DPH Announces Third Human Case of West Nile Virus for 2021

DOVER (Nov. 2, 2021) – The Division of Public Health (DPH) announced today that an 87-year-old Kent County woman has become infected with West Nile Virus (WNV), making it the state’s third case of human WNV in 2021. The woman indicated no travel history that could have led to transmission, meaning she contracted WNV in Delaware. To protect the patient’s privacy, DPH will not provide additional information on this case.

WNV is a mosquito-borne illness that can cause serious health problems. WNV 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 WNV 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 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.

The mosquitoes that cause WNV bite primarily from dusk (evening) to dawn (morning). However, other mosquitoes that cause diseases such as chikungunya, dengue fever, and Zika can bite during the day. It is important to protect yourself by wearing insect repellent whenever you go outdoors. It’s also recommended to wear light-colored, long-sleeved shirts and pants to protect your limbs from insect bites.

In addition to the three human WNV cases, there has been one confirmed case of West Nile Virus (WNV) in a Kent County horse.  West Nile Virus and Eastern Equine Encephalitis (EEE) are diseases transmitted to horses via the bites of mosquitoes. Humans can also be infected with WNV and EEE, but transmission requires a mosquito bite, and the virus cannot be directly transmitted between horses, or between horses and people. Signs of infection in horses include fever (although not always with WNV), anorexia, head pressing, depression or personality change, wobbling or staggering, weakness, blindness, convulsions, muscle spasms in the head and neck, or hind-limb weakness. If owners notice any of these signs in their horses, they should contact their veterinarian immediately.

Horse owners can take several additional steps in the barn and around the farm to help protect horses from mosquito bites. Horses should be kept inside during dawn and dusk, which are peak hours for mosquito activity. Topical insect repellents labeled for use on horses may be applied. The wind generated by fans installed in horse stalls can also help deter mosquitoes. Old tires and containers should be disposed of, and standing water eliminated. Water troughs or buckets should be emptied, cleaned, and refilled every 2-3 days if possible to remove any mosquito eggs or larvae.

Mosquito Bite Prevention: To avoid mosquito bites and reduce the risk of infection, individuals should:

  • Use Environmental Protection Agency (EPA)-registered insect repellents. Follow the manufacturer’s instructions for reapplication times.
  • If using sunscreen, apply it first and insect repellent second.
  • Adults: Spray insect repellent onto your hands and then apply it to the child’s face. Do not apply insect repellent onto a child’s hands, eyes, mouth, or on cut or irritated skin.
  • Do not use insect repellent on babies younger than 2 months of age.
  • When outside, wear shoes, light-colored long-sleeved shirts and pants. Dress your child in clothing that covers arms and legs. Mosquito netting can protect one’s face and neck, and infants in carriages, strollers and playpens.
  • Use permethrin (an insecticide) to treat clothing and gear (such as boots, pants, socks, and tents), but do not apply to skin.
  • Prevent mosquitoes from entering the house by using screens and keeping windows and doorways tightly sealed.

The Department of Natural Resources and Environmental Control’s (DNREC) Mosquito Control section announced WNV had been found in sentinel chickens for the first time this year in July. Delawareans are reminded that the possibility of contracting mosquito-transmitted diseases, including WNV and EEE, will continue until colder weather sets in, which this year could be as late as mid-November. Until that time, in response to findings of WNV or EEE in humans or horses by the Division of Public Health and Delaware Department of Agriculture, respectively, DNREC’s Mosquito Control section typically increases its mosquito population surveillance efforts in the vicinity of the virus findings, and then, depending on types and numbers of mosquitoes encountered, takes appropriate mosquito control measures as warranted. To report suspected cases of human WNV, call the DPH Office of Infectious Disease Epidemiology at 1-888-295-5156.

For more information about mosquitoes and mosquito-borne illnesses, use the following resources:

For mosquito biology/ecology and control, contact the DNREC Mosquito Control section office in Dover at 302-739-9917.

For requests for mosquito relief in upstate areas from Dover north, contact Mosquito Control’s Glasgow field office at 302-836-2555.

