Exposure to comprehensive sexuality education in schools in South Africa: the implications on the uptake of HIV testing services among HIV positive adolescent girls

Comprehensive sexuality education (CSE) is seen as a key instrument through which to affect behaviour and improve sexual and reproductive health (SRH) outcomes amongst adolescents. However, few studies have to date evaluated key SRH outcomes following exposure to CSE within a school setting. This study estimates the association between CSE and HIV testing and HIV testing self-efficacy amongst HIV positive adolescent girls. Data were collected from a cross-sectional survey administered in four high HIV prevalence districts . Independent variables included exposure to CSE, with outcome variables measuring uptake of HIV testing in the 12 months preceding the survey, and HIV testing self-efficacy. The sample comprised 505 HIV positive adolescent girls aged 12-19. . Attending CSE was associated with both; being more confident to get an HIV test (AOR: 2.44, 95% CI: 1.47-4.06, p < 0.001) and having ever tested for HIV (AOR: 2.15, 95% CI: 1.39-3.33, p < 0.001) while controlling for numerous variables. Results suggest CSE can play an important role in not only affecting HIV-related behaviours themselves, but also critical factors that affect HIV behaviours, including self-efficacy.

Associations of Social Support with Sexual Practices, Health Behaviours, and Health Outcomes Among Adolescent Girls and Young Women: Evidence From a Longitudinal Study in KwaZulu-Natal, South Africa

BACKGROUND

Several studies have reported on the benefits of social support for health behaviour, including risky sex. Social support may thus be an important resource for promoting individual health and well-being, particularly in regions where HIV rates are high and healthcare resources are scarce. However, prior research on the implications of social support for the health behaviour of young women has yielded mixed and inconclusive findings. Using prospective data from young women in South Africa, this study examines the associations of social support with subsequent sexual practices, health behaviour, and health outcomes.

METHOD

We used two rounds of longitudinal data from a sample of n = 1446 HIV-negative emerging adult women, aged 18 to 29 years, who participated in a population-based HIV study in KwaZulu-Natal, South Africa. Applying the analytic template for outcome-wide longitudinal designs, we estimated the associations between combinations of social support (i.e. tangible, educational, emotional) and ten HIV risk-related outcomes.

RESULTS

Combinations of tangible, educational, and emotional support, as well as tangible support by itself, were associated with lower risk for several outcomes, whereas educational and emotional support, by themselves or together, showed little evidence of association with the outcomes.

CONCLUSION

This study highlights the protective role of tangible support in an environment of widespread poverty, and the additional effect of combining tangible support with non-tangible support. The findings strengthen recent evidence on the benefits of combining support in the form of cash and food with psychosocial care in mitigating risk behaviours associated with HIV and negative health outcomes among young women.

HIV incidence and associated risk factors in adolescent girls and young women in South Africa: A population-based cohort study

BACKGROUND

In sub-Saharan Africa, high HIV incidence rates in adolescent girls and young women (AGYW) persist despite extensive HIV prevention efforts.

METHODS

A prospective cohort of 2,710 HIV-negative AGYW (15-24 years) in KwaZulu-Natal, South Africa were interviewed at baseline and followed-up approximately 18 months later (2014-2017). Associations between HIV seroconversion and socio-demographic and behavioural variables measured at baseline and follow-up were examined using Cox regression and a proximate determinants framework. Inter-relationships between determinants were measured using logistic regression. Separate models were built for 15-19 and 20-24-year-olds.

RESULTS

Weighted HIV incidence was 3.92 per 100 person-years (95% confidence interval: 3.27-4.69; 163 seroconversions over 4,016 person-years). Among 15-19-year-olds, absence of family support (adjusted hazards ratio (aHR): 3.82 (1.89-7.72)), having a circumcised partner (aHR: 0.5 (0.27-0.94)) or one who was HIV-positive and not on antiretroviral therapy (ART) (aHR: 6.21 (2.56-15.06)) were associated with HIV incidence. Those reporting an absence of family support were also more likely to report >1 partner during follow-up (odds ratio (OR): 2.7(1.11-6.57)). Among 20-24-year-olds, failure to complete secondary school (aHR: 1.89 (1.11-3.21)), inconsistent condom use (aHR: 3.01 (1.14-7.96)) and reporting partner(s) who were HIV-positive and not on ART (aHR: 7.75 (3.06-19.66)) were associated with HIV incidence. Failure to complete secondary school among 20-24-year-olds was associated with inconsistent condom use (OR: 1.82 (1.20-2.77)) and reporting an HIV-positive partner not on ART (OR: 3.53(1.59-7.82)) or an uncircumcised partner (OR: 1.39 (1.08-1.82).

CONCLUSION

Absence of family support and incomplete schooling are associated with risky sexual behaviours and HIV acquisition in AGYW. In addition, partner-level prevention-condom use, medical circumcision, and viral suppression-continue to play an important role in reducing HIV risk in AGYW. These findings support the use of combination HIV prevention programs that consider structural as well as biological and behavioural HIV risk factors in their design.

Role of Schooling and Comprehensive Sexuality Education in Reducing HIV and Pregnancy Among Adolescents in South Africa

BACKGROUND

Comprehensive sexuality education (CSE) seeks to reduce risky sexual behaviour and subsequent incidence of unintended pregnancy and HIV among schoolgoing adolescents. This study estimates the association between exposure to CSE and key biomedical and behavioural indicators among adolescent girls in South Africa.

SETTING

Four DREAMS implementation districts in Gauteng and KwaZulu-Natal provinces in South Africa.

METHODS

Data from a household-based representative sample of adolescent girls (between the ages 12-18 years) (n = 9673) was collected. Independent variables included school attendance and exposure to CSE, with outcome variables measuring prevalence of HIV, pregnancy, and sexual risky behaviour, including condom use, incidence of age-disparate relationships, and transactional sex.

RESULTS

Adolescent girls in school and who had attended CSE classes in the previous 12 months were associated with reduced adjusted odds of being HIV-positive [full sample: adjusted odds ratios (AOR): 0.76, 95% confidence interval [CI]: 0.61 to 0.95, P < 0.05; sexually active sample: AOR: 0.62, 95% CI: 0.40 to 0.96, P < 0.05]. Those in school who attended CSE in the previous 12 months were also more likely to get tested for HIV (AOR: 1.48, 95% CI: 1.32 to 1.65, P < 0.001).

