U.S. experiencing worst outbreak of West Nile virus ever

A wet spring and a mild winter are two of the contributing factors to the worst outbreak of West Nile virus in the United States since the disease was first detected there in 1999, the CDC reports.

A total of 693 cases of the disease were reported as of August 14, including 28 deaths. The number of cases represents more infections with the virus than in any previous year. The first case was reported in Monmouth County, New Jersey, on July 24, the earliest date on record since the first known U.S. case in 1999, the Examiner reports.

The virus, which has been detected in 32 states thus far, is spread by infected mosquitoes but cannot spread via person to person contact.

The people most at risk for the severe form of the illness are people over the age of 50, the very young, people with diseases like HIV and people who take medicines to weaken the immune system. Additionally, people who spend significant time outside should protect themselves from mosquito bites, according to the Examiner.

The CDC grew its Division of Vector-Borne Diseases in the past few years to focus more on diseases transmitted by mosquitoes, fleas and ticks, including West Nile virus.