On 14 April 2023, the Ministry of Health (MoH) of South Sudan declared an outbreak of the Hepatitis E Virus (HEV) in Wau city, the capital of Western Bahr el-Ghazal state, one of the largest cities in South Sudan. The outbreak occurred between 23 March 2023 and 13 April 2023, with a total of 91 HEV suspected cases reported in Wau, of which 35 were confirmed, and five deaths reported with a case fatality ratio (CFR) of 5.5%. A multidisciplinary national rapid response team was deployed by the MoH, supported by WHO, to investigate the outbreak, determine its extent, identify exposures or risk factors, and implement preventive measures.

HEV is a liver disease found worldwide and is common in developing countries with limited access to clean drinking water, poor sanitation, and hygiene. It is transmitted by the fecal-oral route, mainly through contaminated water. South Sudan, with its inadequate water supply, poor environmental sanitation, limited health services, and areas of humanitarian emergencies, is at high risk of HEV outbreaks.

The cases of HEV have been consistently reported in South Sudan since 2018, with recurrent outbreaks in Bentiu, Rubkona county, in the Unity state, where the Bentiu Internally Displaced Persons (IDP) camp, with around 170 000 individuals, is located. In 2022, 2110 cases were reported in the Bentiu IDP camp. Following the continued detection of cases in March, April, and October 2022, the MoH and Médecins Sans Frontières (MSF) carried out the first Hepatitis E vaccination campaign in the Bentiu IDP camp. As of 19 March 2023, 4009 cases of Hepatitis E, including 27 deaths (CFR: 1%) were reported from Bentiu IDP camp.

The outbreak in Wau is a cause for concern as there is a risk of international spread of the disease, given that South Sudan shares borders with Sudan and Ethiopia, with substantial traffic between them. The situation is further aggravated by the highly mobile IDP and refugee population, mainly from Rubkona county, Unity State, where the Bentiu IDP camp is located.

The MoH responded swiftly by deploying a multidisciplinary national rapid response team to investigate the outbreak, characterize the event, determine its magnitude, and identify exposures or risk factors to guide control and prevention measures. Further detailed investigations and sequencing of samples are ongoing.

HEV infections can be prevented by improving water, sanitation, and hygiene, as well as by vaccinating the at-risk population. The MoH, with the support of partners such as WHO, should intensify efforts to improve water supply, sanitation, and hygiene in South Sudan. Vaccination campaigns should be expanded to cover more people in high-risk areas, such as IDP camps and refugee settlements. The MoH should also strengthen its disease surveillance system to ensure timely detection and response to future outbreaks.

In conclusion, the outbreak of HEV in Wau city, South Sudan, is a cause for concern, given the high risk of international spread of the disease. The MoH, with the support of partners such as WHO, should intensify efforts to improve water supply, sanitation, and hygiene and expand vaccination campaigns to cover more people in high-risk areas. The MoH should also strengthen its disease surveillance system to ensure timely detection and response to future outbreaks.