Local disease-ecosystem-livelihood dynamics: reflections from comparative case studies in Africa

Circulating Epstein-Barr Virus Antibody Levels as a Biomarker of Socioecological Adversity in Amazonian Ecuador

OBJECTIVES

Circulating Epstein-Barr virus antibodies (EBV-Ab) are used as a biomarker of chronic stress in high-income settings, but their relevance in environments with a high burden of infectious disease, nutritional constraints, and limited resources is less clear. We investigated EBV-Ab as a biomarker of adversity in a setting where local ecology and economy may affect immune development differently than in wealthy countries.

METHODS

We measured EBV-Ab in finger-prick dried blood spots collected from Indigenous Shuar (n = 433) and non-Indigenous Colonos (n = 84) ranging from < 1 to 87 years old in Amazonian Ecuador. For a subset of adults (≥ 15 years, n = 210), we collected socioeconomic information (income, education, and occupation) and assessed household-level market integration. We determined the most important predictors of EBV-Ab for adults and children using multi-model averaging of linear regression models.

RESULTS

Male children (< 15 years) had lower EBV-Ab than female children (model averaged β [SE]: -0.238 [0.066]). For adults, Shuar had higher EBV-Ab than Colonos (model averaged β [SE]: 0.235 [0.113]), and high systolic blood pressure was an important predictor of elevated EBV-Ab (model averaged β [SE]: 0.088 [0.047]). Individuals who reported unpaid domestic work as their primary occupation had higher EBV-Ab than agricultural workers (model averaged β [SE]: 0.302 [0.113]). Individuals living in houses with more market-sourced infrastructure had lower EBV-Ab (model averaged β [SE]: -0.088 [0.068]).

CONCLUSIONS

Circulating EBV-Ab may capture context-specific aspects of socioecological adversity in Amazonian Ecuador, highlighting disparities in EBV-Ab between Indigenous and non-Indigenous Ecuadorians and differences in immune function related to market integration.

Assessing the Environmental Drivers of Lassa Fever in West Africa: A Systematic Review

The spread of Lassa virus in West Africa is reliant on the abundance and distribution of its rodent host reservoirs. While the impact of environmental change on viral spread has been studied for many zoonotic viruses, there is still a limited understanding of how seasonal impacts, land-use conversion, and biodiversity loss influence the expansion of Lassa virus among reservoirs. This systematic review synthesizes existing research on the association between environmental variables and Lassa virus circulation in West Africa to inform future research, public health interventions, and One Health policy. We searched international and African scientific databases using a set of pre-defined search terms to obtain publications reporting on Lassa virus in West Africa between 1969 and 2023. A total of 9465 articles were retrieved from this search and 70 studies met inclusion criteria for this review. Through systematic data extraction, we identified seasonal precipitation, land-use change, and host expansion as key environmental drivers of Lassa virus in reservoir hosts; however, we also highlight notable gaps in knowledge that limit our current understanding of these complex relationships. This review underscores the need for interdisciplinary research and strategies to mitigate the impacts of environmental change on Lassa virus transmission and protect vulnerable populations in West Africa.

Demography of the Gambian Epauletted Fruit Bat (Epomophorus gambianus) in Ghana

We provide the first estimates of survival and reproductive rates for a population of the Gambian Epauletted Fruit Bat Epomophorus gambianus in Ghana. We focused on a large colony of ca. 5,000 bats over 3 years to estimate population parameters including population size, birth rates, survival, and sex ratios for this species. Reproduction chronology was confirmed as seasonal bimodal polyestry, with births occurring in March/April and August/September each year. The estimated birth rate was 0.89 (95% CI = 0.85 to 0.92) per reproductive season. The overall sex ratio (female to male ratio) of the study population was male-dominated (0.69, 95% CI = 0.64 to 0.75), but female-biased for adults (62% female, χ2 1 = 42, P < 0.0001), and showed temporal and age-specific variations. By radiotracking 60 bats for 10 months, we obtained the first estimates of minimum monthly survival for this species as 0.81 (95% CI = 0.74 to 0.86), but this could be an underestimate due to possible undetected emigration of tagged bats.

