New strain of deadly Ebola
2008-11-21 09:43
Paris - Scientists said Friday an outbreak of Ebola that killed 37 people in Uganda last year was sparked by a hitherto unknown species of one of the world's most notorious viruses.
The strain - provisionally named Bundibugyo ebolavirus after the district where the outbreak occurred - joins four other known species of the pathogen, they said.
More than one in three of patients infected with Bundibugyo died, according to their study, appearing in the US journal PLoS Pathogens, published online by the open-access Public Library of Science (PLoS).
Ebola and the Marburg virus are the two main categories of so-called filovirus which causes haemorrhagic fever (VHF), a disease dubbed a "slate-wiper" for its extreme lethality.
The early signs of VHF are usually a high temperature, exhaustion, dizziness, watery diarrhoea and muscle ache. These symptoms are often mistaken for other fevers, such as flu or yellow fever, because VHF is rare.
Zaire ebolavirus deadliest strain
As the virus spreads, the feverish patient often starts to bleed under the skin and in severe cases, from the mouth, ears and eyes.
Blood loss, shock and organ failure lead to coma and delirium and, in many cases, to death, within three to seven days after onset of symptoms.
Ebola first came to light in 1976 in Zaire, now the Democratic Republic of Congo (DRC) and is named after the Ebola river with which this outbreak is associated.
Approximately 1 850 cases with over 1 200 deaths have been documented since the virus was discovered, according to the World Health Organisation (WHO).
The deadliest strain, Zaire ebolavirus, inflicts a death rate of 80-90%, followed by Sudan ebolavirus, with a mortality of 50-55%.
The least harmful are the Cote d'Ivoire ebolavirus, which was discovered in the Ivory Coast in 1994 and so far has caused only a single, non-fatal case of VHF; and the Reston ebolavirus, identified at a US research facility in 1989, which spread from imported lab monkeys to at least four people, none of whom fell sick.
The newly-discovered species came to light after VHF erupted in the townships of Bundibugyo and Kikyo in November 2007, says the study, authored by US and Ugandan doctors.