Marburg virus disease is an often fatal illness which causes hemorrhagic fever in humans. A cluster of cases was recently reported in Rwanda, where at least 8 people have died and hundreds more are being monitored for signs of the disease.
It is closely related to Ebola and is typically spread by bats, which provide a natural reservoir for the virus.
Once in human populations, Marburg is spread person-to-person via droplets of blood, saliva, mucus and other bodily fluids.
The average fatality rate is around 50 per cent, with rates varying from 24 per cent to 88 per cent in past outbreaks depending on the strain of the virus and quality of medical care.
There is currently no vaccine for the virus.
What is the history of Marburg?
Marburg was first recognised in 1967, when outbreaks of haemorrhagic fever occurred simultaneously in laboratories in Marburg and Frankfurt, Germany and in Belgrade, Yugoslavia (now Serbia).
The infections were traced back to three laboratories which received a shared shipment of infected African green monkeys.
Thirty-one people became ill, initially laboratory workers followed by several medical personnel and family members who had cared for them. Seven deaths were reported. The first people infected had been exposed to Ugandan imported African green monkeys or their tissues while conducting research.
There have been eight subsequent outbreaks involving multiple infections, including the 2023 outbreak in Equatorial Guinea.
Other countries impacted include Angola, the Democratic Republic of the Congo, Kenya, and most recently Rwanda.
What are the symptoms of Marburg?
The incubation period (time from infection to onset of symptoms) varies from two days to three weeks.
Initial symptoms include high fever, severe headache and fatigue. Muscle aches are common, as is diarrhoea, stomach cramps, nausea and vomiting.
The World Health Organization (WHO) describes patients at this phase as “ghost-like”, with drawn features, deep-set eyes and extreme lethargy.
“Many patients develop severe haemorrhagic manifestations between five and seven days, and fatal cases usually have some form of bleeding, often from multiple areas”, adds the WHO.
“Fresh blood in vomitus and faeces is often accompanied by bleeding from the nose, gums, and vagina”.
The virus can also cause confusion and aggression in some patients.
“In fatal cases, death occurs most often between eight and nine days after symptom onset, usually preceded by severe blood loss and shock”, says the WHO.
How is Marburg transmitted?
Human infections typically start in areas where people have exposure to mines or caves inhabited by infected fruit bat colonies.
Human-to-human transmission is caused by direct touch or droplets of blood, sweat, saliva and other secretions.
Contaminated clothing and bedding is a risk, as are burial ceremonies that involve direct contact with the deceased.
Healthcare workers have been frequently infected while treating Marburg patients.
How is Marburg disease diagnosed?
Marburg can appear similar to diseases such as malaria, typhoid, meningitis, Ebola and other viral haemorrhagic fevers.
Confirmation that symptoms are caused by Marburg virus requires laboratory tests of blood samples containing the virus.
Are there vaccines and treatments?
There are no vaccines or antiviral treatments approved to treat Marburg virus.
But good medical care including rehydration with oral or intravenous fluids can significantly improve survival rates.
“A range of potential treatments, including blood products, immune therapies and drug therapies, as well as vaccine candidates with early trial data, are being evaluated”, say the WHO.
How similar is Marburg to Ebola?
Marburg and Ebola are both caused by viruses from the same filovirus family. The diseases are distinct but clinically similar.
Prof Jimmy Whitworth, a specialist in infectious diseases at the London School of Hygiene and Tropical Medicine, said: “Marburg and Ebola have the same clinical features – high fever, muscle pains, abdominal pain, diarrhoea, vomiting, and uncontrolled bleeding.”
Marburg also spreads like Ebola, through “very close contact, and touching bodily fluids,” he added.
Where has Marburg been detected in the past?
Outbreaks and sporadic cases have been reported in Angola, the Democratic Republic of the Congo, Kenya, South Africa (in a person with recent travel history to Zimbabwe) and Uganda.
