| ■ U.S. West Nile Activity Remains Stable | 2008.07.07 |
| In 2007, there were 3,630 reported cases of West Nile Virus disease in people, including 1,227 cases of more serious infection known as West Nile Neuroinvasive Disease (WNND), says an article in the current Morbidity and Mortality Weekly Report, published by the U.S. Centers for Disease Control and Prevention. The overall 2007 incidence of WNND was 0.4 per 100,000 population, similar to that reported from 2004 to 2006, but substantially lower than the incidence in 2002 and 2003. The highest incidence of WNND in 2007 occurred primarily in the west-central United States. The relative stability in the number of reported WNND cases is likely to continue for the foreseeable future, the study authors said. They added that their findings highlight the need for ongoing surveillance, mosquito control, promotion of personal protection from mosquito bites, and research into additional prevention strategies, including a WNV vaccine. "Research is currently being done to develop vaccines to protect humans against West Nile virus infection, but because the virus infects many wild birds and animals and has been detected in 62 different North American mosquito species, it makes development of an effective vaccination strategy very difficult, Stephen Higgs, a member of the American Society of Tropical Medicine and Hygiene (ASTMH), said in a society news release. |