Remodelling selection to optimise disease forecasts and policies

Mathematical models are increasingly adopted for setting disease prevention and control targets. As model-informed policies are implemented, however, the inaccuracies of some forecasts become apparent, for example overprediction of infection burdens and intervention impacts. Here, we attribute these discrepancies to methodological limitations in capturing the heterogeneities of real-world systems. The mechanisms underpinning risk factors of infection and their interactions determine individual propensities to acquire disease. These factors are potentially so numerous and complex that to attain a full mechanistic description is likely unfeasible. To contribute constructively to the development of health policies, model developers either leave factors out (reductionism) or adopt a broader but coarse description (holism). In our view, predictive capacity requires holistic descriptions of heterogeneity which are currently underutilised in infectious disease epidemiology, in comparison to other population disciplines, such as non-communicable disease epidemiology, demography, ecology and evolution

Remodelling selection to optimise disease forecasts and policies

Mathematical models are increasingly adopted for setting disease prevention and control targets. As model-informed policies are implemented, however, the inaccuracies of some forecasts become apparent, for example overprediction of infection burdens and intervention impacts. Here, we attribute these discrepancies to methodological limitations in capturing the heterogeneities of real-world systems. The mechanisms underpinning risk factors of infection and their interactions determine individual propensities to acquire disease. These factors are potentially so numerous and complex that to attain a full mechanistic description is likely unfeasible. To contribute constructively to the development of health policies, model developers either leave factors out (reductionism) or adopt a broader but coarse description (holism). In our view, predictive capacity requires holistic descriptions of heterogeneity which are currently underutilised in infectious disease epidemiology, in comparison to other population disciplines, such as non-communicable disease epidemiology, demography, ecology and evolution

Ending TB means responding to socially produced vulnerabilities of all genders

Globally and in Africa, tuberculosis (TB) affects more men than women, as masculine norms, behaviours, and practices can increase likelihood of exposure to TB whilst undermining engagement in TB care (1). The WHO Africa region remains particularly affected, accounting for nearly a quarter (23%) of the estimated 10.6 million people who developed TB and close to a third (31%) of the 1.6 million people who died from the disease in 2021 (2), despite being home to only 15% of the world’s population (3). 25 African countries are considered high burden countries for TB, HIV-associated TB, and drug-resistant TB (2). TB affects close to 6 million men globally and 1.3 million men in the WHO Africa region every year (2), undermining their physical health, mental well-being, and capacity to contribute to their families and communities

'I will choose when to test, where I want to test': investigating young people's preferences for HIV self-testing in Malawi and Zimbabwe.

OBJECTIVES: The current study identifies young people's preferences for HIV self-testing (HIVST) delivery, determines the relative strength of preferences and explores underlying behaviors and perceptions to inform youth-friendly services in southern Africa. DESIGN: A mixed methods design was adopted in Malawi and Zimbabwe and includes focus group discussions, in-depth interviews and discrete choice experiments. METHODS: The current study was conducted during the formative phase of cluster-randomized trials of oral-fluid HIVST distribution. Young people aged 16-25 years were purposively selected for in-depth interviews (n = 15) in Malawi and 12 focus group discussions (n = 107) across countries. Representative samples of young people in both countries (n = 341) were administered discrete choice experiments on HIVST delivery, with data analyzed to estimate relative preferences. The qualitative results provided additional depth and were triangulated with the quantitative findings. RESULTS: There was strong concordance across methods and countries based on the three triangulation parameters: product, provider and service characteristics. HIVST was highly accepted by young people, if provided at no or very low cost. Young people expressed mixed views on oral-fluid tests, weighing perceived benefits with accuracy concerns. There was an expressed lack of trust in health providers and preference for lay community distributors. HIVST addressed youth-specific barriers to standard HIV testing, with home-based distribution considered convenient. Issues of autonomy, control, respect and confidentiality emerged as key qualitative themes. CONCLUSION: HIVST services can be optimized to reach young people if products are provided through home-based distribution and at low prices, with respect for them as autonomous individuals

Accuracy of upper respiratory tract samples to diagnose Mycobacterium tuberculosis: a systematic review and meta-analysis

