The effects of modern housing on malaria transmission in different endemic zones: a systematic review and meta-analysis.

BACKGROUND: Modern housing has been shown to reduce the risk of malaria infections compared to traditional houses; however, it is unclear if the effects differ in different malaria transmission settings. This study evaluated the effects of modern housing on malaria among different endemic areas. METHODS: Electronic databases, clinical trial registries and grey literature were searched for randomized controlled trials, cohort studies, case-control studies, and cross-sectional surveys on housing done between 1987 and 2022. Forest plots were done, and the quality of evidence was assessed using the Grading of Recommendations, Assessments, Development and Evaluation Framework. RESULTS: Twenty-one studies were included; thirteen were cross-sectional, four were case-control and four were cohort studies. Cohort studies showed an adjusted risk ratio of 0.68 (95% CI 0.48-0.96), and cross-sectional studies indicated an adjusted odds ratio (aOR) of 0.79 (95%CI 0.75-0.83). By endemic transmission regions, the adjusted odds ratio in the high endemic settings was 0.80 (95%CI 0.76-085); in the moderate transmission regions, aOR = 0.76 (95%CI 0.67-0.85) and in the low transmission settings, aOR = 0.67 (95%CI 0.48-0.85). CONCLUSIONS: The evidence from observational studies suggests that there are no differences in the protective effects of modern houses compared to traditional houses on malaria by endemicity level. This implies that good quality modern housing protects against malaria regardless of the malaria transmission settings.

Provision of HIV prevention and care services to farmworkers in sub-Saharan African countries.

OBJECTIVES: To summarise data on human immunodeficiency virus (HIV) services available to farmworkers in sub-Saharan Africa (SSA). METHODS: We conducted a systematic review to understand which HIV prevention and care services were accessed by farm workers in SSA. MEDLINE (PubMed), Embase, CINAHL (EBSCO Host), Cochrane library, African Index Medicus, Scopus, Google Scholar, Open Grey, and Web of Science Proceedings Citation Index were searched. Studies were eligible for inclusion if they measured or reported on the presence of HIV workplace policy frameworks, guidelines, or programmes for HIV prevention, treatment and care services, and other treatment modalities specifically targeting farmworkers. RESULTS: Nine studies published between 2005 and 2019 were included in the review. Six themes emerged from included studies, which include HIV policy, HIV prevention (awareness, education, and condom supply), voluntary counselling and testing, antiretroviral therapy (ART), linkage to care, and mobile clinic. Though availability of an HIV policy was inadequate, a significant positive impact of the HIV policy in influencing behaviour change was reported. Most of the farm workers could access HIV education and condom supply in their places of work. Access to ART, treatment support, and linkage to care was inadequate, but community outreach programmes and mobile clinics showed success in reaching a high number of workers with HIV testing and treatment. A majority of farm workers faced barriers in accessing government health facilities. CONCLUSIONS: The findings suggest that there is poor access to HIV services for farmworkers in SSA. There is a dire need to scale up HIV services and programmes, including mobile health facilities, in agricultural settings. Due to high labour migration patterns among farmworkers, we recommend cross-country HIV programmes that allow continuity of care across borders.

Implications of COVID-19 in high burden countries for HIV/TB: A systematic review of evidence.

BACKGROUND: The triple burden of COVID-19, tuberculosis and human immunodeficiency virus is one of the major global health challenges of the twenty-first century. In high burden HIV/TB countries, the spread of COVID-19 among people living with HIV is a well-founded concern. A thorough understanding of HIV/TB and COVID-19 pandemics is important as the three diseases interact. This may clarify HIV/TB/COVID-19 as a newly related field. However, several gaps remain in the knowledge of the burden of COVID-19 on patients with TB and HIV. This study was conducted to review different studies on SARS-CoV, MERS-CoV or COVID-19 associated with HIV/TB co-infection or only TB, to understand the interactions between HIV, TB and COVID-19 and its implications on the burden of the COVID-19 among HIV/TB co-infected or TB patients, screening algorithm and clinical management. METHODS: We conducted an electronic search of potentially eligible studies published in English in the Cochrane Controlled Register of Trials, PubMed, Medrxiv, Google scholar and Clinical Trials Registry databases. We included case studies, case series and observational studies published between January, 2002 and July, 2020 in which SARS-CoV, MERS-CoV and COVID-19 co-infected to HIV/TB or TB in adults. We screened titles, abstracts and full articles for eligibility. Descriptive and meta-analysis were done and results have been presented in graphs and tables. RESULTS: After removing 95 duplicates, 58 out of 437 articles were assessed for eligibility, of which 14 studies were included for descriptive analysis and seven studies were included in the meta-analysis. Compared to the descriptive analysis, the meta-analysis showed strong evidence that current TB exposure was high-risk COVID-19 group (OR 1.67, 95% CI 1.06-2.65, P = 0.03). The pooled of COVID-19/TB severity rate increased from OR 4.50 (95% CI 1.12-18.10, P = 0.03), the recovery rate was high among COVID-19 compared to COVID-19/TB irrespective of HIV status (OR 2.23, 95% CI 1.83-2.74, P < 0.001) and the mortality was reduced among non-TB group (P < 0.001). CONCLUSION: In summary, TB was a risk factor for COVID-19 both in terms of severity and mortality irrespective of HIV status. Structured diagnostic algorithms and clinical management are suggested to improve COVID-19/HIV/TB or COVID-19/TB co-infections outcomes.

