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."

new Ebola outbreak in Congo

UN officials are desperately rushing in supplies and doctors to south-central Congo to contain a new outbreak of the deadly Ebola virus. More than 150 people have died so far in Kasai province and the World Health Organisation (WHO) is aware of another 372 cases. Congolese ministers are going on radio and television to educate villagers about the crisis. “We are extremely concerned,” said Dr. Benoit Kebela Ilunga, secretary general of the Congo Health Ministry. “But we also have experience dealing with this.”

Makwenge Kaput, Congo’s health minister, said the outbreak of the Ebola virus occurred at Mweka, a village outside the Western Kasai provincial capital of Kananga. The WHO regional office is supporting the Kinshasa health ministry in the field at the location of the outbreak. However the presence of dysentery in blood and urine samples is complicating diagnosis and treatment.

The WHO has confirmed the presence of Ebola virus in samples taken from cases associated with the outbreak after laboratory analysis at the Centre International de Recherches Médicales de Franceville (CIRMF), Gabon, and at the Centres for Disease Control and Prevention (CDC) in Atlanta. They are now sending Personal Protective Equipment (PPE) to the area and Médecins Sans Frontières (Belgium) has deployed clinicians, water and sanitation experts and logisticians to set up quarantine facilities.

Following the announcement of the outbreak, the Health Ministry of neighbouring Uganda has issued a red alert to all border posts. Although Kasai is 2,000kms away, medical experts say the threat of the virus spreading is serious. "We are always concerned that is why we have issued a directive to all border posts to be vigilant," said Dr Sam Okware, the Ugandan commissioner for health and chairperson for the Ebola Task Force. The last outbreak in Uganda in 2000 killed 160 people.

Ebola haemorrhagic fever (EMF) is one of the deadliest pathogens affecting primates, killing up to 90 percent of infected people. The virus is endemic to Africa and the Philippines. There is no known cure. In severe cases, victims haemorrhage and bleed from body orifices before dying. There are four identified subtypes (pdf) of Ebola virus. Three of the four have caused disease in humans: Ebola-Zaire, Ebola-Sudan, and Ebola-Ivory Coast. The fourth, Ebola-Reston, has caused disease in nonhuman primates, but not in humans.

Ebola is an animal-borne highly contagious virus that causes high fevers, diarrhoea, vomiting and often severe internal bleeding, has killed hundreds of people in Africa, where diets include primates. The virus is transmitted by direct contact with the blood, body fluids and tissues of infected persons. Transmission of EHF has also occurred by handling ill or dead infected chimpanzees.

Although the disease is named after a river in the Congo, it was first recognised in a western equatorial province of Sudan in 1976. There it affected 284 people over half of whom died. A few months later, there was a second outbreak in Yambuku in Congo (then known as Zaire). 318 people were affected in the Congo and a staggering 88 per cent of those who contracted the virus died. There have been sporadic outbreaks, mostly in Africa, since that time.

The latest outbreak is the worst the world has seen for several years and is likely to have serious repercussions. It started three months ago when people started falling sick from a mystery virus in several villages around Kananga. Although several villages remain under quarantine, the WHO is saying there no need for any restrictions on travel or trade with the Democratic Republic of the Congo for now. That could change quickly with WHO warning of a “possible concurrent outbreak of another etiology [cause]".