Long-term biological and behavioural impact of an adolescent sexual health intervention in Tanzania: follow-up survey of the community-based MEMA kwa Vijana Trial.

BACKGROUND: The ability of specific behaviour-change interventions to reduce HIV infection in young people remains questionable. Since January 1999, an adolescent sexual and reproductive health (SRH) intervention has been implemented in ten randomly chosen intervention communities in rural Tanzania, within a community randomised trial (see below; NCT00248469). The intervention consisted of teacher-led, peer-assisted in-school education, youth-friendly health services, community activities, and youth condom promotion and distribution. Process evaluation in 1999-2002 showed high intervention quality and coverage. A 2001/2 intervention impact evaluation showed no impact on the primary outcomes of HIV seroincidence and herpes simplex virus type 2 (HSV-2) seroprevalence but found substantial improvements in SRH knowledge, reported attitudes, and some reported sexual behaviours. It was postulated that the impact on "upstream" knowledge, attitude, and reported behaviour outcomes seen at the 3-year follow-up would, in the longer term, lead to a reduction in HIV and HSV-2 infection rates and other biological outcomes. A further impact evaluation survey in 2007/8 ( approximately 9 years post-intervention) tested this hypothesis. METHODS AND FINDINGS: This is a cross-sectional survey (June 2007 through July 2008) of 13,814 young people aged 15-30 y who had attended trial schools during the first phase of the MEMA kwa Vijana intervention trial (1999-2002). Prevalences of the primary outcomes HIV and HSV-2 were 1.8% and 25.9% in males and 4.0% and 41.4% in females, respectively. The intervention did not significantly reduce risk of HIV (males adjusted prevalence ratio [aPR] 0.91, 95%CI 0.50-1.65; females aPR 1.07, 95%CI 0.68-1.67) or HSV-2 (males aPR 0.94, 95%CI 0.77-1.15; females aPR 0.96, 95%CI 0.87-1.06). The intervention was associated with a reduction in the proportion of males reporting more than four sexual partners in their lifetime (aPR 0.87, 95%CI 0.78-0.97) and an increase in reported condom use at last sex with a non-regular partner among females (aPR 1.34, 95%CI 1.07-1.69). There was a clear and consistent beneficial impact on knowledge, but no significant impact on reported attitudes to sexual risk, reported pregnancies, or other reported sexual behaviours. The study population was likely to have been, on average, at lower risk of HIV and other sexually transmitted infections compared to other rural populations, as only youth who had reached year five of primary school were eligible. CONCLUSIONS: SRH knowledge can be improved and retained long-term, but this intervention had only a limited effect on reported behaviour and no significant effect on HIV/STI prevalence. Youth interventions integrated within intensive, community-wide risk reduction programmes may be more successful and should be evaluated. TRIAL REGISTRATION: ClinicalTrials.gov NCT0024846

Liver Fibrosis Linked to Cognitive Performance in HIV and Hepatitis C

Since HIV impairs gut barriers to pathogens, HIV-infected adults may be vulnerable to Minimal Hepatic Encephalopathy (MHE) in the absence of cirrhosis

The need to promote behaviour change at the cultural level: one factor explaining the limited impact of the MEMA kwa Vijana adolescent sexual health intervention in rural Tanzania. A process evaluation

Background - Few of the many behavioral sexual health interventions in Africa have been rigorously evaluated. Where biological outcomes have been measured, improvements have rarely been found. One of the most rigorous trials was of the multi-component MEMA kwa Vijana adolescent sexual health programme, which showed improvements in knowledge and reported attitudes and behaviour, but none in biological outcomes. This paper attempts to explain these outcomes by reviewing the process evaluation findings, particularly in terms of contextual factors. Methods - A large-scale, primarily qualitative process evaluation based mainly on participant observation identified the principal contextual barriers and facilitators of behavioural change. Results - The contextual barriers involved four interrelated socio-structural factors: culture (i.e. shared practices and systems of belief), economic circumstances, social status, and gender. At an individual level they appeared to operate through the constructs of the theories underlying MEMA kwa Vijana - Social Cognitive Theory and the Theory of Reasoned Action – but the intervention was unable to substantially modify these individual-level constructs, apart from knowledge. Conclusion - The process evaluation suggests that one important reason for this failure is that the intervention did not operate sufficiently at a structural level, particularly in regard to culture. Recently most structural interventions have focused on gender or/and economics. Complementing these with a cultural approach could address the belief systems that justify and perpetuate gender and economic inequalities, as well as other barriers to behaviour change

