Using phylogenetics to infer HIV-1 transmission direction between known transmission pairs.

Inferring the transmission direction between linked individuals living with HIV provides unparalleled power to understand the epidemiology that determines transmission. Phylogenetic ancestral-state reconstruction approaches infer the transmission direction by identifying the individual in whom the most recent common ancestor of the virus populations originated. While these methods vary in accuracy, it is unclear why. To evaluate the performance of phylogenetic ancestral-state reconstruction to determine the transmission direction of HIV-1 infection, we inferred the transmission direction for 112 transmission pairs where transmission direction and detailed additional information were available. We then fit a statistical model to evaluate the extent to which epidemiological, sampling, genetic, and phylogenetic factors influenced the outcome of the inference. Finally, we repeated the analysis under real-life conditions with only routinely available data. We found that whether ancestral-state reconstruction correctly infers the transmission direction depends principally on the phylogeny's topology. For example, under real-life conditions, the probability of identifying the correct transmission direction increases from 32%-when a monophyletic-monophyletic or paraphyletic-polyphyletic tree topology is observed and when the tip closest to the root does not agree with the state at the root-to 93% when a paraphyletic-monophyletic topology is observed and when the tip closest to the root agrees with the root state. Our results suggest that documenting larger differences in relative intrahost diversity increases our confidence in the transmission direction inference of linked pairs for population-level studies of HIV. These findings provide a practical starting point to determine our confidence in transmission direction inference from ancestral-state reconstruction.

Going beyond 'regular and casual': development of a classification of sexual partner types to enhance partner notification for STIs.

OBJECTIVES: To develop a classification of sexual partner types for use in partner notification (PN) for STIs. METHODS: A four-step process: (1) an iterative synthesis of five sources of evidence: scoping review of social and health sciences literature on partner types; analysis of relationship types in dating apps; systematic review of PN intervention content; and review of PN guidelines; qualitative interviews with public, patients and health professionals to generate an initial comprehensive classification; (2) multidisciplinary clinical expert consultation to revise the classification; (3) piloting of the revised classification in sexual health clinics during a randomised controlled trial of PN; (4) application of the Theoretical Domains Framework (TDF) to identify index patients' willingness to engage in PN for each partner type. RESULTS: Five main partner types emerged from the evidence synthesis and consultation: 'established partner', 'new partner', 'occasional partner', 'one-off partner' and 'sex worker'. The types differed across several dimensions, including likely perceptions of sexual exclusivity, likelihood of sex reoccurring between index patient and sex partner. Sexual health professionals found the classification easy to operationalise. During the trial, they assigned all 3288 partners described by 2223 index patients to a category. The TDF analysis suggested that the partner types might be associated with different risks of STI reinfection, onward transmission and index patients' engagement with PN. CONCLUSIONS: We developed an evidence-informed, useable classification of five sexual partner types to underpin PN practice and other STI prevention interventions. Analysis of biomedical, psychological and social factors that distinguish different partner types shows how each could warrant a tailored PN approach. This classification could facilitate the use of partner-centred outcomes. Additional studies are needed to determine the utility of the classification to improve measurement of the impact of PN strategies and help focus resources.

Post-exposure prophylaxis completion and condom use in the context of potential sexual exposure to HIV.

