Rwanda is fighting its first outbreak of the “highly virulent” Marburg virus which was first reported in late September.

As of Thursday, 11 people were reported to have died of the virus in Rwanda. The health minister announced the country will begin clinical trials of experimental vaccines and treatments.

So what is the Marburg virus and how concerned should we be?

What is the Marburg virus?

Marburg is from the same family as Ebola, namely the Filoviridae family (filovirus) of viruses. It has been described as more severe than Ebola.

It causes a haemorrhagic fever, which is a type of fever that can damage the walls of blood vessels, according to information from the Mayo Clinic. Other diseases which produce this type of fever include dengue and yellow fever.

According to the Mayo Clinic, a haemorrhagic fever causes internal bleeding, which can be fatal.

The virus was first identified in 1967 in a town in Germany called Marburg, from which it gained its name. Simultaneously, it was identified in Belgrade, Serbia.

The World Health Organization (WHO) estimates the case fatality rate to be between 24 and 88 percent. On average, about half of all those who contract the virus die from it.

After a person is exposed to the virus, it can take between two and 21 days for symptoms to show, according to the WHO.

“Fatal cases usually have some form of bleeding, often from multiple areas,” the website says, adding that the onset of bleeding can occur within five to seven days.

Bleeding in vomit or faeces is often accompanied by bleeding from the nose, gums and vagina, WHO’s website says.

In severe cases, death can occur eight or nine days after symptoms start to show.

“Those with weakened immune systems are more susceptible to severe illness and death from this virus,” infectious disease expert Amira Roess told Al Jazeera. Roess is a global health and epidemiology professor at George Mason University’s College of Public Health.

What are the symptoms?

According to the Centers for Disease Control and Prevention (CDC), Marburg virus symptoms include fever, headache, muscle and joint pain, fatigue, appetite loss, bleeding and gastrointestinal symptoms.

How does the Marburg virus spread?

Some people have contracted the Marburg virus after coming in contact with Rousettus bats, a type of fruit bat found in mines and caves, that carry the virus.

The source of the Rwanda outbreak remains unclear, however.

Once an individual contracts the virus, they can transmit it to others through direct contact with bodily fluids via broken skin or mucous membranes. The WHO website says even surfaces contaminated with bodily fluids, such as bedsheets or clothing, can spread the virus.

According to information from the CDC, the virus is not airborne.

What is the situation in Rwanda?

There are currently 36 confirmed cases of Marburg in Rwanda, with 25 people being cared for in isolation, according to the government’s latest update.

According to the WHO, on September 30 when there were 26 confirmed cases, 70 percent of the cases were in healthcare workers in two of the country’s healthcare facilities, which were not named. 

“It’s not uncommon to see outbreaks in healthcare facilities, especially in low-resourced healthcare facilities that may not have sufficient infection control,” Roess said.

Additionally, Rwanda is monitoring 300 people who have come into contact with known cases.

Where has the Marburg virus spread?

On September 27, Rwanda’s Ministry of Health confirmed the latest outbreak of the Marburg virus.

The current outbreak has only been reported in Rwanda so far.

There were fears that the virus had reached Germany when two passengers on a train from Frankfurt to Hamburg contacted doctors, fearing they had the virus.

However, local authorities announced on Thursday that both had tested negative in a polymerase chain reaction (PCR) test, where a sample from the inner cheek, called a buccal swab, or blood is tested. It tests genetic material from a specific organism, which in this case is the virus.

Small outbreaks of the virus have occurred in recent years including West Africa’s first outbreak in Guinea in 2021, Ghana’s first outbreak in 2022 and the first outbreaks in Tanzania and Equatorial Guinea in 2023.

These were quickly contained. In Equatorial Guinea, 17 confirmed and 23 probable cases were reported. “12 of the 17 confirmed cases died and all of the probable cases were reported deaths,” according to WHO. In Tanzania, there were one probable and eight confirmed cases, of which five resulted in death.

According to the CDC, in Guinea, only one case was diagnosed after the death of the patient; in Ghana, three cases emerged leading to two deaths.

“We know that an infectious disease that emerges in one area has the potential to become a problem across the globe,” Roess said.

How dangerous is the latest Marburg outbreak?

WHO has assessed the risk of this outbreak to be “very high at the national level, high at the regional level, and low at the global level”.

Is there a vaccine or treatment?

There are no approved vaccines or treatments for the virus.

Rwanda’s Minister of Health Sabin Nsanzimana, announced on Thursday that the country is racing to develop a vaccine.

The WHO said some candidate vaccines are being manufactured. These include vaccines developed by the International AIDS Vaccine Initiative (IAVI) and by the Sabin Vaccine Institute which said it is collaborating with the Rwandan government.

The team at Oxford University which formulated the AstraZeneca vaccine for COVID-19 started a trial of its Marburg vaccine candidate this summer in the United Kingdom, employing similar technology to the COVID vaccine.

The WHO told Reuters that it has released funding for vaccine trials in collaboration with the Canadian government and the European Union’s Health Emergency Preparedness and Response Authority (HERA).

Diagnosed patients should promptly seek treatment of symptoms with painkiller medication and stay well hydrated.

How can you avoid catching Marburg?

Roess said: “The best thing to do is to practise good hygiene and to limit your exposure to individuals who are sick.”

She advised wearing masks when in contact with people who have symptoms of the virus, and not sharing food with people who may be infected.

“If you think that you’ve been exposed to the virus, then limit your contact with other individuals, monitor your symptoms and report to your local healthcare worker or health ministry official,” she said.

She added that the situation is difficult with most disease outbreaks because many healthcare facilities globally do not have the resources to properly monitor how many people are infected.

“It is very important for the global community to work together to fund preventative active surveillance and other programmes. If we don’t take the seriously, more human lives will be lost.”

Why are Marburg outbreaks becoming more frequent?

In the 50 years between 1967 and 2017, 13 outbreaks were recorded.

Since 2021, five outbreaks have been recorded, indicating that the outbreaks are becoming more frequent.

Roess said we will likely continue to see outbreaks and cases rise for multiple reasons.

“First, people are coming into closer contact with wildlife everywhere in the world,” she said, adding that wildlife are adapting to contact with humans and both wildlife and humans are becoming less scared of each other.

She added that cases are rising also because of the rise of chronic conditions and immunocompromising conditions such as diabetes and heart disease. These make people more susceptible to contracting the virus.

Due to technological advancements, people with such conditions are living longer “which is great but that also means that there are more people who are now susceptible to getting sick when they are exposed to pathogens”, Roess said.

She added that the spread of the virus is more likely in places with limited healthcare infrastructure. “People will show up to seek care when they are very sick. [At which point] they may be shedding a lot of virus.” This also increases the chance of transmission.