Marburg virus disease - Rwanda
11 October 2024
Situation at a glance
As of 10 October 2024, a total of 58 cases of Marburg virus disease (MVD), including 13 deaths (case fatality ratio (CFR): 22%), have been reported in Rwanda. Fifteen recoveries have been reported among the confirmed cases as of 10 October 2024. Contact tracing is underway, with over 700 contacts under follow-up as of 9 October 2024. WHO classified the outbreak as a grade 3 emergency, the highest internal level for emergencies based on the WHO Emergency Response Framework and a surge team from WHO has travelled to support the in-country response across the functions of incident management: epidemiology, health operations, case management, health logistics, vaccines research, partner coordination and infection prevention and control.
Description of the situation
Since the first
Disease Outbreak News on this event was published on 30 September 2024, 32 additional laboratory-confirmed cases of Marburg virus disease (MVD)have been reported in Rwanda. As of 10 October 2024, a total of 58 cases, including 13 deaths (CFR: 22%), have been reported. The vast majority of the cases have been reported from the three districts within Kigali.
Since the declaration of the outbreak on 27 September and as of 10 October, 15 confirmed cases have recovered, the remaining 30 cases are under care at the designated Marburg treatment center. Health workers from two health facilities in Kigali account for over 80% of confirmed cases. All new confirmed cases reported within the past week, have been associated with the two hospital clusters in Kigali. As of 10 October 2024, a total of 2949 tests for Marburg virus have been conducted, with approximately 200-300 samples being tested daily at the Rwanda Biomedical Center from suspected MVD cases.
Contact tracing is underway, with over 700 contacts under follow-up as of 9 October 2024. A contact is known to have travelled internationally, to Germany, and is currently being monitored by the local health authorities for the recommended 21 days follow-up period. A contact who travelled to Belgium has completed the 21 days follow-up period and no longer poses a public health risk.
The source of the outbreak is still under investigation and additional information will be provided when available.
Epidemiology
MVD is a highly virulent disease that can cause haemorrhagic fever and is clinically similar to Ebola virus disease. Marburg and Ebola viruses are both members of the Filoviridae family (filovirus). People are infected with Marburg virus when they come into close contact with
Rousettus bats, a type of fruit bat, that can carry the Marburg virus and are often found in mines or caves. Marburg virus then spreads between people via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids. Health workers have previously been infected while treating patients with suspected or confirmed MVD. Burial ceremonies that involve direct contact with the body of the deceased can also contribute to the transmission of Marburg virus.
The incubation period varies from two to 21 days. Illness caused by Marburg virus begins abruptly, with high fever, severe headache and severe malaise. Severe watery diarrhoea, abdominal pain and cramping, nausea and vomiting can begin on the third day. Although not all cases present with haemorrhagic signs, severe haemorrhagic manifestations may appear between five and seven days from symptoms onset, and fatal cases usually have some form of bleeding, often from multiple areas. In fatal cases, death occurs most often between eight and nine days after symptom onset, usually preceded by severe blood loss and shock. There is currently no approved treatment or vaccine for MVD. Some candidate vaccines and therapeutics are currently under investigation.
Several outbreaks of MVD have previously been reported from countries neighbouring Rwanda, including the Democratic Republic of the Congo, Uganda and the United Republic of Tanzania. The most recent outbreaks were reported in Equatorial Guinea and the United Republic of Tanzania between February and June 2023. The affected region in the United Republic of Tanzania was the Kagera region, which borders Rwanda. Additional countries that previously reported outbreaks of MVD in the African Region included Angola, Ghana, Guinea, Kenya, and South Africa.
Public health response
Please see the WHO Rwanda Country Office operational update for ongoing response activities in Rwanda.
- The Government of Rwanda is coordinating the response with support from WHO and partners.
- WHO classified the Marburg virus disease outbreak in Rwanda as a grade 3 emergency, the highest internal level for emergencies based on the WHO Emergency Response Framework.
- A surge team from WHO has travelled to support the in-country response across the functions of incident management, epidemiology, health operations, case management, health logistics, vaccines research, partner coordination and infection prevention and control.
- A Global Outbreak Alert and Response Network (GOARN) request for assistance was issued on 2 October 2024, seeking the support of GOARN partners in the functions of case management and therapeutics research. Since then, five GOARN experts have travelled in the functions of case management and therapeutics research.
- A request for expressions of interest was issued by the Ministry of Health of Rwanda, in partnership with the WHO Emergency Medical Teams (EMT) Secretariat, seeking EMT support for deployment to Marburg treatment centers or to provide specialized care teams to tertiary hospitals.
- The Marburg virus disease strategic preparedness and response plan and WHO appeal for the Marburg virus disease outbreak in Rwanda have been published.
- WHO is supporting the transportation of samples to a regional reference laboratory for inter-laboratory comparison.