Engaging community health workers in maternal and infant death identification in Khayelitsha, South Africa: a pilot study.

BACKGROUND: Engaging community health workers in a formalised death review process through verbal and social autopsy has been utilised in different settings to estimate the burden and causes of mortality, where civil registration and vital statistics systems are weak. This method has not been widely adopted. We piloted the use of trained community health workers (CHW) to investigate the extent of unreported maternal and infant deaths in Khayelitsha and explored requirements of such a programme and the role of CHWs in bridging gaps. METHODS: This was a mixed methods study, incorporating both qualitative and quantitative methods. Case identification and data collection were done by ten trained CHWs. Quantitative data were collected using a structured questionnaire. Qualitative data were collected using semi-structured interview guides for key informant interviews, focus group discussions and informal conversations. Qualitative data were analysed thematically using a content analysis approach. RESULTS: Although more than half of the infant deaths occurred in hospitals (n = 11/17), about a quarter that occurred at home (n = 4/17) were unreported. Main causes of deaths as perceived by family members of the deceased were related to uncertainty about the quality of care in the facilities, socio-cultural and economic contexts where people lived and individual factors. Most unreported deaths were further attributed to weak facility-community links and socio-cultural practices. Fragmented death reporting systems were perceived to influence the quality of the data and this impacted on the number of unreported deaths. Only two maternal deaths were identified in this pilot study. CONCLUSIONS: CHWs can conduct verbal and social autopsy for maternal and infant deaths to complement formal vital registration systems. Capacity development, stakeholder's engagement, supervision, and support are essential for a community-linked death review system. Policymakers and implementers should establish a functional relationship between community-linked reporting systems and the existing system as a starting point. There is a need for more studies to confirm or build on our pilot findings.

Community-Based Interventions to Improve and Sustain Antiretroviral Therapy Adherence, Retention in HIV Care and Clinical Outcomes in Low- and Middle-Income Countries for Achieving the UNAIDS 90-90-90 Targets.

Little is known about the effect of community versus health facility-based interventions to improve and sustain antiretroviral therapy (ART) adherence, virologic suppression, and retention in care among HIV-infected individuals in low- and middle-income countries (LMICs). We systematically searched four electronic databases for all available randomized controlled trials (RCTs) and comparative cohort studies in LMICs comparing community versus health facility-based interventions. Relative risks (RRs) for pre-defined adherence, treatment engagement (linkage and retention in care), and relevant clinical outcomes were pooled using random effect models. Eleven cohort studies and eleven RCTs (N = 97,657) were included. Meta-analysis of the included RCTs comparing community- versus health facility-based interventions found comparable outcomes in terms of ART adherence (RR = 1.02, 95 % CI 0.99 to 1.04), virologic suppression (RR = 1.00, 95 % CI 0.98 to 1.03), and all-cause mortality (RR = 0.93, 95 % CI 0.73 to 1.18). The result of pooled analysis from the RCTs (RR = 1.03, 95 % CI 1.01 to 1.06) and cohort studies (RR = 1.09, 95 % CI 1.03 to 1.15) found that participants assigned to community-based interventions had statistically significantly higher rates of treatment engagement. Two studies found community-based ART delivery model either cost-saving or cost-effective. Community- versus facility-based models of ART delivery resulted in at least comparable outcomes for clinically stable HIV-infected patients on treatment in LMICs and are likely to be cost-effective.

Efficacy and safety of abacavir-containing combination antiretroviral therapy as first-line treatment of HIV infected children and adolescents: a systematic review and meta-analysis.

