Newcastle Disease - overview and analysis of the current spread of the disease in Bulgaria and Europe

Abstract

Newcastle disease (ND) is a highly contagious and severe worldwide disease affecting birds. The infection is a mild zoonosis and can cause conjunctivitis in humans, but the condition is usually mild and self-limiting. ND is caused by virulent strains of avian paramyxovirus type 1. The disease occurs in five forms: velogenic viscerotrophic, velogenic neutrotropic, mesogenic, lentogenic Newcastle disease and asymptomatic enteric Newcastle disease. Lentogenic strains are very widespread, but are usually asymptomatic and do not cause outbreaks in poultry. Newcastle disease in its highly pathogenic form, is a WOAH listed disease and must be reported. It usually manifests as severe respiratory disease, depression, nervousness and/or diarrhea. The clinical picture is very similar to bird flu, so laboratory tests are important to confirm the diagnosis.