Gender differences in the risk of HIV infection among persons reporting abstinence, monogamy, and multiple sexual partners in northern Tanzania

The Risk of HIV/STDs Infection and Transmission Among Never-Married Male Migrants in China: Is Risk Attributable to Bachelorhood or Migration?

In the context of sex-ratio imbalance and rural-to-urban migration in China, never-married male migrants may become a vulnerable group as well as a bridge population that facilitates HIV/STDs transmission. It is still not clear, however, whether increased HIV/STDs transmission risk can be attributed to bachelorhood, migration, or both. This study identified the contributions of bachelorhood and migration to an increased risk of HIV/STDs infection, as well as the risk of HIV/STDs transmission across populations and regions. Data were from a cross-sectional questionnaire survey, in which 180 never-married non-migrant males in rural areas, 558 never-married male migrants, and 302 married male migrants in urban areas of China were interviewed in 2017. Results showed that never-married male migrants are more likely to engage in commercial sex and unsafe sex than never-married non-migrant males, and their likelihood of engaging in unsafe sex was also higher than married male migrants. Although never-married male migrants were less likely to have multiple sex partners than married male migrants, they were more likely to have multiple sex partners and sex partners from different regions than never-married non-migrant males. These findings indicate that both migration and bachelorhood increase the risk of HIV/STDs infection for never-married male migrants, and migration also increases the risk of HIV/STDs transmission across populations and regions.

Associations Between Khat Use and HIV Risk and Status Among Voluntary Counseling and Testing Center Clients in Addis Ababa, Ethiopia

OBJECTIVES

Ethiopia is 1 of 15 countries that account for nearly 75% of all people living with HIV. Khat use, a common practice in Ethiopia and sub-Saharan Africa, has gained attention as a potential risk factor for HIV. Our objective was to evaluate associations between khat use and demographic and risk-taking characteristics (alcohol use, sexual behavior), and also associations between HIV status and these characteristics among voluntary counseling and testing clients in Addis Ababa, Ethiopia.

METHODS

This cross-sectional study was conducted among Pro Pride voluntary counseling and testing center clients, aged 18 to 49 years, from November 2009 to March 2010. All clients were approached, and 98.8% of these (684) completed a self-administered questionnaire. Associations between khat use, alcohol use, multiple sexual partners, and HIV status were assessed using logistic regression models.

RESULTS

Using khat in the past 90 days (current khat use) was significantly associated with being Muslim, being male, alcohol use, and having a greater number of sex partners in one's lifetime. The adjusted odds of current khat use was almost 7-fold higher in those having 4 or more sexual partners in their lifetime (adjusted odds ratio 6.89, 95% confidence interval 3.87, 12.25) as compared with those with 1 or none. HIV-positive status was significantly associated with age, employment, marital status, number of sex partners in one's lifetime, and khat use. Having used khat in one's lifetime, but not currently, past khat use, was associated with over a 2-fold increased adjusted odds (adjusted odds ratio 2.64, 95% confidence interval 1.13, 6.19) of being HIV-infected.

CONCLUSIONS

Our findings highlight associations between current khat use and the modifiable factors of number of lifetime sexual partners and alcohol use. In addition, we observed the association between HIV status and past khat use after adjusting for age, marital status, and number of sex partners in one's lifetime.

Would you test for 5000 Shillings? HIV risk and willingness to accept HIV testing in Tanzania

OBJECTIVES

Despite substantial public health efforts to increase HIV testing, testing rates have plateaued in many countries and rates of repeat testing for those with ongoing risk are low. To inform policies aimed at increasing uptake of HIV testing, we identified characteristics associated with individuals' willingness-to-accept (WTA) an HIV test in a general population sample and among two high-risk populations in Moshi, Tanzania.

