The epidemiology of HIV among young people in sub-Saharan Africa: know your local epidemic and its implications for prevention.

BACKGROUND: Broad patterns of HIV epidemiology are frequently used to design generic HIV programs in sub-Saharan Africa. METHODS: We reviewed the epidemiology of HIV among young people in sub-Saharan Africa, and explored the unique dynamics of infection in its different regions. RESULTS: In 2009, HIV prevalence among youth in sub-Saharan Africa was an estimated 1.4% in males and 3.4% in females, but these values mask wide variation at regional and national levels. Within countries there are further major differences in HIV prevalence, such as by sex, urban/rural location, economic status, education, or ethnic group. Within this highly nuanced context, HIV prevention programs targeting youth must consider both where new infections are occurring and where they are coming from. CONCLUSIONS: Given the epidemiology, one-size-fits-all HIV prevention programs are usually inappropriate at regional and national levels. Consideration of local context and risk associated with life transitions, such as leaving school or getting married, is imperative to successful programming for young people

Characterisation of cationic amphiphilic cyclodextrins for neuronal delivery of siRNA: effect of reversing primary and secondary face modifications

Significant research is focused on the development of non-viral vectors for delivery of siRNA to neurons and the central nervous system. Cyclodextrins (CDs) have shown great promise as efficient and low toxicity gene delivery vectors in various cell types. Here, we investigate two CDs for siRNA delivery in a neuronal cell model. These CDs were substituted on opposite faces (primary and secondary) with amphiphilic and cationic groups. Physical properties of CD.siRNA complexes, including size, charge and stability were measured. In vitro investigations were carried out in immortalised hypothalamic neurons. Neuronal cell uptake was measured by flow cytometry and cytotoxicity was assessed by MTT assay. Knockdown of a luciferase reporter gene was used as a measure of gene silencing efficiency. Both CDs interacted with siRNA, yielding nanosized cationic complexes which exhibited good stability on storage. A favourable toxicity profile was demonstrated for the CD.siRNA complexes. However, only one of the two CDs mediated high levels of neuronal uptake and efficient gene silencing, equivalent to those achieved with a commercial lipid-based vector. Despite the suitability of both CDs as siRNA delivery vectors in terms of their ability to complex siRNA and the properties of the complexes yielded, only one CD achieved good transfection efficiency. This was likely due to the differences in their chemical structures. The effective CD offers great potential as a novel non-toxic vector for neuronal siRNA delivery

Behavioural and socio-ecological factors that influence access and utilisation of health services by young people living in rural KwaZulu-Natal, South Africa: Implications for intervention.

BACKGROUND: Young people's health service utilisation (the number accessing a facility) has been the focus of guidelines and health systems strengthening policies. This is due to young people being at an increased health risk because of inequitable access and utilisation of health services, which is more pronounced in rural settings with limited service availability. This is a major concern as globally, youth constitute a considerable and increasing part of the population in Sub-Saharan Africa. OBJECTIVE: The objective of this paper is to present a comprehensive approach for the exploration of health service utilisation by young people in rural KwaZulu-Natal, South Africa. We examined barriers and facilitators conceptualised by the constructs of the Theory of Planned Behaviour, framed within a socio-ecological model. METHODS: Data were collected in January to June 2017 from two sites using in-depth interviews, spiral transect walks and community mapping with young people (aged 10 to 24 years), primary care health providers, school health professionals, community stakeholders and young people's parents. RESULTS: Socio-ecological and behavioural factors influenced young people's intention to use services. Barriers included perceived negative attitudes of health providers and perceived poor staff competencies. Facilitators included an appreciation of receiving health education and assumed improved health. At social and community levels, normative beliefs hindered young people from utilising services as they feared stigmatisation and gossip. At a public policy level, structural elements had a disempowering effect as the physical layout of the clinics hindered utilisation, limited resources influenced staffing, and facility opening times were not convenient for school goers. CONCLUSION: We suggest that to fully appreciate the complexity of health service utilisation, it is necessary to not only consider factors and processes relevant to the individual, but also acknowledge and act upon, the disjuncture between community level cultural values, norms and national policies

HIV Infection among Young People in Northwest Tanzania: The Role of Biological, Behavioural and Socio-Demographic Risk Factors.