Background: Pulmonary tuberculosis due to Mycobacterium tuberculosis can be challenging to diagnose when sputum samples cannot be obtained, which is especially problematic in children and older people. We systematically appraised the performance characteristics and diagnostic accuracy of upper respiratory tract sampling for diagnosing active pulmonary tuberculosis. Methods: In this systematic review and meta-analysis, we searched MEDLINE, Cinahl, Web of Science, Global Health, and Global Health Archive databases for studies published between database inception and Dec 6, 2022 that reported on the accuracy of upper respiratory tract sampling for tuberculosis diagnosis compared with microbiological testing of sputum or gastric aspirate reference standard. We included studies that evaluated the accuracy of upper respiratory tract sampling (laryngeal swabs, nasopharyngeal aspirate, oral swabs, saliva, mouth wash, nasal swabs, plaque samples, and nasopharyngeal swabs) to be tested for microbiological diagnosis of tuberculous (by culture and nucleic acid amplification tests) compared with a reference standard using either sputum or gastric lavage for a microbiological test. We included cohort, case-control, cross-sectional, and randomised controlled studies that recruited participants from any community or clinical setting. We excluded post-mortem studies. We used a random-effects meta-analysis with a bivariate hierarchical model to estimate pooled sensitivity, specificity, and diagnostics odds ratio (DOR; odds of a positive test with disease relative to without), stratified by sampling method. We assessed bias using QUADAS-2 criteria. This study is registered with PROSPERO (CRD42021262392). Findings: We screened 10 159 titles for inclusion, reviewed 274 full texts, and included 71, comprising 119 test comparisons published between May 13, 1933, and Dec 19, 2022, in the systematic review (53 in the meta-analysis). For laryngeal swabs, pooled sensitivity was 57·8% (95% CI 50·5–65·0), specificity was 93·8% (88·4–96·8), and DOR was 20·7 (11·1–38·8). Nasopharyngeal aspirate sensitivity was 65·2% (52·0–76·4), specificity was 97·9% (96·0–99·0), and DOR was 91·0 (37·8–218·8). Oral swabs sensitivity was 56·7% (44·3–68·2), specificity was 91·3% (CI 81·0–96·3), and DOR was 13·8 (5·6–34·0). Substantial heterogeneity in diagnostic accuracy was found, probably due to differences in reference and index standards. Interpretation: Upper respiratory tract sampling holds promise to expand access to tuberculosis diagnosis. Exploring historical methods using modern microbiological techniques might further increase options for alternative sample types. Prospective studies are needed to optimise accuracy and utility of sampling methods in clinical practice. Funding: UK Medical Research Council, Wellcome, and UK Foreign, Commonwealth and Development Office

Intra-urban variation of intimate partner violence against women and men in Kenya: Evidence from the 2014 Kenya Demographic and Health Survey

Although urban areas are diverse and urban inequities are well documented, surveys commonly differentiate intimate partner violence (IPV) rates only by urban versus rural residence. This study compared rates of current IPV victimization among women and men by urban residence (informal and formal settlements). Data from the 2014 Kenya Demographic and Health Survey, consisting of an ever-married sample of 1,613 women (age 15-49 years) and 1,321 men (age 15-54), were analyzed. Multilevel logistic regression was applied to female and male data separately to quantify the associations between residence and any current IPV while controlling for regional variation and other factors. Results show gendered patterns of intra-urban variation in IPV occurrence, with the greatest burden of IPV identified among women in informal settlements (across all types of violence). Unadjusted analyses suggest residing in informal settlements is associated with any current IPV against women, but not men, compared with their counterparts in formal urban settlements. This correlation is not statistically significant when adjusting for women’s education level in multivariate analysis. In addition, reporting father beat mother, use of current physical violence against partner, partner’s alcohol use, and marital status are associated with any current IPV against women and men. IPV gets marginal attention in urban violence and urban health research and our results highlight the importance of spatially disaggregate IPV data – beyond the rural-urban divide – to inform policy and programming. Future research may utilize intersectional and syndemic approaches to investigate the complexity of IPV and clustering with other forms of violence and other health issues in different urban settings, especially among marginalized residents in informal urban settings

Power and poverty: A participatory study on the complexities of HIV and intimate partner violence in an informal urban settlement in Nairobi, Kenya