METHODS

In total, 721 individuals, including randomly selected community members (N = 402), female barworkers (N = 135), and male Kilimanjaro mountain porters (N = 184), were asked in a double-bounded contingent valuation format if they would test for HIV in exchange for 2000, 5000 or 10,000 Shillings (approximately $1.30, $3.20, and $6.40, respectively). The study was conducted between September 2012 and February 2013.

RESULTS

More than one quarter of participants (196; 27 %) stated they would be willing to test for Tanzania Shilling (TSH) 2000, whereas one in seven (98; 13.6 %) required more than TSH 10,000. The average WTA estimate was TSH 4564 (95 % Confidence Interval: TSH 4201 to 4927). Significant variation in WTA estimates by gender, HIV risk factors and other characteristics plausibly reflects variation in individuals' valuations of benefits of and barriers to testing. WTA estimates were higher among males than females. Among males, WTA was nearly one-third lower for those who reported symptoms of HIV than those who did not. Among females, WTA estimates varied with respondents' education, own and partners' HIV testing history, and lifetime reports of transactional sex. For both genders, the most significant association was observed with respondents' perception of the accuracy of the HIV test; those believing HIV tests to be completely accurate were willing to test for approximately one third less than their counterparts. The mean WTA estimates identified in this study suggest that within the study population, incentivized universal HIV testing could potentially identify undiagnosed HIV infections at an incentive cost of $150 per prevalent infection and $1400 per incident infection, with corresponding costs per quality adjusted life year (QALY) gained of $70 for prevalent and $620 for incident HIV infections.

CONCLUSIONS

The results support the value of information about the accuracy of HIV testing, and suggest that relatively modest amounts of money may be sufficient to incentivize at-risk populations to test.

The racial disparities in STI in the U.S.: Concurrency, STI prevalence, and heterogeneity in partner selection

Background

There is a large and persistent racial disparity in STI in the U.S. which has placed non-Hispanic-Blacks at disproportionately high risk. We tested a hypothesis that both individual-level risk factors (partner number, anal sex, condom use) and local-network features (concurrency and assortative mixing by race) combine to account for the association between race and chlamydia status.

Methods

Data from the Longitudinal Survey of Adolescent Health Wave III were used. Chlamydia status was determined using biomarkers. Individual-level risk behaviors were self-reported. Network location variables for concurrency and assortative mixing were imputed using egocentrically sample data on sexual partnerships.

Results

After controlling for demographic attributes including age, sex, marital status, education and health care access there remained a strong association between race and chlamydia status (OR = 5.23, 95% CI] 3.83–7.15], p < .001 for Non-Hispanic Blacks with Non-Hispanic Whites as the reference category). The inclusion of individual-level risk factors did not alter the association between race and chlamydia(OR = 5.23 for Non-Hispanic Blacks). The inclusion of concurrency and assortative mixing by race substantially reduced the association between race and chlamydia status (OR = 1.87, 95% CI [0.89–3.91] p > .05 for Non-Hispanic Blacks).

Heterogeneous HIV testing preferences in an urban setting in Tanzania: results from a discrete choice experiment

BACKGROUND

Efforts to reduce Human Immunodeficiency Virus (HIV) transmission through treatment rely on HIV testing programs that are acceptable to broad populations. Yet, testing preferences among diverse at-risk populations in Sub-Saharan Africa are poorly understood. We fielded a population-based discrete choice experiment (DCE) to evaluate factors that influence HIV-testing preferences in a low-resource setting.

METHODS

Using formative work, a pilot study, and pretesting, we developed a DCE survey with five attributes: distance to testing, confidentiality, testing days (weekday vs. weekend), method for obtaining the sample for testing (blood from finger or arm, oral swab), and availability of HIV medications at the testing site. Cluster-randomization and Expanded Programme on Immunization (EPI) sampling methodology were used to enroll 486 community members, ages 18-49, in an urban setting in Northern Tanzania. Interviewer-assisted DCEs, presented to participants on iPads, were administered between September 2012 and February 2013.