Exploring environmental and climate features associated with yellow fever across space and time in the Brazilian Atlantic Forest biome

The Atlantic Forest Biome (AFB) creates an ideal environment for the proliferation of vector mosquitoes, such as Haemagogus and Sabethes species, which transmit the Yellow Fever virus (YFV) to both human and non-human primates (NHP) (particularly Alouatta sp. and Callithrix sp.). From 2016 to 2020, 748 fatal cases of YF in humans and 1,763 in NHPs were reported in this biome, following several years free from the disease. This underscores the imminent risk posed by the YFV. In this study, we examined the spatiotemporal distribution patterns of YF cases in both NHPs and humans across the entire AFB during the outbreak period, using a generalized linear mixed regression model (GLMM) at the municipal level. Our analysis examined factors associated with the spread of YFV, including environmental characteristics, climate conditions, human vaccination coverage, and the presence of two additional YFV-affected NHP species. The occurrence of epizootics has been directly associated with natural forest formations and the presence of species within the Callithrix genus. Additionally, epizootics have been shown to be directly associated with human prevalence. Furthermore, human prevalence showed an inverse correlation with urban areas, temporary croplands, and savannah and grassland areas. Further analyses using Moran's Index to incorporate the neighborhoods of municipalities with cases in each studied host revealed additional variables, such as altitude, which showed a positive correlation. Additionally, the occurrence of the disease in both hosts exhibited a spatio-temporal distribution pattern. To effectively mitigate the spread of the virus, it is necessary to proactively expand vaccination coverage, refine NHP surveillance strategies, and enhance entomological surveillance in both natural and modified environments.

Innovative governance for transformative energy policy in sub-Saharan Africa after COVID-19: Green pathways in Egypt, Nigeria, and South Africa

Learning from innovations that fail is imperative for innovations that succeed. The theoretical underpinnings for this innovative framing are reflexivity, transformative unlearning, and intelligent failure. This framework proposes a definition of "transformative governance" as governance that creates structural equities. Governments rebuilding their economies after the COVID-19 pandemic seek equitable green transformations; that are gendered, structural, and sustainable, learning from the implemented gender-sensitive responses (hereafter referred to as policy innovations). This paper argues that transformative practices, beliefs, values, assumptions, policies, and systematic learnings are complementary to post-crisis transformations. The aim is to promote systematic learnings from innovation governance failure regarding energy policy through the analysis of COVID-19 practices and the unlearning of policy innovation beliefs, values, and assumptions that are not transformative. I ask: how gender-equitable, structurally equitable, and green-transformative were the COVID-19 policy innovations? The study's approach is qualitative and situated within the constructivist research paradigm. It uses reflexive thematic analysis combined with innovative coded policy narrative and a transformative index-matching technique, to identify the gap within transformative interventions. The study included 58 policy innovations (n = 58) collected from the UNDP, KPMG, government reports, and news flashes from the three most populous nations in sub-Sahara Africa: Egypt, Nigeria, and South Africa. The study found that policy innovations were inequitable in terms of gender, structure, and sustainability whereas the derived transformative pathways are equitable and gender-transformative, structurally transformative, and green-transformative. The rationales behind a transformative approach to policy reflect the systemic failures across key areas: market dynamics, research and development, and green transformation. Policy innovators can align transformative pathways for innovative governance that implements transformative energy policy. To address the needs of multiple fragile and vulnerable identities, the derived post-pandemic framework is an intersectional plan with 10 policy learning pillars. The plan includes local energy transformation and reinforcement of energy justice components, such as the localization of the energy industry, community power, and social norms, including Ubuntu, which translates to "I am because we are." Reengagement in global supply chains requires South-South trade relations to be restrategized.

Ecological correlates and predictors of Lassa fever incidence in Ondo State, Nigeria 2017-2021: an emerging urban trend

Lassa fever (LF) is prevalent in many West African countries, including Nigeria. Efforts to combat LF have primarily focused on rural areas where interactions between rodents and humans are common. However, recent studies indicate a shift in its occurrence from rural to urban areas. We analysed secondary data of reported LF outbreaks from 2017 to 2021 in Ondo State, Nigeria to identify the distribution pattern, ecological variations, and other determinants of disease spread from the ward level using nearest neighbour statistics and regression analysis. Data utilised include LF incidence, ecological variables involving population, nighttime light intensity, vegetation, temperature, market presence, road length, and building area coverage. ArcGIS Pro 3.0 software was employed for spatial analysis. Results revealed spatio-temporal clustering of LF incidents between 2017 and 2021, with an increasing trend followed by a decline in 2021. All wards in Owo Local Government Area were identified as LF hotspots. The ecological variables exhibited significant correlations with the number of LF cases in the wards, except for maximum temperature. Notably, these variables varied significantly between wards with confirmed LF and those without. Therefore, it is important to prioritise strategies for mitigating LF outbreaks in urban areas of Nigeria and other LF-endemic countries.

