First 2022 Delaware Evidence of Eastern Equine Encephalitis Detected in DNREC’s Sentinel Chickens

Public Urged to Take Precautionary Measures Until Colder Weather Arrives in The Fall

Eastern Equine Encephalitis (EEE), a mosquito-transmitted disease, has been detected in Delaware the first time for 2022 in a sentinel chicken, the Delaware Department of Natural Resources and Environmental Control announced today. Mosquito-transmitted virus detections in DNREC’s sentinel chickens are unrelated to Delaware’s poultry industry.

The EEE finding in northern New Castle County was from a sentinel chicken station sampled by the DNREC Division of Fish and Wildlife Mosquito Control section and confirmed by the Delaware Public Health Laboratory Aug. 9. While there have been no reported EEE cases in humans this year in the state, Delawareans are reminded that the possibility of contracting mosquito-transmitted diseases, including EEE and West Nile Virus (WNV), will continue until colder autumn temperatures in late-October or later.

The first EEE-positive sentinel chicken for this year adds to five WNV-positive sentinel chickens found earlier at three other sentinel chicken arbovirus monitoring stations in New Castle and Kent counties – with the first WNV finding occurring in early July. No EEE or WNV human cases have been reported to date in 2022 by the Delaware Public Health Laboratory, nor have any EEE or WNV equine cases been reported by the Delaware Department of Agriculture.

Blood samples are collected by the Mosquito Control section each week from early July into October from the state’s outdoor-caged sentinel chickens that are humanely housed and handled at 20 monitoring stations statewide. The blood samples are tested for EEE and WNV antibodies by the Delaware Public Health Laboratory. Sentinel chickens bitten by mosquitoes carrying EEE or WNV develop antibodies to these diseases but are otherwise unaffected. Mosquitoes can transmit both WNV and EEE to humans and horses.

The public is reminded to take common-sense precautions to avoid mosquito bites, including wearing long-sleeved shirts and long pants when outdoors in mosquito-prone areas, applying insect repellent containing 10 to 30% diethyltoluamide (DEET) in accordance with label instructions and avoiding mosquito-infested areas and at times of peak mosquito activity around dusk, dawn and at night.

Spraying to reduce mosquito populations in areas where EEE or WNV is detected may be initiated by DNREC’s Mosquito Control section as warranted, based on factors to include mosquito population levels and mosquito species present in affected areas. To reduce mosquito-breeding habitat and chances of disease transmission, residents should drain or remove outdoor items that collect water, such as discarded buckets or containers, uncovered trashcans, stagnant birdbaths, unprotected rain barrels or cisterns, old tires, upright wheelbarrows, flowerpot liners, depressions in boat tarps, clogged rain gutters, corrugated downspout extenders and unused swimming pools.

While EEE is rarer than WNV, both EEE and WNV can adversely affect people and horses. Most people who become infected with EEE virus and WNV show either no or mild symptoms. Early symptoms in people contracting EEE or WNV can be similar, but EEE often becomes more pronounced and debilitating, manifested by meningitis or encephalitis typically resulting in hospitalizations. EEE has a higher human mortality rate of approximately 30%, with infants, children and the elderly most vulnerable, according to the U.S. Centers for Disease Control and Prevention. Symptoms in people infected with EEE usually start from four to 10 days after being bitten by a mosquito infected with EEE. Early EEE symptoms can include headache, high fever, stiff neck, tremors or muscle weakness, with more severe cases progressing to stupor, disorientation, coma, convulsions, paralysis and possibly death. Most people infected with WNV do not develop symptoms, but about 20% can develop a mild illness, including fever, body and muscle aches, headache, nausea, vomiting, and rash symptoms. A small number of people infected with WNV can develop serious illness involving neurological problems, paralysis and possibly death. There are no human vaccines for EEE or WNV. Anyone developing the symptoms described above should see their healthcare provider.

Horse owners should contact their veterinarian immediately if they suspect their horse may be showing signs of WNV or EEE. Symptoms of EEE in horses include fever (102.5-104.5°F), loss of appetite, head pressing, depression or personality change, wobbling or staggering, weakness, blindness, convulsions, muscle tremors in the head and neck or hind-limb weakness. These signs are also consistent with WNV, although a fever may or may not be present with WNV.

Additional information about mosquitoes and mosquito-transmitted diseases is available from the following resources:

  • For mosquito biology/ecology and control, contact the 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 302-698-4500.
  • To report suspected cases of human EEE or WNV, call the Division of Public Health Office of Infectious Disease Epidemiology toll-free at 888-295-5156.
  • For more information on Eastern Equine Encephalitis or West Nile Virus, visit www.cdc.gov/ncidod/dvbid/westnile/index.htm.