RESULTS

Nearly three of five males (58%) and 85% of females had previously tested for HIV; 20% of males and 37% of females had tested within the past year. In gender-specific mixed logit analyses, distance to testing was the most important attribute to respondents, followed by confidentiality and the method for obtaining the sample for the HIV test. Both unconditional assessments of preferences for each attribute and mixed logit analyses of DCE choice patterns suggest significant preference heterogeneity among participants. Preferences differed between males and females, between those who had previously tested for HIV and those who had never tested, and between those who tested in the past year and those who tested more than a year ago.

CONCLUSION

The findings suggest potentially significant benefits from tailoring HIV testing interventions to match the preferences of specific populations, including males and females and those who have never tested for HIV.

Love, lust and the emotional context of multiple and concurrent sexual partnerships among young Swazi adults

Men and women in Swaziland who are engaged in multiple or concurrent sexual partnerships, or who have sexual partners with concurrent partners, face a very high risk of HIV infection. Ninety-four in-depth interviews were conducted with 28 Swazi men and women (14 of each sex) between the ages of 20 and 39 to explore participants' sexual partnership histories, including motivations for sexual relationships which carried high HIV risk. Concurrency was normative, with most men and women having had at least one concurrent sexual partnership, and all women reporting having had at least one partner who had a concurrent partner. Men distinguished sexual partnerships that were just for sex from those that were considered to be 'real relationships', while women represented most of their relationships, even those which included significant financial support, as being based on love. Besides being motivated by love, concurrent sexual partnerships were described as motivated by a lack of sexual satisfaction, a desire for emotional support and/or as a means to exact revenge against a cheating partner. Social and structural factors were also found to play a role in creating an enabling environment for high-risk sexual partnerships. These factors included social pressure and norms; a lack of social trust; poverty and a desire for material goods; and geographical separation of partners.

Investigation of HIV Incidence Rates in a High-Risk, High-Prevalence Kenyan Population: Potential Lessons for Intervention Trials and Programmatic Strategies

Cost-effective HIV prevention programs should target persons at high risk of HIV acquisition. We conducted an observational HIV incidence cohort study in Kisumu, Kenya, where HIV prevalence is triple that of the national rate. We used referral and venue-sampling approaches to enroll HIV-negative persons for a 12-month observational cohort, August 2010 to September 2011, collected data using computer-assisted interviews, and performed HIV testing quarterly. Among 1292 eligible persons, 648 (50%) were excluded for HIV positivity and other reasons. Of the 644 enrollees, 52% were women who were significantly older than men (P<.01). In all, 7 persons seroconverted (incidence rate [IR] per 100 person-years=1.11; 95% confidence interval [CI] 0.45-2.30), 6 were women; 5 (IR=3.14; 95% CI 1.02-7.34) of whom were ≤25 years. Most new infections occurred in young women, an observation consistent with other findings in sub-Saharan Africa that women aged ≤25 years are an important population for HIV intervention trials in Africa.

From coitus to concurrency: sexual partnership characteristics and risk behaviors of 15-19 year old men recruited from urban venues in Tanzania

Understanding the uptake and patterns of sexual partnerships of adolescent males reveals their risky behaviors that could persist into adulthood. Using venue-based sampling, we surveyed 671 male youth ages 15-19 from an urban Tanzanian neighborhood about their sexual partnerships during the past 6 months. The proportion of males who had ever had sex increased with age (21 % at age 15; 70 % at age 17; 94 % at age 19), as did the proportion who engaged in concurrency (5 % at age 15; 28 % at age 17; 44 % at age 19). Attendance at ≥2 social venues per day and meeting a sexual partner at a venue was associated with concurrency. Concurrency was associated with alcohol consumption before sex among 18-19 year olds and with not being in school among 15-17 year olds. We find that concurrency becomes normative over male adolescence. Venue-based sampling may reach youth vulnerable to developing risky sexual partnership patterns.

