anal and oral samples were screened by multiplex real-time polymerase chain reaction (Anyplex II HPV 28; Seegene) for HPV DNA.

Results

A total of 61 unvaccinated MSM (mean age, 36.1 years) were enrolled. Anal HPV and HR-HPV prevalences were 93.4% and 81.9%, respectively, and oral HPV and HR-HPV prevalences, 33.9% and 19.6%, respectively. HR-HPV type 33 was the most detected genotype, in both anal and oral samples. Among MSM, 68.8% carried ≥1 anal HPV type targeted by the 9-valent Gardasil-9 vaccine; all oral HPV-positive samples carried ≥1 strain included in the vaccine. Condomless receptive anal intercourse and history of anal gonorrhea were the main factors associated with increased risk for anal HPV infection (adjusted odds ratio, 10.4) and anal infection with multiple HR-HPV genotypes (5.77), respectively. Conversely, having had <10 partners in the last 12 months was associated with decreased risk for anal carriage of both multiple HPV (adjusted odds ratio, 0.19) and HR-HPV (0.17) types.

Conclusion

French MSM using PrEP are at high risk for both anal and oral carriage of HR-HPV that could lead to HPV-related cancers.

HPV vaccine status and sexual behavior among young sexually-active women in the US: evidence from the National Health and Nutrition Examination Survey, 2007-2014

Concern has been expressed that human papillomavirus (HPV) vaccination programs might promote risky sexual behavior through mechanisms such as risk compensation, behavioral disinhibition, or perceived endorsement of sexual activity. This study assesses whether HPV vaccination status is associated with any differences in selected sexual behaviors among young sexually-active women in the US. Our dataset includes young, adult female respondents from questionnaire data collected in the National Center for Health Statistics' National Health and Nutrition Examination Survey from 2007 to 2014. The empirical approach implements a doubly robust estimation procedure, based on inverse probability of treatment weighting. For robustness, we implement several specifications for the propensity model and the outcomes model. We find no consistent association between HPV vaccination and condom usage or frequency of sex. Specifically, we find no evidence that HPV vaccination is associated with condom usage or with whether a person had sex more than 52 or more than 104 times per year. We find inconsistent evidence that HPV vaccination is associated with a person having sex more than 12 times per year. As in previous research, HPV vaccination does not appear to have a substantive effect on sexual behavior among young sexually-active women in the US.

HIV Testing in Clinical and Community Settings for an International Sample of Latino Immigrants and Nonimmigrants

Latino/as in the U.S. and Spain make up a disproportionate percentage of cases of HIV infection, and often are diagnosed later than their non-Latino/a counterparts. Understanding the factors that affect HIV testing in different contexts is critical to best promote HIV testing, which is considered essential to both prevention and early treatment. This study explored differences in HIV testing rates among Latino/a participants in an international study designed to examine behavioral health screening for Latino/a populations. We collected data on testing rates and results from 407 Latino/as - both first generation immigrants and those of Latino/a descent - in the U.S. (Boston) and Spain (Madrid and Barcelona), through interviews conducted in community clinics and agencies. Using multivariate logit models, we evaluated predictors of screening and positive testing, adjusting for sex, age, and clinic type. HIV testing rates were highest in Boston, followed by Barcelona and Madrid (82%, 69%, and 59%, respectively, p < .0001). In multivariate regression models, Barcelona and Madrid patients were significantly less likely to have received testing than Boston patients. Significant positive predictors of HIV testing were: education level higher than high school, HIV concerns, infrequent condom use, other risk behaviors, reports of discrimination, and higher benzodiazepine consumption. Significant differences in HIV testing found in this study help to illuminate best practices for engaging patients in testing across sites.

Perceived HIV-protective benefits of male circumcision: Risk compensatory behaviour among women in Malawi

BACKGROUND

Male circumcision (MC) reduces men's risk of contracting HIV by approximately 60% and has the potential to significantly alter HIV epidemics. However, MC does not significantly reduce the risk of HIV transmission to women from a circumcised man. In Malawi, several researchers has examined the acceptability, accessibility and sexual behaviour change after circumcision in men but behaviour change in women following their partner's circumcision remains uncertain. In order to fully realise the protective benefits of MC against HIV, factors related to risky sexual behaviour is imperative as some studies have shown potentials of increased risky behaviour in men following voluntary medical male circumcision (VMMC). This study aimed to explore the perceptions and opinions of female school teachers and health workers on HIV-protective benefits of MC and its impact on risk compensatory behaviour among women in Malawi.

METHODS

We conducted a cross-sectional survey of women (N = 68) between May and June 2016 in three districts of southern Malawi. Risk compensatory behaviour was measured by number of sexual partners and use of protection during sex among female teachers and health care workers who are involved with educating people on benefits of VMMC. The bivariable analysis was conducted to test for association between HIV-protective benefits and risk compensatory behaviour. Purposive sampling was used to conduct eight qualitative in-depth interviews with women from the selected districts and the qualitative data was analysed thematically.

RESULTS

The mean age of women who participated in the survey was 30 years. Most women (94.1%) correctly indicated that HIV-positive circumcised men can still infect their partner and approximately, 90% of were knowledgeable of risky sexual behaviour for HIV. However, 55.9% perceived MC can lead women to adopt risky sexual behaviour. On the contrary to this finding, qualitative data indicate women's misconceptions regarding their partners' circumcision and HIV-protective benefits. Most women expressed that risky sexual behaviour such as having multiple sexual partners and inconsistent or non-use of condoms can easily be observed among women if they learn of their partners' partial HIV-protective benefits circumcision.

CONCLUSION

Exploring women's sexual behaviour change in the right of HIV-protective benefits of MC fills in a research knowledge important to public health. In-depth studies are therefore required to give more evidence that will guide the development of HIV risk-reduction interventions.

A dynamic network model to disentangle the roles of steady and casual partners for HIV transmission among MSM

HIV is a sexually transmitted infection (STI) whose transmission process is highly dependent on the sexual network structure of the population under consideration. Most sexual behaviour data is egocentric in nature. We develop a stochastic dynamic sexual network model that utilises this type of egocentric network data. The model incorporates both steady and casual sex partners, and can be seen as a stochastic form of a generalised pair-formation model. We model the spread of an infection where individuals are susceptible, infectious, or successfully treated (and unable to transmit) and derive analytical expressions for several epidemiological quantities. We use sexual behaviour and HIV prevalence data that was gathered among 403 MSM at an STI clinic in Stockholm. To accurately capture transmission dynamics for this population, we need to explicitly model both casual sex partners and steady partnerships. Our model yields an estimate for the mean time until diagnosis followed by successful treatment that is in line with literature. This study indicates that small reductions in the time to diagnosis, and thereby, beginning of treatment, may substantially reduce HIV prevalence. Moreover, we find that moderate increases in condom use with casual sex partners have greater impact on reducing prevalence than the same increases in condom use with steady sex partners. This result demonstrates the relative importance of casual contacts on the HIV transmission dynamics among MSM in Sweden. Our results highlight the importance of HIV testing and condom-use interventions, and the role that casual and steady partners play in this, in order to turn the epidemiological trend in Sweden towards decreased HIV incidence.