About DNREC
The Delaware Department of Natural Resources and Environmental Control protects and manages the state’s natural resources, protects public health, provides outdoor recreational opportunities, and educates Delawareans about the environment. The DNREC Division of Fish and Wildlife conserves and manages Delaware’s fish and wildlife and their habitats, and provides fishing, hunting, wildlife viewing and boating access on nearly 68,000 acres of public land. For more information, visit the website and connect with @DelawareDNREC on Facebook, Twitter or LinkedIn.

Media contacts: Michael Globetti, michael.globetti@delaware.gov; Joanna Wilson, joanna.wilson@delaware.gov

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First 2022 Delaware Evidence of West Nile Virus Detected in DNREC’s Sentinel Chickens

No Human Cases of WNV Reported to Date in State; Department of Agriculture Urges Equine Owners to Vaccinate Animals

West Nile Virus (WNV) has been detected in Delaware the first time for 2022 in a sentinel chicken, the Delaware Department of Natural Resources and Environmental Control announced today. This initial finding was from a sentinel chicken station in southern New Castle County sampled by the DNREC Division of Fish and Wildlife Mosquito Control section and confirmed by the Delaware Public Health Laboratory on July 19. While there have been no reported WNV cases in humans this year in the state, Delawareans are reminded that the possibility of contracting mosquito-transmitted diseases, including WNV and Eastern Equine Encephalitis (EEE), will continue until colder autumn temperatures in mid-October or later.

Blood samples are collected by the Mosquito Control section each week from early July into October from the state’s outdoor-caged sentinel chickens that are humanely housed and handled at 20 monitoring stations statewide. The blood samples are tested for WNV and EEE antibodies by the Delaware Public Health Laboratory. Sentinel chickens bitten by mosquitoes carrying WNV or EEE develop antibodies to these diseases but are otherwise unaffected. Mosquitoes can transmit both WNV and EEE to humans and horses.

Most people infected with WNV do not develop symptoms, but about 20% can develop a mild illness, including fever, body and muscle aches, headache, nausea, vomiting, and rash symptoms. A small number of people can develop serious illness involving neurological problems, paralysis, and possibly death. EEE is not as prevalent as WNV but can present more severe symptoms in humans and horses.

The public is reminded to take common-sense precautions to avoid mosquito bites, including wearing long-sleeved shirts and long pants when outdoors in mosquito-prone areas, applying insect repellent containing 10 to 30% diethyltoluamide (DEET) in accordance with label instructions, and avoiding mosquito-infested areas and at times of peak mosquito activity around dusk, dawn and at night.

According to the Delaware Department of Agriculture (DDA), there were no equine cases of WNV or EEE in 2021. With the detection of WNV in a sentinel chicken this early in the season, the state veterinarian urges horse owners to contact their veterinarians as soon as possible to vaccinate horses and other equines against WNV and EEE. Both vaccines are highly effective in minimizing disease and may be the reason why Delaware had no equine cases in 2021. Horses that have been vaccinated in the past will need an annual booster shot. Neither disease has a specific drug treatment, and infections in horses are fatal in 70 to 90% of EEE cases and 30% of WNV cases.

Spraying to reduce mosquito populations in areas where WNV or EEE is detected may be initiated by the DNREC Mosquito Control section as warranted, based on factors to include mosquito population levels and mosquito species present in affected areas. To reduce mosquito-breeding habitat and chances of disease transmission, residents should drain or remove outdoor items that collect water, such as discarded buckets or containers, uncovered trashcans, stagnant birdbaths, unprotected rain barrels or cisterns, old tires, upright wheelbarrows, flowerpot liners, depressions in boat tarps, clogged rain gutters, corrugated downspout extenders, and unused swimming pools.

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 at dawn and dusk, peak hours for mosquito activity. Topical insect repellents labeled for use on horses may be applied. Wind generated by fans installed in horse stalls can also help deter mosquitoes. Water troughs or buckets should be emptied, cleaned, and refilled every 2-3 days to remove mosquito eggs or larvae.

More information about mosquitos and mosquito-borne diseases is available from the following resources:

  • For mosquito biology/ecology and control, contact the 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 302-698-4500.
  • To report suspected cases of human WNV, call the Division of Public Health Office of Infectious Disease Epidemiology toll-free at 888-295-5156.
  • For more information on West Nile virus or Eastern equine encephalitis, visit www.cdc.gov/ncidod/dvbid/westnile/index.htm.

