Cases of Hepatitis E Virus (HEV) have been consistently reported in South Sudan since 2014, with recurrent outbreaks occurring in Bentiu, Rubkona county, Unity state (central-north part of South Sudan), where a camp for internally displaced persons (IDP) is located.

In 2021, the number HEV cases have risen significantly in the country, increasing from 564 reported during the triennium 2018-2020, to 1143 suspected cases with five deaths in 2021 (as of 29 November). In last two years (2020-2021), a total of  1420 suspected cases were reported, of which 47 have been laboratory confirmed by polymerase chain reaction (PCR) at the Uganda Virus Research Institute (UVRI).

The current 2021 outbreak is occurring in Unity State, with cases mainly being reported from Bentiu IDP camp. This led the Ministry of Health (MoH) to declare a HEV outbreak in Bentiu internally displaced people  (IDP) camp in August 2021. A proportion of cases (323; 28.3%) has been reported from outside the camp, in Bentiu and Rubkona towns, suggesting ongoing transmission in the surrounding community.  Males aged 15-44 years are being reported as the most affected group, followed by male children 1-4 years, and females aged 15-44 years. There are no cases currently hospitalized, with clinical management implemented in outpatient departments (OPD).

Bentiu IDP camp hosts over 107,000 people and is divided into five sectors. HEV cases are reported from all sectors, highlighting widespread transmission.

Unity State, is also affected by a flood that has caused a massive displacement and the development of new IDP sites, adding 30,000 more IDPs hosted in the Bentiu IDP camp.

Public health response

Leadership and coordination

• The Ministry of Health has activated a state HEV taskforce that includes camp management and cluster (health and water, sanitation and hygiene - WASH) partners which convenes regularly to review the health situation and humanitarian response.
• The overall humanitarian response to the flooding is underway to address the acute needs of displaced populations and ensure dignified living conditions.

Surveillance

• The MOH with support from WHO and partners, continues the HEV surveillance through Integrated Disease Surveillance and Response/Early Warning, Alert and Response System.
• A joint assessment team has been ensembled to perform active case search, sample collection, WASH-related non-food items (NFI) distribution, and risk communication.
• Rapid diagnostic testing is ongoing at the community and primary care clinics, with identified cases referred to the Médecins Sans Frontières (MSF) hospital.

Supportive case management

• The MSF hospital is providing outpatient supportive case management for mild to moderate cases, as well as admission for severe HEV cases for specialized supportive case management. There are no cases currently hospitalized.

WASH

• A contingency borehole has been activated, water pumping hours increased, daily latrine repair is occurring and maintenance of sanitation facilities.
• Construction started in November of 54 new stances of latrines supported with handwashing stations, and weekly water quality tests.
• Distribution of 200 WASH kits to a targeted population of HEV cases, pregnant, and lactating women.
• The road to the liquid waste treatment facility and landfill outside the site has been reclaimed to ensure that WASH services can continue (treatment of sludge from IDP site, Humanitarian Hub and United Nations Mission in South Sudan).

Community engagement

• Camp Coordination and Camp Management (CCCM) cluster outreach teams continue to sensitize the community in all five sectors of Bentiu IDP camp, on the risks posed by HEV and other water-borne diseases.
• Risk communication messaging is broadcast via a local radio talk show to sensitize listeners on good hygiene practices and HEV prevention.
• Communication centres in each of the five camp sectors are providing information and receiving feedback from the community pertaining to HEV.
• Partners are conducting hygiene promotion activities by disseminating messages through house visits for infection prevention and control with a focus on HEV, acute watery diarrhoea, and COVID-19 awareness.

HEV Vaccination

• An HEV vaccination campaign microplan has been developed which will entail three vaccination rounds and targets camp residents aged 16-40 years including pregnant women.
• A total of 57,000 doses of HEV vaccine are already in South Sudan and will be used for the first two rounds of the campaign.
• Partners along with community actors have engaged the population to support the campaign as well as other HEV control interventions.
• Surveillance for adverse events following vaccination will be monitored at each of the fixed sites and a post coverage survey will be undertaken.