CONCLUSIONS

The results indicate that school attendance and exposure to CSE is associated with a reduction in risky sexual behaviour. Exposure to CSE is also associated with increased access to HIV testing for adolescent girls both in and out of school. Keeping adolescent girls in school produces the greatest positive sexual behavioural effect; this, coupled with the delivery of quality CSE, is a key strategy for reducing HIV risk.

Determining HIV risk for Adolescent Girls and Young Women (AGYW) in relationships with "Blessers" and age-disparate partners: a cross-sectional survey in four districts in South Africa

BACKGROUND

HIV incidence among adolescent girls and young women (AGYW) remains high, with their male partners a prominent factor in sustaining these elevated rates. Partnership characteristics remain important metrics for determining HIV risk, with evidence indicating that AGYW engaged in transactional and age-disparate relationships face greater HIV exposure. This study examines the risk posed to AGYW in a relationship with a "Blesser", defined as male who provides his female partner with their material needs or desires in exchange for a sexual relationship, an age-disparate (5 or more years older) partner, and the potential compounded risk of being a relationship with a partner or partners who are considered both a "Blesser" and age-disparate.

METHODS

A cross -sectional household based representative sample of AGYW (aged between 12-24 years) were enrolled in the study (n = 18 926) from the districts of City of Johannesburg and Ekurhuleni in the Gauteng province and the Districts of eThekwini and uMgungundlovu in the province of KwaZulu-Natal (KZN) in South Africa between March 13, 2017 to June 22, 2018. Participants completed a structured questionnaire and provided finger-prick blood samples for laboratory measurements. Our analysis used descriptive statistics and multiple binary logistic regressions accounting for survey weights, clustering and stratification.

FINDINGS

The median age of the sample was 21 years old (Interquartile range: 19-23) and nearly three quarters (73.7%) were currently attending school. Whilst all relationships exposed AGYW to potential HIV risk, multiple binary logistic regression analysis revealed that AGYW in a relationship with both a Blesser and an age-disparate partner were more likely to be HIV positive (AOR: 3.12, 95% CI: 1.76-5.53, p < 0.001), diagnosed with an STI (AOR: 4.60, 95% CI: 2.99-7.08, p < 0.001), had 2 or more sexual partners in the previous 12 months (AOR: 6.37, 95% CI: 3.85-10.54, p < 0.001), engaged in sexual activity at age 15 or younger (AOR: 3.67, 95% CI: 2.36-5.69, p < 0.001) and more likely to have ever been pregnant (AOR: 2.60, 95% CI: 1.24-5.45, p < 0.05) than those not in a relationship with either a Blesser or age-disparate partner.

CONCLUSION

Different relationships present different HIV risk to AGYW. AGYW who had engaged in relationships with both a Blesser and an age-disparate partner were at greater HIV risk when examined against these relationships independent of one another. The data reveals the compounded HIV risk of being in both a transactional and age-disparate relationship.

Association of HIV Intervention Uptake With HIV Prevalence in Adolescent Girls and Young Women in South Africa

IMPORTANCE

In South Africa, adolescent girls and young women aged 15 to 24 years are among the most high-risk groups for acquiring HIV. Progress in reducing HIV incidence in this population has been slow.

OBJECTIVE

To describe HIV prevalence and HIV risk behaviors among a sample of adolescent girls and young women and to model the association between exposure to multiple or layered interventions and key HIV biological and behavioral outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional survey was conducted between March 13, 2017, and June 22, 2018, in 2 districts in Gauteng province and in 2 districts in KwaZulu-Natal province in South Africa. A stratified cluster random sampling method was used. Participants included adolescent girls and young women aged 12 to 24 years who lived in each sampled household. Overall, 10 384 participants were enrolled in Gauteng province and 7912 in KwaZulu-Natal province. One parent or caregiver was interviewed in each household. Data analysis was performed from March 12, 2021, to March 1, 2022.

EXPOSURES

DREAMS (Determined, Resilient, Empowered, AIDS-free, Mentored, and Safe)-like interventions.

MAIN OUTCOMES AND MEASURES

The primary outcome was HIV prevalence. HIV status was obtained from laboratory-based testing of peripheral blood samples. Secondary outcomes included HIV testing and antiretroviral therapy uptake as well as numerous HIV risk variables that the DREAMS program sought to improve, such as pregnancy, sexually transmitted infection, intimate partner violence, and age-disparate sex.

RESULTS

The final sample included 18 296 adolescent girls and young women (median [IQR] age, 19 [15-21] years) in 10 642 households. Approximately half of participants (49.9%; n = 8414) reported engaging in sexual activity, and 48.1% (n = 3946) reported condom use at the most recent sexual encounter. KwaZulu-Natal province had a higher HIV prevalence than Gauteng province (15.1% vs 7.8%; P < .001). Approximately one-fifth of participants (17.6%; n = 3291) were not exposed to any interventions, whereas 43.7% (n = 8144) were exposed to 3 or more interventions. There was no association between exposure to DREAMS-like interventions and HIV status. Adolescent girls and young women who accessed 3 or more interventions were more likely to have undergone HIV testing (adjusted odds ratio, 2.39; 95% CI, 2.11-2.71; P < .001) and to have used condoms consistently in the previous 12 months (adjusted odds ratio, 1.68; 95% CI, 1.33-2.12; P < .001) than those who were not exposed to any interventions.

CONCLUSIONS AND RELEVANCE

Results of this study suggest that self-reported exposures to multiple or layered DREAMS-like interventions were associated with favorable behavioral outcomes. The beneficial aspects of layering HIV interventions warrant further research to support the sexual and reproductive health of adolescent girls and young women.

Depression symptoms, HIV testing, linkage to ART, and viral suppression among women in a high HIV burden district in KwaZulu-Natal, South Africa: A cross-sectional household study

Achieving the UNAIDS 90-90-90 targets by 2020 is contingent on identifying and addressing mental health challenges that may affect HIV testing and treatment-related behaviors. This study is based on survey data from KwaZulu-Natal, South Africa (2014–2015). HIV positive women who reported higher depression scores had a lower odds of having tested previously for HIV (15–25 years: AOR = 0.90, 95% CI [0.83, 0.98]; 26–49 years: AOR = 0.90, 95% CI [0.84, 0.96]). Because HIV testing behavior represents a gateway to treatment, the findings suggest mental health may be one challenge to attaining the UNAIDS 90-90-90 targets.