For requests for mosquito relief in downstate areas south of Dover, contact Mosquito Control’s Milford field office at 302-422-1512.

For animal health questions, contact the Delaware Department of Agriculture’s Poultry and Animal Health Section at 302-698-4561.

To report suspected cases of human WNV, call the Division of Public Health Office of Infectious Disease Epidemiology toll-free at 1-888-295-5156.

For more information on West Nile virus or Eastern equine encephalitis, visit www.cdc.gov/ncidod/dvbid/westnile/index.htm.

For more information on what you can do to prevent West Nile Virus, visit the Centers For Disease Control and Prevention’s website, www.cdc.gov/westnile/prevention/index.html.

###

Anyone who is deaf, hard of hearing, Deaf-Blind or speech disabled can contact DPH by dialing 711 first using specialized devices (i.e. TTY, TeleBraille, voice devices).  The 711 service is free and to learn more about how it works, please visit http://delawarerelay.com.

The Department of Health and Social Services is committed to improving the quality of the lives of Delaware’s citizens by promoting health and well-being, fostering self-sufficiency, and protecting vulnerable populations. DPH, a division of DHSS, urges Delawareans to make healthier choices with the 5-2-1 Almost None campaign: eat 5 or more fruits and vegetables each day, have no more than 2 hours of recreational screen time each day (includes TV, computer, gaming), get 1 or more hours of physical activity each day, and drink almost no sugary beverages.


DPH Announces Second Human Case of West Nile Virus and First Case Detected in a Horse for 2021

DOVER (Oct. 8, 2021) – The Division of Public Health (DPH) announced today that a 79-year-old Sussex County woman has become infected with West Nile Virus (WNV), the state’s second case of human WNV in 2021. An epidemiological investigation is currently ongoing to confirm any travel history or sources that could have led to transmission. To protect the patient’s privacy, no more information will be provided on the individual at this time.

“As mosquito season continues through the fall months, it is important for everyone to take proper precautions when going outdoors in an environment where mosquitoes are prevalent,” said DPH Director Dr. Karyl Rattay. “Wearing insect repellent and wearing light-colored, long-sleeved shirts and pants are easy measures to take that can protect against this serious and sometimes deadly virus.”

The mosquitoes that cause WNV bite primarily from dusk (evening) to dawn (morning). However, other mosquitoes that cause diseases such as chikungunya, dengue fever, and Zika can bite during the day. It is important to protect yourself by wearing insect repellent whenever you go outdoors.

WNV is a mosquito-borne illness that can cause serious health problems. WNV 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 WNV 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 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.

In addition, the Office of the State Veterinarian has announced a confirmed case of West Nile Virus (WNV) in a horse. The infected horse was a 3-year-old Standardbred gelding residing in Kent County. The horse began showing signs of weakness in the hind limbs, with fever and respiratory signs on Oct. 1. The gelding lost the ability to stand and was therefore euthanized on Oct. 5. Samples were submitted to the Delaware Public Health Laboratory on Oct. 6, which confirmed the diagnosis of WNV on Oct. 7. The affected horse was not currently vaccinated against WNV.

West Nile Virus and Eastern Equine Encephalitis (EEE) are diseases transmitted to horses via the bites of mosquitoes. Humans can also be infected with WNV and EEE, but transmission requires a mosquito bite, and the virus cannot be directly transmitted between horses, or between horses and people. Signs of infection in horses include fever (although not always with WNV), anorexia, head pressing, depression or personality change, wobbling or staggering, weakness, blindness, convulsions, muscle spasms in the head and neck, or hind-limb weakness. If owners notice any of these signs in their horses, they should contact their veterinarian immediately.

“It is essential that owners of horses and other equines work with their veterinarian to set up a routine vaccination protocol to help prevent West Nile Virus and Eastern Equine Encephalitis,” said Dr. Karen Lopez, Deputy State Veterinarian. “Unfortunately, neither disease has a specific drug treatment. Eastern Equine Encephalitis infections are fatal in 70 to 90 percent of the cases, and West Nile Virus is fatal in 30 percent of the horses that contract it.”