Robust evidence for bats as reservoir hosts is lacking in most African virus studies: a review and call to optimize sampling and conserve bats

Africa experiences frequent emerging disease outbreaks among humans, with bats often proposed as zoonotic pathogen hosts. We comprehensively reviewed virus-bat findings from papers published between 1978 and 2020 to evaluate the evidence that African bats are reservoir and/or bridging hosts for viruses that cause human disease. We present data from 162 papers (of 1322) with original findings on (1) numbers and species of bats sampled across bat families and the continent, (2) how bats were selected for study inclusion, (3) if bats were terminally sampled, (4) what types of ecological data, if any, were recorded and (5) which viruses were detected and with what methodology. We propose a scheme for evaluating presumed virus-host relationships by evidence type and quality, using the contrasting available evidence for Orthoebolavirus versus Orthomarburgvirus as an example. We review the wording in abstracts and discussions of all 162 papers, identifying key framing terms, how these refer to findings, and how they might contribute to people's beliefs about bats. We discuss the impact of scientific research communication on public perception and emphasize the need for strategies that minimize human-bat conflict and support bat conservation. Finally, we make recommendations for best practices that will improve virological study metadata.

Understanding Factors that Shape Exposure to Zoonotic and Food-Borne Diseases Across Wild Meat Trade Chains

The rise of zoonotic disease-related public health crises has sparked calls for policy action, including calls to close wildlife markets. Yet, these calls often reflect limited understanding of where, precisely, exposure to risk occurs along wildlife and wild meat trade chains. They also threaten to negatively impact food security and livelihoods. From a public health perspective, it is important to understand the practices that shape food safety all along the trade chain, resulting in meat that is either safe to eat or managed as a potential vector of pathogens. This article uses ethnographic methods to examine the steps that lead a wild animal from the forest to the plate of an urban consumer in Yangambi and Kisangani in the Democratic Republic of Congo (DRC). Focusing on hunters, village-level consumers, transporters, market traders and urban consumers, we highlight specific practices that expose different actors involved in the trade chain to wild meat related health risks, including exposure to food borne illnesses from contaminated meat and zoonotic pathogens through direct contact with wild animals, and the local practices in place to reduce the same. We discuss interventions that could help prevent and mitigate zoonotic and food borne disease risks associated with wild meat trade chains.

Is There Always a Negative Causality between Human Health and Environmental Degradation? Current Evidence from Rural China

This study explores the incidence and trend of zoonoses in China and its relationship with environmental health and proposes suggestions for promoting the long-term sustainable development of human, animal, and environmental systems. The incidence of malaria was selected as the dependent variable, and the consumption of agricultural diesel oil and pesticides and investment in lavatory sanitation improvement in rural areas were selected as independent variables according to the characteristics of nonpoint source pollution and domestic pollution in China's rural areas. By employing a fixed effects regression model, the results indicated that the use of pesticides was negatively associated with the incidence of malaria, continuous investment in rural toilet improvement, and an increase in economic income can play a positive role in the prevention and control of malaria incidence. Guided by the theory of One Health, this study verifies human, animal, and environmental health as a combination of mutual restriction and influence, discusses the complex causal relationship among the three, and provides evidence for sustainable development and integrated governance.