Population prevalence of sexually transmitted infections in a high HIV burden district in KwaZulu-Natal, South Africa: Implications for HIV epidemic control

BACKGROUND

Sexually transmitted infections (STIs) and Human immunodeficiency virus (HIV) share a complex bidirectional relationship, however, population prevalence and the association between the presence of STIs and HIV in a high HIV burden district in KwaZulu-Natal, South Africa is not known.

METHODS

A total of 9812 participants aged 15-49 years were enrolled in a cross-sectional population-based household survey. Participants completed a structured questionnaire and provided first-pass urine (males) or self-collected vulvo-vaginal swabs (females) for the detection of STIs.

RESULTS

Prevalence of herpes simplex virus type-2 (HSV-2) was 57.8%, syphilis was 1.6%, Neisseria gonorrhoeae was 2.8%, Chlamydia trachomatis was 7.1%, Trichomonas vaginalis was 9.0%, Mycoplasma genitalium was 5.5% and HIV was 36.3%. HIV positive status was associated with an increased probability of having M. genitalium (aPR = 1.49, 95% CI 1.02-2.19) among males and syphilis (aPR = 2.54, 95% CI 1.32-4.86), N. gonorrhoeae (aPR = 2.39, 95% CI 1.62-3.52), T. vaginalis (aPR = 1.70, 95% CI 1.43-2.01) and M. genitalium (aPR = 1.60, 95% CI 1.15-2.22) among females. HIV viral load ≥400 copies per mL was associated with an increased probability of N. gonorrhoeae (aPR = 1.91, 95% CI 1.36-2.70), C. trachomatis (aPR = 1.52, 95% CI 1.12-2.05) and M. genitalium (aPR = 1.83, 95% CI 1.27-2.63).

CONCLUSIONS

The high prevalence of STIs and the association between STIs and HIV, and HIV viral load underscores the public health implications of sustained transmission risk of STIs and HIV. These findings highlight the urgent need for expanding STI surveillance and implementing interventions to monitor and reduce the STI burden.

Evaluating DREAMS HIV prevention interventions targeting adolescent girls and young women in high HIV prevalence districts in South Africa: protocol for a cross-sectional study

BACKGROUND

Young women in sub-Saharan Africa remain at the epicentre of the HIV epidemic, with surveillance data indicating persistent high levels of HIV incidence. In South Africa, adolescent girls and young women (AGYW) account for a quarter of all new HIV infections. Determined, Resilient, Empowered, AIDS-free, Mentored and Safe (DREAMS) is a strategy introduced by the United States President's Emergency Plan for AIDS Relief (PEPFAR) aimed at reducing HIV incidence among AGYW in 10 countries in sub-Saharan Africa by 25% in the programme's first year, and by 40% in the second year. This study will assess the change in HIV incidence and reduction in risk associated behaviours that can be attributed to the DREAMS initiative in South Africa, using a population-based cross-sectional survey.

METHODS

Data will be collected from a household-based representative sample of AGYW (between the ages 12-24 years) in four high prevalence districts (more than 10% of the population have HIV in these districts) in South Africa in which DREAMS has been implemented. A stratified cluster-based sampling approach will be used to select eligible participants for a cross-sectional survey with 18,500, to be conducted over 2017/2018. A questionnaire will be administered containing questions on sexual risk behaviour, selected academic and developmental milestones, prevalence of gender based violence, whilst examining exposure to DREAMS programmes. Biological samples, including two micro-containers of blood and self-collected vulvovaginal swab samples, are collected in each survey to test for HIV infection, HIV incidence, sexually transmitted infections (STIs) and pregnancy. This study will measure trends in population level HIV incidence using the Limiting antigen (LAg) Avidity Enzyme Immuno-Assay (EIA) and monitor changes in HIV incidence.

DISCUSSION

Ending the HIV/AIDS pandemic by 2030 requires the continual monitoring and evaluation of prevention programmes, with the aim of optimising efforts and ensuring the achievement of epidemic control. This study will determine the impact DREAMS interventions have had on HIV incidence among AGYW in a 'real world, non-trial setting'.

Recently formed age-disparate partnerships are associated with elevated HIV-incidence among young women in South Africa

OBJECTIVE

Cross-sectional and cohort studies draw different conclusions on whether age-disparate partnerships increase HIV-acquisition risk for young women. We investigated whether age-disparities were associated with HIV-infection risk early in relationships. This could result in the exclusion of women who seroconverted during high-risk age-disparate partnerships from cohort studies of HIV incidence - which exclude HIV-positive women - and explain null findings in these studies.

DESIGN

Prospective cohort study.

METHODS

We used data on 15-24-year-old, HIV-negative women in heterosexual partnerships (N = 830) in KwaZulu-Natal, South Africa. The association between age-disparate partnering (i.e., male partner ≥5 years older) and subsequent HIV seroconversion was assessed using Cox hazard models. We examined heterogeneity in HIV-acquisition risk by duration of partnership (defined by quartiles) at cohort enrolment.

RESULTS

During 1139 person-years (mean: 1.4 years) of follow-up, 54 (6.5%) women seroconverted, a weighted HIV-incidence estimate of 4.41/100 person-years [95% confidence interval (CI): 3.30-6.06]. HIV-acquisition risk did not differ significantly between women in age-disparate vs. age-similar partnerships (adjusted hazard ratios: 1.10, 95% CI: 0.55-2.21). However, for women in the shortest partnership quartile (<1.09 years) at baseline, risk of HIV seroconversion was higher for women in age-disparate partnerships (adjusted hazard ratios: 3.13, 95% CI: 1.02-9.65, P = 0.047). HIV acquisition was not statistically different by partnership type among women in longer partnerships.

CONCLUSION

The association between age-disparate partnerships and HIV-acquisition risk is evident early in young women's relationships. Results provide a potential explanation for null findings in cohort studies, whose research designs may exclude women in such partnerships, and affirms the elevated risk of HIV acquisition for young women in age-disparate relationships.