OBJECTIVES: Post-exposure prophylaxis (PEP) care remains a challenge for individuals with potential sexual exposure to HIV in terms of PEP completion and ongoing risk behaviours. METHODS: A retrospective analysis was carried out on data from the French Dat'AIDS prevention cohort (NCT03795376) for individuals evaluated for PEP between 2004 and 2017. A multivariable analysis was performed of predictors of both PEP completion and condom use [odds ratios (ORs)] and their associated probabilities (P, with P > 95% being clinically relevant). RESULTS: Overall, 29 060 sexual exposures to HIV were evaluated for PEP [36% in men who have sex with men (MSM) and 64% in heterosexuals]. Overall, 12 different PEP regimens were offered in 19 240 cases (46%). Tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) was the preferred backbone (n = 14 304; 74%). We observed a shift from boosted protease inhibitor-based regimens to nonnucleoside reverse transcriptase inhibitor- or integrase inhibitor-based regimens in recent years. Overall, 20% of PEP prescriptions were prematurely discontinued. Older age, MSM, intercourse with a sex worker, rape and intercourse with a known HIV-infected source patient were factors associated with increased rates of PEP completion (OR > 1; P > 98%). None of the 12 PEP regimens was associated with premature discontinuation. We also found 12 774 cases of unprotected sexual intercourse (48%). Condom use decreased (OR < 1; P > 99%) with the year of exposure, and was lower in MSM and rape victims. Condom use increased (OR > 1, P > 99%) with age, and was higher in those who had intercourse with a sex worker or with a female partner and in those with knowledge of the partner's HIV status. CONCLUSIONS: We provide new insights into how rates of condom use and PEP completion might be improved in those receiving PEP by targeting certain groups of individuals for interventions. In particular, youth and MSM at risk should be linked in a prevention-to-care continuum.

Seasonal variations in kissing and sexual activities among men who have sex with men in Melbourne, Australia: implications for seasonal sexually transmissible infection preventions and interventions.

Background Previous studies have shown that there is a peak in sexually transmissible infection (STI) cases and sexual activities around summer, but there has been no study examining whether kissing also follows a similar seasonal pattern. The aim of this study was to examine the seasonal patterns of kissing and sex partners among gay, bisexual and other men who have sex with men (MSM). METHODS: A short cross-sectional study was conducted among MSM attending the Melbourne Sexual Health Centre between March 2016 and February 2017. Participants were asked to report the number of kissing-only, sex-only and kissing-with-sex male partners in the last 3 months. The mean number of male partners was calculated and stratified by Australia's seasons. The seasonal trend in the number of partners was assessed by negative binomial regression models. RESULTS: In total, 4391 MSM were included in the analysis. The number of kissing-only and sex-only partners increased significantly from autumn to summer among MSM in Melbourne (Ptrend <0.001). MSM reported the highest number of male partners for kissing-only (mean: 4.91; 95% confidence intervals (CI): 4.78-5.04) and sex-only (mean: 1.91; 95% CI: 1.83-1.99) around summer compared with other seasons. However, the number of kissing-with-sex partners remained stable across seasons. CONCLUSIONS: The study data suggest that there is a peak in kissing-only and sex-only partners among MSM around summer and holiday seasons.

Getting the terminology right in sexual health research: the importance of accurately classifying fuck buddies among men who have sex with men.

OBJECTIVE: The aim of this report was to raise the issue of the definition and classification of partner terminology in men who have sex with men (MSM) research, particularly in regards to 'fuck buddies'. If definitions in research differ from general consensus in the MSM population, it is possible that public health strategies will be ineffective as the target population may be inaccurate. METHODS: Thirty semistructured interviews with MSM attending the Melbourne Sexual Health Centre were conducted, focusing on the willingness to change sexual practices to reduce the risk of pharyngeal gonorrhoea. As part of these interviews, men were also asked their views on the terminology they used to describe their relationships and sexual partners. RESULTS: The degree of emotional attachment often defined the type or classification of relationships. There was a consensus among men that partners they engaged with for 'sex only' were classified as casual partners and partners with whom there was an emotional attachment or formalisation of the relationship were classified as 'regular partners'. However, the classification of 'fuck buddy' as a regular or casual partner was less clear. CONCLUSIONS: Further research is needed to ascertain the ways in which men conceptualise sexual relationships and define or classify partner types, particularly 'fuck buddy' relationships. A third category for sexual relationships should be considered to encapsulate fuck buddy relationships.

Mining for pairs: shared clinic visit dates identify steady HIV-positive partnerships.