Vulnerability and One Health assessment approaches for infectious threats from a social science perspective: a systematic scoping review

Vulnerability assessments identify vulnerable groups and can promote effective community engagement in responding to and mitigating destabilising events. This scoping review maps assessments for local-level vulnerabilities in the context of infectious threats. We searched various databases for articles written between 1978 and 2019. Eligible documents assessed local-level vulnerability, focusing on infectious threats and antimicrobial resistance. Since few studies provided this dual focus, we included tools from climate change and disaster risk reduction literature that engaged the community in the assessment. We considered studies using a One Health approach as essential for identifying vulnerability risk factors for zoonotic disease affecting humans. Of the 5390 records, we selected 36 articles for review. This scoping review fills a gap regarding vulnerability assessments by combining insights from various approaches: local-level understandings of vulnerability involving community perspectives; studies of social and ecological factors relevant to exposure; and integrated quantitative and qualitative methods that make generalisations based on direct observation. The findings inform the development of new tools to identify vulnerabilities and their relation to social and natural environments.

Using Intersectionality to Identify Gendered Barriers to Health-Seeking for Febrile Illness in Agro-Pastoralist Settings in Tanzania

BACKGROUND

Research has shown that gender is a significant determinant of health-seeking behavior around the world. Gender power relations and lay etiologies of illness can influence the distribution of household resources, including for healthcare. In some rural settings in Africa, gender intersects with multiple forms of health inequities, from proximal socio-cultural factors to more "upstream" or distal health system determinants which can amplify barriers to health-seeking for specific groups in specific contexts.

AIM

We used an intersectionality approach to determine how women in particular, experience gendered barriers to accessing healthcare among Maa and non-Maa speaking agro-pastoralists in northern Tanzania. We also explored lay etiologies of febrile illness, perceptions of health providers and rural health-seeking behavior in order to identify the most common barriers to accessing healthcare in these settings.

METHODS

Mixed method ethnographic approaches were used to collect data between 2016 and 2018 from four Maa-speaking and two Swahili-speaking agro-pastoralist villages in northern Tanzania. Maa-speaking villages were based in Naiti, Monduli district while non-Maa speaking villages were selected from Msitu in Babati district. Data on health seeking behaviors was collected through semi-structured questionnaires, in-depth interviews, focus group discussions, and home and facility-based participant observation.

FINDINGS

The results primarily focus on the qualitative outcomes of both studies. We found that febrile illness was locally categorized across a spectrum of severity ranging from normal and expected illness to serious illness that required hospital treatment. Remedial actions taken to treat febrile illness included attending local health facilities, obtaining medicines from drug sellers and use of herbal remedies. We found barriers to health-seeking played out at different scales, from the health system, community (inter-household decision making) and household (intra-household decision making). Gender-based barriers at the household had a profound effect on health-seeking. Younger married women delayed seeking healthcare the most, as they often had to negotiate health-seeking with husbands and extended family members, including co-wives and mothers-in-law who make the majority of health-related decisions.

CONCLUSION

An intersectional approach enabled us to gain a nuanced understanding of determinants of health-seeking behavior beyond the commonly assumed barriers such lack of public health infrastructure. We propose tapping into the potential of senior older women involved in local therapy-management groups, to explore gender-transformative approaches to health-seeking, including tackling gender-based barriers at the community level. While these social factors are important, ultimately, improving the public health infrastructure in these settings is a first step toward addressing structural determinants of treatment-seeking.

Community health and human-animal contacts on the edges of Bwindi Impenetrable National Park, Uganda

Cross-species transmission of pathogens is intimately linked to human and environmental health. With limited healthcare and challenging living conditions, people living in poverty may be particularly susceptible to endemic and emerging diseases. Similarly, wildlife is impacted by human influences, including pathogen sharing, especially for species in close contact with people and domesticated animals. Here we investigate human and animal contacts and human health in a community living around the Bwindi Impenetrable National Park (BINP), Uganda. We used contact and health survey data to identify opportunities for cross-species pathogen transmission, focusing mostly on people and the endangered mountain gorilla. We conducted a survey with background questions and self-reported diaries to investigate 100 participants' health, such as symptoms and behaviours, and contact patterns, including direct contacts and sightings over a week. Contacts were revealed through networks, including humans, domestic, peri-domestic, and wild animal groups for 1) contacts seen in the week of background questionnaire completion, and 2) contacts seen during the diary week. Participants frequently felt unwell during the study, reporting from one to 10 disease symptoms at different intensity levels, with severe symptoms comprising 6.4% of the diary records and tiredness and headaches the most common symptoms. After human-human contacts, direct contact with livestock and peri-domestic animals were the most common. The contact networks were moderately connected and revealed a preference in contacts within the same taxon and within their taxa groups. Sightings of wildlife were much more common than touching. However, despite contact with wildlife being the rarest of all contact types, one direct contact with a gorilla with a timeline including concerning participant health symptoms was reported. When considering all interaction types, gorillas mostly exhibited intra-species contact, but were found to interact with five other species, including people and domestic animals. Our findings reveal a local human population with recurrent symptoms of illness in a location with intense exposure to factors that can increase pathogen transmission, such as direct contact with domestic and wild animals and proximity among animal species. Despite significant biases and study limitations, the information generated here can guide future studies, such as models for disease spread and One Health interventions.

