Investigation of an EHV-1 Outbreak in the United States Caused by a New H752 Genotype

Pusterla, Nicola; Barnum, Samantha; Miller, Julia; Varnell, Sarah; Dallap‐Schaer, Barbara; Aceto, Helen; Simeone, Aliza

doi:10.3390/pathogens10060747

Cited by 30 publications

(63 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, two recent studies in France and the United States identified a new EHV-1 DNA polymerase (ORF30) genotype. This was followed by the isolation of a C2254/H752 which was then associated with both respiratory and neurological clinical signs [ 28 , 29 ]. Further study will investigate the presence of this new EHV-1 genotype in China’s horses.…”

Section: Discussionmentioning

confidence: 99%

Outbreak of neuropathogenic equid herpesvirus 1 causing abortions in Yili horses of Zhaosu, North Xinjiang, China

et al. 2022

View full text Add to dashboard Cite

Background EHV-1 is one of the most serious viral pathogens that frequently cause abortion in horses around the world. However, so far, relatively little information is available on EHV-1 infections as they occur in China. In January 2021, during an abortion storm which occurred in Yili horses at the Chinese State Studs of Zhaosu (North Xinjiang, China), 43 out of 800 pregnant mares aborted. Results PCR detection revealed the presence of EHV-1 in all samples as the possible cause of all abortions, although EHV-4, EHV-2 and EHV-5 were also found to circulate in the aborted fetuses. Furthermore, the partial ORF33 sequences of the 43 EHV-1 shared 99.3–100% and 99.0–100% similarity in nucleotide and amino acid sequences respectively. These sequences not only indicated a highly conserved region but also allowed the strains to group into six clusters. In addition, based on the predicted ORF30 nucleotide sequence, it was found that all the strains carried a guanine at the 2254 nucleotide position (aspartic acid at position 752 of the viral DNA polymerase) and were, therefore, identified as neuropathogenic strains. Conclusion This study is the first one that establishes EHV-1 as the cause of abortions in Yili horses, of China. Further characterization of the ORF30 sequences revealed that all the EHV-1 strains from the study carried the neuropathogenic genotype. Totally, neuropathogenic EHV-1 infection in China’s horse population should be concerned although the virus only detected in Yili horse abortions.

show abstract

Section: Discussionmentioning

confidence: 99%

Outbreak of neuropathogenic equid herpesvirus 1 causing abortions in Yili horses of Zhaosu, North Xinjiang, China

et al. 2022

View full text Add to dashboard Cite

show abstract

“…tracking the infection source and spread) and some of them were also initially thought to be pathological markers, such as the SNP identified at position 2,254 in the DNA polymerase gene (ORF 30) that was thought to be correlated with neurological disease; therefore, it was considered as a neuropathic marker (Nugent et al, 2006 ). On the basis of this point mutation, the majority of diagnostic laboratories in the USA rely solely on allelic discrimination qPCR assays to detect EHV‐1 (Pusterla et al, 2021 ).…”

Section: Assessmentmentioning

confidence: 99%

“…While EHV‐1 strains carrying the A2254 mutation are frequently (but not exclusively) isolated from abortion cases, EHV‐1 strains isolated from neurological disease cases are carrying mutation either. Recently, a third 2254 mutation (C2254) was isolated from a large outbreak in France (Sutton et al, 2020 ), and subsequently reported in the USA (Pusterla et al, 2021 ), which raised further questions on the prognostic importance of this marker (Sutton et al, 2020 ). Given this evidence, unfortunately, the molecular diagnostic approach based only on allelic discrimination, may lead to missed EHV‐1 cases as exemplified by the outbreak reported in USA (Pusterla et al, 2021 ) and by the recently reported outbreak from France (Sutton et al, 2020 ).…”

Section: Assessmentmentioning

confidence: 99%

“…Recently, a third 2254 mutation (C2254) was isolated from a large outbreak in France (Sutton et al, 2020 ), and subsequently reported in the USA (Pusterla et al, 2021 ), which raised further questions on the prognostic importance of this marker (Sutton et al, 2020 ). Given this evidence, unfortunately, the molecular diagnostic approach based only on allelic discrimination, may lead to missed EHV‐1 cases as exemplified by the outbreak reported in USA (Pusterla et al, 2021 ) and by the recently reported outbreak from France (Sutton et al, 2020 ). It is, therefore, recommended to use molecular laboratories that either incorporate a universal EHV‐1 target gene or expand their ORF 30 SNP assays to include the new genotypes.…”

Section: Assessmentmentioning

confidence: 99%

See 1 more Smart Citation

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

Carvelli¹,

Nielsen²,

Paillot³

et al. 2022

EFS2

View full text Add to dashboard Cite

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.

show abstract

“…However, the link between this mutation and the different forms of disease is still debated [ 9 , 10 , 11 , 12 , 13 ]. Recently, a new ORF30 variant of EHV-1 (C 2254 , coding for a histidine H 752 ), was isolated in France and the USA and associated with respiratory and neurological diseases [ 14 , 15 , 16 ].…”

Section: Introductionmentioning

confidence: 99%

Oral Administration of Valganciclovir Reduces Clinical Signs, Virus Shedding and Cell-Associated Viremia in Ponies Experimentally Infected with the Equid Herpesvirus-1 C2254 Variant

et al. 2022

View full text Add to dashboard Cite

Equid alphaherpesvirus-1 (EHV-1) is one of the main pathogens in horses, responsible for respiratory diseases, ocular diseases, abortions, neonatal foal death and neurological complications such as equine herpesvirus myeloencephalopathy (EHM). Current vaccines reduce the excretion and dissemination of the virus and, therefore, the extent of an epizooty. While their efficacy against EHV-1-induced abortion in pregnant mares and the decreased occurrence of an abortion storm in the field have been reported, their potential efficacy against the neurological form of disease remains undocumented. No antiviral treatment against EHV-1 is marketed and recommended to date. This study aimed to measure the protection induced by valganciclovir (VGCV), the prodrug of ganciclovir, in Welsh mountain ponies experimentally infected with an EHV-1 ORF30-C2254 strain. Four ponies were administered VGCV immediately prior to experimental EHV-1 infection, while another four ponies received a placebo. The treatment consisted in 6.5 mg/kg body weight of valganciclovir administered orally three times the first day and twice daily for 13 days. Clinical signs of disease, virus shedding and viraemia were measured for up to 3 weeks. The severity of the cumulative clinical score was significantly reduced in the treated group when compared with the control group. Shedding of infectious EHV-1 was significantly reduced in the treated group when compared with the control group between Day + 1 (D + 1) and D + 12. Viraemia was significantly reduced in the treated group when compared with the control group. Seroconversion was measured in all the ponies included in the study, irrespective of the treatment received. Oral administration of valganciclovir induced no noticeable side effect but reduced clinical signs of disease, infectious virus shedding and viraemia in ponies experimentally infected with the EHV-1 C2254 variant.

show abstract

Investigation of an EHV-1 Outbreak in the United States Caused by a New H752 Genotype

Cited by 30 publications

References 24 publications

Outbreak of neuropathogenic equid herpesvirus 1 causing abortions in Yili horses of Zhaosu, North Xinjiang, China

Outbreak of neuropathogenic equid herpesvirus 1 causing abortions in Yili horses of Zhaosu, North Xinjiang, China

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

Oral Administration of Valganciclovir Reduces Clinical Signs, Virus Shedding and Cell-Associated Viremia in Ponies Experimentally Infected with the Equid Herpesvirus-1 C2254 Variant

Contact Info

Product

Resources

About