WHO risk assessment

Hepatitis E is a liver disease caused by the hepatitis E virus, transmitted by the faecal-oral route, mainly through contaminated water. It can lead to serious public health impacts particularly among special populations: those in IDP camps and pregnant women. Risk factors for HEV are linked to poor sanitation conditions, allowing viruses excreted in the stools of infected individuals to enter water intended for human consumption.

Usually, the infection resolves spontaneously within 2 to 6 weeks, with a case fatality ratio (CFR) of 0.5-4%. In rare cases, acute hepatitis E can be severe and progress to fulminant hepatitis (acute liver failure). Generally, CFR for pregnant women is reported to be higher than the overall CFR for HEV infections, reaching 25%. Displaced persons and refugees experience the highest attack rates when outbreaks occur given the overcrowded nature of their living conditions and poor hygiene situation.

Cases of HEV have consistently been reported from Bentiu IDP camp since 2014 but have risen and surpassed epidemic threshold levels in 2021.

The overall risk at the global level remains low, while at the national level is assessed as high due to:

• Poor sanitation and hygiene practices especially in the Bentiu IDP camp and limited availability of safe drinking water.
• Limited access to essential medical services in the Bentiu IDP camp and surrounding area.
• The overall population movements in the affected area, and the presence of large internally displaced population, with a worsening situation due to the ongoing flooding, and the influx of new IDPs that might increase the risk of HEV spread.
• The ongoing floods have impacted the implementation of response activities pausing the HEV vaccination response and consequently increasing the risk of death in high-risk individuals including pregnant women. It has also exacerbated the already-existing poor hygiene conditions in the Bentiu IDP camp.

As the affected area is close to the border with Sudan and Ethiopia, at the regional level the overall risk is considered moderate due to the presence of the mobile IDP populations and refugees that cross these borders. While there have been fewer documented refugees coming from Ethiopia into South Sudan, a significant amount of traffic occurs for people heading to Sudan, particularly from Rubkona county - where the Bentiu IDP camp is located - to Khartoum, the capital of Sudan.

Additionally, there is a current outbreak of HEV at the border with South Darfur state in Sudan, that poses potential risk of cross-border spread.

WHO advice

There is no specific treatment for HEV. Prevention is the most effective approach against this disease.

To prevent the spread of acute hepatitis E, WHO recommends improving access to safe drinking water and adequate sanitation. The quality of drinking water should be regularly monitored in neighbourhoods affected by this epidemic. Coverage of latrines and drinking water sources should be increased to prevent open defecation and to ensure hand hygiene. Health promotion and prevention activities, as well as ensuring early, appropriate, and equitable health care services to combat HEV epidemics, can help improve public health outcomes, especially in resource-limited settings. At the individual level, infectious risks can be reduced by maintaining hygienic practices such as washing hands with clean water and soap - especially before handling food, avoiding consumption of water and/or ice of unknown purity, and following WHO hygiene practices for food safety.

Since the incubation period for HEV ranges from 2-10 weeks, cases may continue to occur up to the tenth week (maximum incubation period) even after measures to ensure safe water, sanitation and hygiene promotion have been adopted.

Interventions must continue to target vulnerable populations by establishing or strengthening antenatal diagnosis for pregnant women with symptoms, strengthening national capacities for diagnosis and clinical case management, and cross-border collaboration with neighbouring countries.

To date, a hepatitis E vaccine has been developed for commercialization, and licensed in China and Pakistan. While WHO does not recommend the introduction of the vaccine as part of national routine population immunization programs, WHO recommends that national authorities may decide to use the vaccine in outbreak settings, including in populations at high risks, such as pregnant women. Vaccine use should therefore be considered to mitigate or prevent an outbreak of hepatitis E, as well as to reduce the effects of an outbreak in high-risk individuals, such as pregnant women.

WHO advises against the application of any travel or trade restrictions on South Sudan or any of the affected countries based on the currently available information.