Outbreak of Marburg fever: six deaths reported so far

There has been an outbreak of the highly dangerous Marburg fever in Rwanda. Six people have died from the infection so far. A total of 26 cases have been confirmed, the country’s Ministry of Health announced.

The majority of cases and deaths involve medical personnel. Health Minister Sabin Nsanzimana said the sick patients would be isolated and closely monitored. The origin of the outbreak is still being investigated and prevention measures have been tightened in all health facilities in Rwanda. Rwanda is also affected by the Mpox epidemic, for which the WHO recently declared an international health emergency.

The Marburg virus is a highly contagious and often fatal viral disease that, depending on medical care, can have a mortality rate of up to 88 percent. So far, outbreaks have only occurred rarely. The virus is not yet well adapted to humans: Since the symptoms appear quickly and the infections are often fatal, it cannot spread well.

But that could change, especially as more and more people come into contact with infected animals due to the destruction of natural habitats. The natural host of the Marburg virus is probably the Egyptian flying fox species Rousettus aegyptiacus. These animals are widespread across much of Africa and often live in caves or abandoned mines, where they gather in large colonies. People who come into contact with flying foxes, for example by entering such caves or by eating flying foxes as food, can become infected.

Discovery in Marburg

The Marburg virus is transmitted primarily through direct contact with body fluids from infected people. These include blood, saliva, urine, stool and sweat. Medical staff are particularly at risk, as can be seen from the current outbreak.

The virus was discovered in 1967. The first known infection occurred in the German city of Marburg, where the virus got its name. At that time, several laboratory workers became ill after working with laboratory animals, particularly monkeys, that had been imported from Uganda. A total of seven people died as a result of the infection.

Previous outbreaks of Marburg fever have occurred predominantly in African countries, particularly Angola, the Democratic Republic of Congo and Uganda. The worst outbreak to date in Angola in 2006 had 422 cases, of whom 356 died

Overreaction by the immune system

Like the coronavirus, the Marburg virus is an RNA virus and belongs to the family of filamentous filoviruses, which also includes the better-known Ebola virus. Both viruses cause hemorrhagic fever, which can lead to severe internal and external bleeding. The problem: The human immune system generally has no experience with the virus and reacts with a “cytokine storm,” a violent, misdirected immune response.

High fever, severe headaches, muscle pain and general weakness occur. As the disease progresses, severe gastrointestinal symptoms such as diarrhea, abdominal pain, nausea and vomiting may occur. The disease often proceeds aggressively, and after a few days bleeding can occur in various organs, which rapidly deteriorates the patient’s condition.

Vaccines already being tested

As with many viral diseases, there is no treatment that targets the Marburg virus itself. However, two vaccine candidates are currently in development. One is being developed by the US National Institutes of Health. Successful results a phase 1 study in the USA were published in January 2023. Another candidate is being developed by the British Oxford Vaccine Group, undergoing initial clinical testing have recently started.