Outbreak of deadly Marburg virus in Uganda

(cc photo by Shek Graham) The World Health Organisation (WHO) has warned people against visiting the bat caves in western Uganda after a tourist suspected to have contracted the Marburg virus died on Friday. The Ugandan Wildlife Authority (UWA) has temporarily stopped visits to the caves in Maramagambo forest while they investigate the link to the deadly virus, which is related to Ebola. Experts are now in the area to confirm that Maramagambo is the source of the Marburg disease which killed the Dutch woman last week.

The unidentified 40 year old women died in Leiden University Medical Centre on Friday. Because the disease is highly infectious, doctors are now monitoring the health on a daily basis of people who were in close contact with the victim. No-one else has shown any symptoms. The women visited two caves during a three-week trip to Uganda and suffered fever and chills four days after her return home. She was admitted to Leiden hospital on 2 July.

The Dutch Government notified WHO after a lab test confirmed a tourist had contracted the virus. The Hamburg based Bernhard Nocht Institute isolated the virus in the women who was in Uganda between 5-28 June and entered caves on two occasions. On her second visit, she went to the popular Maramagambo Forest between Queen Elisabeth Park and Kabale. There she had contact with a fruit bat species known to carry filoviruses. Filoviruses cause two types of viral haemorrhagic fever: Marburg and Ebola.

WHO spokesman Gregory Hartl played down the outbreak saying it was an isolated case of “imported Marburg." He advised people should not think about amending their travel plans to Uganda but should not go into caves with bats. His advice was reiterated by the Ugandan Health Ministry. They advised people who have to enter caves in Uganda that they should exercise "maximum precaution not to get into close contact with the bats and non-human primates in the nearby forests".

Marburg is an acute, infectious, hemorrhagic viral fever which affects both human and nonhuman primates. Marburg is a contagious disease that causes sudden bleeding and high fever. Other early symptoms include severe diarrhoea, abdominal pain, nausea and vomiting, severe chest pain, and sometimes sore throat and coughing. The incubation period is 3 to 9 days. Contact with bodily fluids of infected people is the main risk factor for infection. There is no treatment or vaccine. The natural source of the virus remains unknown.

Although endemic to Central and East Africa, the virus is named after the German town in which some of the first cases were described when local workers were exposed to green monkeys imported from Uganda. It is spread through contact with blood, semen or other bodily fluids. The Marburg virus is identical to Ebola in most respects, differing only in that it stimulates the production of different antibodies. Death rates are currently 80 to 90 percent of sufferers. At least 220 people died in the largest ever Marburg epidemic in Angola in 2004 and 2005, which followed an outbreak in the Democratic Republic of Congo which cost 128 lives between 1998 and 2000.

While no cure is yet available, North American scientists have successfully demonstrated an experimental Marburg vaccine in monkeys. Researchers from Maryland's Army Medical Research Institute of Infectious Diseases and Winnipeg's National Microbiology Laboratory injected eight monkeys with an extremely high dose of the virus. After half an hour, five of the eight were given the vaccine. The vaccinated animals all survived for at least 80 days, but the others died within 12 days. The vaccine is not yet ready for human testing but researchers are hopeful it may eventually be possible to immunise researchers infected in laboratory accidents. "Quite honestly, we were astonished," said Dr Thomas Geisbert, a senior US army virologist involved in the test. "We never thought it would work that well for something acute like Marburg, where the infection happens so fast that you don't have time to intervene."