OBJECTIVES: Here we examined the hypothesis that some stable HIV-infected partnerships can be found in cohort studies, as the patients frequently attend the clinic visits together. METHODS: Using mathematical approximations and shuffling to derive the probabilities of sharing a given number of visits by chance, we identified and validated couples that may represent either transmission pairs or serosorting couples in a stable relationship. RESULTS: We analysed 434 432 visits for 16 139 Swiss HIV Cohort Study patients from 1990 to 2014. For 89 pairs, the number of shared visits exceeded the number expected. Of these, 33 transmission pairs were confirmed on the basis of three criteria: an extensive phylogenetic tree, a self-reported steady HIV-positive partnership, and risk group affiliation. Notably, 12 of the validated transmission pairs (36%; 12 of 33) were of a mixed ethnicity with a large median age gap [17.5 years; interquartile range (IQR) 11.8-22 years] and these patients harboured HIV-1 of predominantly non-B subtypes, suggesting imported infections. CONCLUSIONS: In the context of the surge in research interest in HIV transmission pairs, this simple method widens the horizons of research on within-pair quasi-species exchange, transmitted drug resistance and viral recombination at the biological level and targeted prevention at the public health level.

Prevalence of and factors associated with unprotected anal intercourse with regular and nonregular male sexual partners among newly diagnosed HIV-positive men who have sex with men in China.

OBJECTIVES: This study investigated the prevalence of, and multi-dimensional factors associated with, unprotected anal intercourse (UAI) with regular male sexual partners ('regular partners') and nonregular male sexual partners ('nonregular partners') among newly diagnosed HIV-positive men who have sex with men (MSM) in Chengdu, China. METHODS: A total of 225 newly diagnosed HIV-positive MSM were interviewed using a combined interviewer-computer-assisted method in Chengdu, China. RESULTS: The prevalence of UAI with regular and nonregular partners since diagnosis was 27.7% and 33.8% among participants reporting having sex with regular and nonregular partners (n = 159 and 133), respectively. Adjusted analysis showed that: (1) cognitive variables based on the Health Belief Model (perceived susceptibility to HIV transmission and perceived severity of the consequences of HIV transmission, perceived barriers and perceived self-efficacy related to consistent condom use), (2) emotion-related variables (worry about transmitting HIV to others), (3) psychological factors (post-traumatic growth) and (4) socio-structural factors (perceived partners' responsibility for condom use) were significantly associated with UAI with regular and/or nonregular partners. CONCLUSIONS: Interventions are warranted, and should be designed with consideration of multi-dimensional factors and be partner type-specific.

How can we objectively categorise partnership type? A novel classification of population survey data to inform epidemiological research and clinical practice.

BACKGROUND: Partnership type is a determinant of STI risk; yet, it is poorly and inconsistently recorded in clinical practice and research. We identify a novel, empirical-based categorisation of partnership type, and examine whether reporting STI diagnoses varies by the resulting typologies. METHODS: Analyses of probability survey data collected from 15 162 people aged 16-74 who participated in Britain's third National Survey of Sexual Attitudes and Lifestyles were undertaken during 2010-2012. Computer-assisted self-interviews asked about participants' ≤3 most recent partners (N=14 322 partners/past year). Analysis of variance and regression tested for differences in partnership duration and perceived likelihood of sex again across 21 'partnership progression types' (PPTs) derived from relationship status at first and most recent sex. Multivariable regression examined the association between reporting STI diagnoses and partnership type(s) net of age and reported partner numbers (all past year). RESULTS: The 21 PPTs were grouped into four summary types: 'cohabiting', 'now steady', 'casual' and 'ex-steady' according to the average duration and likelihood of sex again. 11 combinations of these summary types accounted for 94.5% of all men; 13 combinations accounted for 96.9% of all women. Reporting STI diagnoses varied by partnership-type combination, including after adjusting for age and partner numbers, for example, adjusted OR: 6.03 (95% CI 2.01 to 18.1) for men with two 'casual' and one 'now steady' partners versus men with one 'cohabiting' partner. CONCLUSIONS: This typology provides an objective method for measuring partnership type and demonstrates its importance in understanding STI risk, net of partner numbers. Epidemiological research and clinical practice should use these methods and results to maximise individual and public health benefit.