BACKGROUND: Abacavir is one of the recommended nucleoside reverse transcriptase inhibitors (NRTIs) for the treatment of HIV infections among children and adolescents. However, there are concerns that the antiviral efficacy of abacavir might be low when compared to other NRTIs especially among children. There are also concerns that abacavir use may lead to serious adverse events such as hypersensitivity reactions and has potential predisposition to developing cardiovascular diseases METHODS: We searched four electronic databases, four conference proceedings and two clinical trial registries in August 2014, without language restrictions. Experimental and observational studies with control groups that examined the efficacy and safety of abacavir-containing regimens in comparison with other NRTIs as first-line treatment for HIV-infected children and adolescents aged between one month and eighteen years were eligible. Two authors independently screened search results, extracted data and assessed the risk of bias of included studies using a pre-specified, standardised data extraction form and validated risk of bias tools. We also assessed the quality of evidence per outcome with the GRADE tool. RESULTS: We included two randomised controlled trials (RCTs) and two analytical cohort studies with a total of 10,595 participants. Among the RCTs we detected no difference in virologic suppression after a mean duration of 48 weeks between abacavir- and stavudine-containing regimens (2 trials; n = 326: RR 1.28; 95 % CI 0.67-2.42) with significant heterogeneity (P = 0.02; I(2) = 81 %). We also found no significant differences between the two groups for adverse events and death. After five years of follow-up, virologic suppression improved with abacavir (1 trial; n = 69: RR 1.96; 95 % CI 1.11-3.44). For cohort studies, we detected that the virologic suppression activity of abacavir was less effective than stavudine in both the lopinavir/ritonavir (1 study, n = 2165: RR 0.79, 95 % CI 0.67-0.92) and efavirenz sub-groups (1 study, n = 3204: RR 0.79, 95 % CI 0.67-0.92) respectively. The quality of evidence from RCTs was moderate for virologic suppression but low for death and adverse events, while that of cohort studies was low for all three these outcomes. CONCLUSIONS: Available evidence showed little or no difference between abacavir-containing regimen and other NRTIs regarding efficacy and safety when given to children and adolescents as a first-line antiretroviral therapy.

Spatial distribution and determinants of HIV high burden in the Southern African sub-region.

BACKGROUND: Spatial analysis at different levels can help understand spatial variation of human immunodeficiency virus (HIV) infection, disease drivers, and targeted interventions. Combining spatial analysis and the evaluation of the determinants of the HIV burden in Southern African countries is essential for a better understanding of the disease dynamics in high-burden settings. METHODS: The study countries were selected based on the availability of demographic and health surveys (DHS) and corresponding geographic coordinates. We used multivariable regression to evaluate the determinants of HIV burden and assessed the presence and nature of HIV spatial autocorrelation in six Southern African countries. RESULTS: The overall prevalence of HIV for each country varied between 11.3% in Zambia and 22.4% in South Africa. The HIV prevalence rate was higher among female respondents in all six countries. There were reductions in prevalence estimates in most countries yearly from 2011 to 2020. The hotspot cluster findings show that the major cities in each country are the key sites of high HIV burden. Compared with female respondents, the odds of being HIV positive were lesser among the male respondents. The probability of HIV infection was higher among those who had sexually transmitted infections (STI) in the last 12 months, divorced and widowed individuals, and women aged 25 years and older. CONCLUSIONS: Our research findings show that analysis of survey data could provide reasonable estimates of the wide-ranging spatial structure of the HIV epidemic in Southern African countries. Key determinants such as individuals who are divorced, middle-aged women, and people who recently treated STIs, should be the focus of HIV prevention and control interventions. The spatial distribution of high-burden areas for HIV in the selected countries was more pronounced in the major cities. Interventions should also be focused on locations identified as hotspot clusters.

Access to HIV healthcare services by farm workers in sub-Saharan Africa (SSA): a systematic review protocol.

