On 16 September 2021, the Ministry of Health of Guinea declared the end of the Marburg virus disease outbreak in Guéckédou prefecture, Nzérékoré Region. In accordance with WHO recommendations, the declaration was made 42 days after the safe and dignified burial of the only confirmed patient reported in this outbreak. This was the first-ever Marburg virus disease case reported in Guinea.

From 3 August 2021 to the end of outbreak declaration, only one confirmed case was reported.  The patient, a man, had onset of symptoms on 25 July. On 1 August he went to a small health facility near his village, with symptoms of fever, headache, fatigue, abdominal pain and gingival hemorrhage. A rapid diagnostic test for malaria returned a negative result, and the patient received ambulatory supportive care with rehydration and symptomatic treatment. Upon returning home, his condition worsened, and he died on 2 August. An alert was subsequently raised by the sub-prefecture public health care facility to the prefectorial department of health in Guéckédou. The investigation team was immediately deployed to the village to conduct an in-depth investigation and collected a post-mortem oral swab sample, which was shipped on the same day to the viral hemorrhagic fever laboratory in Guéckédou city. On 3 August, the sample tested positive for Marburg virus disease by reverse transcriptase-polymerase chain reaction (RT-PCR) and negative for Ebola virus disease. The deceased patient was buried safely and with dignity on 4 August, with the support of the national Red Cross.

On 5 August, the National Reference Laboratory in Conakry provided confirmation by real-time PCR of the positive Marburg result, and on 9 August, the Institut Pasteur Dakar in Senegal provided an additional confirmation that the result was positive for Marburg virus disease and negative for Ebola virus disease. 

Public health response

The Ministry of Health activated the national and district emergency management committees to coordinate the response and engage with the community. Additionally, the Ministry of Health together with WHO, the United States Centers for Disease Control, the Alliance for International Medical Action, the Red Cross, UNICEF, the International Organization for Migration, and other partners, initiated measures to control the outbreak and prevent further spread including the implementation of contact tracing and active case search in health facilities and at the community level.

During the outbreak, a total of one confirmed case who died, (CFR=100%) and 173 contacts were identified, including 14 high risk contacts based on exposure. Among them, 172 were followed for a period of 21 days, of which none developed symptoms. One high-risk contact was lost to follow up. At the different points of entry in Guéckédou prefecture where passengers were screened, no alerts were generated.

Ongoing activities include:

• Capturing and sampling of bats in the localities of Temessadou M´Boké, Baladou Pébal and Koundou to better understand the involvement of bats in the ecology of Marburg viruses;
• Development of a sero-surveillance protocol in the sub-prefecture of Koundou;
• Development and implementation of plans to strengthen Infection Prevention and Control (IPC) programmes at the national and facility level including establishing and mentoring of IPC focal persons, IPC/hygiene committees, ongoing training of health workers and adequate procurement and distribution of supplies such as personal protective equipment (PPE);
• Implementation of water, sanitation and hygiene measures with partners including in health facilities and communities;
• Supporting training on community-based surveillance in Guéckédou prefecture; and
• Risk communication and community mobilization activities in Guéckédou prefecture as a component of a health emergency preparedness and response action plan.

WHO risk assessment

Marburg virus disease (MVD) is an epidemic-prone disease associated with high case fatality ratios (CFR 24-90%). In the early course of the disease, clinical diagnosis of MVD is difficult to distinguish from many other tropical febrile illnesses, because of the similarities in the clinical symptoms. Other viral hemorrhagic fevers need to be excluded, particularly Ebola virus disease (EVD), as well as malaria, typhoid fever, leptospirosis, rickettsial infection and plague. MVD is transmitted by direct contact with the blood, bodily fluids and/or tissues of infected persons or wild animals (e.g., monkeys and fruit bats).

Investigations are ongoing to identify the source of the infection. Guinea has previous experience in managing viral hemorrhagic diseases such as EVD and Lassa fever, but this was the first time that MVD was reported. The country has a fragile health care system due to the overburden of disease outbreaks, COVID-19 pandemic, and the recurrent threat of epidemics such as malaria, yellow fever, measles, Lassa fever, EVD, health care-associated infections, high rates of acute malnutrition, cyclical natural disasters such as floods, and socio-political unrest.

