Outbreak Alert: February 16, 2022 – Equine Herpesvirus Myeloencephalopathy, Equine Herpesvirus-Neurologic in San Mateo County, CA

Source: California Department of Food and Agriculture

Number Confirmed: 18;

Number Suspected: 5;

Number Exposed: 300;

Facility Type: Boarding Facility;

Gender: Gelding; Onset of Clinical Signs: 2/10/2022;
Clinical Signs: Fever; Confirmation Date: 2/15/2022; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;

Gender: Gelding; Onset of Clinical Signs: 2/10/2022;
Clinical Signs: Fever; Confirmation Date: 2/15/2022; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;

Gender: Gelding; Onset of Clinical Signs: 2/10/2022;
Clinical Signs: Fever; Confirmation Date: 2/15/2022; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;
Age: 4; Gender: Gelding; Breed: Thoroughbred (TB); Onset of Clinical Signs: 2/12/2022;

Clinical Signs: Fever; Confirmation Date: 2/15/2022; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;

Notes: Update 2/16/22: Previous Alert IDs: 2405, 2406, 2408, 2410, 2415: Four (4) additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on February 15th, and have been isolated at the index premises. To date, two (2) EHM cases (EHV-1 positive with neurologic signs) and sixteen (16) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.;