Trends in HIV Prevention, Treatment, and Incidence in a Hyperendemic Area of KwaZulu-Natal, South Africa

IMPORTANCE

In Africa, the persistently high HIV incidence rate among young women is the major obstacle to achieving the goal of epidemic control.

OBJECTIVE

To determine trends in coverage of HIV prevention and treatment programs and HIV incidence.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study consisted of 2 sequential, community-based longitudinal studies performed in the Vulindlela and Greater Edendale area in KwaZulu-Natal, South Africa. Participants enrolled from June 11, 2014, to June 22, 2015 (2014 survey), with a single follow-up visit from June 24, 2016, to April 3, 2017 (2016 cohort), or enrolled from July 8, 2015, to June 7, 2016 (2015 survey), with a single follow-up visit from November 7, 2016, to August 30, 2017 (2017 cohort). Men and women aged 15 to 49 years were enrolled in the 2014 and 2015 surveys, and HIV-seronegative participants aged 15 to 35 years were followed up in the 2016 and 2017 cohorts. Analysis was conducted from January 1 through December 31, 2018.

EXPOSURES

HIV prevention and treatment programs in a real-world, nontrial setting.

MAIN OUTCOMES AND MEASURES

Trends in sex- and age-specific HIV incidence rates, condom use, voluntary medical male circumcision, knowledge of HIV-seropositive status, uptake of antiretroviral therapy, and viral suppression.

RESULTS

A total of 9812 participants (6265 women [63.9%]; median age, 27 years [interquartile range, 20-36 years]) from 11 289 households were enrolled in the 2014 survey, and 10 236 participants (6341 women [61.9%]; median age, 27 years [interquartile range, 20-36 years]) from 12 247 households were enrolled in the 2015 survey. Of these, 3536 of 4539 (annual retention rate of 86.7%) completed follow-up in the 2016 cohort, and 3907 of 5307 (annual retention rate of 81.4%) completed follow-up in the 2017 cohort. From 2014 to 2015, condom use with last sex partner decreased by 10% from 24.0% (n = 644 of 3547) to 21.6% (n = 728 of 3895; P = .12) in men and by 17% from 19.6% (n = 1039 of 6265) to 16.2% (n = 871 of 6341; P = .002) in women. Voluntary medical male circumcision increased by 13% from 31.9% (1102 of 3547) to 36.1% (n = 1472 of 3895); P = .007) in men, and the proportion of women reporting that their partner was circumcised increased by 35% from 35.7% (n = 1695 of 4766) to 48.2% (n = 2519 of 5207; P < .001). Knowledge of HIV-seropositive status increased by 21% from 51.8% (n = 504 of 3547) to 62.9% (n = 570 of 3895; P < .001) in men and by 14% from 64.6% (n = 1833 of 6265) to 73.4% (n = 2182 of 6341; P < .001) in women. Use of antiretroviral therapy increased by 32% from 36.7% (n = 341 of 3547) to 48.6% (n = 432 of 3895; P < .001) in men and by 29% from 45.6% (n = 1251 of 6265) to 58.8% (n = 1743 of 6341; P < .001) in women; HIV viral suppression increased by 20% from 41.9% (n = 401 of 3547) to 50.3% (n = 456 of 3895; P = .005) in men and by 13% from 54.8% (n = 1547 of 6265) to 61.9% (n = 1828 of 6341; P < .001) in women. Incidence of HIV declined in women aged 15 to 19 years from 4.63 (95% CI, 3.29-6.52) to 2.74 (95% CI, 1.84-4.09) per 100 person-years (P = .04) but declined marginally or remained unchanged among men and women in other age groups.

CONCLUSIONS AND RELEVANCE

This study showed a significant decline in HIV incidence in young women; however, to further reduce HIV incidence, HIV prevention and treatment program coverage must be intensified and scaled up.

Impact of HIV testing and treatment services on risky sexual behaviour in the uMgungundlovu District, KwaZulu-Natal, South Africa: a cross-sectional study

INTRODUCTION

The South African public health system plays an important role in the delivery of HIV testing and treatment services. The health system is also an important conduit for targeted behaviour change communication with the expectation that clients who undergo counselling from health personnel, adopt safer sexual practices. Literature remains mixed on the impact these HIV services have on risky sexual behaviour. This analysis examines the sexual behaviour of clients following the utilisation of HIV testing and treatment services in Kwazulu-Natal, South Africa.

METHODS

Data were used from two consecutive cross-sectional household surveys undertaken from June 2014 to June 2015 (2014/2015 survey) and from July 2015 to June 2016 (2015/2016 survey) in the uMgungundlovu District of KwaZulu-Natal, South Africa. Collectively, 20,048 randomly selected individuals aged 15 to 49 years old were interviewed across the two surveys. Utilisation of HIV testing and treatment services were used as independent variables and three sexual risk behaviours were used as dependent variables. Multiple regression models assessed the impact HIV testing and treatment services had on sexual risk behaviour while controlling for socio-demographic characteristics.

RESULTS

Having tested for HIV had no association with any of the three sexual risk behaviours. However, receiving an HIV positive diagnosis reduced the likelihood of using condoms inconsistently with the respondents' most recent partner (AOR: 0.64; 95% CI 0.54-0.77). Antiretroviral use was negatively associated with inconsistent condom use (AOR: 0.45; 95% CI 0.35-0.58) and number of sexual partners in the previous year (AOR: 0.61; 95% CI 0.46-0.81).

CONCLUSIONS

Results indicate that HIV testing and treatment services and the assumed exposure of clients to behaviour change communication, had a limited effect in reducing risky sexual behaviour. Data suggests that the engagement between health personnel and individuals accessing HIV testing and treatment services does not necessarily translate into the adoption of safer sexual practices, with the exception of individuals testing positive for HIV and those on ARV treatment, who had adopted safer sexual practices.

Coital frequency and condom use in age-disparate partnerships involving women aged 15 to 24: evidence from a cross-sectional study in KwaZulu-Natal, South Africa

OBJECTIVE

This study examines the role of age-disparate partnerships on young women's HIV risk by investigating coital frequency and condom use within age-disparate partnerships involving women aged 15 to 24.

DESIGN

A community-based, cross-sectional study was conducted.