About DNREC
The Delaware Department of Natural Resources and Environmental Control protects and manages the state’s natural resources, protects public health, provides outdoor recreational opportunities, and educates Delawareans about the environment. The DNREC Division of Fish and Wildlife conserves and manages Delaware’s fish and wildlife and their habitats, and provides fishing, hunting, wildlife viewing and boating access on nearly 68,000 acres of public land. For more information, visit the website and connect with @DelawareDNREC on Facebook, Twitter or LinkedIn.

Media Contacts:
DNREC: Michael Globetti, michael.globetti@delaware.gov; Nikki Lavoie, nikki.lavoie@delaware.gov
DDA: Stacey Hofmann, stacey.hofmann@delaware.gov

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DNREC Mosquito Control Section to Begin Spraying Woodland Pools

DNREC Mosquito Control Section will begin aerial spraying of woodland pools this week to limit the emergence of biting adult mosquitoes later in the spring. /DNREC photo

 

Spring Campaign Will Reduce Numbers of Year’s First Biting Mosquitoes

The Delaware Department of Natural Resources and Environmental Control will begin annual spraying of spring woodland pools to control aquatic immature (larval) mosquitoes on Wednesday, March 16, weather permitting. Spraying by DNREC’s Mosquito Control section will begin in southern Sussex County, then expand into Kent and New Castle counties over the next several weeks. Controlling early-season woodland pool larval mosquitoes limits the emergence of biting adult mosquitoes later in the spring.

Up to 10,000 acres of wet woodlands near select populated areas will be treated with a helicopter applying the bacteria-derived insecticide Bti. As with all insecticides used by the Mosquito Control section within the DNREC Division of Fish and Wildlife, Bti has been determined by the U.S. Environmental Protection Agency to pose no unreasonable risks to human health, wildlife or the environment when applied in accordance with product label instructions as required by federal law.

The spring woodland mosquito larvae spraying campaign marks the beginning of Delaware’s mosquito control season, which in most years continues until late October or early November. Control activities will be expanded starting in mid-April to larval and adult saltmarsh mosquitoes, other freshwater mosquitoes, and urban and suburban container-breeding mosquitoes to manage mosquito populations for improving the state’s quality of life and to protect public health.
Locations and times for scheduled mosquito spraying activity can be obtained by calling toll-free 800-338-8181. Mosquito spraying announcements can also be received by email, text or voicemail by subscribing to Mosquito Control’s Spray Zone Notification System at de.gov/mosquitospray.

To request local mosquito control service, please call the following Mosquito Control field offices

  • Glasgow Office, 302-836-2555, serving New Castle County and the northern half of Kent County, including Dover.
  • Milford Office, 302-422-1512, serving the southern half of Kent County south of Dover and all of Sussex County.
    For more information on mosquito control in Delaware, call the Mosquito Control Dover office at 302-739-9917.

About DNREC
The Delaware Department of Natural Resources and Environmental Control protects and manages the state’s natural resources, protects public health, provides outdoor recreational opportunities, and educates Delawareans about the environment. The DNREC Division of Fish and Wildlife conserves and manages Delaware’s fish and wildlife and their habitats, and provides fishing, hunting, wildlife viewing and boating access on nearly 68,000 acres of public land. For more information, visit the website and connect with @DelawareDNREC on Facebook, Twitter or LinkedIn.

Media Contacts: Michael Globetti, michael.globetti@delaware.gov; Nikki Lavoie, nikki.lavoie@delaware.gov

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Mosquito-transmitted Eastern Equine Encephalitis Detected in DNREC’s Sentinel Chickens

Public Urged to Take Precautionary Measures Until Colder Weather Arrives

Eastern Equine Encephalitis (EEE), a mosquito-transmitted disease, has been detected in Delaware for the first time in 2021, at a sentinel chicken station in southwestern Sussex County sampled Oct. 11 by the Delaware Department of Natural Resources and Environmental Control to monitor for certain mosquito-transmitted diseases. Twenty sentinel chicken stations are sampled weekly throughout the state each summer and fall to help track Eastern Equine Encephalitis (EEE) and West Nile virus (WNV), the primary mosquito-transmitted diseases that are human health threats in Delaware. Mosquito-transmitted virus detections in DNREC’s sentinel chickens are unrelated to Delaware’s poultry industry.