The effectiveness of community-led initiatives in livestock disease control: a case of African swine fever in rural areas of Uganda

Proper implementation of biosecurity is currently the only control measure of African swine fever (ASF) in the absence of an effective vaccine or drug against the disease. Despite the efforts that Uganda's local and central governments have invested to reduce livestock diseases, ASF outbreaks still persist in the country. In this study, we assessed the effectiveness of community-led initiatives in the control of ASF in Mukono District, central Uganda. In Mukono district, a community-led pilot program was initiated where stakeholders in the pig value chain organized themselves into an ASF control task force to enforce on-farm and pig value chain activities intended to limit the spread of ASF. Semi-structured interviews with pig famers (n = 211) were conducted in two areas with contrasting practices: one with active community-initiated and monitored ASF control initiatives since 2016 (Kasawo and Namuganga) and the other without such initiative as the control (Mpunge and Ntenjeru). A significant decline (Wilcoxon ranked sign test: Z =  - 5.412, p = 0.000) in the annual frequency of ASF outbreaks in both Kasawo and Namuganga sub-counties was observed after the implementation of community-led initiatives. The level of practice of most ASF control measures was significantly higher (p < 0.01) in sub-counties that instituted community-led ASF control initiatives than in the control sub-counties. The results of this study demonstrate the power of community-led initiatives in reducing ASF disease outbreaks in endemic areas.

Post-pandemic transformations: How and why COVID-19 requires us to rethink development

COVID-19 is proving to be the long awaited 'big one': a pandemic capable of bringing societies and economies to their knees. There is an urgent need to examine how COVID-19 - as a health and development crisis - unfolded the way it did it and to consider possibilities for post-pandemic transformations and for rethinking development more broadly. Drawing on over a decade of research on epidemics, we argue that the origins, unfolding and effects of the COVID-19 pandemic require analysis that addresses both structural political-economic conditions alongside far less ordered, 'unruly' processes reflecting complexity, uncertainty, contingency and context-specificity. This structural-unruly duality in the conditions and processes of pandemic emergence, progression and impact provides a lens to view three key challenge areas. The first is how scientific advice and evidence are used in policy, when conditions are rigidly 'locked in' to established power relations and yet so uncertain. Second is how economies function, with the COVID-19 crisis having revealed the limits of a conventional model of economic growth. The third concerns how new forms of politics can become the basis of reshaped citizen-state relations in confronting a pandemic, such as those around mutual solidarity and care. COVID-19 demonstrates that we face an uncertain future, where anticipation of and resilience to major shocks must become the core problematic of development studies and practice. Where mainstream approaches to development have been top down, rigid and orientated towards narrowly-defined economic goals, post-COVID-19 development must have a radically transformative, egalitarian and inclusive knowledge and politics at its core.

Artificial Intelligence and One Health: Knowledge Bases for Causal Modeling

Scientists all over the world are moving toward building database systems based on the One Health concept to prevent and manage outbreaks of zoonotic diseases. An appreciation of the process of discovery with incomplete information and a recognition of the role of observations gathered painstakingly by scientists in the field shows that simple databases will not be sufficient to build causal models of the complex relationships between human health and ecosystems. Rather, it is important also to build knowledge bases which complement databases using non-monotonic logic based artificial intelligence techniques, so that causal models can be improved as new, and sometimes contradictory, information is found from field studies.

