WHO reports new Ebola virus subtype in Uganda

Nov 30, 2007 (CIDRAP News) – The World Health Organization (WHO) today announced an outbreak of Ebola hemorrhagic fever in Uganda involving a new subtype of the virus that officials suspect was responsible for sickening 51 patients, including 16 who died.

The focus of the outbreak is Bundibugyo district in the western part of the country, the WHO said in a statement today. The reported case-patients include three healthcare workers, one of whom died. Patients are being treated at hospitals in Kikyo and Bundibugyo, the WHO reported.

Analysis of patient samples at the National Reference Laboratories in Uganda and the Centers for Disease Control and Prevention (CDC) in Atlanta have confirmed that a new species of the Ebola virus was involved in the outbreak, the WHO said. Four Ebola subtypes have previously been identified: Zaire, Sudan, Cote d'Ivoire, and Reston.

Investigators from Uganda's health ministry and the WHO said the outbreak might have begun in September, the WHO said. A task force involving the health ministry, the WHO, and international health groups is responding to the outbreak.

WHO spokesman Gregory Hartl said the WHO was particularly concerned about the outbreak because patients are presenting with somewhat unusual symptoms for Ebola, such as vomiting, the Associated Press (AP) reported today.

Pierre Formenty, a WHO hemorrhagic fever expert, told the AP that news of a new Ebola strain "is an important discovery for the scientific community."

"This could be a milder strain of the disease, but we still need additional information to confirm that," Formenty said.

The Ebola virus is highly contagious and known for its high fatality rate, ranging from about 50% to 90%. Initial symptoms include fever, headache, joint and muscle aches, sore throat, and weakness, followed by diarrhea, vomiting, and stomach pain, according to the US Centers for Disease Control and Prevention (CDC). Some patients have internal and external bleeding. There is no vaccine or specific treatment for the disease.

Uganda's last Ebola outbreak occurred in 2000 and involved the Sudan subtype, according to the CDC. In that outbreak, 425 cases and 224 deaths were reported.

The Democratic Republic of the Congo (DRC) had an Ebola outbreak in the DRC's Kasai Occidental (West Kasai) province that began in August and involved at least 17 cases and 6 deaths, according to previous reports. The DRC health ministry said on Nov 20 that it had been contained.

See also:

Nov 30 WHO statement
http://www.who.int/csr/don/2007_11_30a/en/index.html

CDC reports of recent Ebola and other viral hemorrhagic fever outbreaks
http://www.cdc.gov/ncidod/dvrd/spb/outbreaks/index.htm

CDC information about Ebola

CIDRAP overview of viral hemorrhagic fevers
http://www.cidrap.umn.edu/cidrap/content/bt/vhf/biofacts/index.html

Nov 20 CIDRAP News story "Congo says Ebola outbreak is contained"

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