What is Marburg virus and how worrisome is it?

Rwanda is battling its first outbreak of the deadly Marburg virus, with 36 cases reported so far and 11 deaths.

The World Health Organization said this week that the risk of the outbreak is very high in Rwanda, high in the African region and low globally.

What is Marburg virus?

Marburg is a virus in the same family as Ebola. It causes hemorrhagic fever and has an average fatality rate of 50 percent, according to the WHO, although rates have been as high as 88 percent in previous outbreaks. Early clinical care and rehydration can improve survival, the UN health agency says.

Symptoms usually include a sudden high fever and extreme headache, as well as vomiting and diarrhea, followed by uncontrolled bleeding.

It was first identified in Marburg, Germany – hence the name – and Belgrade, Serbia in 1967 after laboratory work with Ugandan African green monkeys led to human infections. Since then, there have been outbreaks and sporadic cases in Angola, the Democratic Republic of Congo, Kenya, South Africa and Uganda, the WHO says.

How does it spread?

Marburg spreads to humans through prolonged exposure to mines or caves where Rousettus fruit bats live. It can also spread between people by direct contact with the bodily fluids of infected people or with surfaces or materials contaminated with those fluids, such as blood.

Is there a vaccine?

There are no approved vaccines or treatments for Marburg, but there are a number of promising candidates that could begin trials soon, Rwanda’s health minister said. These include vaccine candidates developed by non-profit organizations including the Sabin Vaccine Institute, which said it was working with Rwandan officials at the outbreak, as well as the International AIDS Vaccine Initiative (IAVI).

The team that developed AstraZeneca’s COVID-19 vaccine at Oxford University began a trial of its Marburg candidate this summer in the UK, using similar technology.

What else is going on?

Rwanda is also monitoring about 300 contacts with known cases. About 70 percent of the confirmed cases are health workers from two health facilities in the capital, Kigali, although cases have been reported from seven of the country’s 30 districts. In addition to spreading in healthcare facilities, the disease can also spread at funerals for those killed by the disease, which involve close physical contact with the deceased in some cultures as they prepare for burial, said Paul Hunter, a professor of medicine at the University of East Anglia.

Health authorities around the world are on alert for any spread to neighboring countries or beyond.

Marburg is reaching new places and why?

Yes – in 2021, Guinea reported the first case of Marburg in West Africa. In 2022, Ghana declared its first outbreak, and Tanzania and Equatorial Guinea followed suit in 2023. These generally small outbreaks were brought under control through public health measures. Scientists said the increased frequency of outbreaks appeared to be linked to the encroachment of animal habitats.

The outbreak in Rwanda is already one of the largest ever.

(Reporting by Jennifer Rigby; Editing by Chizu Nomiyama)

Photo: In this Oct. 8, 2014 file photo, an infection prevention and control medical worker wearing full protective gear carries a table into an isolation tent housing a man in quarantine after entering the contact in Uganda with a carrier of the Marburg Virus at the Kenyatta National Hospital in Nairobi, Kenya. (AP Photo/Ben Curtis, File)