Ebola virus disease - Guinea

On 19 June 2021, the Ministry of Health (MoH) of Guinea declared the end of the Ebola outbreak that affected Nzérékoré Prefecture, Nzérékoré Region, Guinea. This was the first Ebola outbreak in Guinea since the large outbreak that affected West Africa in 2014-2016.

This recent outbreak was announced on 14 February 2021 following the identification of a cluster of seven suspected Ebola cases in Gouécké and Nzérékoré City sub-prefectures in N’zérékoré prefecture. Between 14 February and 19 June 2021, a total of 23 cases (16 confirmed, 7 probable) were identified in four sub-prefectures of N’zérékoré Prefecture. Of these confirmed and probable cases 11 survived and 12 died. Five of the cases were health workers and one was a traditional health practitioner.

The index case of this recent outbreak was a health worker.  She had onset of symptoms on 15 January 2021 and after seeking care at two health facilities and a traditional practitioner, died on 28 January 2021. She was buried on 1 February 2021 in Gouécké sub-prefecture without using safe and dignified burial practices.

Seventeen secondary cases were reported with epidemiological links to the initial probable case between 5 February and 4 March 2021. After more than three weeks with no new cases reported, on 27 March 2021, a cluster of three community deaths was identified in Soulouta sub-prefecture, and were later classified as probable cases. Two individuals who had cared for and/ or attended these burials, were confirmed with Ebola infection in early April 2021. One of these last two confirmed cases was lost to follow up soon after he was confirmed on 1 April 2021 and until 18 June 2021 where he was found in apparent good health. Since 2 April 2021, no new confirmed or probable cases have been reported.  

Figure 1: Weekly incidence of Ebola virus disease cases in Guinea by sub-prefecture 

Laboratory:

• From 14 February to 17 June, 1 239 samples (758 blood samples and 483 swabs) were received and analyzed by PCR for EVD;
• PCR testing capacities were established at N’Zérékoré laboratory and sequencing capacities were strengthened in Conakry laboratories;
• Rapid diagnostic tests (OraQuick) for oral swabs were used for post-mortem testing of community deaths for EVD surveillance in N’Zérékoré Préfecture;

Surveillance:

• As of 17 June 2021, a total of 10 089 alerts were notified and 96% were investigated;
• Of the 1110 contacts of confirmed and probable cases 1031 were followed daily by contact tracing teams;
• An integrated outbreak analytics cell to guide response activities was established;
• Investigations were undertaken into the origin of the outbreak;

Points of entry (PoE):

• a total of 10 Points of Entry and 12 Points of Control were activated that performed 2 529 993 screenings and reported a total of 237 alerts in which 209 were classified as suspected cases following investigation. In addition, cross border  coordination meetings were conducted with neighboring countries that facilitated information exchange and experience sharing between national and local public health teams;

Vaccination:

• A total of 10 873 people  were vaccinated including 885 contacts and 2779 front line workers as of 27 May 2021;

Patient management:

• Clinical Management of Ebola cases was strengthened through the rehabilitation of two Centers of Epidemics Diseases Treatment (CTEpi) in Gouécké Sub-prefecture and N’Zérékoré city. Medical teams were deployed in those centres to strengthen Ebola case management and infection preven­tion and control. Fifteen patients were admitted at the CTEpi, ten of whom survived;
• Regulatory authorities in Guinea approved the use of the monoclonal antibodies MAb114, and REGN-EB3 therapeutic molecules. Eight of 15 individuals with confirmed Ebola infection who were admitted to CTEpi received specific Ebola treatment. In addition, psychosocial support was given to patients and relatives;

Infection prevention and control activities (IPC)

• Decontamination of 18 health facilities, the donation of 109 IPC kits and the decontamination of several schools were organized following the IPC ring approach
• Hand washing equipment and points of water were provided to the population (community and health facilities in collaboration with Water Sanitation and Hygiene teams).
• Additionally, 123 priority health facilities in 8 health districts were assessed by the IPC team using the IPC Rapid Scorecard and training was provided to over 1700 health workers and traditional healers on IPC in the context of Ebola.