Spatial epidemiology of yellow fever: Identification of determinants of the 2016-2018 epidemics and at-risk areas in Brazil

Optimise control strategies of infectious diseases, identify factors that favour the circulation of pathogens, and propose risk maps are crucial challenges for global health. Ecological niche modelling, once relying on an adequate framework and environmental descriptors can be a helpful tool for such purposes. Despite the existence of a vaccine, yellow fever (YF) is still a public health issue. Brazil faced massive sylvatic YF outbreaks from the end of 2016 up to mid-2018, but cases in human and non-human primates have been recorded until the beginning of 2020. Here we used both human and monkey confirmed YF cases from two epidemic periods (2016/2017 and 2017/2018) to describe the spatial distribution of the cases and explore how biotic and abiotic factors drive their occurrence. The distribution of YF cases largely overlaps for humans and monkeys, and a contraction of the spatial extent associated with a southward displacement is observed during the second period of the epidemics. More contributive variables to the spatiotemporal heterogeneity of cases were related to biotic factors (mammal richness), abiotic factors (temperature and precipitation), and some human-related variables (population density, human footprint, and human vaccination coverage). Both projections of the most favourable conditions showed similar trends with a contraction of the more at-risk areas. Once extrapolated at a large scale, the Amazon basin remains at lower risk, although surrounding forest regions and notably the North-West region, would face a higher risk. Spatial projections of infectious diseases often relied on climatic variables only; here for both models, we instead highlighted the importance of considering local biotic conditions, hosts vulnerability, social and epidemiological factors to run the spatial risk analysis correctly: all YF cases occurring later on, in 2019 and 2020, were observed in the predicted at-risk areas.

A Critical Analysis of the Drivers of Human Migration Patterns in the Presence of Climate Change: A New Conceptual Model

Both climate change and migration present key concerns for global health progress. Despite this, a transparent method for identifying and understanding the relationship between climate change, migration and other contextual factors remains a knowledge gap. Existing conceptual models are useful in understanding the complexities of climate migration, but provide varying degrees of applicability to quantitative studies, resulting in non-homogenous transferability of knowledge in this important area. This paper attempts to provide a critical review of climate migration literature, as well as presenting a new conceptual model for the identification of the drivers of migration in the context of climate change. It focuses on the interactions and the dynamics of drivers over time, space and society. Through systematic, pan-disciplinary and homogenous application of theory to different geographical contexts, we aim to improve understanding of the impacts of climate change on migration. A brief case study of Malawi is provided to demonstrate how this global conceptual model can be applied into local contextual scenarios. In doing so, we hope to provide insights that help in the more homogenous applications of conceptual frameworks for this area and more generally.

A Review of Antimicrobial Resistance in Poultry Farming within Low-Resource Settings

The emergence, spread, and persistence of antimicrobial resistance (AMR) remain a pressing global health issue. Animal husbandry, in particular poultry, makes up a substantial portion of the global antimicrobial use. Despite the growing body of research evaluating the AMR within industrial farming systems, there is a gap in understanding the emergence of bacterial resistance originating from poultry within resource-limited environments. As countries continue to transition from low- to middle income countries (LMICs), there will be an increased demand for quality sources of animal protein. Further promotion of intensive poultry farming could address issues of food security, but it may also increase risks of AMR exposure to poultry, other domestic animals, wildlife, and human populations. Given that intensively raised poultry can function as animal reservoirs for AMR, surveillance is needed to evaluate the impacts on humans, other animals, and the environment. Here, we provide a comprehensive review of poultry production within low-resource settings in order to inform future small-scale poultry farming development. Future research is needed in order to understand the full extent of the epidemiology and ecology of AMR in poultry within low-resource settings.

Ecological niche modelling for predicting the risk of cutaneous leishmaniasis in the Neotropical moist forest biome

A major challenge of eco-epidemiology is to determine which factors promote the transmission of infectious diseases and to establish risk maps that can be used by public health authorities. The geographic predictions resulting from ecological niche modelling have been widely used for modelling the future dispersion of vectors based on the occurrence records and the potential prevalence of the disease. The establishment of risk maps for disease systems with complex cycles such as cutaneous leishmaniasis (CL) can be very challenging due to the many inference networks between large sets of host and vector species, with considerable heterogeneity in disease patterns in space and time. One novelty in the present study is the use of human CL cases to predict the risk of leishmaniasis occurrence in response to anthropogenic, climatic and environmental factors at two different scales, in the Neotropical moist forest biome (Amazonian basin and surrounding forest ecosystems) and in the surrounding region of French Guiana. With a consistent data set never used before and a conceptual and methodological framework for interpreting data cases, we obtained risk maps with high statistical support. The predominantly identified human CL risk areas are those where the human impact on the environment is significant, associated with less contributory climatic and ecological factors. For both models this study highlights the importance of considering the anthropogenic drivers for disease risk assessment in human, although CL is mainly linked to the sylvatic and peri-urban cycle in Meso and South America.