Guinea health authorities responded rapidly to the event, and measures were rapidly implemented to control the outbreak. Cross-border population movement and community mixing between Guinea and neighboring Sierra Leone and Liberia increased the risk of cross-border spread. Sierra Leone and Liberia health authorities activated contingency plans and started public health measures at the points of entry with Guinea.

The affected village is in a remote forest area located at the border with Sierra Leone, about 9 km from a main international border crossing point between the two countries. The proximity of the affected area to an international border, cross-border movement between the affected district and Sierra Leone, and the potential transmission of the virus between bat colonies and humans posed an increased risk for cross-border spread.

These factors suggested a high risk at the national and regional level, and given that Guéckédou prefecture is well connected to Foya in Liberia, and Kailahun in Sierra Leone, this outbreak required an immediate and coordinated response with support from international partners. The risk associated with the event at the global level was assessed as low.

WHO advice

Human-to-human transmission of Marburg virus is primarily associated with direct contact with blood and/or bodily fluids of infected persons, and Marburg virus transmission associated with the provision of health care has been reported when appropriate infection control measures have not been implemented.

Health care workers caring for patients with suspected or confirmed Marburg virus disease should apply standard and transmission-based IPC precautions to avoid any exposure to blood and/or bodily fluids, as well as unprotected contact with the possibly contaminated environment. IPC precautions include:

• Early recognition (screening, triage) and isolation of suspected cases;
• Appropriate isolation capacity (including infrastructure and human resources);
• Health care workers’ access to hand hygiene resources (i.e., soap and water or alcohol-based hand rub);
• Appropriate and accessible PPE for health care workers;
• Safe infection practices (emphasize on single-use only needles);
• Procedures and resources for decontamination and sterilization of medical devices; and
• Appropriate management of infectious waste.

IPC assessments of health facilities in affected areas using the IPC Scorecard revealed sub-optimal results highlighting the need for ongoing supportive supervision and mentorship for implementation of IPC in health care settings in addition to implementing IPC minimum requirements to support and strengthen future preparedness for emerging and re-emerging infectious diseases.

Integrated disease surveillance and response activities, including community-based surveillance must continue to be strengthened within all affected health zones.

Raising awareness of the risk factors for Marburg virus disease and the protective measures individuals can take to reduce human exposure to the virus are the key measures to reduce human infections and deaths. Key public health communication messages include:

• Reducing the risk of human-to-human transmission in the community arising from direct contact with infected patients, particularly with their bodily fluids;
• Avoiding close physical contact with patients who have Marburg virus disease;
• Any suspected case ill at home should not be managed at home, but immediately transferred to a health facility for treatment and isolation. During this transfer, health care workers should wear appropriate PPE;
• Regular hand washing should be performed after visiting sick relatives in hospital; and
• Communities affected by Marburg should make efforts to ensure that the population is well informed, both about the nature of the disease itself to avoid further transmission, community stigmatization, and encourage early presentation to treatment centers and other necessary outbreak containment measures, including safe burial of the dead. People who have died from Marburg should be promptly and safely buried.

To reduce the risk of wildlife-to-human transmissions, such as through contact with fruit bats, monkeys, and apes:

• Handle wildlife with gloves and other appropriate protective clothing;
• Cook animal products such as blood and meat thoroughly before consumption and avoid consumption of raw meat; and
• During work, research activities or tourist visits in mines or caves inhabited by fruit bat colonies, people should wear gloves and other appropriate protective clothing including masks.

Further information

• Disease Outbreak News – Marburg virus disease in Guinea, published on 9 August 2021
• Health topic - Marburg virus disease
• Ebola and Marburg virus disease epidemics: preparedness, alert, control, and evaluation, interim version 1.2
• Field guideline: How to conduct safe and dignified burial of a patient who has died from suspected or confirmed Ebola virus disease
• Case definition recommendations for Ebola or Marburg virus diseases
• Marbug haemorrhagic fever - factsheet; Fièvre hémorragique de Marburg - Aide-mémoire.  Relevé épidémiologique hebdomadaire, 80 (‎15)‎, 135 - 138
• Organisation mondiale de la Santé. (‎2014)‎. Définitions de cas recommandées pour la surveillance des maladies à virus Ebola ou Marburg : recommandation provisoire. Organisation mondiale de la Santé
• Organisation mondiale de la Santé & Bureau international du Travail. (‎2020)‎. Sécurité et santé au travail durant les crises sanitaires : un manuel pour la protection des personnels de santé et des équipes d’intervention d’urgence