TY - JOUR

T1 - Clinical impact, diagnosis and control of Equine Herpesvirus-1 infection in Europe

AU - European Food Safety Authority (EFSA), null

AU - Carvelli, Andrea

AU - Nielsen, Søren Saxmose

AU - Paillot, Romain

AU - Broglia, Alessandro

AU - Kohnle, Lisa

N1 - https://doi.org/10.2903/j.efsa.2022.7230

PY - 2022

Y1 - 2022

N2 - Abstract Equine herpesvirus-1 (EHV-1) can affect the entire equine sector in EU, and the large outbreak reported in 2021 in Spain drew attention to the needs of the European Commission for scientific advice for the assessment of EHV-1 infection within the framework of Animal Health Law. EHV-1 is considered endemic in the EU; its main risk is linked to the characteristic of producing latent life-long infections. These can reactivate producing clinical disease, which can include respiratory, abortive and possibly fatal neurological forms. From the epidemiological and genomic viewpoint, there are no specific neuropathogenic EHV-1 strains; the respiratory, reproductive and neurological signs are not found to be strain-specific. This was also the case of the virus that caused the outbreak in Valencia (Spain) in 2021, which was genetically closely related to other viruses circulating before in Europe, and did not present the so-called neuropathogenic genotype. The outbreak reported in Valencia was followed by wide geographic spread of the virus possibly due to a delay in diagnosis and late application of biosecurity measures. The recommended and most sensitive diagnostic test for detecting EHV-1 is PCR performed on swabs collected according to the type of clinical signs. Serological assays on paired blood samples can help to detect a recent infection, while no diagnostic methods are available to detect EHV-1 latent infections. Safe movements of horses can be ensured at premovement phase by testing and issuing health certificates, and by isolating animals upon arrival at new premises with regular health monitoring. In case of suspicion, movements should be forbidden and EHV-1 infection early detected/confirmed by validated diagnostic tools. During outbreaks, no movements should be allowed until 21?days after the detection of the last case. In general, vaccination against EHV-1 should be promoted, although this offers limited protection against the neurological form of the disease.

AB - Abstract Equine herpesvirus-1 (EHV-1) can affect the entire equine sector in EU, and the large outbreak reported in 2021 in Spain drew attention to the needs of the European Commission for scientific advice for the assessment of EHV-1 infection within the framework of Animal Health Law. EHV-1 is considered endemic in the EU; its main risk is linked to the characteristic of producing latent life-long infections. These can reactivate producing clinical disease, which can include respiratory, abortive and possibly fatal neurological forms. From the epidemiological and genomic viewpoint, there are no specific neuropathogenic EHV-1 strains; the respiratory, reproductive and neurological signs are not found to be strain-specific. This was also the case of the virus that caused the outbreak in Valencia (Spain) in 2021, which was genetically closely related to other viruses circulating before in Europe, and did not present the so-called neuropathogenic genotype. The outbreak reported in Valencia was followed by wide geographic spread of the virus possibly due to a delay in diagnosis and late application of biosecurity measures. The recommended and most sensitive diagnostic test for detecting EHV-1 is PCR performed on swabs collected according to the type of clinical signs. Serological assays on paired blood samples can help to detect a recent infection, while no diagnostic methods are available to detect EHV-1 latent infections. Safe movements of horses can be ensured at premovement phase by testing and issuing health certificates, and by isolating animals upon arrival at new premises with regular health monitoring. In case of suspicion, movements should be forbidden and EHV-1 infection early detected/confirmed by validated diagnostic tools. During outbreaks, no movements should be allowed until 21?days after the detection of the last case. In general, vaccination against EHV-1 should be promoted, although this offers limited protection against the neurological form of the disease.

KW - Equine herpesvirus-1 infection

KW - horse

KW - Equidae

KW - latent infection

KW - PCR

KW - diagnosis

KW - risk mitigation

U2 - 10.2903/j.efsa.2022.7230

DO - 10.2903/j.efsa.2022.7230

M3 - Journal article

C2 - 35414834

VL - 20

SP - 1

EP - 15

JO - E F S A Journal

JF - E F S A Journal

SN - 1831-4732

IS - 4

M1 - e07230

ER -