BACKGROUND: Young people are at high risk of HIV and developing appropriate prevention programmes requires an understanding of the risk factors for HIV in this age group. We investigated factors associated with HIV among participants aged 15-30 years in a 2007-8 cross-sectional survey nested within a community-randomised trial of the MEMA kwa Vijana intervention in 20 rural communities in northwest Tanzania. METHODS: We analysed data for 7259(53%) males and 6476(47%) females. Using a proximate-determinant conceptual framework and conditional logistic regression, we obtained sex-specific Odds Ratios (ORs) for the association of HIV infection with socio-demographic, knowledge, behavioural and biological factors. RESULTS: HSV-2 infection was strongly associated with HIV infection (females: adjOR 4.4, 95%CI 3.2-6.1; males: adjOR 4.2, 95%CI 2.8-6.2). Several socio-demographic factors (such as age, marital status and mobility), behavioural factors (condom use, number and type of sexual partnerships) and biological factors (blood transfusion, lifetime pregnancies, genital ulcers, Neisseria gonorrhoeae) were also associated with HIV infection. Among females, lifetime sexual partners (linear trend, p<0.001), ≥2 partners in the past year (adjOR 2.0, 95%CI 1.4-2.8), ≥2 new partners in the past year (adjOR 1.9 95%CI 1.2, 3.3) and concurrent partners in the past year (adjOR 1.6 95%CI 1.1, 2.4) were all associated with HIV infection. CONCLUSIONS: Efforts must be intensified to find effective interventions to reduce HSV-2. Effective behavioural interventions focusing on reducing the number of sexual partnerships and risk behaviour within partnerships are also needed. An increase in risky sexual behaviour may occur following marriage dissolution or when a young woman travels outside of her community and interventions addressing the needs of these subgroups of vulnerable women may be important. TRIAL REGISTRATION: ClinicalTrial.gov NCT00248469

Uptake of voluntary counselling and testing among young people participating in an HIV prevention trial: comparison of opt-out and opt-in strategies.

BACKGROUND: HIV voluntary counselling and testing (VCT) is an integral component of HIV prevention and treatment programmes. However, testing coverage in sub-Saharan Africa is still low, particularly among young people. As treatment becomes more widely available, strategies to expand VCT coverage are critically important. We compare VCT uptake using two delivery strategies (opt-in and opt-out) within the MEMA kwa Vijana trial in 20 communities in northwest Tanzania. METHODS: We analysed data from 12,590 young persons (median (IQR) age 22 years (20-23)) to assess the effect of delivery strategy on VCT uptake. Ten communities used an opt-in approach and 10 used opt-out, balanced across intervention and control. Conditional logistic regression was used to examine factors associated with uptake within each strategy. RESULTS: VCT uptake was significantly higher with the opt-out approach (90.9% vs 60.5%, prevalence ratio = 1.51, CI = 1.41-1.62). Among females, uptake in the opt-out approach was associated with decreased knowledge of HIV acquisition, sex with a casual partner, and being HSV-2 seronegative; among males, uptake was associated with lower education and increasing lifetime partners. In contrast, uptake using the opt-in approach varied by ethnic group, religion and marital status, and increased with increasing knowledge of STI acquisition (males) or pregnancy prevention (females). CONCLUSION: VCT uptake among young people was extremely high when offered an opt-out strategy. Sociodemographic and knowledge factors affected uptake in different ways depending on delivery strategy. Increased knowledge may increase young persons' self-efficacy, which may have a different impact on testing uptake, depending on the approach used

Modern contraceptive use among unmarried girls aged 15-19 years in South Western Nigeria: results from a cross-sectional baseline survey for the Adolescent 360 (A360) impact evaluation.

PURPOSE: Adolescents 360 (A360) is an initiative being rolled out across Nigeria with the aim of increasing voluntary modern contraception use among women aged 15 to 19 years. Using evaluation study baseline data, we identified sexuality, fertility and contraceptive use characteristics of young unmarried girls in South Western Nigeria. METHODS: A cross-sectional baseline survey of unmarried girls aged 15 to 19 years was conducted in Ogun state, Nigeria in August 2017. A clustered sampling design was used. We identified determinants of modern contraceptive use in this subpopulation using logistic regression. RESULTS: Of 12,024 women interviewed, 15.3% reported sexual intercourse in the past year. The majority of respondents (79.6%, 9525/11,967) had heard of contraception. 45.3% of sexually active respondents were using a modern contraceptive method. Of those using any method of contraception, male condoms (50.3%) were the most widely used modern method followed by the emergency contraceptive pill (16.7%). Following adjustment for socio-demographic characteristics, there was evidence that the use of modern contraception was positively associated with having never given birth, living in an urban area, current enrolment in education, high level of education, high socioeconomic status, exposure to information about contraception, perceived social support for contraception, and self-efficacy for contraception. CONCLUSIONS: In South Western Nigeria, unmarried sexually active adolescent girls have relatively low levels of modern contraceptive use. Programmes should aim to increase access to modern contraception and to increase social support and acceptability of contraceptive use

Application of the STRAY statistical learning algorithm for the evaluation of in-situ process monitoring data during L-PBF additive manufacturing.