Modernization, sexual risk-taking, and gynecological morbidity among Bolivian Forager-horticulturalists

Sexual risk-taking and reproductive morbidity are common among rapidly modernizing populations with little material wealth, limited schooling, minimal access to modern contraception and healthcare, and gendered inequalities in resource access that limit female autonomy in cohabiting relationships. Few studies have examined how modernization influences sexual risk-taking and reproductive health early in demographic transition. Tsimane are a natural fertility population of Bolivian forager-farmers; they are not urbanized, reside in small-scale villages, and lack public health infrastructure. We test whether modernization is associated with greater sexual risk-taking, report prevalence of gynecological morbidity (GM), and test whether modernization, sexual risk-taking and parity are associated with greater risk of GM. Data were collected from 2002-2010 using interviews, clinical exams, and laboratory analysis of cervical cells. We find opposing effects of modernization on both sexual risk-taking and risk of GM. Residential proximity to town and Spanish fluency are associated with greater likelihood of men's infidelity, and with number of lifetime sexual partners for men and women. However, for women, literacy is associated with delayed sexual debut after controlling for town proximity. Fifty-five percent of women present at least one clinical indicator of GM (n = 377); 48% present inflammation of cervical cells, and in 11% the inflammation results from sexually transmitted infection (trichomoniasis). Despite having easier access to modern healthcare, women residing near town experience greater likelihood of cervical inflammation and trichomoniasis relative to women in remote villages; women who are fluent in Spanish are also more likely to present trichomoniasis relative to women with moderate or no fluency. However, literate women experience lower likelihood of trichomoniasis. Parity has no effect on risk of GM. Our results suggest a net increase in risk of reproductive morbidity among rapidly modernizing, resource-stressed populations.

Variation in concurrent sexual partnerships and sexually transmitted diseases among African men in Cape Town, South Africa

BACKGROUND

Most studies that assess the relationship between concurrent sexual partnerships and sexually transmitted diseases (STDs) use dichotomous measures of whether concurrency was reported or not. However, different forms of concurrency have different degrees of associated risk for disease transmission, and this should be considered. This article examines variation in both individual concurrency and partner concurrency among African men in Cape Town, South Africa, and assesses the relationship between different types of concurrent partnerships and STDs.

METHODS

Longitudinal data from sexual partner history tables are used to form measures of concurrency and the type of partner (main vs. nonmain) and degree of condom use (consistent vs. inconsistent) associated with these concurrent relationships. Cross-sectional data from a self-administered module are also used to assess the number of partners men have had concurrently and duration of individual concurrency. Probit regression models assess the association between the partner concurrency measures and self-reported STD history.

RESULTS

Substantial differences between concurrent sexual partnerships were observed and these variations were associated with different disease risk. Men had a greater chance of reporting an STD when partner concurrency was associated with main partners and inconsistent condom use.

CONCLUSION

Partnership dynamics must be taken into account in studies assessing the role of concurrency in STD transmission.

Changes in HIV risk behavior and seroincidence among clients presenting for repeat HIV counseling and testing in Moshi, Tanzania

While HIV counseling and testing (HCT) has been considered an HIV preventive measure in Africa, data are limited describing behavior changes following HCT. This study evaluated behavior changes and estimated HIV seroincidence rate among returning HCT clients. Repeat and one-time testing clients receiving HCT services in Moshi, Tanzania were identified. Information about sociodemographic characteristics, HIV-related behaviors and testing reasons were collected, along with HIV serostatus. Six thousand seven hundred and twenty-seven clients presented at least once for HCT; 1235 (18.4%) were HIV seropositive, median age was 29.7 years and 3712 (55.3%) were women. 1382 repeat and 4272 one-time testers were identified. Repeat testers were more likely to be male, older, married, or widowed, and testing because of unfaithful partner or new sexual partner. One-time testers were more likely to be students and testing due to illness. At second test, repeat testers were more likely to report that partners had received HIV testing, not have concurrent partners, not suspect partners have HIV, and have partners who did not have other partners. Clients who intended to change behaviors after the first test were more likely to report having changed behaviors by remaining abstinent (OR 2.58; p<0.0001) or using condoms (OR 2.00; p=0.006) at the second test. HIV seroincidence rate was 1.49 cases/100 person-years (PY). Clients presenting for repeat HCT reported some reduction of risky behavior and improved knowledge of sexual practices and HIV serostatus of their partners. Promoting behavior change through HCT should continue to be a focus of HIV prevention efforts in sub-Saharan Africa.

