Explainer: What is Marburg Virus and How Concerning Is It? By Reuters

By Jennifer Rigby

LONDON (Reuters) – Rwanda is currently facing its first outbreak of the lethal Marburg virus, with 36 reported cases and 11 fatalities.

The World Health Organization has assessed the outbreak, stating that the risk is very high within Rwanda, high across the African region, and low on a global scale.

What is Marburg virus?

Marburg is a virus belonging to the same family as Ebola, causing a hemorrhagic fever with an average fatality rate of approximately 50%. However, in past outbreaks, the fatality rate has soared to as high as 88%. The WHO emphasizes that early clinical care and rehydration can enhance survival chances.

Symptoms generally begin with a sudden onset of high fever and severe headache, progressing to vomiting, diarrhea, and later, uncontrolled bleeding.

The virus was first identified in 1967 in Marburg, Germany, and Belgrade, Serbia, following laboratory exposure to African green monkeys imported from Uganda. Since then, outbreaks have been reported sporadically in countries such as Angola, the Democratic Republic of the Congo, Kenya, South Africa, and Uganda.

How does it spread?

Marburg is transmitted to humans through prolonged contact with caves or mines inhabited by Rousettus fruit bats. It can also spread among humans through direct contact with the bodily fluids of infected individuals or surfaces contaminated with these fluids, such as blood.

Is there a vaccine?

Currently, there are no approved vaccines or treatments for Marburg, though several promising candidates are in development and could enter trials soon, according to Rwanda’s health minister. These candidates include efforts supported by non-profit organizations like the Sabin Vaccine Institute and the International AIDS Vaccine Initiative (IAVI). Additionally, the team that developed the AstraZeneca COVID-19 vaccine began trials for a Marburg vaccine candidate this summer in the UK, utilizing similar technology.

What else is happening?

Rwanda is actively monitoring around 300 contacts of confirmed cases. Notably, about 70% of confirmed cases involve healthcare workers from two medical facilities in the capital, Kigali. Cases have been reported in seven out of the country’s 30 districts. The virus can also spread at funerals, where cultural practices involve close contact with the deceased.

Health officials worldwide are on alert for potential spread to neighboring countries and beyond.

Is Marburg reaching new places, and why?

Recent trends indicate that Marburg is indeed emerging in new regions. In 2021, Guinea reported its first case, followed by Ghana in 2022, and Tanzania and Equatorial Guinea in 2023. These outbreaks have been manageable due to swift public health interventions. Experts suggest that the increasing frequency of these outbreaks may be related to human encroachment into wildlife habitats.

The ongoing outbreak in Rwanda is already among the largest recorded.