Marburg disease is a zoonotic (animal-borne) viral haemorrhagic fever, naturally occurring in Africa. It is closely related to Ebola, and both are members of the family Filoviridae ('thread viruses').
The first recorded outbreak of the disease occurred in Marburg and Frankfurt (Germany) and in Belgrade, Yugoslavia, when a shipment of African green monkeys (Cercopithecus aethiops) was imported from Uganda. Twenty-five laboratory workers who had worked with material from the monkeys were infected. Seven of those cases were fatal. An additional six cases occurred later, when the disease was spread by infected human hosts. The monkeys had been imported for research and to prepare polio vaccine.
Marburg is rare - apart from a few outbreaks over the years1, it is not often seen in humans.
Once a human host is infected, the disease has an incubation period of between 5-10 days, after which symptoms rapidly appear - fever and chills, accompanied by headache and myalgia (muscle pain). Around five days after the onset of symptoms, a fine pinpoint rash may appear on the chest, back and stomach. After the appearance of the rash, the patient's condition rapidly worsens: nausea, vomiting, sore throat, chest and abdominal pain and diarrhoea may appear, followed by jaundice, inflammation of the pancreas, severe weight loss, delirium, shock, liver failure, massive haemorrhaging, and multi-organ dysfunction.
Within another 5-10 days, patients may begin to recover. Recovery can take over a month, and may involve additional complications, including inflammation of the eye, liver, spinal cord, bone marrow, testes and parotid gland. Temporary amnesia has also been reported.
Patients who do not show signs of recovery usually die of shock 6-9 days after the onset of symptoms, after undergoing coma and convulsions. The fatality rate in cases of Marburg is between 23-25%.
As the disease is so rare, no specific treatment has been developed. Patient care mostly involves trying to stabilise the patient's condition by replacing lost fluids, blood and electrolytes, and treating any complicating infections that occur. Experimental treatments involve transfusions of blood plasma, to replenish proteins involved in blood clotting, or the use of heparin (an anti-clotting agent) to block clotting and halt the rapid consumption of clotting factors that occurs.
There is no vaccine for Marburg, since as with other filoviruses, exposure to the virus does not result in immunity. Not enough is known about the disease itself to allow preventative measures to be established. Currently, the only way to prevent the disease spreading is to totally isolate patients suspected or confirmed to be infected with the disease from human contact. This involves setting up an isolation area for the patient, inside which all personnel must wear protective masks, gloves and clothing.
The method of transmission of the virus from animal to human host is currently unknown, but is linked to the handling of green monkeys, as well as fluids and cell cultures deriving from them. Once infected, the disease passes from human to human through direct contact, via droplets of bodily fluid, or by contact with contaminated equipment. Outbreaks usually occur in hospitals or other situations where people are in close contact with the infected patient.
South Africa, 1975: one fatality (a hitchhiker travelling through Zimbabwe) plus two non-fatal secondary infections, in his travelling partner and, later, in the nurse that cared for the partner.
South Africa, 1982: one fatality.
Kenya, 1980: one fatality, in a visitor to the Kitum cave on top of Mt. Elgon in Kenya, and one non-fatal secondary infection in the doctor that treated him.
Kenya, 1987: one fatality, also in a visitor to the Kitum cave.
Durba, Democratic Republic of Congo, 1998: small-scale outbreak linked to miners working illegally in rebel-held goldmines.
- Dr Richard Darwood, Travellers' health: How to stay healthy abroad, Oxford University Press, 2002
- Tara K. Harper, TKH Virology Notes: Marburg Hemorrhagic Fever: http://www.tarakharper.com/v_marbrg.htm
- Special Pathogens Branch: Diseases: Marburg Hemorrhagic Fever: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/marburg.htm - Center for Disease Control