Modelling the potential spread of COVID-19 in a refugee camp
Research and impact 26th April 2020
Dr Tucker Gilman and Professor Andrew Chamberlain report on an international collaborative effort to model the potential spread of the Covid-19 virus amongst the residents of the Moria camp on the island of Lesvos. The aim of this project is to use computational models to test the effectiveness of different mitigation measures that may help to limit the rate of spread of infection amongst the refugee and migrant community living in the camp.
Photo credit: Kitrinos Healthcare
Earlier this week across the world the last cruise ships were finally allowed to dock and their passengers were free to return to their homes. But for the 19,000 asylum seekers and migrants marooned in the Moria refugee camp at the edge of Europe, there is little prospect of onward travel and the enclosed community lives in the fear of an outbreak of the Covid-19 virus. The Moria camp has notoriously bad living conditions, with overcrowding, poor sanitation, existing chronic disease and limited access to health care. Last month Chris Harkensee, a volunteer doctor who works for the Kitrinos Healthcare charity at the Moria camp, appealed for scientific assistance in the construction of an epidemiological model to guide public health measures that could mitigate an anticipated outbreak of the Covid-19 respiratory virus amongst the residents of the camp.
Andrew Chamberlain and Tucker Gilman responded to Harkensee’s call. Many epidemic models rely on just a few equations that describe how the number of infected people in a population changes over time. However, Gilman and Chamberlain used an individual-based model (sometimes called an agent-based model, or ABM) to simulate the spread of Covid-19 across space in the Moria camp. This kind of model produces a much more detailed representation of the camp, with social features such as food lines, physical features such as taps and toilets, and even the age, sex and pre-existing health states of the people in the camp. Gilman and Chamberlain used their model to test the effects of specific interventions, such as spatial segregation, additional sanitation measures, and isolation of vulnerable individuals, on the spread of the virus.
Photo credit: Kitrinos Healthcare
The model predicts that each intervention will have some ability to “flatten the curve” but the effect is most pronounced if several interventions are used together. Restricting movement in the camp is particularly important. But, any intervention must be undertaken quickly. If Covid-19 arrives in the camp, it could easily spread to all corners of the camp before it is detected. Thus, interventions to slow the spread of the virus will need to be in place before the virus arrives. The team’s results are currently being used by Kitrinos Healthcare and the UNHCR to plan strategies that will protect this vulnerable population during a potential Covid-19 outbreak, and the team is working to make their results generally applicable to other refugee camps.
This figure shows the projected total number of people infected over time without interventions (blue), with transmission control (e.g., face masks; red), and with transmission control and movement restrictions together (orange). The purple line shows the result if movement restrictions are not imposed until after 1% of the population shows symptoms.
You can follow Tucker on Twitter @GilmanTucker
More information about the work of Kitrinos at the Moria camp can be found at www.kitrinoshealthcare.org
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