The Delaware Division of Public Health announced that West Nile virus is confirmed in a 73-year-old New Castle County man, who was hospitalized since late August.

This is the third case of West Nile confirmed in humans in the last month. The first case involved a 60-year-old Sussex County man, and the second a 68-year-old New Castle County man. Additionally, DPH is awaiting results from the Centers for Disease Control and Prevention in a fourth potential case of the disease. The Delaware Department of Agriculture recently announced two cases of West Nile in horses.

“We are extremely concerned about this situation and are urging people to use insect repellent whenever you go out,” said DPH Director Karyl Rattay. “Peak transmission period for West Nile Virus lasts for another six weeks. With people spending more time outside as the temperatures begin to cool down, and for after-school sports, it is vitally important that everyone take this basic step to protect themselves.”

While the mosquitoes that cause West Nile bite primarily from dusk to dawn, other mosquitoes that cause diseases such as chikungunya, dengue fever and Zika, can bite during the day. The CDC now recommends wearing insect repellent whenever you go out.

West Nile is a mosquito-borne illness that can cause serious health problems. West Nile is transmitted by mosquitoes, generally in summer and fall, with a peak period for disease transmissions from mid-August to mid-October. Nearly 80 percent of people infected with West Nile will not become ill. While only a little less than 20 percent of those infected with the virus 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 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.

The Delaware Department of Natural Resources and Environmental Control Mosquito Control Section has seen an increase of West Nile found in wild birds and sentinel chickens this year throughout the state. To assist the state’s mosquito control efforts and to reduce mosquito-breeding habitat for mosquitoes that can transmit West Nile, DNREC urges homeowners to practice good water sanitation on their property by eliminating standing water, particularly as might be collected in buckets, containers, uncovered trash cans, stagnant bird baths, old tires and unused swimming pools.

For more, visit cdc.gov/westnile/prevention/index.html.