The virus is highly contagious and has even claimed the lives of 14 nurses and two doctors who were treating the patients. It can spread through blood, vomit and other body fluids. Multiplying rapidly, it can kill a person within a week of infection by destroying the white blood cells. In the earliest stage of infection, symptoms include diarrhoea, abdominal pain, nausea and chest pain. Haemorrhagic manifestations occur between days 5 and 7.

Marburg virus disease has no cure. However, death rates can be kept down by providing patients with medical support such as attention to fluid and electrolyte balance and blood pressure. In 2002, GenPhar Inc., a US-based company doing research for the US army’s biodefence programme, announced an experimental vaccine that protected animals from a high dose of Marburg virus. The company is now testing the vaccine on non-human primates.

The Marburg virus belongs to the family Filoviridae, which also includes the deadly Ebola virus. And like Ebola, Marburg contains only ribonucleic acid. It can be killed by detergents and commercial hypochlorite and phenolic disinfectants.

The virus was first detected in 1967 when monkeys from Uganda infected laboratory workers in Marburg, Germany. Only sporadic cases were reported till 1998 when 149 cases surfaced from the Democratic Republic of Congo. Initial epidemiological findings by researchers from France suggest that the first cases involved miners who were probably infected by contact with animals such as bats that inhabit mines. This was confirmed by antibody surveys carried out by CDC researchers. According to their results published in 2003, two per cent of the 912 participants in the chosen areas were positive for antibodies against the virus of these 87 per cent were men who worked in the local gold mines. While epidemiologists have tested bats, monkeys, spiders and ticks for the virus, they were not able to come to a conclusion.

According to experts, it is not just chance that such outbreaks occur in regions wracked by civil strife and extreme poverty. People faced with dismal economic prospects push deeper into previously uncharted areas, such as hunting in distant forests or entering into faraway mines in search of precious minerals and expose themselves to pathogens not previously encountered as frequently. "We can certainly invoke environmental stresses from worsening socio-political situations in some areas of the world as factors in an increasing incidence of Marburg and other haemorrhagic fevers," says Daniel G Bausch, Associate Professor, Tulane School of Public Health and Tropical Medicine, New Orleans, USA.