SETTING

Participants were randomly selected using a two-stage random sampling method in uMgungundlovu district, KwaZulu-Natal, South Africa, between June 2014 and June 2015.

PARTICIPANTS

A total of 1306 15-24-year-old women in an ongoing heterosexual partnership were included in the analysis. Participants had to be a resident in the area for 12 months, and able to provide informed consent and speak one of the local languages (Zulu or English).

PRIMARY AND SECONDARY OUTCOME MEASURES

Sexual frequency was assessed by asking participants how many times they had sex with each partner in the past 12 months. The degree of condomless sex within partnerships was assessed in the survey by asking participants how often they used a condom with their partners.

RESULTS

Age-disparate partnerships were associated with a higher order category (once, 2-5, 6-10, 11-20, >20) of coital frequency (adjusted OR (aOR) 1.32, p<0.05, 95% CI 1.02 to 1.71) and with sex on more than 10 occasions (aOR 1.48, p<0.01, 95% CI 1.12 to 1.96) compared with age-similar partnerships. Age-disparate partnerships were also more likely to involve sex on more than 10 occasions with inconsistent condom use (aOR 1.43, p<0.05, 95% CI 1.04 to 1.96) in the previous 12 months.

CONCLUSION

The finding that increased sexual activity is positively associated with age-disparate partnerships adds to the evidence that age-disparate partnerships pose greater HIV risk for young women. Our study results indicate that interventions to reduce risky sexual behaviour within age-disparate partnerships remain relevant to reducing the high HIV incidence rates among adolescent girls and young women.

Age-disparate partnerships and HSV-2 among adolescent girls and young women in South Africa: implications for HIV infection risk

OBJECTIVE

There is an urgent need to understand high HIV-infection rates among young women in sub-Saharan Africa. While age-disparate partnerships have been characterised with high-risk sexual behaviours, the mechanisms through which these partnerships may increase HIV-risk are not fully understood. This study assessed the association between age-disparate partnerships and herpes simplex virus type-2 (HSV-2) infection, a factor known to increase HIV-infection risk.

METHODS

Cross-sectional face-to-face questionnaire data, and laboratory HSV-2 and HIV antibody data were collected among a representative sample in the 2014/2015 household survey of the HIV Incidence Provincial Surveillance System in KwaZulu-Natal, South Africa. Among 15-24-year-old women who reported having ever had sex (n=1550), the association between age-disparate partnerships (ie, male partner ≥5 years older) and HSV-2 antibody status was assessed using multivariable Poisson regression models with robust variance. Analyses were repeated among HIV-negative women.

RESULTS

HSV-2 prevalence was 55% among 15-24-year-old women. Women who reported an age-disparate partnership with their most recent partner were more likely to test HSV-2 positive compared with women with age-similar partners (64% vs 51%; adjusted prevalence ratio (aPR):1.19 (95% CI 1.07 to 1.32, p<0.01)). HSV-2 prevalence was also significantly higher among HIV-negative women who reported age-disparate partnerships (51% vs 40 %; aPR:1.25 (95% CI 1.05 to 1.50, p=0.014)).

CONCLUSIONS

Results indicate that age-disparate partnerships are associated with a greater risk of HSV-2 among young women. These findings point towards an additional mechanism through which age-disparate partnerships could increase HIV-infection risk. Importantly, by increasing the HSV-2 risk, age-disparate partnerships have the potential to increase the HIV-infection risk within subsequent partnerships, regardless of the partner age-difference in those relationships.

Community-based HIV prevalence in KwaZulu-Natal, South Africa: results of a cross-sectional household survey

BACKGROUND

In high HIV burden settings, maximising the coverage of prevention strategies is crucial to achieving epidemic control. However, little is known about the reach and effect of these strategies in some communities.

METHODS

We did a cross-sectional community survey in the adjacent Greater Edendale and Vulindlela areas in the uMgungundlovu district, KwaZulu-Natal, South Africa. Using a multistage cluster sampling method, we randomly selected enumeration areas, households, and individuals. One household member (aged 15-49 years) selected at random was invited for survey participation. After obtaining consent, questionnaires were administered to obtain sociodemographic, psychosocial, and behavioural information, and exposure to HIV prevention and treatment programmes. Clinical samples were collected for laboratory measurements. Statistical analyses were done accounting for multilevel sampling and weighted to represent the population. A multivariable logistic regression model assessed factors associated with HIV infection.

FINDINGS

Between June 11, 2014, and June 22, 2015, we enrolled 9812 individuals. The population-weighted HIV prevalence was 36·3% (95% CI 34·8-37·8, 3969 of 9812); 44·1% (42·3-45·9, 2955 of 6265) in women and 28·0% (25·9-30·1, 1014 of 3547) in men (p<0·0001). HIV prevalence in women aged 15-24 years was 22·3% (20·2-24·4, 567 of 2224) compared with 7·6% (6·0-9·3, 124 of 1472; p<0·0001) in men of the same age. Prevalence peaked at 66·4% (61·7-71·2, 517 of 760) in women aged 35-39 years and 59·6% (53·0-66·3, 183 of 320) in men aged 40-44 years. Consistent condom use in the last 12 months was 26·5% (24·1-28·8, 593 of 2356) in men and 22·7% (20·9-24·4, 994 of 4350) in women (p=0·0033); 35·7% (33·4-37·9, 1695 of 5447) of women's male partners and 31·9% (29·5-34·3, 1102 of 3547) of men were medically circumcised (p<0·0001), and 45·6% (42·9-48·2, 1251 of 2955) of women and 36·7% (32·3-41·2, 341 of 1014) of men reported antiretroviral therapy (ART) use (p=0·0003). HIV viral suppression was achieved in 54·8% (52·0-57·5, 1574 of 2955) of women and 41·9% (37·1-46·7, 401 of 1014) of men (p<0·0001), and 87·2% (84·6-89·8, 1086 of 1251) of women and 83·9% (78·5-89·3, 284 of 341; p=0·3670) of men on ART. Age, incomplete secondary schooling, being single, having more than one lifetime sex partner (women), sexually transmitted infections, and not being medically circumcised were associated with HIV-positive status.