INTRODUCTION: Sub-Saharan Africa (SSA) region harbours the highest burden of HIV infections in the world. Agricultural work has been reported as one of the occupations with a high prevalence of HIV. Farm workers generally have poor access to health services, which prevents them from receiving proper HIV prevention and care. Furthermore, poor policies and policy implementation, and lack of workplace programmes increases farm workers' vulnerability to HIV infection. Thus, the aim of this study is to conduct a systematic review to assess HIV prevention and treatment services and national policies governing access to healthcare services by farm workers in SSA. METHODS AND ANALYSIS: Our systematic review will include studies published from January 1990 to December 2021 within SSA countries. We will use a sensitive search strategy for electronic bibliographic databases and grey literature sources. Databases will include PubMed, CINAHL, Cochrane library, African Index Medicus and Scopus. The main outcomes to be reported will be HIV policy for farmworkers, availability of HIV prevention service(s), availability of treatment and support to farmworkers who are living with HIV, presence of referral structures for farmworkers through the health system and follow-up services for farmworkers who are on antiretroviral therapy. We will synthesise the main characteristics of included studies and use summary measures to describe study characteristics. In a situation where data are not sufficiently homogeneous to perform a quantitative synthesis, we will conduct a narrative synthesis. We will explore themes and relationships between included studies for qualitative data. ETHICS AND DISSEMINATION: The study will use publicly available data and ethics exemption has been obtained from Human Research Ethics Committees, Faculty of Medicine & Health Sciences, Stellenbosch University. The results of this study will be disseminated through peer-reviewed journals, conference presentations and seminars. PROSPERO REGISTRATION NUMBER: CRD42021277528.

Male partner unknown HIV status as a risk factor for HIV incidence and clinical outcomes in prevention of mother-to-child transmission of HIV programmes in 21 WHO priority countries: a systematic review protocol.

INTRODUCTION: Research has shown an association between increased disclosure of HIV status by pregnant and breastfeeding women and improved clinical health and that of their infant. Increasing awareness about their male partner's HIV status will no doubt lead to even better outcomes at the population level. Male partner involvement is important for improving outcomes of prevention of mother-to-child transmission of HIV (MTCT) as it improves social support and commitment from both parents of the baby to ensure sustained good health. Although lack of knowledge of the HIV status of a male partner is of great concern, limited research has been done to determine whether it remains one of the barriers to reaching the proposed goals of eliminating MTCT in pregnant or postpartum women. Our aim is to determine if lack of knowledge of a male partner's HIV status is a significant risk factor for HIV incidence and poor HIV clinical outcomes among pregnant women and postpartum women and their infants. METHODS AND ANALYSIS: A systematic review and meta-analysis of experimental and observational studies will be conducted. The review will focus on knowledge of male partner's HIV status in the 21 priority countries most affected by HIV in Africa. We will search electronic databases such as PubMed/Medline, Scopus, Web of Science and Cochrane library, Science Direct, CINAHL, LILACS and SciELO databases from January 2011 to December 2021. We will also search the Pan African and WHO clinical trial registries and conference archives. We will conduct a quality assessment of eligible studies and evaluate the heterogeneity of the pooled studies using the I 2 statistic. The statistical analysis will be performed using STATA statistical software V.16. ETHICS AND DISSEMINATION: The study will use publicly available data and ethics exemption has been obtained from Human Research Ethics Committees, Faculty of Medicine & Health Sciences, Stellenbosch University. The protocol was registered on Prospective Register of Systematic Reviews, registration number CRD42021247686, in May 2021. Findings of this systematic review will be disseminated in peer-review journals including various media platforms, that is, webinars, symposia, conferences or congresses. PROSPERO REGISTRATION NUMBER: Registration number CRD42021247686.

Classification Schemes of COVID-19 High Risk Areas and Resulting Policies: A Rapid Review.

The COVID-19 pandemic has posed a significant global health threat since January 2020. Policies to reduce human mobility have been recognized to effectively control the spread of COVID-19; although the relationship between mobility, policy implementation, and virus spread remains contentious, with no clear pattern for how countries classify each other, and determine the destinations to- and from which to restrict travel. In this rapid review, we identified country classification schemes for high-risk COVID-19 areas and associated policies which mirrored the dynamic situation in 2020, with the aim of identifying any patterns that could indicate the effectiveness of such policies. We searched academic databases, including PubMed, Scopus, medRxiv, Google Scholar, and EMBASE. We also consulted web pages of the relevant government institutions in all countries. This rapid review's searches were conducted between October 2020 and December 2021. Web scraping of policy documents yielded additional 43 country reports on high-risk area classification schemes. In 43 countries from which relevant reports were identified, six issued domestic classification schemes. International classification schemes were issued by the remaining 38 countries, and these mainly used case incidence per 100,000 inhabitants as key indicator. The case incidence cut-off also varied across the countries, ranging from 20 cases per 100,000 inhabitants in the past 7 days to more than 100 cases per 100,000 inhabitants in the past 28 days. The criteria used for defining high-risk areas varied across countries, including case count, positivity rate, composite risk scores, community transmission and satisfactory laboratory testing. Countries either used case incidence in the past 7, 14 or 28 days. The resulting policies included restrictions on internal movement and international travel. The quarantine policies can be summarized into three categories: (1) 14 days self-isolation, (2) 10 days self-isolation and (3) 14 days compulsory isolation.