Horse owners can take several additional steps in the barn and around the farm to help protect horses from mosquito bites. Horses should be kept inside during dawn and dusk, which are peak hours for mosquito activity. Topical insect repellents labeled for use on horses may be applied. The wind generated by fans installed in horse stalls can also help deter mosquitoes. Old tires and containers should be disposed of, and standing water eliminated. Water troughs or buckets should be emptied, cleaned, and refilled every 2-3 days if possible to remove any mosquito eggs or larvae.

Mosquito Bite Prevention: To avoid mosquito bites and reduce the risk of infection, individuals should:

  • Use Environmental Protection Agency (EPA)-registered insect repellents. Follow the manufacturer’s instructions for reapplication times.
  • If using sunscreen, apply it first and insect repellent second.
  • Adults: Spray insect repellent onto your hands and then apply it to the child’s face. Do not apply insect repellent onto a child’s hands, eyes, mouth, or on cut or irritated skin.
  • Do not use insect repellent on babies younger than 2 months of age.
  • When outside, wear shoes, light-colored long-sleeved shirts and pants. Dress your child in clothing that covers arms and legs. Mosquito netting can protect one’s face and neck, and infants in carriages, strollers and playpens.
  • Use permethrin (an insecticide) to treat clothing and gear (such as boots, pants, socks, and tents), but do not apply to skin.
  • Prevent mosquitoes from entering the house by using screens and keeping windows and doorways tightly sealed.

The Department of Natural Resources and Environmental Control’s (DNREC) Mosquito Control section announced WNV in sentinel chickens for the first time this year in July. Delawareans are reminded that the possibility of contracting mosquito-transmitted diseases, including WNV and EEE, will continue until colder autumn temperatures in mid-October or later. Until that time, in response to findings of WNV or EEE in humans or horses by the Division of Public Health and Delaware Department of Agriculture, respectively, DNREC’s Mosquito Control Section typically increases its mosquito population surveillance efforts in the vicinity of the virus findings, and then, depending on types and numbers of mosquitoes encountered, takes appropriate mosquito control measures as warranted. To report suspected cases of human WNV, call the DPH Office of Infectious Disease Epidemiology at 1-888-295-5156.

For more information about mosquitoes and mosquito-borne illnesses, use the following resources:

  • For mosquito biology/ecology and control, contact the DNREC Mosquito Control section office in Dover at 302-739-9917.
  • For requests for mosquito relief in upstate areas from Dover north, contact Mosquito Control’s Glasgow field office at 302-836-2555.
  • For requests for mosquito relief in downstate areas south of Dover, contact Mosquito Control’s Milford field office at 302-422-1512.
  • For animal health questions, contact the Delaware Department of Agriculture’s Poultry and Animal Health Section at 302-698-4561.
  • To report suspected cases of human WNV, call the Division of Public Health Office of Infectious Disease Epidemiology toll-free at 1-888-295-5156.
  • For more information on West Nile virus or Eastern equine encephalitis, visit www.cdc.gov/ncidod/dvbid/westnile/index.htm.

For more information on what you can do to prevent West Nile Virus, visit the Centers For Disease Control and Prevention’s website, www.cdc.gov/westnile/prevention/index.html.


DNREC’s Mosquito Control Section announces expanded detection of Eastern Equine Encephalitis

Continued awareness and precautions encouraged

The logo for the Department of Natural Resources and Environmental ControlDOVER (Sept. 20, 2018) – The recent detection of Eastern Equine Encephalitis (EEE) in sentinel chickens monitored for mosquito-borne diseases by the DNREC Division of Fish & Wildlife’s Mosquito Control Section reinforces the fact that mosquitoes remain active and that precautions should continue to be taken to avoid mosquitoes whose bites could transmit EEE and other mosquito-borne diseases.

