Empowering the crowd: Feasible strategies for epidemic management in high-density informal settlements. The case of COVID-19 in Northwest Syria

Abstract

AbstractMore than 1 billion people live in informal settlements worldwide, where precarious living conditions pose unique challenges to managing a COVID-19 outbreak. Taking Northwest Syria as a case-study, we simulated an outbreak in high-density informal Internally Displaced Persons (IDP) camps using a stochastic Susceptible-Exposed-Infectious-Recovered model. Expanding on previous studies, taking social conditions and population health/structure into account, we modeled several interventions feasible in these settings: moderate self-distancing, self-isolation of symptomatic cases, and protection of the most vulnerable in “safety zones”. We considered complementary measures to these interventions that can be implemented autonomously by these communities, such as buffer zones, health-checks, and carers for isolated individuals, quantifying their impact on the micro-dynamics of disease transmission. All interventions significantly reduce outbreak probability and some of them reduce mortality when an outbreak does occur. Self-distancing reduces mortality by up to 35% if contacts are reduced by 50%. A reduction in mortality by up to 18% can be achieved by providing 1 self-isolation tent per 8 people. Protecting the most vulnerable in a safety zone reduces the outbreak probability in the vulnerable population and has synergistic effects with the other interventions. Our model predicts that a combination of all simulated interventions may reduce mortality by more than 90% and delay an outbreak’s peak by almost two months. Our results highlight the potential for non-medical interventions to mitigate the effects of the pandemic. Similar measures may be applicable to controlling COVID-19 in other informal settlements, particularly IDP camps in conflict regions, around the world.Key questionsWhat is already known?Since the onset of the COVID-19 pandemic, many studies have provided evidence for the effectiveness of strategies such as social distancing, testing, contact tracing, case isolation, use of personal protective equipment/facemasks and improved hygiene to reduce the spread of the disease. These studies underlie the recommendations of the World Health Organisation, but their implementation is contingent on local conditions and resources.Mathematical modelling is the basis of many epidemiological studies and has helped inform policymakers considering COVID-19 responses around the world. Nevertheless, only a limited number of studies have applied these models to informal settlements.What are the new findings?We developed a mathematical model to study the dynamics of COVID-19 in Syrian IDP camps, elaborating on previous efforts done in similar settings by explicitly parameterizing the camps’ demographics, living conditions and micro-dynamics of interpersonal contacts in our modelization.We designed interventions such as self-distancing, self-isolation and the creation of safety zones to protect the most vulnerable members of the population, among others, through conversations with camp managers with on-the-ground knowledge of what interventions would be feasible and have community buy-in.Our results show how low-cost, feasible, community-led non-medical interventions can significantly mitigate the impact of COVID-19 in Northwest Syrian IDP camps.What do the new findings imply?Our model represents a step forward in the much-needed search for epidemiological models that are sufficiently flexible to consider specific social questions. The model can also help inform similar interventions in refugee camps in conflict-torn regions, and potentially be adapted to other informal settlements and vulnerable communities around the world.