Sexually transmitted infections associated with alcohol use and HIV infection among men who have sex with men in Kampala, Uganda.

OBJECTIVES: Few studies have been conducted in Africa to assess prevalence of sexually transmitted infections (STIs) and risk factors among men who have sex with men (MSM). We report findings from the first behavioural survey to include STI testing among MSM in Kampala, Uganda. METHODS: Respondent-driven sampling (RDS) was used to recruit MSM for a biobehavioural survey. Eligible participants were men who reported anal sex with another man in the previous 3 months, were 18 years or older, and resided in Kampala. Information was collected on demographics, sexual behaviour, alcohol and drug use, and STI symptoms. Blood, urine and rectal specimens were tested for syphilis, HIV, rectal and urethral gonorrhoea, and chlamydia. Analyses weighted for RDS were conducted to assess associations with STI diagnosis. RESULTS: A total of 295 MSM participated in the survey. Almost half (weighted percentage: 47.3%) reported STI symptoms in the last 6 months and 12.9% tested HIV-positive. Prevalence of non-HIV STI was 13.5%; syphilis prevalence was 9.0%. Adjusting for age and education, STI was associated with HIV (adjusted OR (AOR)=3.46, 95% CI 1.03 to 11.64), alcohol use before sex (AOR=4.99, 95% CI 1.86 to 13.38) and having sold sex in the last 3 months (AOR=3.17, 95% CI 1.25 to 8.07), and inversely associated with having anonymous sex partners (AOR=0.20, 95% CI 0.07 to 0.61). CONCLUSIONS: We observed high levels of self-reported STI symptoms and STI prevalence associated with alcohol use and HIV among MSM in Kampala. Public health interventions supporting MSM are needed to address STI risk and facilitate access to diagnosis and treatment services.

Sexual sensation seeking in Spanish young men and women with different sexual orientations.

This study analyzes the relation of sexual orientation and gender to sexual sensation seeking. Participants were 382 individuals (200 men, 182 women) between 17 and 29 years old who completed the Sexual Sensation Seeking Scale. Of the 382 participants, 52.46% self-reported heterosexual orientation, and 47.64% self-reported homosexual orientation. The results showed differences with Sexual Sensation Seeking being more frequent among heterosexuals and men. There were no differences between heterosexual and homosexual men. Heterosexual women had higher sexual sensation seeking scores than did homosexual women. These results and their possible implications for the effective development of prevention and intervention programs in affective-sexual education are discussed.

Alcohol use and its association with HIV risk behaviors among a cohort of patients attending HIV clinical care in Tanzania, Kenya, and Namibia.

This article describes the frequency of alcohol use among HIV-positive patients attending clinical care in sub-Saharan Africa and explores the association between alcohol use, medication adherence, and sexual risk behavior. Data from 3538 patients attending an HIV clinic in Kenya, Tanzania, or Namibia were captured through interview and medical record abstraction. Participants were categorized into three drinking categories: nondrinkers, nonharmful drinkers, and harmful/likely dependent drinkers. A proportional odds model was used to identify correlates associated with categories of alcohol use. Overall, 20% of participants reported alcohol use in the past 6 months; 15% were categorized as nonharmful drinkers and 5% as harmful/likely dependent drinkers. Participants who reported missing a dose of their HIV medications [adjusted odds ratio (AOR): 2.04, 95% confidence interval (CI): 1.67, 2.49]; inconsistent condom use (AOR: 1.49, 95% CI: 1.23, 1.79); exchanging sex for food, money, gifts, or a place to stay (AOR: 1.57, 95% CI: 1.06, 2.32); and having a sexually transmitted infection symptom (AOR: 1.40, 95% CI: 1.10, 1.77) were more likely to be categorized in the higher risk drinking categories. This research highlights the need to integrate alcohol screening and counseling into the adherence and risk reduction counseling offered to HIV-positive patients as part of their routine care. Moreover, given the numerous intersections between alcohol and HIV, policies that focus on reducing alcohol consumption and alcohol-related risk behavior should be integrated into HIV prevention, care, and treatment strategies.