Health trends, inequalities and opportunities in South Africa's provinces, 1990-2019: findings from the Global Burden of Disease 2019 Study.

BACKGROUND: Over the last 30 years, South Africa has experienced four 'colliding epidemics' of HIV and tuberculosis, chronic illness and mental health, injury and violence, and maternal, neonatal, and child mortality, which have had substantial effects on health and well-being. Using data from the 2019 Global Burden of Diseases, Injuries and Risk Factors Study (GBD 2019), we evaluated national and provincial health trends and progress towards important Sustainable Development Goal targets from 1990 to 2019. METHODS: We analysed GBD 2019 estimates of mortality, non-fatal health loss, summary health measures and risk factor burden, comparing trends over 1990-2007 and 2007-2019. Additionally, we decomposed changes in life expectancy by cause of death and assessed healthcare system performance. RESULTS: Across the nine provinces, inequalities in mortality and life expectancy increased over 1990-2007, largely due to differences in HIV/AIDS, then decreased over 2007-2019. Demographic change and increases in non-communicable diseases nearly doubled the number of years lived with disability between 1990 and 2019. From 1990 to 2019, risk factor burdens generally shifted from communicable and nutritional disease risks to non-communicable disease and injury risks; unsafe sex remained the top risk factor. Despite widespread improvements in healthcare system performance, the greatest gains were generally in economically advantaged provinces. CONCLUSIONS: Reductions in HIV/AIDS and related conditions have led to improved health since 2007, though most provinces still lag in key areas. To achieve health targets, provincial governments should enhance health investments and exchange of knowledge, resources and best practices alongside populations that have been left behind, especially following the COVID-19 pandemic.

Effect of community-based interventions targeting female sex workers along the HIV care cascade in sub-Saharan Africa: a systematic review and meta-analysis.

BACKGROUND: Female sex workers are extremely vulnerable and highly susceptible to being infected with human immunodeficiency virus. As a result, community-based targeted interventions have been recommended as one of the models of care to improve access to HIV services and continued engagement in care. We conducted a systematic review to (1) assess the effect of FSW-targeted community interventions on the improvement of HIV services access along the treatment cascade and (2) describe community-based interventions that positively affect continuation in HIV care across the HIV treatment cascade for FSWs in sub-Saharan Africa. METHODS: We defined the 5 steps that make up the HIV care cascade and categorized them as outcomes, namely, HIV testing and diagnosis, linkage to care, receipt of ART, and achievement of viral suppression. We conducted a systematic search of randomized controlled trials, cohort, and cross-sectional studies done in sub-Saharan African countries and published from 2004 to 2020. The period was selected based on the time span within which ART was scaled up through widespread roll-out of comprehensive HIV programs in sub-Saharan Africa. We reviewed studies with data on the implementation of community interventions for any of the HIV care cascade stage. The data were analyzed using random effects meta-analysis where possible, and for the rest of the studies, data were synthesized using summary statistics. RESULTS: The significant impact of the community interventions was observed on HIV testing, HIV diagnosis, and ART use. However, for HIV testing and ART use, the improvement was not sustained for the entire period of implementation. There were minimal interventions that had impact on HIV diagnosis, with only one community service delivery model showing significance. Generally, the interventions that had reasonable impact are those that implemented targeted and comprehensive package of HIV services provided at one location, and with unique strategies specific to each cascade stage. CONCLUSIONS: The evidence brought forward from this review shows that the effect of community-based interventions varies across the different stages of HIV care cascade. A broad package of interventions including a combination of behavioral, biomedical, and structural, designed with specific strategies, unique to each cascade stage appears to be more effective, although information on long-term treatment outcomes and the extent to which FSWs remain engaged in care is sparse. There is need to conduct a further research to deepen the assessment of the effectiveness of community-based interventions on HIV care cascade for FSWs. This will enhance identification of evidence-based optimal interventions that will guide effective allocation of scarce resources for strategies that would have a significant impact on HIV service delivery. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020157623.

Missed opportunities for vaccination in Africa.