Interventions to Reduce Antibiotic Prescribing in LMICs: A Scoping Review of Evidence from Human and Animal Health Systems

This review identifies evidence on supply-side interventions to change the practices of antibiotic prescribers and gatekeepers in low- and middle-income countries (LMICs). A total of 102 studies met the inclusion criteria, of which 70 studies evaluated interventions and 32 provided insight into prescribing contexts. All intervention studies were from human healthcare settings, none were from animal health. Only one context study examined antibiotic use in animal health. The evidence base is uneven, with the strongest evidence on knowledge and stewardship interventions. The review found that multiplex interventions that combine different strategies to influence behaviour tend to have a higher success rate than interventions based on single strategies. Evidence on prescribing contexts highlights interacting influences including health system quality, education, perceptions of patient demand, bureaucratic processes, profit, competition, and cultures of care. Most interventions took place within one health setting. Very few studies targeted interventions across different kinds of providers and settings. Interventions in hospitals were the most commonly evaluated. There is much less evidence on private and informal private providers who play a major role in drug distribution in LMICs. There were no interventions involving drug detailers or the pharmaceutical companies despite their prominent role in the contextual studies.

Using physical contact heterogeneity and frequency to characterize dynamics of human exposure to nonhuman primate bodily fluids in central Africa

Emerging infectious diseases of zoonotic origin constitute a recurrent threat to global health. Nonhuman primates (NHPs) occupy an important place in zoonotic spillovers (pathogenic transmissions from animals to humans), serving as reservoirs or amplifiers of multiple neglected tropical diseases, including viral hemorrhagic fevers and arboviruses, parasites and bacteria, as well as retroviruses (simian foamy virus, PTLV) that are pathogenic in human beings. Hunting and butchering studies in Africa characterize at-risk human social groups, but overlook critical factors of contact heterogeneity and frequency, NHP species differences, and meat processing practices. In southeastern Cameroon, a region with a history of zoonotic emergence and high risk of future spillovers, we conducted a novel mixed-method field study of human physical exposure to multiple NHP species, incorporating participant-based and ecological methodologies, and qualitative interviews (n = 25). We find frequent physical contact across adult human populations, greater physical contact with monkeys than apes, especially for meat handling practices, and positive correlation of human exposure with NHP species abundance and proximity to human settlement. These fine-grained results encourage reconsideration of the likely dynamics of human-NHP contact in past and future NTD emergence events. Multidisciplinary social science and ecological approaches should be mobilized to generate more effective human and animal surveillance and risk communications around neglected tropical diseases. At a moment when the WHO has included "Disease X", a presumably zoonotic pathogen with pandemic potential, on its list of blueprint priority diseases as, new field-based tools for investigating zoonotic disease emergence, both known and unknown, are of critical importance.

Avoiding bites and scratches? Understanding the public health implication of human-bat interactions in Ghana

Zoonotic pathogens cause an estimated 70% of emerging and re-emerging infectious diseases in humans, affecting various aspects of human development on a global scale. The significance of bats as a source of emerging infectious diseases is being progressively appreciated. This study was undertaken post-Ebola virus disease in West Africa and assessed the public health implications of human-bat interactions by exploring the reasons for contact between humans and bats, as well as reported actions taken upon experiencing bat bites or scratches. The paper highlights the nuances of human-bat interactions, stressing zoonotic disease risk awareness as well as the sources of information. The study used questionnaires to solicit information from 788 respondents in five communities with significant bat populations. We show that bat consumption was one of the main reasons for human-bat interactions. More men across the various communities ate bat meat. Only a small number of respondents (4.4%) reported being bitten by a bat, and 6.1% had been scratched by a bat. More than 21% had come into direct contact with bat blood. An even lower number went to the hospital after been bitten or scratched by bats. There was little knowledge on post-exposure management. The most common places human-bat interactions occurred were at home and on farms. Seventy-three per cent of the respondents believed that bats carried diseases, with Ebola virus disease being the most mentioned. Respondents indicated that the way they interacted with bats had not changed, even though they believed bats carried diseases and 46% stated that they had not changed the way they interacted with bats over the last two years. Apart from providing information on avoiding bites and scratches, a more holistic framework is needed to reduce human-bat interactions. The paper recommends a comprehensive and coordinated approach to optimizing an effective response to a potential bat-borne zoonotic disease spillover.

