A 70-year-old Kent County woman was briefly hospitalized with West Nile virus (WNV) and is now recovering at home. The case is the first lab-confirmed human WNV case reported in 2017. There were no cases in 2016. The mosquito-borne illness can become serious and the Division of Public Health (DPH) reminds people to take precautions to avoid mosquito bites.


The Department of Natural Resources and Environmental Control (DNREC) recently announced the continued presence of West Nile virus in sentinel chickens monitored for mosquito-borne diseases. Mosquitoes remain very active, especially during the unseasonably warm weather the state is now experiencing.

“This new case is a reminder that West Nile virus is still active in Delaware,” said DPH Director Dr. Karyl Rattay. “It is just as important during these unseasonably warm fall months as it was in the summer to protect yourself and your loved ones from mosquito bites. These bites can cause much more serious health problems than just itching and discomfort.”

WNV is transmitted by mosquitoes, generally in summer and fall, with a peak period for disease transmissions from mid-August to mid-October. Although nearly 80 percent of people infected with WNV will not become ill, and only a little less than 20 percent of those infected will develop West Nile fever, with mild symptoms (fever, headache, body aches, a skin rash on the chest or back and swollen lymph glands), one in 150 people infected will develop severe infection (West Nile encephalitis or meningitis).

Symptoms of severe WNV infection include headache, high fever, stiff neck, and/or tremors and muscle weakness. The elderly and those with weakened immune systems are most at risk. Anyone who experiences any of these severe symptoms should seek medical help immediately. Symptoms may progress to stupor, disorientation, coma, convulsions, paralysis, and possibly death.

As of October 10, 2017, a total of 47 states and the District of Columbia have reported West Nile virus infections in people, birds, or mosquitoes in 2017. Overall, 1,295 cases of West Nile virus disease in people have been reported to CDC. Of these, 840 (65%) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 455 (35%) were classified as non-neuroinvasive disease.