Test results reported to the Mosquito Control Section last week by the Delaware Division of Public Health Laboratory indicated EEE-positive chickens from three additional stations of the 20 stations monitored by the Mosquito Control Section throughout the state. Two of these positive stations were in New Castle County and one in Sussex County, increasing the total number of EEE-positive sentinel chicken stations this year to six: three in New Castle County and three in Sussex County. This higher-than-average detection rate for EEE suggests increased EEE activity and distribution in Delaware.

Eastern Equine Encephalitis is a rare, but potentially fatal, viral disease spread by mosquitoes, and is considered one of the more serious mosquito-borne illnesses. Although there is an EEE vaccine for horses, an EEE vaccine is not available for people. No human cases of EEE have been reported to date this year in Delaware.

Anyone in an area where the virus is circulating can be infected with EEE. The risk is highest for people exposed to high numbers of mosquito bites, including people who live in, visit, or work outside in areas with high mosquito populations where there is greater exposure to potentially infected mosquitoes. Those over age 50 and under age 15 appear to be at greatest risk for developing severe disease when infected with EEE.

While most patients infected with EEE have no apparent illness, severe cases of EEE (involving encephalitis, an inflammation of the brain) begin with the sudden onset of headache, high fever, chills, and vomiting. The illness may then progress into disorientation, seizures, or coma. Symptoms of EEE often appear four to 10 days after being bitten by an infected mosquito. Approximately 33 percent of EEE cases lead to death, and many of those who do survive experience significant brain damage. There is no specific treatment for EEE; care is based on symptoms. If you think you or a family member may have contracted EEE, it is important to consult your health care provider for proper diagnosis.

In response to DNREC’s recent EEE detections, along with ongoing West Nile virus activity, the Mosquito Control Section will increase mosquito population surveillance in areas where these detections have occurred and take mosquito control actions as warranted to include possible aerial spraying and/or fogging with a spray truck. However, the best protection to lessen the chance of contracting a mosquito-borne disease is to avoid mosquito bites by:

  • Properly using insect repellent containing DEET whenever outdoors;
  • Covering up exposed skin as much as possible by wearing long-sleeved shirts and pants; and
  • Avoiding known high mosquito population areas or being outside during times of peak mosquito activity, typically dawn and dusk.

In addition to avoiding mosquito bites, the Mosquito Control Section advises residents to also reduce mosquito breeding habitat on their individual properties and communities/neighborhoods by draining or removing items that collect water, such as discarded buckets or containers, uncovered trash cans, stagnant birdbaths, unprotected rain barrels or cisterns, old tires, upright wheelbarrows, flower pot liners, depressions in tarps covering boats, clogged rain gutters, corrugated downspout extenders and unused swimming pools.

The Mosquito Control Section also encourages residents to report intolerable numbers of biting mosquitoes by calling the numbers below between 8 a.m. and 4 p.m. Monday through Friday. Callers after business hours or during weekends or holidays should leave their name, phone number, address and a brief message.

  • Glasgow Office, serving New Castle County and northern Kent County including the Dover area: 302-836-2555
  • Milford Office, serving Sussex and southern Kent counties: 302-422-1512

For more information about:

  • Mosquito biology/ecology and control – Contact the Mosquito Control Section’s Dover office at 302-739-9917.
  • Reporting WNV-suspect wild birds, or for requests for mosquito relief – For upstate areas from Dover north, contact Mosquito Control’s Glasgow field office at 302-836-2555; for downstate areas south of Dover, contact Mosquito Control’s Milford field office at 302-422-1512.
  • WNV or EEE in humans and related medical issues – Contact the Delaware Division of Public Health at 888-295-5156.
  • Animal health questions should be directed to the Delaware Department of Agriculture at 800-282-8685 (Delaware only) or 302-698-4500. Ask for the Poultry and Animal Health Section.
  • For more information on West Nile Virus or Eastern equine encephalitis – Visit the CDC website, www.cdc.gov/ncidod/dvbid/westnile/index.htm.

Contact: Joanna Wilson, DNREC Public Affairs Office, 302-739-9902

Vol. 48, No. 253