Outbreaks with infectious laryngotracheitis wild-type virus in the Gelderse Vallei, Netherlands

From July to September 25, fourteen poultry flocks were infected with infectious laryngotracheitis (ILT) wild-type virus, eight of which were in the poultry-dense region of the Gelderse Vallei (postcode area 37 and 38). The three cases in postcode area 77 and the cases in postcode area 41 and 67 are also linked to the Gelderse Vallei. The laying flock had been moved from the rearing location in that region to the laying farm shortly before developing symptoms of the disease due to ILT. The symptoms of ILT consist of respiratory symptoms, in which the trachea can be inflamed to the point of bleeding. In addition, there may be increased mortality, reduced feed intake and a decrease in egg production. The severity of the symptoms is determined by various factors. For example, there may be differences in the pathogenic capacity of the virus strain and sensitivity of the animals due to, among other things, protection by vaccinations. Wild-type ILT is regularly found in hobby poultry, ...