Ineffective responses to unlikely outbreaks: Hypothesis building in newly-emerging infectious disease outbreaks.

Over the last 30 years, there has been significant investment in research and infrastructure aimed at mitigating the threat of newly emerging infectious diseases (NEID). Core epidemiological processes, such as outbreak investigations, however, have received little attention and have proceeded largely unchecked and unimproved. Using ethnographic material from an investigation into a cryptic encephalitis outbreak in the Brong-Ahafo Region of Ghana in 2010-2013, in this paper we trace processes of hypothesis building and their relationship to the organizational structures of the response. We demonstrate how commonly recurring features of NEID investigations produce selective pressures in hypothesis building that favor iterations of pre-existing "exciting" hypotheses and inhibit the pursuit of alternative hypotheses, regardless of relative likelihood. These findings contribute to the growing anthropological and science and technology studies (STS) literature on the epistemic communities that coalesce around suspected NEID outbreaks and highlight an urgent need for greater scrutiny of core epidemiological processes.

The factors affecting household transmission dynamics and community compliance with Ebola control measures: a mixed-methods study in a rural village in Sierra Leone.

BACKGROUND: Little is understood of Ebola virus disease (EVD) transmission dynamics and community compliance with control measures over time. Understanding these interactions is essential if interventions are to be effective in future outbreaks. We conducted a mixed-methods study to explore these factors in a rural village that experienced sustained EVD transmission in Kailahun District, Sierra Leone. METHODS: We reconstructed transmission dynamics using a cross-sectional survey conducted in April 2015, and cross-referenced our results with surveillance, burial, and Ebola Management Centre (EMC) data. Factors associated with EVD transmission were assessed with Cox proportional hazards regression. Following the survey, qualitative semi-structured interviews explored views of community informants and households. RESULTS: All households (n = 240; 1161 individuals) participated in the survey. 29 of 31 EVD probable/confirmed cases died (93·5% case fatality rate); six deaths (20·6%) had been missed by other surveillance systems. Transmission over five generations lasted 16 weeks. Although most households had ≤5 members there was a significant increase in risk of Ebola in households with > 5 members. Risk of EVD was also associated with older age. Cases were spatially clustered; all occurred in 15 households. EVD transmission was better understood when the community experience started to concord with public health messages being given. Perceptions of contact tracing changed from invading privacy and selling people to ensuring community safety. Burials in plastic bags, without female attendants or prayer, were perceived as dishonourable. Further reasons for low compliance were low EMC survival rates, family perceptions of a moral duty to provide care to relatives, poor communication with the EMC, and loss of livelihoods due to quarantine. Compliance with response measures increased only after the second generation, coinciding with the implementation of restrictive by-laws, return of the first survivor, reduced contact with dead bodies, and admission of patients to the EMC. CONCLUSIONS: Transmission occurred primarily in a few large households, with prolonged transmission and a high death toll. Return of a survivor to the village and more effective implementation of control strategies coincided with increased compliance to control measures, with few subsequent cases. We propose key recommendations for management of EVD outbreaks based on this experience.

Propagating Visions of a Forest Reservoir: A Supposed Zoonotic Outbreak in the Brong-Ahafo Region of Ghana.

When examined closely, the backgrounds of some of the most widely cited origin stories for zoonotic disease outbreaks have been found to be irreconcilable with empirical data. Stated simply, these explanatory landscapes do not appear to have existed. Here, I present a detailed case study of one such fictional landscape, that of a monkey-filled forest which was identified as the source of a suspected zoonotic outbreak in the Brong-Ahafo Region of Ghana in 2010. Taking my approach from cultural epidemiology, I elucidate the mechanisms by which this fictional landscape was constructed and transmitted among the professionals involved in the response.

Investigating outbreaks of initially unknown aetiology in complex settings: findings and recommendations from 10 case studies.

BACKGROUND: Outbreaks of unknown aetiology in complex settings pose challenges and there is little information about investigation methods. We reviewed investigations into such outbreaks to identify methods favouring or impeding identification of the cause. METHODS: We used two approaches: reviewing scientific literature and soliciting key informants. Case studies were developed through interviews with people involved and triangulated with documents available from the time of the investigation. RESULTS: Ten outbreaks in African or Asian countries within the period 2007-2017 were selected. The cause was identified in seven, of which two had an unclear mode of transmission, and in three, neither origin nor transmission mode was identified. Four events were caused by infectious agents and three by chemical poisoning. Despite differences in the outbreaks, similar obstacles were noted: incomplete or delayed description of patients, comorbidities confounding clinical pictures and case definitions wrongly attributed. Repeated rounds of data collection and laboratory investigations were common and there was limited capacity to ship samples. DISCUSSION: It was not possible to define activities that led to prompt identification of the cause in the case studies selected. Based on the observations, we conclude that basing case definitions on precise medical observations, implementing initial comprehensive data collection, including environmental, social and behavioural information; and involving local informants could save precious time and hasten implementation of control measures.

