Epidemiology and Public Health

The West Nile Virus was first discovered in the West Nile province of Uganda in 1937. Throughout the 20th century, it emerged as a serious cause of disease as a result of widespread epidemics in Europe and the Middle East. It did not reach the level of pandemic threat, however, until 1999, when the first case of West Nile encephalitis was confirmed in New York City. Within a year, it spread to New Jersey, Connecticut, and other areas of New York, and is now present in almost every state (1).

Figure 4.1: The spread of West Nile Virus infection across the United States from 1999 to 2004 (1). 

Figure 4.2: Disease is endemic or potentially endemic in 83 countries. As shown here, it is most common in the United States (9).

The numbers of people infected continue to rise faster than predicted. This video, aired on CNN in 2012, discusses the dramatic rise in cases in the United States: http://www.cnn.com/2012/08/22/health/west-nile-virus/