Correlates of HIV Infection Among Sexually Active Adults in Kenya: A National Population-Based Survey

OBJECTIVE

To identify factors associated with prevalent HIV in a national HIV survey in Kenya.

METHODS

The Kenya AIDS Indicator Survey was a nationally representative population-based sero-survey that examined demographic and behavioral factors and serologic testing for HIV, HSV-2 and syphilis in adults aged 15-64 years. We analyzed questionnaire and blood testing data to identify significant correlates of HIV infection among sexually active adults.

RESULTS

Of 10,957 eligible women and 8,883 men, we interviewed 10,239 (93%) women and 7,731 (87%) men. We collected blood specimens from 9,049 women and 6,804 men of which 6,447 women and 5,112 men were sexually active during the 12 months prior to the survey. HIV prevalence among sexually active adults was 7.4%. Factors independently associated with HIV among women were region (Nyanza vs Nairobi: adjusted OR [AOR] 1.6, 95%CI 1.1-2.3), number of lifetime sex partners (6-9 vs 0-1 partners: AOR 3.0, 95%CI 1.6-5.9), HSV-2 (AOR 6.5, 95%CI 4.9-8.8), marital status (widowed vs never married: AOR 2.7, 95%CI 1.5-4.8) and consistent condom use with last sex partner (AOR 2.3, 95%CI 1.6-3.4). Among men, correlates of HIV infection were 30-to-39-year-old age group (AOR 5.2, 95%CI 2.6-10.5), number of lifetime sex partners (10+ vs 0-1 partners, AOR 3.5, 95%CI 1.4-9.0), HSV-2 (AOR 4.7, 95%CI 3.2-6.8), syphilis (AOR 2.4, 95%CI 1.4-4.0), consistent condom use with last sex partner (AOR 2.1, 95% CI 1.5-3.1) and lack of circumcision (AOR 4.0, 95%CI 2.8 - 5.5).

CONCLUSION

Kenya's heterogeneous epidemic will require regional and gender-specific prevention approaches.

Risk factors for HIV-1 infection in a longitudinal, prospective cohort of adults from the Mbeya Region, Tanzania

BACKGROUND

To control the global HIV epidemic, targeted interventions to reduce the incidence of HIV infections are urgently needed until an effective HIV vaccine is available. This study describes HIV-1 incidence and associated risk factors in a general population cohort of adults from Mbeya region, Tanzania, who participated in a vaccine preparedness study.

METHODS

We conducted a closed prospective cohort study with 6-monthly follow-up from 2002 to 2006 enrolling adults from the general population. HIV-1 incidence and risk factors for HIV-1 acquisition were analyzed using Cox regression.

RESULTS

We observed 2578 seronegative participants for a mean period of 3.06 person years (PY) (7471 PY in total). Overall HIV-1 incidence was 1.35 per 100 PY (95% confidence interval [CI], 1.10-1.64/100 PY). The highest overall HIV-1 incidence was found in females from Itende village (1.55 per 100 PY; 95% CI, 0.99-2.30/100 PY); the highest age-specific incidence was observed in semiurban males aged 30 to 34 years (2.75 per 100 PY; 95% CI, 0.75-7.04). HIV-1 acquisition was independently associated with female gender (hazard ratio [HR], 1.64; 95% CI, 1.05-2.57), younger age at enrollment (age 18-19 versus 35-39 years: HR, 0.29; 95% CI, 0.11-0.75), alcohol consumption (almost daily versus none: HR, 2.01; 95% CI, 1.00-4.07), education level (secondary school versus none: HR, 0.39; 95% CI, 0.17-0.89), and number of lifetime sex partners (more than five versus one: HR, 2.22; 95% CI, 1.13-4.36).