Identifying the research gap of zoonotic disease in displacement: a systematic review.

BACKGROUND: Outbreaks of zoonotic diseases that transmit between animals and humans, against a backdrop of increasing levels of forced migration, present a major challenge to global public health. This review provides an overview of the currently available evidence of how displacement may affect zoonotic disease and pathogen transmission, with the aim to better understand how to protect health and resilience of displaced and host populations. METHODS: A systematic review was conducted aligned with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Between December 2019 - February 2020, PubMed, Web of Science, PLoS, ProQuest, Science Direct and JSTOR were searched for literature. Studies were included based on a focus on zoonotic disease risks in displacement and/or humanitarian emergencies, and relevance in terms of livestock dependency of the displaced populations. Evidence was synthesised in form of a table and thematic analysis. RESULTS: Of all records, 78 papers were selected for inclusion. Among the included studies, the majority were based on secondary data, including literature reviews (n=43) and case studies (n=5), while the majority of papers covered wide geographical areas such as the Global South (n=17) and Africa (n=20). The review shows significant gaps in the literature, which is specifically lacking primary data on zoonotic diseases in displacement. Risk factors for the transmission of zoonoses in displacement are based on generic infectious disease risks, which include the loss of health services, increased population density, changes in environment, reduced quality of living conditions and socio-economic factors. Regardless of the presence of these disease drivers during forced migration however, there is little evidence of large-scale zoonotic disease outbreaks linked directly to livestock in displacement. CONCLUSION: Due to the lack of primary research, the complex interlinkages of factors affecting zoonotic pathogen transmission in displacement remain unclear. While the presence of animals may increase the burden of zoonotic pathogens, maintaining access to livestock may improve livelihoods, nutrition and mental health, with the potential to reduce people's vulnerability to disease. Further primary interdisciplinary and multi-sectoral research is urgently required to address the evidence gaps identified in this review to support policy and program development.

Disaster displacement and zoonotic disease dynamics: The impact of structural and chronic drivers in Sindh, Pakistan.

Projected increases in human and animal displacement driven by climate change, disasters and related environmental degradation will have significant implications to global health. Pathways for infectious disease transmission including zoonoses, diseases transmitted between animals and humans, are complex and non-linear. While forced migration is considered an important driver for the spread of zoonoses, actual disease dynamics remain under researched. This paper presents the findings of a case study investigating how disaster displacement affected zoonotic disease transmission risk following the 2010 'superfloods' in Sindh province, Pakistan. We interviewed 30 key informants and 17 household members across 6 rural communities between March and November 2019, supported by observational studies and a review of secondary data. Results were analysed using the ecosocial theoretical framework. Buffalo, cattle and goats were often the only moveable asset, therefore livestock was an important consideration in determining displacement modality and destination location, and crowded locations were avoided to protect human and animal health. Meanwhile however, livestock was rarely included in the humanitarian response, resulting in communities and households fragmenting according to the availability of livestock provisions. We found that rather than a driver for disease, displacement acted as a process affecting community, household and individual zoonotic disease risk dynamics, based on available resources and social networks before, during and after displacement, rooted in the historical, political and socio-economic context. We conclude that in rural Sindh, disaster displaced populations' risk of zoonoses is the result of changes in dynamics rooted in pre-existing structural and chronic inequalities, making people more or less vulnerable to disease through multiple interlinked pathways. Our findings have implications for policy makers and humanitarian responders assisting displaced populations dependent on livestock, with a call to integrate livestock support in humanitarian policies and responses for health, survival and recovery.

Lockdowns, lives and livelihoods: the impact of COVID-19 and public health responses to conflict affected populations - a remote qualitative study in Baidoa and Mogadishu, Somalia.

BACKGROUND: Authorities in Somalia responded with drastic measures after the first confirmed COVID-19 case in mid-March 2020, closing borders, schools, limiting travel and prohibiting most group functions. However, the impact of the pandemic in Somalia thereafter remained unclear. This study employs a novel remote qualitative research method in a conflict-affected setting to look at how some of the most at-risk internally displaced and host populations were impacted by COVID-19, what determined their responses, and how this affected their health and socio-economic vulnerability. METHODS: We conducted a remote qualitative study, using Katikati, a 1-to-1 conversation management and analysis platform using short message service (SMS) developed by Lark Systems with Africa's Voices Foundation (AVF), for semi-structured interviews over three months with participants in Mogadishu and Baidoa. We recruited a gender balanced cohort across age groups, and used an analytical framework on the social determinants of health for a narrative analysis on major themes discussed, triangulating data with existing peer-reviewed and grey literature. RESULTS: The remote research approach demonstrated efficacy in sustaining trusted and meaningful conversations for gathering qualitative data from hard-to-reach conflict-affected communities. The major themes discussed by the 35 participants included health, livelihoods and education. Two participants contracted the disease, while others reported family or community members affected by COVID-19. Almost all participants faced a loss of income and/or education, primarily as a result of the strict public health measures. Some of those who were heavily affected economically but did not directly experienced disease, denied the pandemic. Religion played an important role in participants' beliefs in protection against and salvation from the disease. As lockdowns were lifted in August 2020, many believed the pandemic to be over. CONCLUSIONS: While the official COVID-19 burden has remained relatively low in Somalia, the impact to people's daily lives, income and livelihoods due to public health responses, has been significant. Participants describe those 'secondary' outcomes as the main impact of the pandemic, serving as a stark reminder of the need to broaden the public health response beyond disease prevention to include social and economic interventions to decrease people's vulnerability to future shocks.