- Given the increasing number of survivors, WHO is supporting the Government in the establishment of a programme for survivors, by sharing technical guidance and protocols for the establishment of a national programme, including exploring a potential prospective observational study.
- WHO is supporting the Government of Rwanda and partners in the launch of the therapeutics clinical trials in Rwanda.
- WHO has provided technical advice to public health authorities in Rwanda and at-risk countries on the implementation of evidence-informed and risk-based health measures; the strengthening of detection, reporting and management capacities at points of entry and across borders; and travel advice.
- WHO has published interim guidance on the Considerations for border health and points of entry for filovirus disease outbreaks, which applies to but is not limited to the current MVD outbreak in Rwanda.
- WHO has also published a statement advising against any travel restrictions and against any trade restrictions with Rwanda in the context of the ongoing MVD outbreak.
- WHO is providing support in surrounding countries to assess the readiness of healthcare facilities within surrounding countries and specifically risk mapping for areas bordering Rwanda.
WHO risk assessment
Marburg virus disease (MVD) is caused by the same family of viruses (Filoviridae) that causes Ebola virus disease. MVD is an epidemic-prone disease associated with high CFR (24-88%). In the early course of the disease, MVD is challenging to distinguish from other infectious diseases such as malaria, typhoid fever, shigellosis, meningitis and other viral haemorrhagic fevers. Epidemiologic features can help differentiate between viral hemorrhagic fevers (including history of exposure to bats, caves, or mining) and laboratory testing is important to confirm the diagnosis.
The notification of 58 confirmed cases, of which over 80% are healthcare workers from two different health facilities in the country is of great concern. Healthcare-associated infections (also known as nosocomial infections) of this disease can lead to further spread if not controlled early. The importance of screening all persons entering health facilities as well as inpatient surveillance for prompt identification, isolation, and notification cannot be overemphasized. This is in addition to the importance of contact identification and monitoring of all probable and confirmed cases. The source of the outbreak, the likely date of onset of the first case and additional epidemiological information on cases are still pending further outbreak investigation.
On 30 September WHO assessed the risk of this outbreak as very high at the national level, high at the regional level, and low at the global level. However, based on the evolution of the outbreak and ongoing investigations, this risk assessment may be revised. MVD is not easily transmissible (i.e. in most instances it requires contact with the body fluids of a sick patient presenting with symptoms or with surfaces contaminated with these fluids). In addition, there are ongoing public health measures in place, including active surveillance in facilities and communities, testing suspected cases, contact tracing, isolation and treatment of cases.
WHO advice
MVD outbreak control relies on using a range of interventions, including prompt isolation and case management; surveillance including active case search, case investigation and contact tracing; a laboratory service; infection prevention and control, including prompt safe and dignified burial; and social mobilization – community engagement is key to successfully controlling MVD outbreaks. Raising awareness of risk factors for Marburg virus infection and protective measures that individuals can take is an effective way to reduce human transmission. WHO advises the following risk reduction measures as an effective way to reduce MVD transmission in healthcare facilities and in communities:
- To reduce human infections and deaths, it is essential to raise community awareness about the risk factors for Marburg virus infection particularly of human-to-human transmission, and the protective measures individuals can take to minimize exposure to the virus. This includes encouraging anyone with symptoms to seek immediate care at a health facility or designated treatment center to lower the risk of community transmission and improve their chances for recovery.
- Surveillance activities, including the wide dissemination of the MVD case definition, should be strengthened in all affected districts, including contact tracing and active case finding.
- Critical infection prevention and control measures should be implemented and/or strengthened in all health care facilities, per WHO’s Infection prevention and control guideline for Ebola and Marburg disease.
- A comprehensive strategy to manage deceased individuals in communities should be implemented in communities. Safe and dignified burials should be carried out, with strong engagement communities.
- Rapid qualitative assessments should be implemented to collect socio-behavioural data, which can then be utilized to guide the response.
- Timely laboratory testing of all suspected cases needs to be maintained and supported with a reliable sample transportation system.
- Border health readiness and response capacities should be strengthened at points of entry and in communities bordering areas reporting MVD cases and onboard conveyances, and public health advice should be provided to travellers in line with WHO’s interim guidance on considerations for border health and points of entry for filovirus disease outbreaks.
- WHO encourages all countries to send the first samples that tested positive for Marburg virus and a subset of negative samples to a WHO Collaborating Centre or a regional reference laboratory for inter-laboratory comparison.
- WHO recommends that clinical data from suspected and confirmed Marburg virus disease cases be systematically collected to improve the limited understanding of the clinical course and direct causes and risk factors for poor outcomes. This can be done by contributing anonymized data to the WHO Global Clinical Platform for viral haemorrhagic fevers.
Based on the current risk assessment, WHO advises against any travel restrictions and against any trade restrictions with Rwanda. For further information, please see
WHO advice for international traffic in relation to the Marburg virus disease outbreak in Rwanda.
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https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON539
