For 9 consecutive months (March November 2008), faecal samples were collected monthly from 129 horses residing within 40 km of Salzburg, Austria.
It is probably the only feral herd of horses residing in Africa, with a population ranging between 90 and 150.
An epidemic of WNV encephalitis occurred during the late summer of 1998, among horses residing in a wetland area in the Valdinievole Valley, in the provinces of Florence and Pistoia, Tuscany.
In Italy, the first outbreak of West Nile virus (WNV) infection was reported in 1998 among horses residing in Tuscany region [ 1].
Blood samples were collected from horses residing at the Hoof Diagnostic and Rehabilitation Clinic (Bryan, TX) in accordance with the Texas A&M University College of Veterinary Medicine guidelines regarding research performed on non university-owned animals.
During the late summer of 1998, veterinary authorities in Tuscany, Italy, received reports of cases of neurologic disease among horses residing in a large wetland area located in the provinces of Florence and Pistoia.
Maps of the density of horses per postcode area using the NED owner and Stakeholder horse datasets are illustrated in Figure 2. The majority of horses are concentrated in England (82% in both datasets), with a smaller percentage of horses residing in Wales (11% the NED owner dataset, 9% Stakeholder horse dataset) and Scotland (7% the NED owner dataset, 8% Stakeholder horse dataset).
As similar IgG ELISA prevalence rates were obtained both in these stables with silent infections located in zone A and in stables in zone B (sampled in early 1999), we assume that, apart from the observation of neurologic signs, all horses residing in the study area had the same level of exposure to the virus.
No significant differences in age-specific prevalence were observed, suggesting that the horses residing in the area had not been exposed previously to West Nile virus and supporting the hypothesis of its introduction in the wetland area during the first half of 1998.