People in informal urban settlements in Kenya face multiple inequalities, yet researchers investigate issues such as HIV or intimate partner violence (IPV) in isolation, targeting single populations and focusing on individual behaviour, without involving informal settlement dwellers. We formed a study team of researchers (n = 4) and lay investigators (n = 11) from an informal settlement in Nairobi, Kenya to understand the power dynamics in the informal urban settlement that influence vulnerability to IPV and HIV among women and men from key populations in this context. We facilitated participatory workshops with 56 women and 32 men from different marginalised groups and interviewed 10 key informants. We used a participatory data analysis approach. Our findings suggest the IPV and HIV nexus is rooted in the daily struggle for cash and survival in the informal settlement where lucrative livelihoods are scarce and a few gatekeepers regulate access to opportunities. Power is gendered and used to exercise control over people and resources. Common coping strategies applied to mitigate against the effects of poverty and powerlessness amplify vulnerabilities to HIV and IPV. These complex power relations create and sustain an environment conducive to IPV and HIV. Prevention interventions thus need to address underlying structural drivers, uphold human rights, create safe environments, and promote participation to maximise and sustain the positive effects of biomedical, behavioural, and empowerment strategies

Point of care ultrasound in acutely breathless patients-A qualitative study of the enablers and challenges in a teaching hospital in Kenya

OBJECTIVES: Acute breathlessness is a common and distressing symptom experienced by patients presenting to the emergency department (ED). Adoption of clinician-performed bedside ultrasound could promote accurate, early diagnosis and treatment to acutely breathless patients. This may be particularly pertinent in low resource settings with limited human resources and lack of access to advanced (gold standard) diagnostic testing. The aim of the study was to explore the experience of point-of-care ultrasound (PoCUS) users in the emergency department, and to understand the facilitators and constraints of PoCUS incorporation into patient investigation pathways. MATERIALS AND METHODS: This was an exploratory qualitative study. Data collection entailed key informant interviews using a semi-structured interview guide between September 2019 and February 2020. Participants were purposively sampled according to role and responsibility in the acute care system at Kenyatta National Hospital, including front-line health practitioners and mid-level clinical hospital managers. Data collection proceeded until no new concepts emerged (thematic saturation). The analytical framework method was used for the thematic analysis of interview transcripts. RESULTS: At individual level, the lack of training on the use of PoCUS, as well as fears and beliefs impacted on capability and motivation of the clinicians to perform PoCUS for clinical diagnosis. Hospital level influencers such as hospital norms, workloads, and staffing influenced the use of PoCUS by impacting on the clinician’s capability, motivation, and opportunity. General health system influencers such as relationships and power dynamics between clinical specialties and key stakeholders, and the lack of policy and practice guidelines challenged the uptake of the bedside ultrasound by the clinicians. CONCLUSION: Lack of PoCUS training for clinicians, limited resources and a fragmented health system structure impacted the clinician’s capability, motivation, and opportunity in performing PoCUS in diagnostics. PoCUS for diagnosis of acute breathlessness requires: (1) Well-maintained and accessible equipment; (2) highly trained individuals with time to perform the examination with access to ongoing support for the operators; and (3) finally, researchers must more accurately identify the optimal scope of ultrasound examination, the diagnostic benefits, and the opportunity costs. All three will be required to ensure patient’s benefit

Local Response in Health Emergencies: Key Considerations for Addressing the COVID-19 Pandemic in Informal Urban Settlements

This paper highlights the major challenges and considerations for addressing COVID-19 in informal settlements. It discusses what is known about vulnerabilities and how to support local protective action. There is heightened concern about informal urban settlements because of the combination of population density and inadequate access to water and sanitation, which makes standard advice about social distancing and washing hands implausible. There are further challenges to do with the lack of reliable data and the social, political and economic contexts in each setting that will influence vulnerability and possibilities for action. The potential health impacts of COVID-19 are immense in informal settlements, but if control measures are poorly executed these could also have severe negative impacts. Public health interventions must be balanced with social and economic interventions, especially in relation to the informal economy upon which many poor urban residents depend. Local residents, leaders and communitybased groups must be engaged and resourced to develop locally appropriate control strategies, in partnership with local governments and authorities. Historically, informal settlements and their residents have been stigmatized, blamed, and subjected to rules and regulations that are unaffordable or unfeasible to adhere to. Responses to COVID-19 should not repeat these mistakes. Priorities for enabling effective control measures include: collaborating with local residents who have unsurpassed knowledge of relevant spatial and social infrastructures, strengthening coordination with local governments, and investing in improved data for monitoring the response in informal settlements