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Eastern Equine Encephalitis Virus

Public Notice: Aerial mosquito spraying to occur in northern Indiana to reduce disease risk

The Indiana Department of Health will be conducting the aerial application of pesticide in portions of Elkhart, Kosciusko, LaGrange, LaPorte, Marshall and Noble counties next week to control Eastern equine encephalitis (EEE) virus in northern Indiana.

As of Sept. 18, one lab-confirmed human case has been reported in LaPorte County, and cases have been identified in two horses in LaGrange County, one horse in Kosciusko County and one horse in LaPorte County. The Indiana Board of Animal Health (BOAH) suspects EEE in three additional horses in LaGrange County.

Due to the detection of EEE activity in the area, health officials will perform targeted mosquito control utilizing aerial spraying to help protect residents from EEE. While rare, EEE virus can cause serious illness and has a fatality rate of about 33 percent in people.

Mosquito control professionals will apply an approved pesticide, Dibrom, as an ultra-low volume (ULV) spray. ULV sprayers dispense very fine aerosol droplets that stay suspended in the air and kill adult mosquitoes on contact. Dibrom has been registered by the U.S. Environmental Protection Agency (EPA) since 1959 for use in the United States. Dibrom immediately begins to break down upon release of the spray droplets in the open air and breaks down rapidly in water and in sunlight.

Health officials plan targeted mosquito control to help protect residents from EEE beginning Tuesday evening and continuing Wednesday if needed as weather permits. Residents should take actions to protect ornamental fish ponds and bee hives.

Protecting the public health is the primary goal of the decision. The spray area is centered around the area where human and equine cases have been detected. Mosquito spraying is not expected to pose a risk to humans.

People who wish to minimize exposure may choose to stay indoors for several hours, beginning at dusk on the treatment dates. People may also choose to bring animals indoors and cover their ornamental fishponds prior to the spraying. Evening application of Dibrom is not expected to be harmful to bees, but beekeepers may choose to cover their hives overnight and prevent bees from exiting during the application as a precaution.

While the spraying is expected to kill 90 percent of mosquitoes, residents in the area are urged to continue to take precautions until the first hard freeze, including:

  • Avoiding areas where mosquitoes breed
  • Staying indoors when mosquitoes are active
  • Utilizing an EPA-registered insect repellent
  • Wearing long-sleeved shirts and pants in areas of high mosquito activity

In addition, residents are urged to check their property for mosquito breeding sites and take the following actions: 

  • Empty containers that are holding water
  • Unclog gutters
  • Keep overgrown vegetation mowed
  • Dispose of old tires
  • Maintain screens in doorways and windows 
  • Swimming pools should be maintained clean and operational
  • Ornamental ponds should be aerated to prevent the collection of mosquito larvae.  .

.For more information about EEE, visit the CDC’s website at https://www.cdc.gov/easternequineencephalitis/index.html.

Flight areas:

Notificación pública: Se detectó encefalitis equina oriental (EEE por sus siglas en inglés) en la zona norte de Indiana

El Departamento de Salud de Indiana conducirá la aplicación aérea del pesticida en algunas partes de los condados de Elkhart, Kosciusko, LaGrange, LaPorte, Marshall y Noble la próxima semana con el fin de controlar el virus de la encefalitis equina oriental (EEE por sus siglas en inglés) en la zona norte de Indiana.

Los departamentos de salud de los condados de Elkhart, Kosciusko, LaGrange, LaPorte, Marshall y Noble; y el Departamento de Salud de Indiana han estado trabajando juntos para monitorear la actividad viral de la encefalitis equina oriental (EEE por sus siglas en inglés).  Hasta el 18 de septiembre, una prueba de laboratorio ha confirmado el reporte de un caso en un humano en el condado de LaPorte. Se han identificado también, casos en dos caballos en el condado de LaGrange, un caballo en el condado de Kosciusko y un caballo en el condado de LaPorte. La Junta Estatal de Sanidad Animal (BOAH por sus siglas en inglés) sospecha de la enfermedad EEE en tres caballos más en el condado de LaGrange.

Debido a la detección de actividad de EEE en el área, los oficiales de salud planean orientar el control del mosquito haciendo una fumigación aérea para proteger a los residentes de la enfermedad EEE. Aunque sea poco probable, el virus EEE puede causar serias enfermedades y tiene una tasa de fatalidad de alrededor de 33% en las personas.

Los profesionales en control de mosquitos aplicarán un pesticida aprobado, Dibrom, como aerosol de muy bajo volumen (ULV por sus siglas en inglés). Los aerosoles ULV (de muy bajo volumen) sueltan unas gotitas muy finas que quedan suspendidas en el aire y mata a los mosquitos adultos al hacer contacto con ellos.  Dibrom ha sido registrado por la Agencia de Protección del Ambiente de Estados Unidos (EPA por sus siglas en inglés) desde 1959 para su uso en los Estados Unidos.  Las gotas de aerosol Dibrom, una vez son expulsadas, comienzan a descomponerse inmediatamente sobre el aire y se descompone rápidamente en el agua y en la luz solar.

