Marburg Virus Disease Outbreak in Rwanda- Solomon Awiagah

The Marburg virus, a highly contagious virus with a high case fatality ratio, has been reported to have emerged in Rwanda, posing a serious threat to public health. The Rwandan Ministry of Health announced the country’s first-ever outbreak of the Marburg virus disease (MVD) on September 27, 2024. We reported isolated cases in Guinea and Ghana in 2021 and 2022,respectively.

Background information on Marburg virus

The Marburg virus is a member of the filovirus family, which also includes the Ebola virus. Two strains of the virus, Marburg virus and Ravn virus are currently known to cause disease in humans. The natural host of Marburg virus is Rousettus bat species (Egyptian fruit bats), notably Rousettus aegyptiacus. These bats are primarily found in sub-Saharan Africa and the Middle East. The virus is known for causing severe viral hemorrhagic fever in humans. The discovery of Marburg virus dates back to 1967 following outbreaks in Germany (Marburg and Frankfurt) and Serbia (Belgrade). The outbreak occurred among laboratory workers exposed to imported African green monkeys from Uganda. There were 31 cases and 7 deaths.

The Chronology of Marburg virus outbreaks

The Marburg virus has triggered several deadly outbreaks across different parts of the world since its discovery in 1967. Following its discovery in Germany, Marburg virus outbreaks have primarily occurred in Sub-Saharan Africa. Significant outbreaks include;

• Germany and Yugoslavia, 1967: The world was first introduced to the Marburg virus through simultaneous outbreaks in Marburg and Frankfurt, Germany, and Belgrade, Yugoslavia. Laboratory workers exposed to African green monkeys from Uganda became infected, resulting in 29 cases in Germany and 7 deaths, with a 24% case fatality rate. Interestingly, Yugoslavia had 2 cases but no fatalities.
• South Africa, 1975: An outbreak struck South Africa, leading to 3 reported cases and 1 death (33% case fatality rate), showing how the virus transcended African borders to affect a broader region.
• Kenya, 1980 and 1987: Kenya experienced two significant outbreaks. The first in 1980 had 2 cases and 1 death (50% fatality), and the second in 1987 saw 1 case (100%).
• Democratic Republic of the Congo, 1998-2000: One of the most severe outbreaks occurred in the Democratic Republic of the Congo, linked to gold mining activities. Over two years, 154 people were infected, and 128 died (83% fatality rate), underlining the deadliness of the virus in this region.
• Angola, 2005: The largest and deadliest outbreak in history occurred in Angola, with 374 reported cases and a staggering 329 deaths (88% case fatality rate). This outbreak shook the global health community due to its unprecedented scale.
• Uganda, 2007-2017: Uganda has been a recurrent hotspot for Marburg virus outbreaks. In 2007, 4 cases and 2 deaths were reported (50% fatality rate). The country faced additional outbreaks in 2012 (15 cases, 4 deaths, 27% fatality rate), 2014 (1 case, 1 death, 100% fatality rate), and 2017 (3 cases, 3 deaths, 100% fatality rate), reinforcing its vulnerability to the virus.

In 2008, cases were exported to both the Netherlands and the United States. The Netherlands recorded 1 case, which resulted in 1 death (100% fatality rate), while the U.S. case did not lead to any fatalities. Both cases were traced back to exposures in Uganda, highlighting the virus’s potential for international transmission.

The first documented cases of Marburg virus in West Africa were reported in 2022 in Ghana, marking an important geographical spread of the disease. We also reported to you about the outbreak that occurred in Equatorial Guinea in 2023, leading to the death of the infected person.

The Marburg virus continues to pose a significant threat, as there are no approved vaccines and limited treatment options, with outbreaks occurring sporadically but often leading to high mortality rates.

The current situation in Rwanda

As of October 2, 2024, Rwanda has recorded 36 laboratory confirmed cases, including 11 deaths, representing 36% case fatality rate from Marburg virus disease. Out of the 36 cases reported, about 19 cases are in health workers, majority of whom work in the intensive care unit. The cases have been reported from 7 out Rwanda’s 30 districts, with three districts (Gasabo, Kicukiro, Nyarugenge) in Kigali province reporting the highest number of cases.

Close to 300 contacts to cases are being monitored in Rwanda. Health officials are conducting investigations to determine to the potential source of the outbreak and transmission chains.

 

How do people become infected with Marburg virus?

People are primarily infected with Marburg virus through contact with the Rousettus fruit bats that are often found in mines or caves.

Human to human transmission is mainly through direct contact with the body fluids of infected individuals (blood, feces, vomitus, saliva, urine, sweat, breast milk, semen, pregnancy fluids). The virus can also be transmitted through contact with people who died from MVD, or surfaces contaminated with the fluids listed above.