The purpose of this review is to assess the extent of missed opportunities for vaccination (MOV) in Africa, determine the associated factors, and provide recommendations that countries could adopt in reducing MOV. Two databases were searched for multinational studies and systematic reviews reporting MOV and involving African countries. A total of 288 records were identified and 12 studies included for synthesis. The prevalence ranged from 47.0% to 62.1%, with a weighted mean of 27.3%. This review highlighted caregiver utilization, health service delivery, and healthcare worker' factors associated with MOV. Understanding the extent of MOV in Africa presents an opportunity for multiple approaches to resolve the differential factors that contribute to MOV, and to bridge the gap in vaccination coverage in the continent.

Predictors of post-operative outcomes in patients with peripheral arterial disease and critical limb ischaemia: a systematic review and meta-analysis.

Background: A very small proportion (1%) of patients with peripheral artery disease (PAD) present with critical limb threatening ischaemia (CLTI) with poor prognosis. The present review showcased several pre-operative predictors and key post-operative outcomes. Identification of any modifiable predictors may impact positively on surgical outcomes. Design: PubMed/Medline, Google scholar and Cochrane databases were searched using terms such as "peripheral arterial disease" AND "critical limb ischemia," "post-operative outcome," AND "predictors of post-operative outcomes". Search was for relevant English-language articles published between January 1997 and December 2007 Selected articles were screened first by title and abstract, and selection of full articles was based on relevance using our inclusion and exclusion criteria and quality ratings performed with the MINORS score. Results: The included studies were published between 1997 and 2007. Only six (6) articles out of a total of 2,114 were deemed suitable for analysis. Ambulatory recovery was >70% at six months, 86.7% and 70.0% at one year and five years respectively. Rate of local wound complications was between 12% and 24%. Reported limb salvage rates were >90% at six months, >70% at one year and 70.0-90.0% at five years. Primary graft patency rate at one year ranged from 63% and 76.6%. Gangrene, diabetes and impaired pre-operative ambulatory function are associated with more wound complications, low limb salvage, reduced graft patency and poor functional outcome. Conclusion: Pre-operative ambulatory status was the most important predictor of post-operative ambulatory recovery. Diabetes mellitus was an important risk factor for prolonged wound healing, local wound complications and major amputation. Funding: None declared.

African based researchers' output on models for the transmission dynamics of infectious diseases and public health interventions: A scoping review.

BACKGROUND: Applied epidemiological models are used in predicting future trends of diseases, for the basic understanding of disease and health dynamics, and to improve the measurement of health indicators. Mapping the research outputs of epidemiological modelling studies concerned with transmission dynamics of infectious diseases and public health interventions in Africa will help to identify the areas with substantial levels of research activities, areas with gaps, and research output trends. METHODS: A scoping review of applied epidemiological models of infectious disease studies that involved first or last authors affiliated to African institutions was conducted. Eligible studies were those concerned with the transmission dynamics of infectious diseases and public health interventions. The review was consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) extension for scoping reviews. Four electronic databases were searched for peer-reviewed publications up to the end of April 2020. RESULTS: Of the 5927 publications identified, 181 met the inclusion criteria. The review identified 143 publications with first authors having an African institutional affiliation (AIA), while 81 had both first and last authors with an AIA. The publication authors were found to be predominantly affiliated with institutions based in South Africa and Kenya. Furthermore, human immunodeficiency virus, malaria, tuberculosis, and Ebola virus disease were found to be the most researched infectious diseases. There has been a gradual increase in research productivity across Africa especially in the last ten years, with several collaborative efforts spread both within and beyond Africa. CONCLUSIONS: Research productivity in applied epidemiological modelling studies of infectious diseases may have increased, but there remains an under-representation of African researchers as leading authors. The study findings indicate a need for the development of research capacity through supporting existing institutions in Africa and promoting research funding that will address local health priorities.

The Impact of Rubella Vaccine Introduction on Rubella Infection and Congenital Rubella Syndrome: A Systematic Review of Mathematical Modelling Studies.