Estimating undetected Ebola spillovers.

The preparedness of health systems to detect, treat, and prevent onward transmission of Ebola virus disease (EVD) is central to mitigating future outbreaks. Early detection of outbreaks is critical to timely response, but estimating detection rates is difficult because unreported spillover events and outbreaks do not generate data. Using three independent datasets available on the distributions of secondary infections during EVD outbreaks across West Africa, in a single district (Western Area) of Sierra Leone, and in the city of Conakry, Guinea, we simulated realistic outbreak size distributions and compared them to reported outbreak sizes. These three empirical distributions lead to estimates for the proportion of detected spillover events and small outbreaks of 26% (range 8-40%, based on the full outbreak data), 48% (range 39-62%, based on the Sierra Leone data), and 17% (range 11-24%, based on the Guinea data). We conclude that at least half of all spillover events have failed to be reported since EVD was first recognized. We also estimate the probability of detecting outbreaks of different sizes, which is likely less than 10% for single-case spillover events. Comparing models of the observation process also suggests the probability of detecting an outbreak is not simply the cumulative probability of independently detecting any one individual. Rather, we find that any individual's probability of detection is highly dependent upon the size of the cluster of cases. These findings highlight the importance of primary health care and local case management to detect and contain undetected early stage outbreaks at source.

'When Ebola enters a home, a family, a community': A qualitative study of population perspectives on Ebola control measures in rural and urban areas of Sierra Leone.

BACKGROUND: During the West Africa Ebola outbreak, cultural practices have been described as hindering response efforts. The acceptance of control measures improved during the outbreak, but little is known about how and why this occurred. We conducted a qualitative study in two administrative districts of Sierra Leone to understand Ebola survivor, community, and health worker perspectives on Ebola control measures. We aimed to gain an understanding of community interactions with the Ebola response to inform future intervention strategies. METHODOLOGY/PRINCIPAL FINDINGS: Participants (25 survivors, 24 community members, and 16 health workers) were recruited purposively. A flexible participatory method gathered data through field notes and in-depth, topic-led interviews. These were analysed thematically with NVivo10© by open coding, constant comparison, and the principles of grounded theory. The primary theme, 'when Ebola is real', centred on denial, knowledge, and acceptance. Ebola was denied until it was experienced or observed first-hand and thus health promotion was more effective if undertaken by those directly exposed to Ebola rather than by mass media communication. Factors that enabled acceptance and engagement with control measures included: access to good, proximate care and prevention activities; seeing that people can survive infection; and the co-option of trusted or influential local leadership, with bylaws implemented by community leaders being strongly respected. All participants noted that dignity, respect, and compassion were key components of effective control measures. CONCLUSIONS: Successful control approaches need strong community leadership, with the aim of achieving collective understanding between communities and health workers. Health promotion for communities at risk is best conducted through people who have had close interaction with or who have survived Ebola as opposed to reliance on broad mass communication strategies.

Facility-based surveillance for emerging infectious diseases; diagnostic practices in rural West African hospital settings: observations from Ghana.

The aim of this study was to better understand the effectiveness of Integrated Disease Surveillance and Response (IDSR) facility-based surveillance in detecting newly emerging infectious diseases (EIDs) in rural West African settings. A six-month ethnographic study was undertaken in 2012 in the Techiman Municipality of the Brong-Ahafo Region of Ghana, aimed at documenting the trajectories of febrile illness cases of unknown origin occurring within four rural communities. Particular attention was paid to where these trajectories involved the use of formal healthcare facilities and the diagnostic practices that occurred there. Seventy-six participants were enrolled in the study, and 24 complete episodes of illness were documented. While participants routinely used hospital treatment when confronted with enduring or severe illness, the diagnostic process within clinical settings meant that an unusual diagnosis, such as an EID, was unlikely to be considered. Facility-based surveillance is unlikely to be effective in detecting EIDs due to a combination of clinical care practices and the time constraints associated with individual episodes of illness, particularly in the resource-limited settings of rural West Africa, where febrile illness due to malaria is common and specific diagnostic assays are largely unavailable. The success of the 'One Health' approach to EIDs in West Africa is predicated on characterization of accurately diagnosed disease burdens. To this end, we must address inefficiencies in the dominant approaches to EID surveillance and the weaknesses of health systems in the region generally.This article is part of the themed issue 'One Health for a changing world: zoonoses, ecosystems and human well-being'.