In 1999, a deadly strain of West Nile virus struck parts of the northeastern United States. Caused by a virus from the family Flaviridae, genus Flavivirus, the disease was common in Africa and the Middle East. Today, it can be found across North America, Europe, and Asia. West Nile can cause serious illness, and in severe cases, lead to encephalitis, a swelling of the brain, which can be fatal. This revised edition of "West Nile Virus" contains new illustrations and up-to-date information, and takes a look at the origins of this disease, how it is transmitted, how it is treated, and what measures are being taken to combat it. Updates to this edition include expanded information on West Nile virus strains and genetic sequencing of the virus, as well as the latest outbreak statistics and a section discussing recent efforts to create a West Nile virus vaccine. Chapters of this title include: The West Nile Panic; A Virus Transmitted by Mosquitoes; How West Nile Virus Causes Disease; Diagnosis and Treatment of West Nile Virus; and Vaccines and Prevention.