The first EEE finding in Delaware adds to an active year for WNV, which has been detected in 18 of DNREC’s 20 sentinel chicken stations involving a total of 74 WNV-positive chickens from late July to date. Two WNV-human cases have been reported to date in 2021 by the Delaware Public Health Laboratory, and one WNV-equine case has been reported by the Delaware Department of Agriculture. No EEE cases have been reported in humans or horses to date in 2021.

While EEE is rarer than WNV, both EEE and WNV can adversely affect people and horses. Early symptoms of contracting EEE or WNV can be similar, but EEE often becomes more pronounced and debilitating, manifested by meningitis or encephalitis typically resulting in hospitalizations. EEE has a higher human mortality rate of over 30%, with infants, children and the elderly most vulnerable, according to the U.S. Centers for Disease Control and Prevention. Symptoms of EEE usually start from 4 to 10 days after being bitten by a mosquito infected with EEE. Early EEE symptoms can include headache, high fever, stiff neck, tremors or muscle weakness, with more severe cases progressing to stupor, disorientation, coma, convulsions, paralysis and possibly death. There are no human vaccines for EEE or WNV.

About 80% of people infected with WNV do not show symptoms. About 20% of those infected with WNV develop mild symptoms such as fever, headache, body aches, a skin rash on the chest or back and swollen lymph glands. About one in 150 people infected with WNV might develop severe infection indicted by high fever, disorientation, tremors or convulsions, encephalitis or meningitis, all possibly leading to hospitalization and very rarely death. Survivors of severe cases of WNV can have long-lasting medical complications, including lingering paralysis.

Horse owners should contact their veterinarian immediately if they suspect their horse may be showing signs of WNV or EEE. Symptoms of EEE in horses include fever (102.5-104.5°F), loss of appetite, head pressing, depression or personality change, wobbling or staggering, weakness, blindness, convulsions, muscle tremors in the head and neck, and hind-limb weakness. These signs are also consistent with WNV, although a fever may or may not be present with WNV.

Fall is the peak time of year for mosquito-transmitted disease activity, which will continue until colder weather, possibly until early- to mid-November. While the recent EEE and WNV findings are not cause for alarm, Delaware residents and visitors are urged to be vigilant over the next few weeks to avoid or reduce exposures to mosquito bites. People should take precautions when outdoors in mosquito-prone areas, including wearing long-sleeved shirts and long pants, applying insect repellent containing 10 to 30% diethyl toluamide (DEET) or other EPA-approved insect repellents in accordance with label instructions and avoiding mosquito-infested areas and times of peak mosquito activity around dusk, dawn and at night.

To reduce mosquito-breeding habitat and mosquito populations and chances for disease transmission, DNREC’s Mosquito Control section recommends that property owners drain or remove outdoor items that collect water, such as discarded buckets or containers, uncovered trashcans, stagnant birdbaths, uncovered rain barrels or cisterns, old tires, upright wheelbarrows, flowerpot liners and saucers, depressions in boat tarps, clogged rain gutters, corrugated downspout extenders and unused swimming pools.

In response to EEE and WNV activity, DNREC’s Mosquito Control section has increased mosquito population surveillance efforts in the vicinity of virus-positive findings and initiated targeted mosquito control actions as warranted, based on the mosquito species and numbers encountered.

Additional information about mosquitoes and mosquito-transmitted diseases is available from the following resources:

  • For mosquito biology/ecology and control, contact the 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 302-698-4500.
  • To report suspected cases of human EEE or WNV, call the Division of Public Health Office of Infectious Disease Epidemiology toll-free at 888-295-5156.
  • For more information on Eastern Equine Encephalitis or West Nile Virus, visit www.cdc.gov/westnile/index.html.

About DNREC
The Delaware Department of Natural Resources and Environmental Control protects and manages the state’s natural resources, protects public health, provides outdoor recreational opportunities, and educates Delawareans about the environment. The DNREC Division of Fish and Wildlife conserves and manages Delaware’s fish and wildlife and their habitats, and provides fishing, hunting, wildlife viewing and boating access on nearly 68,000 acres of public land. For more information, visit the website and connect with @DelawareDNREC on Facebook, Twitter or LinkedIn.