CONCLUSIONS

A high incidence of HIV was observed in this cohort, and incident infection was strongly associated with young age, alcohol consumption, low school education level, and number of sex partners. Targeted interventions are needed to address the elevated risk associated with these factors.

Concurrency revisited: increasing and compelling epidemiological evidence

Multiple sexual partnerships must necessarily lie at the root of a sexually transmitted epidemic. However, that overlapping or concurrent partnerships have played a pivotal role in the generalized epidemics of sub-Saharan Africa has been challenged. Much of the original proposition that concurrent partnerships play such a role focused on modelling, self-reported sexual behaviour data and ethnographic data. While each of these has definite merit, each also has had methodological limitations. Actually, more recent cross-national sexual behaviour data and improved modelling have strengthened these lines of evidence. However, heretofore the epidemiologic evidence has not been systematically brought to bear. Though assessing the epidemiologic evidence regarding concurrency has its challenges, a careful examination, especially of those studies that have assessed HIV incidence, clearly indicates a key role for concurrency.Such evidence includes: 1) the early and dramatic rise of HIV infection in generalized epidemics that can only arise from transmission through rapid sequential acute infections and thereby concurrency; 2) clear evidence from incidence studies that a major portion of transmission in the population occurs via concurrency both for concordant negative and discordant couples; 3) elevation in risk associated with partner's multiple partnering; 4) declines in HIV associated with declines in concurrency; 5) bursts and clustering of incident infections that indicate concurrency and acute infection play a key role in the propagation of epidemics; and 6) a lack of other plausible explanations, including serial monogamy and non-sexual transmission. While other factors, such as sexually transmitted infections, other infectious diseases, biological factors and HIV sub-type, likely play a role in enhancing transmission, it appears most plausible that these would amplify the role of concurrency rather than alter it. Additionally, critics of concurrency have not proposed plausible alternative explanations for why the explosive generalized epidemics occurred. Specific behaviour change messaging bringing the concepts of multiple partnering and concurrency together appears salient and valid in promoting safer individual behaviour and positive social norms.

A cost-effectiveness analysis of alternative HIV retesting strategies in sub-saharan Africa

BACKGROUND

Guidelines in sub-Saharan Africa on when HIV-seronegative persons should retest range from never to annually for lower-risk populations and from annually to every 3 months for high-risk populations.

METHODS

We designed a mathematical model to compare the cost-effectiveness of alternative HIV retesting frequencies. Cost of HIV counseling and testing, linkage to care, treatment costs, disease progression, and mortality, and HIV transmission are modeled for three hypothetical cohorts with posited annual HIV incidence of 0.8%, 1.3%, and 4.0%, respectively. The model compared costs, quality-adjusted life-years gained, and secondary infections averted from testing intervals ranging from 3 months to 30 years. Input parameters from sub-Saharan Africa were used and explored in sensitivity analyses.

RESULTS

Accounting for secondary infections averted, the most cost-effective testing frequency was every 7.5 years for 0.8% incidence, every 5 years for 1.3% incidence, and every 2 years for 4.0% incidence. Optimal testing strategies and their relative cost-effectiveness were most sensitive to assumptions about HIV counseling and testing and treatment costs, rates of CD4 decline, rates of HIV transmission, and whether tertiary infections averted were taken into account.

CONCLUSIONS

While higher risk populations merit more frequent HIV testing than low risk populations, regular retesting is beneficial even in low-risk populations. Our data demonstrate benefits of tailoring testing intervals to resource constraints and local HIV incidence rates.