Symptoms

Symptoms of MVD usually appear 3 to 21 days after exposure and can include;

• High fever
• Severe headache
• Muscle pain
• Vomiting
• Bleeding from various body parts
• Diarrhoea

How Marburg Virus causes disease in humans

The Marburg virus enters the body through mucous membranes or broken skin, subsequently attaching to various target cells, including dendritic cells, monocytes, macrophages, and Kupffer cells. These cells play a vital role in the immune defense.

To evade immune detection, the Marburg virus alters the expression of specific proteins on the surfaces of infected cells, effectively masking them from the immune system. Additionally, the virus inhibits the production of interferons, key signaling proteins that are crucial for antiviral response, further allowing it to escape immune attacks.

Once inside the body, the virus replicates extensively, leading to the infection of more cells. In response, the immune system releases inflammatory mediators, such as cytokines, to initiate an inflammatory response. This process recruits more immune cells to the sites of infection, resulting in significant cellular damage and heightened inflammation.

In severe cases, the disease can progress to hemorrhagic fever, which is characterized by bleeding from mucous membranes, the gastrointestinal tract, and injection sites. This bleeding occurs due to the destruction of endothelial cells, which line the blood vessels, leading to compromised vascular integrity.

Treatment for MVD

There are currently no approved vaccines or antivirals for MVD. Antivirals such as Remdesivir (initially developed for Ebola virus), Galidesivir (BCX4430) and Favipiravir (T-705), are yet to be approved for specifically managing MVD. Their effectiveness in humans is still under investigation.

Vaccine development for the Marburg virus includes several promising candidates, such as recombinant vesicular stomatitis virus (VSV-ΔG/MARV) and adenovirus vectors (Ad26/MARV), both showing activeness in preclinical and early-phase clinical trials.

Therefore, management of MVD is aimed at providing supportive care. This includes fluid and electrolyte management, oxygen therapy, and treating secondary infections or complications.

Prevention and Control

The World Health Organization (WHO) provides guidelines for the general public and healthcare workers to prevent and control Marburg virus disease (MVD).

For the general public;

• Stay informed about MVD outbreaks in your region and participate in community awareness programs to educate others about the virus.
• Do not touch the bodily fluids of anyone suspected to be infected with the Marburg virus, including blood, saliva, vomit, or other secretions.
• Wash hands frequently with soap and water or use alcohol-based hand sanitizers, especially after coming into contact with potentially contaminated surfaces or materials.
• Marburg virus is associated with bats, particularly fruit bats. Avoid contact with bats and non-human primates (like monkeys and apes), and do not consume bush meat from these animals.
• If in an area where outbreaks occur, wear appropriate PPE (gloves, masks, gowns) when caring for suspected cases.
• If experiencing symptoms such as fever, severe headache, or unexplained bleeding, seek medical attention immediately and inform healthcare providers of potential exposure to MVD.

For Healthcare Workers

For Healthcare Workers

• Adhere strictly to IPC protocols in healthcare settings, including hand hygiene, use of PPE, and proper waste management.
• Isolate suspected and confirmed cases in designated healthcare facilities to prevent transmission to other patients and staff.
• Handle all bodily fluids of infected patients with caution. Use PPE and dispose of contaminated materials safely.
• Engage in training sessions on recognising symptoms, handling suspected cases, and using PPE effectively. Ensure that all staff are familiar with outbreak response protocols.
• If a vaccine becomes available, ensure that healthcare workers are vaccinated to reduce the risk of infection.
• If exposed to the virus, follow guidelines for post-exposure prophylaxis, which may include monitoring for symptoms and possible antiviral treatment.
• Monitor patients for signs of MVD and report any suspected cases to public health authorities immediately for further investigation and response.

Preventing the spread of Marburg virus will require strict adherence to the above health guidelines as individuals, communities and healthcare workers.

Stay with us for more authentic information on global health trends and how to remain healthy.

 

For further reading;

• Chakraborty, S., Deepak C., Ranjan K. M., Mahmoud A., Mohd I. Y., Md. A. I., Anil K. S. & Kuldeep D. (2022). Marburg Virus Disease-A Mini-Review. Journal of Experimental Biology and Agricultural Sciences, 10(4), pp. 689–696. https://doi.org/10.18006/2022.10(4).689.696.
• Kortepeter, M.G., Kerry D., Erica S. S. & Theodore J. C. (2020). Marburg virus disease: A summary for clinicians. International Journal of Infectious Diseases. 99, pp. 233–242. https://doi.org/10.1016/j.ijid.2020.07.042.
• Mitu, R.A. and Islam, M.R. (2024). The Current Pathogenicity and Potential Risk Evaluation of Marburg Virus to Cause Mysterious “Disease X”—An Update on Recent Evidences. Environmental Health Insights. https://doi.org/10.1177/11786302241235809.
• Shanmugaraj, B. (2024). Marburg virus: an emerging global threat. Journal of Zoonotic Diseases. 8(4), pp. 603–609. https://doi.org/10.22034/jzd.2024.18312