News Briefs Archive

United States (Colorado, Wyoming, Nebraska)—Chronic Wasting Disease
Both wild and captive deer and elk testing positive for chronic wasting disease (CWD) have been found in areas of Colorado, Wyoming, and Nebraska. CWD belongs to a class of diseases, transmissible spongiform encephalopathy (TSE), which include Bovine Spongiform Encephalopathy and "new variant" Creutzfeldt–Jakob Disease (vCJD). The disease attacks the brains of infected deer and elk, causing the animals to become emaciated, display abnormal behavior, lose bodily functions, and die.

Four fawns in Sioux County, Nebraska ranging in age from six to eight months old tested positive for chronic wasting disease (CWD), according to reports on 26 Jan 2002. The fawns, which did not show any physical symptoms of the disease, were part of a highly infected captive herd in the northwestern part of Nebraska. Officials are not certain how the fawns in Nebraska became infected, but it is believed that the illness was not passed on in the womb. It is thought that close physical contact between an infected doe and her fawn after birth is the vehicle. CWD first appeared in Nebraska in 1997, when an infected animal was found in a captive herd.

News that the disease has turned up in free–roaming deer in Nebraska prompted a review of Colorado's efforts to contain CWD. Colorado State agricultural officials are considering a quarantine of all wild deer and elk killed in northeastern Colorado in an attempt to bring the spread of chronic wasting disease (CWD) to an end. Under the proposed quarantine deer and elk killed by hunters, game wardens, or ranchers or deer and elk found dead in endemic areas would not be removed from the area without being checked for CWD. If any test positive, they would be disposed of in high–temperature furnaces.
[Promed 01/31/02, 02/01/02; Associated Press 02/02/02]

United States (Washington)—New Mosquito Species
West Nile Virus (WNV), a virus that is carried by mosquitoes, may cause encephalitis in horses, birds, and humans. The virus first emerged in 1999 in the eastern United States and continues to be detected in regions further westward. In 2001, 47 human cases of WNV encephalitis occurred in eight eastern states resulting in four deaths. West Nile Virus has not yet been reported in Washington, but cases of western equine encephalitis (WEE) and St. Louis encephalitis (SLE) have occurred previously in Washington State in horses and humans. The mosquitoes that carry WEE and SLE are thought to be widespread throughout the state.

A mosquito species previously not found in the western United States, Ochlerotatus japonicus japonicus, was recently discovered in Washington State by the Washington WNV surveillance project. The newly discovered Asian mosquito, formerly known as Aedes japonicus, is difficult to control because it deposits eggs in areas where water may collect and is harder to avoid because it bites during the day. The surveillance program has also identified other potential mosquito carriers of WNV, western equine encephalitis (WEE) and St. Louis encephalitis (SLE) in other areas of Washington. In 2002 officials will concentrate on ascertaining the geographic distribution of this new species of mosquito in Washington State. The collection and analysis of dead birds that are susceptible to WNV has begun, but no birds have tested positive for WNV in Washington. A project report can be found at http://www.doh.wa.gov/Publicat/2002_news/WestNileVirusSurv.pdf.
[Washington State Department of Health News Releases http://www.doh.wa.gov/Publicat/2002_News/02㪡.htm]

RELATED NEWS

Venezuela—Hemorrhagic Fever Outbreak
Eighteen cases of Venezuelan hemorrhagic fever (VHF), or Guanarito hemorrhagic fever, have been confirmed in the Venezuelan states of Portuguesa (15 cases) and Barinas (three cases). VHF, which is caused by an arenavirus called Guanarito virus, is characterized by high fever, headache, sore throat, loss of appetite, nausea, vomiting, seizures, and bleeding of the nose and gums. The fatality rate ranges between 30 to 40 percent. In 2002 two deaths as a results of infection have occurred in Venezuela, as of 01 Feb. To date, this disease has been limited to Venezuela. Samples from patients with a suspected infection are being analyzed by the National Institute of Hygiene.
[Promed 02/03/02, 02/04/02]

2. UPDATES

Republic of the Congo and Gabon—Ebola Hemorrhagic Fever
On 31 Jan 2002 the World Health Organization (WHO) announced that the outbreak of Ebola hemorrhagic fever in Gabon and the Republic of Congo is under control. On 20 January 2002, the Gabonese government reported ten laboratory–confirmed and 16 epidemiologically linked cases as well as 22 suspected cases under investigation.
As of 20 January 2002, 16 confirmed cases have been reported in villages in the Republic of the Congo. The outbreak has killed 23 people in Gabon and 11 people in the Republic of Congo. Ebola, which spreads through contact with bodily fluids and causes bloody diarrhea as well as vomiting, kills 50 to 90 percent of those infected. Infected individuals usually die within two weeks of massive blood loss.
[World Health Organization Update 15]

3. NOTICES