Sexual risk for HIV among gay male couples: a longitudinal study of the impact of relationship dynamics.

While the relationship context itself is increasingly being examined to understand sexual risk behavior among gay male couples, few studies have examined relationship dynamics and HIV risk longitudinally. We aimed to investigate relationship dynamics and psychosocial predictors of unprotected anal intercourse (UAI) with outside partners of serodiscordant or unknown HIV serostatus (UAIOUT) over time as well as UAI with primary partner in serodiscordant couples (UAIPP). We recruited a sample of 566 ethnically diverse, seroconcordant and serodiscordant couples and interviewed them six times over the course of 3 years. The surveys encompassed relationship dynamics between the partners and sexual behavior with primary and outside partners. We fit generalized linear mixed models for both the UAI outcomes with time and relationship dynamics as predictors while controlling for relationship length. Analyses of the longitudinal data revealed that, in both categories of couples, those with higher levels of positive relationship dynamics (e.g., commitment, satisfaction) were less likely to engage in UAIOUT. Higher investment in sexual agreement and communication were among the factors that significantly predicted less UAIOUT for seroconcordant couples, but not for the serodiscordant couples. For serodiscordant couples, greater levels of attachment and intimacy were associated with greater odds of UAIPP while increased HIV-specific social support was associated with lower odds of UAIPP. These results underscore the importance of creating and tailoring interventions for gay couples that help maintain and strengthen positive relationship dynamics as they have the potential to produce significant changes in HIV risk behavior and thereby in HIV transmission.

Effectiveness of a combination prevention strategy for HIV risk reduction with men who have sex with men in Central America: a mid-term evaluation.

BACKGROUND: Despite over a decade of research and programming, little evidence is available on effective strategies to reduce HIV risks among Central American men who have sex with men (MSM). The Pan-American Social Marketing Organization (PASMO) and partners are implementing a HIV Combination Prevention Program to provide key populations with an essential package of prevention interventions and services: 1) behavioral, including interpersonal communications, and online outreach; 2) biomedical services including HIV testing and counseling and screening for STIs; and 3) complementary support, including legal support and treatment for substance abuse. Two years into implementation, we evaluated this program's effectiveness for MSM by testing whether exposure to any or a combination of program components could reduce HIV risks. METHODS: PASMO surveyed MSM in 10 cities across Guatemala, El Salvador, Nicaragua, Costa Rica, and Panama in 2012 using respondent-driven sampling. We used coarsened exact matching to create statistically equivalent groups of men exposed and non-exposed to the program, matching on education, measures of social interaction, and exposure to other HIV prevention programs. We estimated average treatment effects of each component and all combined to assess HIV testing and condom use outcomes, using multivariable logistic regression. We also linked survey data to routine service data to assess program coverage. RESULTS: Exposure to any program component was 32% in the study area (n = 3531). Only 2.8% of men received all components. Men exposed to both behavioral and biomedical components were more likely to use condoms and lubricant at last sex (AOR 3.05, 95% CI 1.08, 8.64), and those exposed to behavioral interventions were more likely to have tested for HIV in the past year (AOR 1.76, 95% CI 1.01, 3.10). CONCLUSIONS: PASMO's strategies to reach MSM with HIV prevention programming are still achieving low levels of population coverage, and few men are receiving the complete essential package. However, those reached are able to practice HIV prevention. Combination prevention is a promising approach in Central America, requiring expansion in coverage and intensity.

[High-risk sexual behaviour by partner type among men who have sex with men]. / Conductas sexuales de alto riesgo en hombres que tienen relaciones sexuales con hombres según tipo de pareja sexual.