Immunological insights into COVID-19 in Southern Nigeria

Introduction: One of the unexpected outcomes of the COVID-19 pandemic was the relatively low levels of morbidity and mortality in Africa compared to the rest of the world. Nigeria, Africa's most populous nation, accounted for less than 0.01% of the global COVID-19 fatalities. The factors responsible for Nigeria's relatively low loss of life due to COVID-19 are unknown. Also, the correlates of protective immunity to SARS-CoV-2 and the impact of pre-existing immunity on the outcome of the COVID-19 pandemic in Africa are yet to be elucidated. Here, we evaluated the natural and vaccine-induced immune responses from vaccinated, non-vaccinated and convalescent individuals in Southern Nigeria throughout the three waves of the COVID-19 pandemic in Nigeria. We also examined the pre-existing immune responses to SARS-CoV-2 from samples collected prior to the COVID-19 pandemic. Methods: We used spike RBD and N- IgG antibody ELISA to measure binding antibody responses, SARS-CoV-2 pseudotype assay protocol expressing the spike protein of different variants (D614G, Delta, Beta, Omicron BA1) to measure neutralizing antibody responses and nucleoprotein (N) and spike (S1, S2) direct ex vivo interferon gamma (IFNγ) T cell ELISpot to measure T cell responses. Result: Our study demonstrated a similar magnitude of both binding (N-IgG (74% and 62%), S-RBD IgG (70% and 53%) and neutralizing (D614G (49% and 29%), Delta (56% and 47%), Beta (48% and 24%), Omicron BA1 (41% and 21%)) antibody responses from symptomatic and asymptomatic survivors in Nigeria. A similar magnitude was also seen among vaccinated participants. Interestingly, we revealed the presence of preexisting binding antibodies (N-IgG (60%) and S-RBD IgG (44%)) but no neutralizing antibodies from samples collected prior to the pandemic. Discussion: These findings revealed that both vaccinated, non-vaccinated and convalescent individuals in Southern Nigeria make similar magnitude of both binding and cross-reactive neutralizing antibody responses. It supported the presence of preexisting binding antibody responses among some Nigerians prior to the COVID-19 pandemic. Lastly, hybrid immunity and heterologous vaccine boosting induced the strongest binding and broadly neutralizing antibody responses compared to vaccine or infection-acquired immunity alone

Geographical variations in the prevalence of HIV and other sexually transmitted infections in rural Tanzania.

The prevalence and incidence of HIV and other sexually transmitted infections (STIs) were recorded in two lake-island and eight rural mainland communities in Mwanza, Tanzania. The prevalence and incidence of HIV and syphilis were lower on the islands, but this pattern was not seen for herpes simplex virus type-2, gonorrhoea, chlamydia, male urethritis or antenatal prevalences of Trichomonas vaginalis. Island men reported fewer sexual partners than mainland men but no differences were found for women. Island men were more likely to be circumcised, island women less mobile and there were differences in marriage patterns. Possible explanations for the differences in HIV and syphilis include: slower introduction of HIV into the islands because of geographical isolation, more core-group sexual contact on the mainland, higher prevalence of male circumcision on the islands and differences in marital status. Differences in transmission dynamics may lead to geographical patterns that vary between STIs

Impact of the MEMA kwa Vijana adolescent sexual and reproductive health interventions on use of health services by young people in rural Mwanza, Tanzania: results of a cluster randomized trial.