Media Contacts: Michael Globetti, michael.globetti@delaware.gov; Nikki Lavoie, nikki.lavoie@delaware.gov

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Increased West Nile Virus Activity Occurring in Delaware

The Asian Tiger mosquito is among mosquito species that can transmit West Nile virus

 

Public Urged to Take Precautionary Measures from Biting Mosquitoes

An increase in mosquito-transmitted West Nile Virus (WNV) activity is occurring in many areas in Delaware as indicated in sentinel chickens used by the Delaware Department of Natural Resources and Environmental Control to monitor for certain mosquito-transmitted diseases. Twenty sentinel chicken stations are sampled weekly throughout the state each summer and fall to help track WNV and Eastern Equine Encephalitis (EEE), the primary mosquito-transmitted human health threats in Delaware. Mosquito-transmitted virus occurrences in these sentinel chickens are unrelated to Delaware’s poultry industry.

A statewide total of 40 sentinel chickens have tested positive for WNV to date, with over half of these findings, 25, having occurred in the last few weeks. WNV has been detected from a total of 10 sentinel chicken stations, involving 32 chickens in New Castle County from six stations, four chickens in Kent County from two stations, and four chickens in Sussex County from two stations. This typically higher initial gradient of WNV detection upstate is followed in most years with increased WNV occurrences downstate in mid-fall. EEE has not been found this year in the sentinel chickens.

There has been one WNV-human case to date in 2021, reported Sept. 3 by the Delaware Division of Public Health. No EEE human cases have been reported this year.

Staff from DNREC’s Division of Fish and Wildlife humanely care for DNREC’s sentinel chickens. Blood samples collected from sentinel chickens by the DNREC Mosquito Control section are tested for evidence of WNV and EEE by the Delaware Public Health Laboratory.

This is the peak time of year for mosquito-transmitted disease activity, which will continue well into October or beyond until the onset of colder weather. While these recent WNV findings are not cause for excessive alarm, Delaware residents and visitors are urged to be vigilant over the coming month and weeks to avoid or reduce exposures to mosquito bites. Common-sense precautions when outdoors in mosquito-prone areas include wearing long-sleeved shirts and long pants, applying insect repellent containing 10 to 30% diethyl toluamide (DEET) or other EPA-approved insect repellents in accordance with label instructions and avoiding mosquito-infested areas and times of peak mosquito activity around dusk, dawn and at night.

More measures can be taken by property owners to reduce mosquito-breeding habitat and mosquito populations and the chances for disease transmission. DNREC’s Mosquito Control section recommends draining or removing outdoor items that collect water, a lengthy list that includes discarded buckets or containers, uncovered trashcans, stagnant birdbaths, uncovered rain barrels or cisterns, old tires, upright wheelbarrows, flowerpot liners and saucers, depressions in boat tarps, clogged rain gutters, corrugated downspout extenders and unused swimming pools. All these items from the home landscape can become mosquito habitat very quickly and abet WNV activity.

Both WNV and EEE can adversely affect people and horses, and there are no human vaccines for WNV or EEE. About 80% of people infected with WNV show no symptoms, while about 20% of those infected will develop mild symptoms such as low fever, headache, body aches, a skin rash on chest or back and swollen lymph glands. Only about one in 150 people infected with WNV might develop severe infection indicted by high fever, disorientation, tremors or convulsions, encephalitis or meningitis, all possibly leading to hospitalization and very rarely death. Some survivors of severe cases of WNV can have long-lasting medical complications, including lingering paralysis. EEE can be a more severe disease than WNV, typically with more serious symptoms and a human fatality rate greater than 30%, though EEE is much rarer than WNV.

In response to WNV activity as has been recently detected or future EEE occurrences, the Mosquito Control section has increased mosquito population surveillance efforts in the vicinity of virus-positive findings and initiated targeted mosquito control actions as warranted, based on biting mosquito species and the numbers of them encountered.

Additional information about mosquitos and mosquito-borne diseases is available from the following resources:

  • For mosquito biology/ecology and control, contact the 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 302-698-4500.
  • To report suspected cases of human WNV, call the Division of Public Health Office of Infectious Disease Epidemiology toll-free at 888-295-5156.
  • For more information on West Nile Virus or Eastern Equine Encephalitis, visit www.cdc.gov/ncidod/dvbid/westnile/index.htm.

About DNREC
The Delaware Department of Natural Resources and Environmental Control protects and manages the state’s natural resources, protects public health, provides outdoor recreational opportunities, and educates Delawareans about the environment. The DNREC Division of Fish and Wildlife conserves and manages Delaware’s fish and wildlife and their habitats, and provides fishing, hunting, wildlife viewing and boating access on nearly 65,000 acres of public land. For more information, visit the website and connect with @DelawareDNREC on Facebook, Twitter or LinkedIn.

Media Contacts: Michael Globetti, michael.globetti@delaware.gov or Nikki Lavoie, nikki.lavoie@delaware.gov

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