OBJECTIVE: To identify factors associated with high risk sexual practices among men who have sex with men (MSM) in Spain. METHODS: An online survey was conducted in 2010, which included, among others, questions on HIV/STI sexual behaviours and prevention needs. Unprotected anal intercourse (UAI) with a partner of unknown or discordant HIV status in the past year was defined as a high risk sexual behaviour. RESULTS: Of the 13,111 participants, 49.4% had had sex with steady partners (SP) and 73.4% with non-steady partners (NSP) in the last 12months; and the prevalence of high risk UAI was 25.4% and 29.4%, respectively. Factors associated with high risk UAI with SP were: living in a city of less than 500,000 inhabitants (OR=1.42 <100,000 inhabitants), being out to no-one or only a few people (OR=1.42), and being HIV-positive with undetectable viral load among those with a high level of HIV/STI knowledge (OR=3.18). Factors associated with high risk UAI with NSP were mainly: having a higher number of sexual partners (OR=4.31 >50 partners), having used drugs for sex (OR=1.33), and at parties (OR=1.19), having a medium (OR=1.82) or low (OR=1.33) level of HIV/STI knowledge, and being HIV-positive (OR=1.56). CONCLUSIONS: Among MSM, the prevalence of high risk sexual practices is high with both SP and NSP. Factors associated with high risk UAI vary by type of sexual partner (e.g., having HIV with an undetectable viral load). These must be taken into account when planning strategies for primary and secondary prevention.

Winners and losers in health insurance: access and type of coverage for women in same-sex and opposite-sex partnerships.

Using data from the American Community Survey, 2009 (N=580,754), we compared rates of health insurance coverage and types of coverage used between women in same-sex and opposite-sex partnerships. This large, national dataset also allowed us to investigate regional variation in insurance coverage for women in same-sex partnerships by comparing "gay-tolerant" states versus other states. Multivariate analyses revealed that women in same-sex partnerships consistently had lower rates of health insurance coverage than married women in opposite-sex partnerships, but always more than unmarried women in opposite-sex partnerships. We also found that state-level variation in gay tolerance did not contribute to the access or type of coverage used by women in same-sex partnerships.

A cross-sectional study of sexually transmitted pathogen prevalence and condom use with commercial and noncommercial sex partners among clients of female sex workers in southern India.

BACKGROUND: Clients of female sex workers (FSWs) are an important bridging population for HIV and other sexually transmitted infections. However, the extent of risk to female noncommercial partners (NCPs) of clients has not been explored. METHODS: Data originated from a cross-sectional behavioral and biological survey of FSW clients from 5 districts in Karnataka state, southern India. Clients were classified into 3 groups: married, single with at least 1 NCP, and single without an NCP. Bivariate and multivariable logistic regression models were constructed to examine the association between group membership and condom use patterns with FSWs and, where applicable, NCPs. HIV, herpes simplex virus type 2 (HSV-2), and other sexually transmitted infections were examined. Normalized weights were used to account for a complex sampling design. RESULTS: Most respondents in our sample (n = 2328) were married (61%). Compared with single respondents without an NCP, married clients were more likely to never use condoms with both occasional (adjusted odds ratio [AOR], 1.8; 95% confidence interval [CI], 1.3-2.5; P < 0.0001) and regular (AOR, 1.7; 95% CI, 1.1-2.6; P = 0.015) FSWs. Among clients with an NCP, married clients were at higher odds of never using a condom with their NCP (AOR, 5.5; 95% CI, 3.7-8.1; P < 0.0001). Overall prevalence for HIV, HSV-2, syphilis, and chlamydia or gonorrhea infection was 5.7%, 28.3%, 3.6%, and 2.1%, respectively. The prevalence of HSV-2 was 37%, 16%, and 19% among those who were married, those single without an NCP, and those single with an NCP, respectively. CONCLUSIONS: Married respondents were least likely to use condoms with both commercial and noncommercial sexual partners, while also having the highest prevalence of HSV-2. These results illustrate the risk posed to both commercial partners and NCPs of married clients.