INTERPRETATION

The HIV burden in specific age groups, the suboptimal differential coverage, and uptake of HIV prevention strategies justifies a location-based approach to surveillance with finer disaggregation by age and sex. Intensified and customised approaches to seek, identify, and link individuals to HIV services are crucial to achieving epidemic control in this community.

FUNDING

The President's Emergency Plan for AIDS Relief through the Centers for Disease Control and Prevention.

Factors associated with the take-up of voluntary medical male circumcision amongst learners in rural KwaZulu-Natal

Voluntary medical male circumcision (VMMC) is an integral part of South Africa's HIV prevention programme. School-going males, in particular, are considered a cost-effective target population. However, ambitious policy targets have not been achieved due to the plateau in demand for VMMC. This study documents the factors influencing demand for VMMC amongst school-going males. Data were collected from 750 learners (251 circumcised and 499 uncircumcised) from 42 secondary schools in KwaZulu-Natal, South Africa. There was a positive association between the perceived benefit of VMMC and the likelihood of undergoing circumcision (AOR: 1.41, p = 0.01). There was a negative association between self-efficacy to use condoms and likelihood of undergoing VMMC (AOR: 0.75, p < 0.01). Learners who perceived VMMC as having a number of health benefits, including reducting of the chances of contracting HIV and sexually transmitted infections (STIs), increasing penile hygiene and the belief that VMMC allows them to use condoms less frequently, were more likely to undergo VMMC. Of concern, learners who were confident in their ability to access condoms and t use a condom with their partner were less likely to undergo VMMC.

Early Resumption of Sex following Voluntary Medical Male Circumcision amongst School-Going Males

Voluntary medical male circumcision is an integral part of the South African government’s response to the HIV and AIDS epidemic. Following circumcision, it is recommended that patients abstain from sexual activity for six weeks, as sex may increase the risk of female-to-male HIV transmission and prolong the healing period. This paper investigates the resumption of sexual activity during the healing period among a cohort of school-going males in the KwaZulu-Natal province of South Africa. The analysis for this paper compares two groups of sexually active school-going males: the first group reported having sex during the healing period (n = 40) and the second group (n = 98) reported no sex during the healing period (mean age: 17.7, SD: 1.7).The results show that 29% (n = 40) of young males (mean age: 17.9, SD: 1.8) who were previously sexually active, resumed sexual activity during the healing period, had on average two partners and used condoms inconsistently. In addition, those males that engage in sexual activity during the healing period were less inclined to practice safe sex in the future (AOR = 0.055, p = 0.002) than the group of males who reported no sex during the healing period. These findings suggest that a significant proportion of young males may currently and in the future, subject themselves to high levels of risk for contracting HIV post circumcision. Education, as part of a VMMC campaign, must emphasize the high risk of HIV transmission for both the males their partners during the healing period.

Refrigeration and freezing of porcine tissue does not affect the retardation of fragment simulating projectiles

Explosively propelled fragments are the most common cause of injury to UK service personnel in modern conflicts. Numerical injury models to simulate such injuries utilise algorithms based upon gelatin and animal tissue testing but data is limited on many fragment simulating projectiles and these simulants cannot represent human anatomy. Testing with post mortem specimens may overcome this limitation but no information exists about how post mortem tissue changes and storage conditions in humans or animals may affect projectile penetration. Two chisel nosed cylinders (0.49 g and 1.10 g) and a 0.51 g (5 mm) sphere were fired into three groups of porcine tissue (fresh, refrigerated and frozen then refrigerated) and compared to 20% gelatin. Depth of projectile penetration was ascertained with the assistance of computed tomography and kinetic energy absorption by tissues measured using Doppler radar and high speed photography. No difference in depth of penetration was found between porcine tissue stored in the different manners compared with 20% gelatin by impact velocities less than 100 m/s. Insufficient numbers of projectiles were retained in tissue at higher velocities for statistical analysis to be undertaken. Energy absorbed per millimetre of tissue ranged between 0.42 and 0.98 J/mm for different porcine tissue despite differing storage. This pilot study would suggest that the effect of refrigerating or freezing porcine tissue followed by thawing has no effect on its ability to retard these projectiles. Further research is required to ascertain if these results occur at greater velocities and for other types of projectile.

Bone mineral crystallisation kinetics

The kinetics of bone apatite crystallisation are examined using a novel approach to obtain quantitative, direction dependence features such as growth rate and activation energy. X-ray diffraction was employed for analysis of bovine, porcine and 'anorganic' bone specimens. Apatite coherence length was utilised as the independent variable within a Johnson-Mehl-Avrami (JMA) model. A direction averaged crystallisation activation energy of 183 ± 8 kJ mol(-1) was observed for the three bone groups. The Johnson-Mehl-Avrami 'n' exponent decreased with increasing temperature for all bone groups, indicating that apatite crystallisation changes to a diffusion limited process at higher temperatures. The results revealed little evidence to support any organic component 'protective' effect, and, on the contrary indicated that the organic matrix promotes apatite crystallisation.

High-cocoa polyphenol-rich chocolate improves HDL cholesterol in Type 2 diabetes patients

AIM

To examine the effects of chocolate on lipid profiles, weight and glycaemic control in individuals with Type 2 diabetes.

METHODS

Twelve individuals with Type 2 diabetes on stable medication were enrolled in a randomized, placebo-controlled double-blind crossover study. Subjects were randomized to 45 g chocolate with or without a high polyphenol content for 8 weeks and then crossed over after a 4-week washout period. Changes in weight, glycaemic control, lipid profile and high-sensitivity C-reactive protein were measured at the beginning and at the end of each intervention.

RESULTS

HDL cholesterol increased significantly with high polyphenol chocolate (1.16 ± 0.08 vs. 1.26 ± 0.08 mmol/l, P = 0.05) with a decrease in the total cholesterol: HDL ratio (4.4 ± 0.4 vs. 4.1 ± 0.4 mmol/l, P = 0.04). No changes were seen with the low polyphenol chocolate in any parameters. Over the course of 16 weeks of daily chocolate consumption neither weight nor glycaemic control altered from baseline.

CONCLUSION

High polyphenol chocolate is effective in improving the atherosclerotic cholesterol profile in patients with diabetes by increasing HDL cholesterol and improving the cholesterol:HDL ratio without affecting weight, inflammatory markers, insulin resistance or glycaemic control.