PURPOSE: To assess the impact of an adolescent sexual health intervention on the use of health services by young people in Tanzania. METHODS: Twenty communities, including 39 health facilities, were randomly allocated to the intervention or comparison arm. Health workers from the intervention arm were trained in the provision of youth-friendly health services, as part of a package of interventions. Independent process evaluations were conducted in health facilities, and simulated patients visited clinics using sexual and reproductive health problem scenarios. The impact on health facility attendances were assessed in 1998 (baseline) and 1999-2001. Reported sexually transmitted infection (STI) symptoms and use of health services were evaluated in young people in the trial cohort. RESULTS: The mean monthly attendance for STI symptoms per health facility, per month was .5 for young males and 1.0 for young females at baseline. Attendance by young males was greater in the intervention communities in 1999-2000 after adjustment for baseline differences (p = .005), and this difference increased over time (p-trend = .022). The mean difference in attendance was however relatively modest, at 1.1 per month in 2001 after adjustment for baseline (95% CI: .5, 1.7). There was weaker evidence of an intervention effect on attendance by young women (p = .087). Few condoms were distributed, although a greater number were distributed in intervention facilities (p = .008). Generally, intervention health workers tended to be less judgmental and provided more comprehensive information. CONCLUSIONS: Training staff to provide more youth-friendly health services can increase the utilization of health services for suspected STIs by young people, especially among young men

Biological and behavioural impact of an adolescent sexual health intervention in Tanzania: a community-randomized trial.

OBJECTIVE: The impact of a multicomponent intervention programme on the sexual health of adolescents was assessed in rural Tanzania. DESIGN: A community-randomized trial. METHODS: Twenty communities were randomly allocated to receive either a specially designed programme of interventions (intervention group) or standard activities (comparison group). The intervention had four components: community activities; teacher-led, peer-assisted sexual health education in years 5-7 of primary school; training and supervision of health workers to provide 'youth-friendly' sexual health services; and peer condom social marketing. Impacts on HIV incidence, herpes simplex virus 2 (HSV2) and other sexual health outcomes were evaluated over approximately 3 years in 9645 adolescents recruited in late 1998 before entering years 5, 6 or 7 of primary school. RESULTS: The intervention had a significant impact on knowledge and reported attitudes, reported sexually transmitted infection symptoms, and several behavioural outcomes. Only five HIV seroconversions occurred in boys, whereas in girls the adjusted rate ratio (intervention versus comparison) was 0.75 [95% confidence interval (CI) 0.34, 1.66]. Overall HSV2 prevalences at follow-up were 11.9% in male and 21.1% in female participants, with adjusted prevalence ratios of 0.92 (CI 0.69, 1.22) and 1.05 (CI 0.83, 1.32), respectively. There was no consistent beneficial or adverse impact on other biological outcomes. The beneficial impact on knowledge and reported attitudes was confirmed by results of a school examination in a separate group of students in mid-2002. CONCLUSION: The intervention substantially improved knowledge, reported attitudes and some reported sexual behaviours, especially in boys, but had no consistent impact on biological outcomes within the 3-year trial period

Risk factors for herpes simplex virus type 2 and HIV among women at high risk in northwestern Tanzania: preparing for an HSV-2 intervention trial.

OBJECTIVES: To determine prevalence of and risk factors for herpes simplex virus type 2 (HSV-2) and HIV among women being screened for a randomized, controlled trial of HSV suppressive therapy in northwestern Tanzania. METHODS: Two thousand seven hundred nineteen female facility workers aged 16 to 35 were interviewed and underwent serological testing for HIV and HSV-2. Factors associated with HSV-2 and HIV in women aged 16 to 24 were examined using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: HSV-2 seroprevalence was 80%, and HIV seroprevalence was 30%. Among women aged 16 to 24, both infections were significantly and independently associated with older age, being a bar worker, working at a truck stop, and having more lifetime sexual partners. HSV-2 infection was also associated with lower socioeconomic status, increased alcohol intake, younger age at first sex, inconsistent condom use, and vaginal douching. There was a strong association between the 2 infections after adjustment for other factors (OR = 4.22, 95% CI: 2.6 to 6.9). CONCLUSIONS: Female facility workers in northwestern Tanzania are vulnerable to HSV-2 and HIV infections. Programs designed to increase safer sexual behavior and reduce alcohol use could be effective in reducing HSV-2 incidence and, in turn, HIV infection. This is a suitable population for an HSV suppressive therapy trial