BACKGROUND: There is little information on the duration of nasal shedding of EHV-1 from horses with naturally occurring equine herpesvirus myeloencephalopathy (EHM). OBJECTIVES: To evaluate the duration of nasal shedding of EHV-1 in horses affected by EHM. ANIMALS: One hundred and four horses naturally exposed to EHV-1, 20 of which had clinical signs of EHM. METHODS: All horses on affected premises were monitored. Those horses developing EHM were sampled in a longitudinal outbreak investigation. Nasal swabs were collected daily from 16 of 20 horses affected by EHM. A qPCR was performed on 98 of 246 nasal swab samples to determine nasal shedding duration. Historical and clinical information was analyzed to evaluate potential risk factors for developing EHM and duration of shedding during this outbreak. RESULTS: The last day shedding was detected in any horse was Disease Day 9. EHV-1 was detected in two-thirds of horses tested on Disease Days 0-3. The amount of EHV-1 DNA found in nasal swabs varied markedly and was not associated with disease severity or age. The odds of developing EHM were greater for febrile horses (OR = 20.3; 95% CI 3.4-390.3; P = .01) as well as for horses attending the riding clinic (OR = 4.1; 95% CI 0.84-21.65; P = .08). CONCLUSIONS AND CLINICAL IMPORTANCE: Biosecurity measures should be implemented for a minimum of 14 days beyond the onset of clinical signs of EHM. Animal managers cannot rely on the severity of clinical signs to predict the duration of EHV-1 shedding.
BACKGROUND: There is little information on the duration of nasal shedding of EHV-1 from horses with naturally occurring equineherpesvirus myeloencephalopathy (EHM). OBJECTIVES: To evaluate the duration of nasal shedding of EHV-1 in horses affected by EHM. ANIMALS: One hundred and four horses naturally exposed to EHV-1, 20 of which had clinical signs of EHM. METHODS: All horses on affected premises were monitored. Those horses developing EHM were sampled in a longitudinal outbreak investigation. Nasal swabs were collected daily from 16 of 20 horses affected by EHM. A qPCR was performed on 98 of 246 nasal swab samples to determine nasal shedding duration. Historical and clinical information was analyzed to evaluate potential risk factors for developing EHM and duration of shedding during this outbreak. RESULTS: The last day shedding was detected in any horse was Disease Day 9. EHV-1 was detected in two-thirds of horses tested on Disease Days 0-3. The amount of EHV-1 DNA found in nasal swabs varied markedly and was not associated with disease severity or age. The odds of developing EHM were greater for febrile horses (OR = 20.3; 95% CI 3.4-390.3; P = .01) as well as for horses attending the riding clinic (OR = 4.1; 95% CI 0.84-21.65; P = .08). CONCLUSIONS AND CLINICAL IMPORTANCE: Biosecurity measures should be implemented for a minimum of 14 days beyond the onset of clinical signs of EHM. Animal managers cannot rely on the severity of clinical signs to predict the duration of EHV-1 shedding.
Authors: Søren Saxmose Nielsen; Julio Alvarez; Dominique Joseph Bicout; Paolo Calistri; Elisabetta Canali; Julian Ashley Drewe; Bruno Garin-Bastuji; José Luis Gonzales Rojas; Christian Gortázar; Mette Herskin; Virginie Michel; Miguel Ángel Miranda Chueca; Helen Clare Roberts; Barbara Padalino; Paolo Pasquali; Hans Spoolder; Karl Ståhl; Antonio Velarde Calvo; Arvo Viltrop; Christoph Winckler; Andrea Carvelli; Romain Paillot; Alessandro Broglia; Lisa Kohnle; Francesca Baldinelli; Yves Van der Stede Journal: EFSA J Date: 2022-01-12
Authors: Nicola Pusterla; Samantha Barnum; Julia Miller; Sarah Varnell; Barbara Dallap-Schaer; Helen Aceto; Aliza Simeone Journal: Pathogens Date: 2021-06-13