Risk communications activities included (RCCE):

• Training and deployment of RCCE focal points to 17 “health areas” of Nzérékoré to support with community alert reporting and management of referral refusal, as well as community-based surveillance
• Social mobilization interventions led by more than 900 trained mobilisers from a range of local and community subgroups. 
• Teams were trained in safe and dignified burials to support communities performing safe burial rites.
• A dedicated programme has been implemented to provide care to the 11 EVD survivors and perform biological screening.
• A national strategic plan and multi-national preparation and response plan were made and implemented.
• Bordering countries have increased surveillance capacity and have established EVD preparedness plans

Detection of EVD cases is not unexpected in Guinea given that the virus is enzootic in some animal populations in the country and can persist in certain body fluids of survivors. In a limited number of cases, secondary transmissions resulting from exposure to survivor’s body fluids have been documented in previous outbreaks. Investigations into the source of this outbreak using genomic sequencing,  demonstrated that the identified 2021 virus lineage was very closely related to a virus circulating in Guinea in 2014. However, the index case in this outbreak was not a known survivor of the 2014-2016 outbreak. They were however a health worker who is known to be at an increased risk of contracting EVD when infection prevention and control measures are not fully practiced as was likely in this situation. In-depth epidemiological investigations into the source of this outbreak have not drawn conclusive hypotheses to date, as to where and how the index case was infected. Thus, Investigations remain ongoing and a risk of additional undetected cases remains.

A functioning surveillance system is key to detect cases of EVD however throughout this outbreak the surveillance system met several challenges. For example, only nine (39%) of the 23 cases were known contacts at the time of detection indicating that case investigation and contact listing was not comprehensive. Additionally, the alert system reported a suboptimal numbers of alerts and faced difficulties to investigate and test suspect cases of EVD. Neighboring prefectures of Nzérékoré also reported few alerts, even fewer of which were validated and tested demonstrating the challenges faced with surveillance in these remote hard-to-reach areas. Therefore, although 42 days after the last confirmed case tested negative for the second time the outbreak has been declared over (as per WHO recommendations) there remains a possibility that there are unrecognized chains of transmission in the community.

WHO considers that ongoing challenges of access and epidemiological surveillance, coupled with the emergence of COVID-19 and a recent yellow fever outbreak, might challenge the country’s ability to rapidly detect and respond to a new EVD outbreak.

WHO advises the following risk reduction measures as an effective way to reduce EVD transmission:

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; and
• Cook animal products (blood and meat) thoroughly before consumption and avoid consumption of raw meat from wild animals.

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 in healthcare facilities and at home; and
• Wash hands regularly after visiting patients in a hospital, as well as after taking care of patients at home or touching or coming into contact with any bodily fluids.

Activities that can support at-risk countries to prepare for future outbreaks include:

• Continuous training of the health workforce for; early detection, isolation and treatment of EVD cases; basics of IPC measures including standard and transmission based precautions; as well as re-training on safe and dignified burials and the IPC interventions;
• Strengthening public health surveillance capacity at sub-prefecture level through use of IDSR 3^rd Edition and integrated community-based surveillance together with efficient tools for contact tracing and alert surveillance;
• Preparing for vaccination of health workers and implementing ring vaccination around confirmed cases accordingly to the SAGE recommendations.
• Strengthening of health care systems, including WaSH elements, to ensure safe delivery of care to patients and protection of health workers.

To reduce the risk of possible transmission from virus persistence in some body fluids of survivors, WHO recommends providing medical care, psychological support and biological testing (until two consecutive negative tests) through an EVD survivors care programme. WHO does not recommend the isolation of male or female convalescent patients whose blood has been tested negative for the Ebola virus. There also is a need to maintain collaborative relationships with survivors, survivor associations, their families, and their communities while monitoring individuals health to prevent further stigmatization.

Based on the current risk assessment and prior evidence on Ebola outbreaks, WHO advises against any restriction of travel and trade to Guinea.

Ebola virus disease fact sheet

Optimized Supportive Care for Ebola Virus Disease. Clinical management standard operating procedures. WHO. 2019. 

Weekly Outbreaks and Emergencies Bulletin