The four cases were reported in August and were discovered as part of routine blood tests related to medical procedures, the Division of Public Health said. None of those infected reported any symptoms related to the virus.
Fewer than 20 percent of those infected will develop West Nile fever, with mild symptoms including 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 division said, and anyone with these should seek immediate medical care. Symptoms may progress to stupor, disorientation, coma, convulsions, paralysis and possibly death.
The infections generally happen from spring to fall. The elderly and those with weak 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 and paralysis.
“West Nile Virus may not cause symptoms in most people, but in others it can cause a serious illness or even be fatal,” said Dr. Karyl Rattay, Division of Public Health director. “It’s easy to forget that something as simple as a mosquito bite can make someone very sick.”
The division offered these tips to avoid mosquito bites and reduce the risk of infection:
• When outside, wear shoes, long-sleeved shirts, and pants. Mosquito netting can protect the face and neck, and infants in carriages, strollers, and playpens. Mosquitoes are most active at dusk and during the early morning hours.
• Mosquito repellents containing DEET can be applied to the skin, but will last only a few hours before reapplication is necessary. Use insect repellent containing less than 50 percent DEET for adults. The current American Academy of Pediatrics and Centers for Disease Control and Prevention recommend using 10 percent to 30 percent DEET for children older than 2 months old. The higher the strength, the longer the DEET provides protection which varies from two to five hours.
• Read labels carefully and always follow the instructions. DEET should not be used on children younger than 2 months.
• Prevent mosquitoes from entering the house by using screens and keeping windows and doorways tightly sealed. Mosquitoes prefer shallow water and tall vegetation. Eliminate standing water in your yard by changing birdbath water weekly, regularly draining pet dishes and plant pot saucers, and checking gutters, pool covers, and tarps for standing water. Store buckets, wheelbarrows, and wading pools upside down. Keep grass mowed.
In Delaware, there were no reported human West Nile virus cases in 2014, three cases in 2013, and nine cases in 2012 with one fatality.
To report suspected cases, call the division’s Office of Infectious Disease Epidemiology at 888-295-5156.
To report high numbers of biting mosquitoes or other concerns, contact the Department of Natural Resources and Environmental Control Mosquito Control Section field offices:
• Glasgow Office – 302-836-2555, for all of New Castle County and the northern half of Kent County, including Dover.
• Milford Office – 302-422-1512, for Kent County south of Dover, and for all of Sussex County.
Calls will be answered by staff from Monday through Friday between 8 a.m. and 4 p.m. Callers after business hours or during weekends or holidays should leave a message giving their name, phone number, address and a brief description of their need or problem.