It is often challenging to obtain the most up-to-date burden of infectious diseases among refugees and internally displaced persons. Well-conducted observational studies and clinical trials require time, financial and human resources, and may not adapt to rapidly changing conditions during humanitarian emergencies. In these settings, alternative sources of data may provide valuable insights into disease epidemiology and burden.
A recent study (Emerg Infect Dis. 2022;28(5):1074-1076) led by Dr. Angel N. Desai, Dr. Amir M. Mohareb, and Dr. Britta Lassmann used the ProMED database to better understand the epidemiology of hepatitis E virus (HEV) among refugees and internally displaced persons in sub-Saharan Africa. ProMED’s global subject matter experts use formal and informal disease surveillance mechanisms to rapidly validate and report emerging disease events in animals, humans, and plants globally (1). ProMED has been validated as a rapid and accurate tool for determining and describing global outbreaks. The authors verified all reports via PubMed, ReliefWeb, the UN High Commission for Refugees, World Health Organization (WHO), and references secondarily collected from ProMED. They concentrated on sub-Saharan Africa because it has among the highest numbers of refugees and internally displaced persons, and it is also a region known to have had large-scale outbreaks of hepatitis E.
So what did they find? Their study reported 12 large hepatitis E outbreaks in camps and settlements in the region between 2010- 2020 (2). A thirteenth outbreak was ongoing at the time of their search, in South Sudan’s Bentiu camp for internally displaced persons that included >1,000 cases since 2019. The largest outbreak of acute HEV infections (>11,000 cases) was reported in a protracted outbreak in South Sudan, during July 2012–October 2013, among persons fleeing violence in Sudan. HEV can be severe in pregnant women with high mortality rates. HEV cases and fatalities in pregnant women were reported for 3 hepatitis E outbreaks in this study: 2 reported deaths among 18 cases in pregnant women in Ethiopia (2014); 17 reported deaths in pregnant women in Niger (2017), comprising 45% of the recorded deaths in that outbreak; and 12 reported deaths in pregnant women in Namibia (2019). The most common contributors to hepatitis E outbreaks were overcrowding, poor sanitation, and flooding: these are all recognized risk factors for HEV outbreaks.
While their study was limited by varying levels of confirmatory testing available and possible misclassification given the overlap between symptoms of HEV and other endemic infectious diseases, this study demonstrates the potential scope and magnitude of HEV outbreaks among refugees and internally displaced persons. Future work is needed to better target interventions aimed at reducing morbidity associated with HEV, particularly among vulnerable populations.
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