Does perception of relationship type impact sexual health risk?

A sample of 327 men (age, 16-36 years) responded to self-completed questionnaires, which included questions regarding their most recent female sexual partner and specific behaviors pertaining to that partner. Analyses showed significant differences in several variables including condom use and sexually transmitted infection history, among the different relationship types.

HIV risk behaviors among Black/African American and Hispanic/Latina Female partners of men who have sex with men and women.

We examined the frequencies of HIV-related risk factors among women reporting and not reporting sex with a man who has sex with men and women (MSMW).We used data from 15,625 visits of Black and Hispanic/Latina females, ages 15­64 years, to Los Angeles County HIV testing sites (2007­2008). The following risk factors were associated with reporting an MSMW partner: number of sex partners, use of party drugs, anal sex, and sexual partners with other risk factors. Overall, females who reported an MSMW partner differed little in their likelihood of testing HIV positive (0.93%) compared to those who did not (0.58%, p value = 0.19). Among females reporting one male sex partner, having an MSMW partner was strongly associated with HIV (2.8 vs. 0.63%, p = 0.03). Interventions targeting women who report other risky behaviors may reach many who have been with MSMW. Women with one partner are an important focus of such efforts.

Sexual partnership types as determinant of HIV risk in South African MSM: an event-level cluster analysis.

While individual determinants of HIV risk among MSM have been widely studied, there is limited understanding of how relational characteristics determine sexual risk. Based on data collected among 300 South African men who have sex with men (MSM) and using cluster analysis, this study developed a typology of four partnership types: the "Race-Economic Similar," "Age-Race-Economic Discordant," "Non-regular Neighbourhood," and "Familiar" partnership types. Support for the meaningfulness of these types was found through associations of these partnership types with participant characteristics and characteristics of the last anal sex event. Furthermore, in a multivariate analysis, only partnership type independently predicted whether the last anal sex event was unprotected. Findings of the study illustrate the importance of taking into account the relational context in understanding unprotected sexual practices and present ways to target intervention efforts as well as identify relationship specific determinants of unprotected sex.

Consistent condom use among men with non-marital partners in four sub-Saharan African countries.

Data from the Demographic and Health Surveys for Namibia, Swaziland, and Zambia and the AIDS Indicator Survey from Tanzania were used to examine the influence of marital status and number of partners on consistent condom use among men with casual sexual partnerships in four generalized HIV epidemic settings. We restrict the sample to the 26% (Zambia), 29% (Tanzania), 35% (Swaziland), and 42% (Namibia) of men, who, in the last 12 months before the survey, had any non-marital/non-cohabiting (i.e., casual) sexual partners. We use "condom always used with any partner in the last 12 months" as a dichotomous-dependent measure of consistent condom use. Analyses were stratified by country. Of men with casual partners, 41% (Zambia) to 70% (Namibia) used a condom every time with at least one partner. The majority of men were unmarried/non-cohabiting with one casual partner in the last year. In Swaziland and Zambia, multivariate results suggest that unmarried/non-cohabiting men with one casual partner had significantly lower odds than married/cohabiting men with casual partners to use condoms consistently (odds ratio [OR]=0.56, p=0.01 and OR=0.41, p<0.001, respectively.). In Namibia, unmarried/non-cohabiting men with two or more casual partners had significantly greater odds than married/cohabiting men with casual partners to use condoms consistently (OR=2.80, p<0.01). With some exceptions by country, higher education, religious group, wealth, having no children, knowing HIV results, having an STI, having one lifetime partner, and positive condom knowledge and beliefs also were significantly associated with using a condom every time with any partner. We conclude that consistent condom use remains an elusive goal even among men with casual sexual relationships. Condom use messages should be refined and targeted to men based on their number and types of relationships and combined with other messages to decrease concurrent relationships.