The Ebola outbreak in the Democratic Republic of the Congo and Uganda has raised concerns among global health officials due to the less common strain detected, the Bundibugyo virus.
As of Sunday, when the World Health Organization declared a public health emergency, there were nearly 250 suspected cases and 80 suspected deaths. The WHO stated that these numbers are expected to rise as uncertainties remain about the true number of infected persons and their geographic spread.
Health officials have confirmed that the virus behind this outbreak is the Bundibugyo virus, which has only been known to cause outbreaks three times in history. There are no approved vaccines or treatments for this strain; the only available vaccine targets the Zaire strain.
Ebola disease is caused by multiple species of orthoebolaviruses, with three causing large outbreaks: Ebola (Zaire), Sudan virus, and Bundibugyo virus. The Bundibugyo virus was first discovered in Uganda in 2007 and again in Congo in 2012. Due to fewer outbreaks, less data exists on its behavior compared to the Zaire strain.
Bundibugyo virus disease is severe and often fatal, spreading from person to person through direct contact with bodily fluids of an infected individual. Early symptoms can be mistaken for other illnesses but may progress to include fever, headache, muscle pain, vomiting, diarrhea, and bleeding. The fatality rate based on past outbreaks is about 30 to 50%. The World Health Organization advises early intensive supportive care to improve survival rates.