Effects of lesioning noradrenergic neurones in the locus coeruleus on conditioned and unconditioned aversive behaviour in the rat

1. The brain noradrenergic system may have a role in anxiety disorder. This study has examined the effect of bilateral 6-hydroxydopamine lesions of the noradrenergic neurones in the locus coeruleus (LC) of male Lister hooded rats on behaviour produced by unconditioned and conditioned aversive stimuli. 2. The 6-hydroxydopamine (4 microg) lesions markedly reduced the noradrenaline content of the locus coeruleus hypothalamus, frontal cortex and the periaqueductal grey area without altering the levels of either dopamine or 5-hydroxytryptamine measured 14 days after administration. 3. Exposure to ultrasound (20 kHz at 98 dB for 60 sec), an unconditioned aversive stimulus, induced a defence response in the rats characterised by an increase in activity (running and jumping) followed by a period of inactivity (freezing). 4. Lesioning of the LC significantly attenuated the duration of freezing but was without effect on the active phase of the response. A similar reduction in freezing behaviour was seen with LC lesions when rats were exposed (3 hours after the acquisition) to the contextual cue of the conditioned emotion response paradigm. 5. These findings confirm that the locus coeruleus is involved in the regulation of fear-related behaviour in the rat both in an unconditioned and a conditioned model. Furthermore the results indicate that noradrenaline modifies defence behaviour rather than being the principle activating mechanism.

E-5842 (Laboratories Dr Esteve)

Esteve is developing E-5842, a sigma1 opioid receptor ligand, as a potential therapy for psychosis. It has completed phase I trials [344879,346244]. As of May 1999, the site and protocol for phase II schizophrenia trials in the UK had been finalized and these were scheduled to begin shortly thereafter, with results likely to be available by the end of 2000 [365516]. E-5842 acted as an atypical antipsychotic in preclinical neurochemical and behavioral tests. Both acute (40 mg/kg ip for 2 h) and chronic (20 mg/kg ip daily for 21 days) administration of E-5842 increased PLC activity and the drug may thus achieve its antipsychotic effects via a signalling pathway involving phosphoinositide second messengers [336324]. E-5842 has a K(i) value of 4 nM at the sigma receptor [306875]. It blocks apomorphine-induced climbing, and antagonizes amphetamine-induced locomotor activity in mice [271405].

Acoustically elicited behaviours in Lister hooded and Wistar rats

It has been reported previously that experimenter-presented 20-kHz tones at low intensities produce bursts of locomotor running in Lister hooded rats, but reduced locomotion (freezing) in Wistar rats. Because rats emit 20-kHz tones when stressed, it was proposed that this ultrasound-elicited running and freezing behaviour in Lister hooded and Wistar rats, respectively, represents a model for qualitative strain differences in fear behaviour. The present studies examined the acoustic specificity of acoustically elicited locomotor behaviours in Lister hooded and Wistar rats. In Experiment 1, it was found that brief exposure (i.e., 15 s) of Lister hooded rats to tones at frequencies of 7, 12, or 20 kHz and intensities of 85-95 dB SPL, elicited running behaviour characterised by brief bursts of locomotion followed by periods of quiescence. Somewhat surprisingly, the 7- and 12-kHz tones elicited running behaviour at lower intensities than did the 20-kHz tones. In Experiment 2, it was found that exposure of Lister hooded rats to the 20-kHz acoustic stimulus (91-101 dB, SPL) for a much longer duration, up to 9 min, resulted in episodic bursts of locomotion and convulsions in a significant proportion of subjects. Both the maximal velocity of locomotion and the likelihood of occurrence of convulsions was related to the intensity of the acoustic stimulus. Exposure of Lister hooded rats to white noise for up to 9 min also elicited episodic bursts of locomotion and convulsions in an intensity-dependent manner. The white noise stimulus was found to be a more effective stimulus than the 20-kHz stimulus in this regard. In Experiment 3, it was found that Lister hooded rats exhibited reduced locomotion when they were exposed to a low-intensity 20-kHz acoustic stimulus (e.g., 81 dB, SPL). In Experiment 4, it was found that Wistar rats did not exhibit locomotor bursts or convulsions when presented with 20-kHz tones using stimulus parameters equal to and even greater than those that had been shown to be effective in producing locomotor bursts in Lister hooded rats. Rather, Wistar rats exhibited only reduced locomotion. The present data indicate that (1) running behaviour in Lister hooded rats is not specific for the 20-kHz stimulus. Moreover, (2) when compared to Lister hooded rats, Wistar rats are relatively insensitive to the running and convulsions elicited by acoustic stimuli. Finally, (3) both Lister hooded and Wistar rats exhibited reduced locomotion when presented with the 20-kHz tones, although the range of stimulus intensities that produces freezing behaviour is much more limited in Lister hooded rats because of their propensity to exhibit locomotor bursting and convulsions. Thus, it appears that the difference between the two strains with respect to their unconditioned locomotor responses to novel acoustic stimuli relates to the fact that Lister hooded rats are uniquely susceptible to acoustically elicited locomotor bursts and/or convulsions.

Economic evaluation of three anthelmintic strategies for lamb flocks affected by benzimidazole-resistant nematodes

OBJECTIVE

To compare the profitability of three anthelmintic strategies in growing lambs in flocks with nematodes resistant to benzimidazole anthelmintics.

METHOD

A partial-budgeting analysis was carried out by means of a stochastic simulation model, which allows inputs to be described as distributions rather than as fixed values, and hence permits variation between farms to be considered in the analysis.

RESULTS

The results show that control of nematode parasites by use of an effective anthelmintic provides the highest net returns, yielding a margin over ineffectively treated lambs of A$114 per 100 lambs on average. Suppressive treatment based on the administration of two controlled-release capsules and monthly with moxidectin resulted in an average loss of A$131 per 100 lambs in comparison with animals treated with an ineffective anthelmintic. Analysis of the results from capsule-treated lambs did not take into account the unmeasured benefits associated with less contamination of pastures. Sensitivity analysis using a stochastic model indicates that apart from the effect of treatment on weight gain variation in carcase price greatly influences the profitability of all the parasite control programs examined.

CONCLUSION

The results suggest that it is economically important for farmers to adjust their strategy in the presence of anthelmintic resistance. But as a result of uncertainty in the factors influencing economic return, the expected economic benefit is likely to vary substantially.

