Marburg virus disease (MVD) is caused by the Marburg virus, a form of hemorrhagic fever virus of the Filoviridae family of viruses and a member of the species Marburg Marburgvirus, genus Marburgvirus. The virus is extremely dangerous.
The average MVD case fatality rate is around 50%. Case fatality rates have varied from 24% to 88% in past outbreaks depending on virus strain and case management. Marburg virus disease was initially detected in 1967 after simultaneous outbreaks in Marburg and Frankfurt in Germany, and in Belgrade, Serbia.
Early supportive care with rehydration, and symptomatic treatment improves survival. There is as yet no licensed treatment proven to neutralize the virus, but a range of blood products, immune therapies and drug therapies are currently under development.
Rousettus aegyptiacus, fruit bats of the Pteropodid family, are natural hosts of Marburg virus. The Marburg virus is transmitted to people from fruit bats and spreads among humans through human-to-human transmission. Hence community engagement is key to successfully controlling outbreaks.
Marburg spreads through human-to-human transmission via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected , and with surfaces and materials (e.g., bedding, clothing) contaminated with these fluids.
Burial ceremonies that involve direct contact with the body of the deceased can also contribute in the transmission of Marburg.
People remain infectious if their blood contains the virus.
Symptoms of Marburg virus disease
The incubation period (interval from infection to onset of symptoms) varies from 2 to 21 days.
Illness caused by Marburg virus begins, with high fever, severe headache, severe malaise and muscle aches. Severe watery diarrhoea, abdominal pain and cramping, nausea and vomiting can begin on the third day. Diarrhoea can persist for a week. The appearance of patients at this phase has been described as showing “ghost-like” drawn features, deep-set eyes, expressionless faces,
and extreme lethargy.
Many patients develop severe haemorrhagic manifestations between 5 and 7 days, and fatal cases usually have some form of bleeding, often from multiple areas. Fresh blood in vomitus and faeces is often accompanied by bleeding from the nose, gums, and vagina. Spontaneous bleeding at venepuncture sites (where intravenous access is obtained to give fluids or obtain blood samples) can be particularly troublesome. During the severe phase of illness, patients have sustained high fevers. Involvement of the central nervous system can result in confusion, irritability, and aggression. Orchitis (inflammation of one or both testicles) has been reported occasionally in the late phase of disease (15 days).
In fatal cases, death occurs most often between 8 and 9 days after symptom onset, usually preceded by severe blood loss and shock.
Prevention and control
Good outbreak control relies on using a range of interventions, namely case management, surveillance and contact tracing, a good laboratory service, safe and dignified burials, and social mobilization. Community engagement is key to successfully controlling outbreaks. Raising awareness of risk factors for Marburg infection and protective measures that individuals can take is an effective way to reduce human transmission.
Risk reduction messaging should focus on several factors: