EHV-4 Reported in Chile for First Time

By María Paz Zúñiga Barrera, DVM, WEVA Board Member

Last October, equine herpesvirus-4 (EHV-4) was reported for the first time in Chile. The sentinel case was a yearling Thoroughbred filly living on a farm near the nation's capital, Santiago.

The filly had presented with signs of pneumonia, and Chilean Agricultural and Livestock Service (SAG) officials tested the filly for the reportable viruses in Chile, which include equine viral arteritis, equine influenza, and EHV-1 and -4. They confirmed the EHV-4 positive on a polymerase chain reaction (PCR) test.

This represents the first confirmed EHV-4 diagnosis in Chile. Officials consider this finding very important because of the possible economic impact on the country's racing industry. Due to these concerns SAG implemented increased surveillance with particular focus on differentiating between EHV strains.

As a result of the increased surveillance, authorities have also diagnosed three cases of EHV-1: two cases of rhinopneumonitis and one abortion. To date no cases of myeloencephalopathy have been reported in Chile. This might not necessarily mean the virus is not present in Chile, but rather that its signs are poorly recognized and regular testing is lacking.

Officials from SAG continue to expand testing for this and other infectious diseases. Authorities are working with practicing veterinarians and the industry to maintain high levels of awareness in terms of sanitation and potential diagnosis and reporting of affected horses.

Currently in Chile there is only one registered vaccine against EHV for abortion control. However, following the EHV-4 diagnosis SAG approved the use of a limited number of doses of a vaccine that included EHV-1 and 4.

The diagnosis of EHV-4 sets the stage for a new era of disease management in Chile.

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