This study investigates the use of a statistical anomaly detection method to analyse in-situ process monitoring data obtained during the Laser Powder Bed Fusion of Ti-6Al-4V parts. The printing study was carried out on a Renishaw 500M Laser-Powder Bed Fusion system. A photo diodebased system called InfiniAM was used to monitor the melt-pool emissions along with the operational behaviour of the laser during the build process. The analysis of the in-process data was carried out using an unsupervised machine learning approach called the Search and TRace AnomalY algorithm. The ability to detect defects during the manufacturing of metal alloy parts was demonstrated

What do adolescents value most and is this affected by HIV status? Aspirations and self-perceptions from a large cohort study in South Africa.

Hundreds of millions of adolescents across Africa face challenges in many areas of their lives, including elevated risk of HIV exposure and acquisition. Understanding the aspirations and self-perceptions of adolescents could play an important role in better targeting effective investments to break the cycle of adversity for adolescents and into their adulthood. Aiming to understand what adolescents value most for themselves and their future, we analysed and summarised cross-sectional data on the aspirations and self-perceptions of 1519 adolescents living in South Africa, overall and by HIV status. Outcomes were coded from participant responses to two open-ended questions: 'What job do you want to do when you grow up?' and 'What are you most proud of about yourself?'. Associations with HIV status were then evaluated using multivariable logistic regression adjusting for six sociodemographic factors measured from the same cohort. The sample had a mean age of 14 years, 55% were female, and 70% were living with HIV. The five most common job aspirations were: 'Health and Medical Science Professionals' (28%), 'Law Enforcement and Public Safety Professionals' (14%), 'Social Work Associate Professionals' (12%), 'Legal Professionals' (9%), and 'Education Institutions Teaching Professionals' (6%). The top five themes for what adolescents were most proud of about themselves were 'School performance' (22%), 'Outward appearance' (15%), 'Sports skills' (12%), 'Personality' (11%), and 'Behaviour at home/with elders' (7%). Adjusted analysis showed no evidence that HIV status was associated with important differences in aspirations or self-perceptions. In conclusion, adolescents facing high levels of adversity in South Africa hold high value for their education and aspirations for their futures. Policies and initiatives should focus on meeting these aspirations as vehicles for development, independent of their HIV status. Therefore, more needs to be done to not just help adolescents survive but thrive into adulthood

Exploring adolescents and young people's candidacy for utilising health services in a rural district, South Africa.

BACKGROUND: We use the 'candidacy framework' to describe adolescents' and young people's (AYP) experiences of health services in a rural KwaZulu-Natal district, South Africa. METHODS: A qualitative approach was used including group discussions, in-depth and key informant interviews with a purposive sample of AYP (n = 70), community leaders (n = 15), school health teams (n = 10), and health service providers (n = 6). RESULTS: Findings indicate tacit understanding among AYP that they are candidates for general health services. However, HIV stigma, apprehensions and misconceptions about sexual and reproductive health, and socio-cultural views which disapprove of AYP pre-marital sex undermine their candidacy for sexual and reproductive services. CONCLUSION: Consideration and understanding of the vulnerabilities and reasons AYP exclude themselves will inform interventions to address their health needs. AYP's participation in the design of health services will increase their acceptability and encourage uptake of services

The long-term impact of the MEMA kwa Vijana adolescent sexual and reproductive health intervention: effect of dose and time since intervention exposure.

BACKGROUND: Despite recent decreases in HIV incidence in many sub-Saharan African countries, there is little evidence that specific behavioural interventions have led to a reduction in HIV among young people. Further and wider-scale decreases in HIV require better understanding of when behaviour change occurs and why. The MEMA kwa Vijana adolescent sexual and reproductive health intervention has been implemented in rural Mwanza, Tanzania since 1999. A long-term evaluation in 2007/8 found that the intervention improved knowledge, attitudes to sex and some reported risk behaviours, but not HIV or HSV2 prevalence. The aim of this paper was to assess the differential impact of the intervention according to gender, age, marital status, number of years of exposure and time since last exposure to the intervention. METHODS: In 2007, a cross-sectional survey was conducted in the 20 trial communities among 13,814 young people (15-30 yrs) who had attended intervention or comparison schools between 1999 and 2002. Outcomes for which the intervention had an impact in 2001 or 2007 were included in this subgroup analysis. Data were analysed using cluster-level methods for stratified cluster-randomised trials, using interaction tests to determine if intervention impact differed by subgroup. RESULTS: Taking into account multiplicity of testing, concurrence with a priori hypotheses and consistency within the results no strong effect-modifiers emerged. Impact on pregnancy knowledge and reported attitudes to sex increased with years of exposure to high-quality intervention. CONCLUSIONS: The desirable long-term impact of the MEMA kwa Vijana intervention did not vary greatly according to the subgroups examined. This suggests that the intervention can have an impact on a broad cross-section of young people in rural Mwanza. TRIAL REGISTRATION: ClinicalTrials.gov NCT00248469