INTRODUCTION: Rubella vaccines have been used to prevent rubella and congenital rubella syndrome (CRS) in several World Health Organization (WHO) regions. Mathematical modelling studies have simulated introduction of rubella-containing vaccines (RCVs), and their results have been used to inform rubella introduction strategies in several countries. This systematic review aimed to synthesize the evidence from mathematical models regarding the impact of introducing RCVs. METHODS: We registered the review in the international prospective register of systematic reviews (PROSPERO) with registration number CRD42020192638. Systematic review methods for classical epidemiological studies and reporting guidelines were followed as far as possible. A comprehensive search strategy was used to identify published and unpublished studies with no language restrictions. We included deterministic and stochastic models that simulated RCV introduction into the public sector vaccination schedule, with a time horizon of at least five years. Models focused only on estimating epidemiological parameters were excluded. Outcomes of interest were time to rubella and CRS elimination, trends in incidence of rubella and CRS, number of vaccinated individuals per CRS case averted, and cost-effectiveness of vaccine introduction strategies. The methodological quality of included studies was assessed using a modified risk of bias tool, and a qualitative narrative was provided, given that data synthesis was not feasible. RESULTS: Seven studies were included from a total of 1393 records retrieved. The methodological quality was scored high for six studies and very high for one study. Quantitative data synthesis was not possible, because only one study reported point estimates and uncertainty intervals for the outcomes. All seven included studies presented trends in rubella incidence, six studies reported trends in CRS incidence, two studies reported the number vaccinated individuals per CRS case averted, and two studies reported an economic evaluation measure. Time to CRS elimination and time to rubella elimination were not reported by any of the included studies. Reported trends in CRS incidence showed elimination within five years of RCV introduction with scenarios involving mass vaccination of older children in addition to routine infant vaccination. CRS incidence was higher with RCV introduction than without RCV when public vaccine coverage was lower than 50% or only private sector vaccination was implemented. Although vaccination of children at a given age achieved slower declines in CRS incidence compared to mass campaigns targeting a wide age range, this approach resulted in the lowest number of vaccinated individuals per CRS case averted. CONCLUSION AND RECOMMENDATIONS: We were unable to conduct data synthesis of included studies due to discrepancies in outcome reporting. However, qualitative assessment of results of individual studies suggests that vaccination of infants should be combined with vaccination of older children to achieve rapid elimination of CRS. Better outcomes are obtained when rubella vaccination is introduced into public vaccination schedules at coverage figures of 80%, as recommended by WHO, or higher. Guidelines for reporting of outcomes in mathematical modelling studies and the conduct of systematic reviews of mathematical modelling studies are required.

Predicting the environmental suitability for onchocerciasis in Africa as an aid to elimination planning.

Recent evidence suggests that, in some foci, elimination of onchocerciasis from Africa may be feasible with mass drug administration (MDA) of ivermectin. To achieve continental elimination of transmission, mapping surveys will need to be conducted across all implementation units (IUs) for which endemicity status is currently unknown. Using boosted regression tree models with optimised hyperparameter selection, we estimated environmental suitability for onchocerciasis at the 5 × 5-km resolution across Africa. In order to classify IUs that include locations that are environmentally suitable, we used receiver operating characteristic (ROC) analysis to identify an optimal threshold for suitability concordant with locations where onchocerciasis has been previously detected. This threshold value was then used to classify IUs (more suitable or less suitable) based on the location within the IU with the largest mean prediction. Mean estimates of environmental suitability suggest large areas across West and Central Africa, as well as focal areas of East Africa, are suitable for onchocerciasis transmission, consistent with the presence of current control and elimination of transmission efforts. The ROC analysis identified a mean environmental suitability index of 0·71 as a threshold to classify based on the location with the largest mean prediction within the IU. Of the IUs considered for mapping surveys, 50·2% exceed this threshold for suitability in at least one 5 × 5-km location. The formidable scale of data collection required to map onchocerciasis endemicity across the African continent presents an opportunity to use spatial data to identify areas likely to be suitable for onchocerciasis transmission. National onchocerciasis elimination programmes may wish to consider prioritising these IUs for mapping surveys as human resources, laboratory capacity, and programmatic schedules may constrain survey implementation, and possibly delaying MDA initiation in areas that would ultimately qualify.

Effect of female sex work-targeted community-based interventions along the HIV treatment cascade in sub-Saharan Africa: a systematic review protocol.

