New Jersey Department of Agriculture MEMO: First EEE Positive Horse Cases in New Jersey in 2020

A 4-year-old mare in Atlantic County is the first reported case of Eastern Equine Encephalitis (EEE) in New Jersey in 2020. The unvaccinated mare and was humanely euthanized on September 8 due to the severity of the disease. There has been no reported animal West Nile Virus (WNV) cases this season in New Jersey.

In 2019, EEE was diagnosed in 11 horses, one alpaca, and one deer in New Jersey. In horses, EEE causes inflammation of the brain tissue with a significantly higher risk of death than infection with the West Nile Virus. A mosquito bite transmits the disease with the virus circulating between birds and mosquitoes. Humans, horses, and other mammals are “dead-end” hosts as they do not develop high levels of virus in their bloodstream and cannot pass the virus on to other biting mosquitoes.

Effective vaccines for EEE are available commercially. The vaccination schedule and timing of administration play a role in the individual susceptibility of clinical disease in each horse. Horse owners should contact their veterinarians if their animals are not up-to-date on their vaccinations against EEE and other preventable diseases.

For more information about EEE and WNV in horses, visit the New Jersey Department of Agriculture web site at:

EEE, like other viral diseases affecting horses’ neurological systems, must be reported to the state veterinarian within 48 hours, and a neurologic disease worksheet must be completed for each case reported. The worksheet is available at the following website and, once completed, can be faxed to the Division.

The NJDA – Animal Health Diagnostic Laboratory (AHDL) offers diagnostic tests for EEE, WNV, and EHV-1. The EEE and WNV tests on NJ horses are offered free of charge (tests sponsored by the State Mosquito Control Commission).

EEE ELISA (no charge)
1 ml serum, w/cold pack
PCR (no charge)
1 ml whole blood PTT*/CSF**/brain tissue
2-3 days
WNV PCR (no charge)
Whole blood PTT */CSF**/brain tissue
ELISA (no charge)
1 ml serum, w/cold pack
2-3 days
EHV-1 Neurologic PCR ($50.00)
Whole blood PTT/Nasal swab, brain tissue
EHV-1 SN titer ($15.00)
1 ml serum, w/cold pack
2-4 days

*PTT-purple top tube **spinal fluid

Contact Dr. Amar Patil (609) 406-6999 or via email at

Division of Animal Health
Phone: (609) 671-6400
Fax: (609) 671-6413
Animal Health Diagnostic Laboratory
Phone: (609) 406-6999
Fax: (609) 671-6414


Mail laboratory specimen(s) and laboratory submission form to:

(If sent via courier service):NJ Department of Agriculture
Animal Health Diagnostic Laboratory
NJPHEAL, 3 Schwarzkopf Drive
Ewing, NJ 08628
(If sent via U.S. Postal Service):NJ Department of Agriculture
Animal Health Diagnostic Laboratory
P.O. Box 330
Trenton, NJ 08625