Clinical and neuropathological features of West Nile virus equine encephalomyelitis in Italy

Equine Veterinary Journal - Tập 32 Số 1 - Trang 31-35 - 2000
Carlo Cantile1, Giovanni Di Guardo2, Claudia Eleni2, M. Arispici1
1Dipartimento di Patologia Animale, Facoltà di Medicina Veterinaria, Università degli Studi di Pisa, Viale delle Piagge, 2, I-56124 Pisa
2Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Via Appia Nuova, 1411, I-00178 Rome, Italy

Tóm tắt

Summary

West Nile (WN) virus infection is a mosquito‐borne flavivirosis endemic in Africa and Asia. Clinical disease is usually rare and mild and only in a few cases the infection causes encephalomyelitis in horses, fever and meningoencephalitis in man. We report here the clinical and pathological findings in an epidemic of the disease involving 14 horses from Tuscany, Italy. All cases were observed from August to October 1998. Affected horses showed ataxia, weakness paresis of the hindlimbs and, in 6 cases, there was paraparesis progressing to tetraplegia and recumbency within 2 to 9 days. Eight animals recovered without any important consequences. Serological investigations revealed positivity to WN virus in all the 14 horses and the agent was isolated from the cerebellum and spinal cord of an affected horse. Postmortem examination was carried out on 6 horses. The neuropathological pattern was that of a mild to moderate, nonsuppurative polioencephalomyelitis with constant involvement of the ventral horns of the thoracic and lumbar spinal cord, where focal gliosis and haemorrhage were also apparent in some cases. Differential diagnoses with other equine viral encephalomyelitides are discussed. Climatological and environmental characteristics of the geographic area in which the outbreaks occurred suggest the existence of suitable conditions for the development of the disease. This is the first report of WN virus equine encephalomyelitis in Italy.

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