A quantitative assessment of the validity of animal-health surveys using stochastic modelling

This paper presents a stochastic simulation model to evaluate the efficacy of regional or national surveys aimed at identifying infection in populations of animals. The process of evaluation involves specification or calculation of cluster-level test sensitivity and specificity, which are derived from two probability distributions of the number of individual-level positive tests expected from non-infected and infected clusters, respectively. Probability distributions for the number of positive clusters expected in a situation of freedom from infection and under various levels of cluster prevalence are specified and used to determine survey properties (the survey being considered a diagnostic system), and ROC curves are drawn. Likelihood ratios allow investigators to state the extent to which a survey result is more likely to be observed if the region or country is infected at a given prevalence than if it is free from infection. The result of a survey carried out to investigate the presence of porcine reproductive and respiratory syndrome (PRRS) in Switzerland is used to illustrate this approach. The model can be adapted to a wide range of survey designs.

Effects of monensin on the reproduction, health, and milk production of dairy cows

A randomized clinical trial including 1109 cows from 12 Australian dairy herds was used to evaluate the effects of monensin on the health (n = > 686 cows), production (n = 915 cows), and reproduction (n = > 908 cows) of dairy cows. Cows were allocated to a treatment group receiving a slow-release intraruminal bolus containing 32 g of sodium monensin that was administered 40 d before and 50 d following the anticipated calving date or to a control group. Treatment did not significantly alter any reproductive outcome; 54.5% of cows treated with monensin and 58.2% of control cows were pregnant at first service, and days to conception were lower for cows treated with monensin. The hazard rate (0.95) was not significant for these cows. The percentage of cows pregnant was 83.8 for control cows, and days to first estrus (hazard rate = 1.04) and first service (hazard rate = 1.04) were not significantly higher for treated cows. Treatment with monensin did not significantly alter the risk of any disease. The incidence of retained fetal membranes, pyometra, lameness, abortion, and infectious diseases was not significantly lower for cows in the treatment group, and the incidence of mastitis was not significantly higher for cows in the treatment group. Monensin significantly increased milk production by 0.75 L/d per cow and tended to increase milk fat and protein yields but had no significant effect on milk fat or milk protein percentages. Changes in the production of milk and milk constituents were consistent throughout lactation.

The effect of central and systemic injection of the 5-HT1A receptor agonist 8-OHDPAT and the 5-HT1A receptor antagonist WAY100635 on periaqueductal grey-induced defence behaviour

The effects of the selective 5-HT(1A) agonist, 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OHDPAT) and the selective 5-HT(1A) antagonist, N-[2-[4-(2-methoxyphenyl)-1-piperzinyl]ethyl]-N-(pyridinyl) cyclohexanecarboxamide trichloride (WAY100635) on periaqueductal grey (PAG)-stimulated defence behaviour were tested in the rat. Microinjection of the excitatory amino acid, D, L-homocysteic acid (DLH) into the dorsal region of the PAG produced overt aversive behaviour characteristic of the defence response, consisting of explosive motor behaviours which were quantified in terms of their duration and the number of arena revolutions and jumps made by the animal. Intra-PAG pre-treatment with 8-OHDPAT (3, 10 and 25 nmol in 250 nl) 10 min before DLH stimulation significantly attenuated the defence behaviour. This could be reversed by peripheral application of WAY100635 (0.1 mg/kg). In contrast, peripheral 8-OHDPAT (0.03, 0.1 and 0.3mg/kg) produced a significant potentiation of the DLH response which could also be blocked by peripheral WAY100635. When WAY100635 (10 nmol in 250 nl) alone was given into the PAG a significant increase in DLH induced behaviours was observed whereas peripherally applied WAY100635 (0.1 mg/kg) was without effect. These data support previous findings which indicate that serotonergic modulation of aversive behaviours such as defence can be mediated by 5-HT(1A) receptors. Furthermore there is evidence to indicate a differential involvement of pre- and postsynaptic 5-HT(1A) receptors.

Perinatal cocaine reduces responsiveness to cocaine and causes alterations in exploratory behavior and visual discrimination in young-adult rats

Lister hooded female rats were exposed to either saline or cocaine (20 mg/kg s.c.) from gestational day 10 every other day until weaning (postnatal day 25). The effects of maternal cocaine exposure on novelty-induced exploration and on spontaneous and cocaine-induced motor activity were evaluated in young-adult male offspring (4 weeks after weaning). Rats exposed to cocaine during development spent less time exploring two novel objects. Lack of habituation upon the second presentation of the objects and failure in the ability to discriminate between the novel and familiar object were also found in cocaine exposed offspring. Moreover, maternal cocaine treatment did not affect spontaneous motor activity (active time, average speed and rearing) in rats subjected to an open field test. Furthermore, perinatal exposure to cocaine significantly attenuated acute cocaine (15 mg/kg i.p.)-induced hyperactivity. These data indicate that developmental exposure to cocaine, at dose levels below those producing gross malformations and/or overt signs of neurotoxicity, causes behavioral changes characterized by an altered responsiveness to environmental and pharmacological challenges.

Computer analysis and quantification of periaqueductal grey-induced defence behaviour

The pharmacological study of midbrain-evoked aversive behaviours is commonly measured in terms of electrical escape thresholds, although studies which examine the actual expression of the behaviour are being introduced. A computer-driven automated tracking system has been developed to record and analyse the very rapid locomotor activity produced by the defence response. Stimulation of the midbrain periaqueductal grey (PAG) matter in rats with the excitatory amino acid D,L-homocysteic acid (DLH) produced very rapid and short-lasting escape behaviour which was tracked by computer. The system, VideoTrack, determines the speed and distance travelled by the animal and stores and statistically analyses the data. VideoTrack was able to detect a pharmacological modifications of the response; anti-aversive effects produced by intra-PAG pretreatment with the 5-HT1A agonist 8-hydroxy 2-(di-n-propylamino)tetralin (8-OHDPAT) and its reversal by peripheral pretreatment with the 5-HT1A antagonist N-[2-[-(2-methoxyphenyl)-1-piperazinyl]ethyl-N- (pyridinyl)cyclohexanecarboxanide (WAY 100635).