Los oficiales de salud planean tomar esta medida de control contra el mosquito para proteger a los residentes del EEE comenzando el atardecer del martes, continuando el miércoles en caso de ser necesario y si el clima lo permite. Los residentes deben tomar acciones para proteger los estanques piscícolas ornamentales y las colmenas de abejas.

Proteger la salud pública es el objetivo principal de esta decisión. El área donde se fumigará está centrada en las zonas donde los casos en humanos y equinos han sido detectados. Se espera que esta actividad no represente un riesgo para los humanos. Las personas que deseen reducir su exposición a la fumigación del mosquito pueden elegir permanecer dentro de sus casas por alrededor de una hora, al comenzar el atardecer del martes y miércoles.

Aunque se espera que la fumigación mate el 90% de los mosquitos, se les pide a los residentes que continúen tomando precauciones hasta que llegue la primera nevada, incluidas:

  • Evitar las áreas donde se reproducen los mosquitos
  • Permanecer dentro de sus casas cuando los mosquitos estén activos
  • Utilizar un repelente aprobado por la Agencia de Protección Ambiental (EPA por sus siglas en inglés)
  • Usar camisetas de manga larga y pantalones en las áreas donde hay alta actividad de mosquitos

Adicionalmente, se les pide a los residentes que revisen en sus propiedades los lugares donde haya reproducción de mosquitos y tomen las siguientes acciones:

  • Vacíe los recipientes que contengan agua
  • Limpie los canales de agua
  • Mantenga los lugares con abundante vegetación podados
  • Deshágase de llantas viejas
  • Mantenga rejillas en las entradas y en las ventanas
  • Las piscinas deben mantenerse limpias y en funcionamiento
  • Los estanques ornamentales deben estar aireados para prevenir la acumulación de la larva de mosquito

Para más información sobre EEE, visite la página web del Centro de Control y Prevención de Enfermedades (CDC por sus siglas en inglés) en el siguiente enlace: https://www.cdc.gov/easternequineencephalitis/index.html

General information

Eastern equine encephalitis virus (EEEV) is an arthropod-borne virus (arbovirus) that is primarily transmitted in Indiana by mosquitoes in the genus Coquillettidia. People infected with EEEV can develop severe inflammation in the brain. Only a few cases of EEEV disease are reported in the United States each year. Most occur in eastern or Gulf Coast states. To see current 2020 EEEV data for Indiana, please click here

On this page:

Transmission | Signs and Symptoms | Diagnosis | Treatment | Prevention | Maps and Statistics | Resources | Information for Providers

Eastern equine encephalitis virus. Centers for Disease Control and Prevention.


Transmission

EEEV can be transmitted in Indiana by mosquitoes in the genus Coquillettidia, but some members of the genus Aedes may also play a role in transmission to humans and animals. These mosquitoes become infected when they feed on infected wild birds. Infected mosquitoes can then spread EEEV to people, horses, and other mammals. Once infected, people and other mammals are “dead-end hosts,” which means that they do not pass the virus on to other biting mosquitoes.  

Signs and Symptoms

Signs and symptoms of EEEV disease usually appear within 4 – 10 days of a bite from an infected mosquito. EEEV infection can result in one of two types of illness, systemic or encephalitic (involving swelling of the brain). It is possible that some people who become infected with EEEV may not develop any symptoms.

Symptoms of systemic EEEV infection appear abruptly and include chills, fever, body aches, and joint pain. People with systemic EEEV infection are usually sick for 1 to 2 weeks and recover completely if the infection does not spread to the central nervous system. In some older children and adults, systemic EEEV infection can progress to encephalitis (inflammation of the brain). In infants, encephalitis can happen abruptly.

Approximately one third of all cases of encephalitis due to EEEV are fatal. Many people who recover will experience severe ongoing complications. People who are younger than 15 years and older than 50 years are at the greatest risk of severe disease if infected with EEE virus. 

Diagnosis

Diagnosis of EEEV disease is based on the patient’s signs and symptoms and appropriate laboratory testing. If you think you have EEEV disease, contact your healthcare provider.

Treatment

No specific medication is available to treat EEEV disease. People with severe illness usually require hospitalization, supportive care, and/or rehabilitation.

Prevention

The best way to prevent EEEV disease is to avoid mosquito bites. See our mosquito prevention page for more information. 

For more information about Eastern Equine encephalitis virus, visit the CDC EEEV webpage.

Maps and Statistics

This map shows current Indiana EEEV activity as of September 23, 2020. For maps showing recent infections of other arboviral diseases in people, horses, and mosquitoes, click here.

While equine cases are occasionally detected, human EEEV disease is rare in Indiana. One case was reported in 2019. For more information, please visit:

National statistics for EEEV disease can be found at the CDC EEEV Statistics and Maps webpage.

Resources

EEEV Quick Facts

Information for Providers

For EEEV disease diagnosis, treatment, and testing information, click here.

 

Page Last Updated: September 23, 2020

Page Last Reviewed: July 22, 2019