On 18 November 2020, the Minister of Health of the Democratic Republic of the Congo declared the end of the Ebola Virus Disease (EVD) outbreak in Equateur Province. The declaration was made in accordance with WHO recommendations, 42 days after the last confirmed case tested negative for the second time on 6 October 2020 in Makanza Health Zone, Equateur Province.
This outbreak was declared on 1 June 2020 following investigations and laboratory confirmation of EVD in samples taken after four deaths reported in Mbandaka Health Zone. Further investigations identified cases with dates of symptom onset from May to September 2020 in 41 health areas across 13 health zones, namely Bikoro, Bolenge, Bolomba, Bomongo, Iboko, Ingende, Lilanga Bobangi, Lolanga Mampoko, Lotumbe, Makanza, Mbandaka, Monieka and Wangata Health Zones.
This was the 11th EVD outbreak reported in the Democratic Republic of the Congo since the virus was first identified in 1976, and the second in Equateur Province. Two genetically distinct Ebola Zaire viruses were in circulation during this outbreak, based on available information. Four cases that were linked through one chain of transmission in Iboko Health Zone were infected with the same Ebola virus as the 2018 outbreak in Equateur Province, and a new Ebola Zaire virus that had emerged in 2020 was identified in all the other cases.
The outbreak response was led by the Ministry of Health with support from WHO and partners. Priorities during this response included strengthening diagnostic capabilities, infection prevention and control in health facilities and communities, ring vaccination around confirmed and probable cases and vaccination of frontline workers, delivering care and monoclonal antibody treatment for patients, supporting safe and dignified burials, risk communication and community engagement and establishment of 52 points of entry or points of control to screen population movements.
Response efforts were mounted in the context of significant logistical challenges. For example, cellular coverage for mobile phones was severely constrained and limitations in ground transportation necessitated aerial or riverine transport, which hampered communication among surveillance teams. This complicated the transportation and testing of quality laboratory samples, and delayed deployment of technical experts to affected areas.
Disease surveillance was consistently challenged by low levels of reported alerts, particularly among deaths. Overall, 67% of confirmed cases were not identified as known contacts at the time of detection, highlighting the challenges of performing rigorous case investigation and the potential for undetected transmission. Moreover, the geographical distribution and epidemiological links between cases have not yet been well-understood. Despite these challenges, multi-sectoral coordination was strengthened, and surveillance and investigation activities were enhanced. No new confirmed cases have been reported since 28 September 2020.
From 1 June to 18 November 2020, a total of 130 EVD cases including 119 confirmed and 11 probable cases were reported from 13 health zones. Of the total confirmed and probable cases, 45% (n=58) were female and 23% (n=30) were children aged less than 18 years. There were 55 deaths recorded (overall proportion of deaths among reported cases was 42%), 29% (34/119) of cases died outside Ebola treatment centres, and 75 cases recovered from EVD. Over the course of the outbreak, more than 26 000 contacts of cases were registered in Equateur Province.
However, the risk of re-emergence of EVD remains, even after human-to-human transmission of EVD has been interrupted in Equateur Province. Ebola Zaire virus is present in animal reservoirs in the region, and it can persist in some body fluids of survivors for several months, which in rare events may result in secondary transmission. Therefore, cases of EVD may continue to be reported in the Democratic Republic of the Congo. A robust and coordinated surveillance system must be maintained to rapidly detect, isolate, test and provide care for new suspected cases, and operations must continue to care for people who have recovered from EVD.
Under the longer-term plan that is currently in development, enhanced surveillance, a programme for long-term care of Ebola survivors and other response mechanisms remain in place after the end of the outbreak. These activities will help maintain heightened vigilance and contribute to strengthening a resilient health care system.
Public health response
In response to this EVD outbreak, from 1 June 2020 to 18 November 2020:
five field laboratories were set up for specimen testing using the GeneXpert PCR system. To date, more than 15 000 samples have been tested;
six Ebola treatment centres (ETC) were set up to care for people with EVD. Since the beginning of the outbreak, 78 confirmed EVD patients have been treated in the various ETCs, transit and isolation centers, of whom 32 received EVD-specific monoclonal antibody treatment;
thirteen transit and isolation centres were set up to care for suspected cases and for referral of confirmed cases;
over 43 000 people, including almost 9000 frontline health workers were vaccinated against EVD;
over 26 000 contacts of cases were registered in Equateur province;
over 3 million people have been screened at points of entry and points of control for Ebola symptoms at borders or other province points of control;
an EVD survivors care programme was established in October 2020 to provide medical care, biological testing and psychological support for the 75 persons who recovered.
WHO risk assessment
On 18 November 2020, the Ministry of Health of the Democratic Republic of the Congo declared the end of human-to-human transmission of EVD over in Equateur Province after two maximum incubation periods (42 days) had elapsed since the last confirmed case tested negative for the second time on 6 October 2020. However, there remains a risk of re-emergence of EVD because alert rates have remained sub-optimal in all affected and non-affected health zones, including death alerts throughout the outbreak, and cases may have gone undetected. In addition, Ebola virus is enzootic in the Democratic Republic of the Congo, and it can persist in some body fluids of survivors for several months which, in rare events, may result in secondary transmission.
There are ongoing challenges for surveillance, including access to affected areas and community mistrust toward authorities and outbreak responders. Other health emergencies such as coronavirus 2019 (COVID-19), cholera and measles outbreaks may jeopardize the country’s ability to rapidly detect and respond to re-emergence of EVD cases.
WHO advises the following risk reduction measures as an effective way to reduce EVD transmission in humans:
- Continue to train and retrain the health workforce for early detection, isolation and treatment of EVD cases.
To reduce the risk of wildlife-to-human transmission, such as through contact with fruit bats, monkeys and apes:
- Handle wildlife with gloves and other appropriate protective clothing;
- Cook animal products (blood and meat) thoroughly before consumption and avoid consumption of raw bushmeat.
To reduce the risk of human-to-human transmission from direct or close contact with people with EVD symptoms, particularly with their bodily fluids:
- Wear gloves and appropriate personal protective equipment when taking care of ill patients at home;
- Wash hands regularly after visiting patients in hospital, as well as after taking care of patients at home.
To reduce the risk of possible transmission from virus persistence in some body fluids of survivors, WHO recommends establishing an EVD survivors care programme to provide medical care, psychological support and biological testing (until two negative consecutive tests). WHO does not recommend isolation of male or female convalescent patients whose blood has been tested negative for Ebola virus.