INTRODUCTION: Female sex workers (FSWs) are a known high-risk group that are at increased risk of HIV transmission due to exposure to multiple sexual partners and inability to negotiate safe sex attributed to challenging economic circumstances. Previous systematic reviews have examined the effectiveness of HIV interventions prioritising FSWs and have shown that targeted interventions improve access to HIV prevention and treatment services. Interventions that increase FSWs' uptake of services are well documented; however, evidence on specific interventions aimed at improving FSWs' continuity in HIV care along the treatment cascade is lacking. This systematic review aims to document the performance of community-based interventions along the HIV treatment cascade. METHODS AND ANALYSIS: We will use a sensitive search strategy for electronic bibliographic databases, bibliographies of included articles and grey literature sources. In addition, the Joint United Nations Programme on HIV/AIDS and the WHO websites, peer-reviewed conference papers and grey literature sources will be searched for additional reports of sex work programmes. We will include randomised controlled trials, cross-sectional surveys and cohort interventions where community-based HIV services were provided to FSWs and measure the performance of the HIV intervention on one or more cascade stages. We will conduct a systematic review of studies published from 2004 to present within the sub-Saharan Africa region. We will report quantitative study outcomes of HIV testing and diagnosis, linkage to care, initiation on antiretroviral therapy and viral suppression. We will analyse the data using the random-effects meta-analysis method, and funnel plots will be used to assess the publication bias. ETHICS AND DISSEMINATION: This systematic review will not require ethical approval; we will publish data from manuscripts. The results of this study will be disseminated in peer-reviewed journals and conference presentations. PROSPERO REGISTRATION NUMBER: CRD42020157623.

Immunogenicity and safety of fractional dose yellow fever vaccination: A systematic review and meta-analysis.

BACKGROUND: Recent upsurges in yellow fever outbreaks are increasing the demand for yellow fever vaccine, while enormously straining global vaccine supply. Fractional dose yellow fever vaccination is being considered as a dose-sparing strategy to address current vaccine shortages. This systematic review and meta-analysis aimed to assess the effects of fractional dose yellow fever vaccination, in comparison with those of standard dose vaccination. METHODS: We registered this review on the International Prospective Register of Systematic Reviews (PROSPERO, registration number: CRD42018084214), developed the protocol in line with the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols (PRISMA-P) and synthesised the evidence in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). We stratified meta-analyses by vaccine dose. RESULTS: We retrieved 2524 records from the literature search, eleven of them potentially eligible. From these studies, we included eight eligible trials, with a total of 2371 participants. Seroconversion rates at four to five weeks following vaccination were similar between participants who received standard doses and participants who received fractional doses containing one-third (547 participants: risk ratio [RR] 1.02, 95% confidence interval [CI] 1.00-1.04), one-fifth (155 participants: RR 1.00, 95% CI 0.98-1.03), one-tenth (890 participants: RR 0.99, 95% CI 0.96-1.01), and one-fiftieth (661 participants: RR 0.97, 95% CI 0.92-1.02) of the standard dose. However, the rates of seroconversion were substantially lower among participants who received fractional doses containing one-hundredth and lower fractions of the standard dose. Immunogenicity similarly persisted 8-10 years following both fractional and standard dose vaccination. Minor adverse events following vaccination did not differ across doses, and no serious adverse events were reported in any study arm. CONCLUSIONS: These findings support the use of fractional dosing as a strategy for mitigating vaccine shortages. The strategy should be specifically considered for individuals who are young, immuno-competent and well nourished.

Cochrane corner: universal screening for SARS-CoV-2 infection.

INTRODUCTION: coronavirus disease 2019 (COVID-19) is caused by the novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Most people infected with SARS-CoV-2 have mild disease with non-specific symptoms, although a few becoming critically ill with septic shock and multiple organ failure. There is an unknown proportion of infected individuals who remain asymptomatic and infectious. Universal screening for COVID-19 infections to detect individuals who are infected before they present clinically could therefore be an important measure to contain the spread of the disease. We highlight a Cochrane rapid review which assessed the effectiveness and accuracy of universal screening for COVID-19 infection. METHODS: the authors of the Cochrane review searched multiple electronic databases to identify studies reporting on the effectiveness of universal screening and reporting on screening test accuracy. Eligible participants for the review included people who had not sought care for potential COVID-19 symptoms. RESULTS: the authors included 22 publications, with none of them conducted in Africa. Two modelling studies reported on the beneficial and negative effects of screening; and 20 studies (cohort and modelling) reported data on the accuracy of screening tests. The included studies had wide variability in the baseline prevalence of COVID-19 infection as well as study settings and methods. All cohort studies compared screening strategies to reverse transcriptase-polymerase chain reaction (RT-PCR) as the gold standard. The rapid review suggests that there is low certainty of evidence that screening at travel hubs may slow the importation of infected cases. Furthermore, the review highlights the uncertainty and variation in the accuracy of screening. CONCLUSION: given the low accuracy of the tests included in this review, a high proportion of COVID-19 infected individuals may be missed and go on to infect others. In addition, some healthy individuals may be falsely identified as positive, requiring confirmatory testing and potentially leading to the unnecessary isolation of these individuals.