One Health for a changing world: new perspectives from Africa

The concept of One Health, which aims to drive improvements in human, animal and ecological health through an holistic approach, has been gaining increasing support and attention in recent years. While this concept has much appeal, there are few examples where it has been successfully put into practice. This Special Issue explores the challenges in African contexts, with papers looking at the complex interactions between ecosystems, diseases and poverty dynamics; at underlying social and political dimensions; at the potentials for integrative modelling; and at the changes in policy and practice required to realise a One Health approach. This introductory paper offers an overview of the 11 papers, coming from diverse disciplinary perspectives, that each explore how a One Health approach can work in a world of social, economic and environmental change.

Structural drivers of vulnerability to zoonotic disease in Africa

This paper argues that addressing the underlying structural drivers of disease vulnerability is essential for a ‘One Health’ approach to tackling zoonotic diseases in Africa. Through three case studies—trypanosomiasis in Zimbabwe, Ebola and Lassa fever in Sierra Leone and Rift Valley fever in Kenya—we show how political interests, commercial investments and conflict and securitization all generate patterns of vulnerability, reshaping the political ecology of disease landscapes, influencing traditional coping mechanisms and affecting health service provision and outbreak responses. A historical, political economy approach reveals patterns of ‘structural violence’ that reinforce inequalities and marginalization of certain groups, increasing disease risks. Addressing the politics of One Health requires analysing trade-offs and conflicts between interests and visions of the future. For all zoonotic diseases economic and political dimensions are ultimately critical and One Health approaches must engage with these factors, and not just end with an ‘anti-political’ focus on institutional and disciplinary collaboration.

This article is part of the themed issue ‘One Health for a changing world: zoonoses, ecosystems and human well-being’.

Zoonoses, One Health and complexity: wicked problems and constructive conflict

Infectious zoonoses emerge from complex interactions among social and ecological systems. Understanding this complexity requires the accommodation of multiple, often conflicting, perspectives and narratives, rooted in different value systems and temporal–spatial scales. Therefore, to be adaptive, successful and sustainable, One Health approaches necessarily entail conflicts among observers, practitioners and scholars. Nevertheless, these integrative approaches have, both implicitly and explicitly, tended to marginalize some perspectives and prioritize others, resulting in a kind of technocratic tyranny. An important function of One Health approaches should be to facilitate and manage those conflicts, rather than to impose solutions.

This article is part of the themed issue ‘One Health for a changing world: zoonoses, ecosystems and human well-being’.

Integrative modelling for One Health: pattern, process and participation

This paper argues for an integrative modelling approach for understanding zoonoses disease dynamics, combining process, pattern and participatory models. Each type of modelling provides important insights, but all are limited. Combining these in a '3P' approach offers the opportunity for a productive conversation between modelling efforts, contributing to a 'One Health' agenda. The aim is not to come up with a composite model, but seek synergies between perspectives, encouraging cross-disciplinary interactions. We illustrate our argument with cases from Africa, and in particular from our work on Ebola virus and Lassa fever virus. Combining process-based compartmental models with macroecological data offers a spatial perspective on potential disease impacts. However, without insights from the ground, the 'black box' of transmission dynamics, so crucial to model assumptions, may not be fully understood. We show how participatory modelling and ethnographic research of Ebola and Lassa fever can reveal social roles, unsafe practices, mobility and movement and temporal changes in livelihoods. Together with longer-term dynamics of change in societies and ecologies, all can be important in explaining disease transmission, and provide important complementary insights to other modelling efforts. An integrative modelling approach therefore can offer help to improve disease control efforts and public health responses.This article is part of the themed issue 'One Health for a changing world: zoonoses, ecosystems and human well-being'.