Newcastle Disease Virus (NDV) testing

Pathogen overview

A notifiable avian pathogen causing nervous signs, respiratory distress and high mortality. A priority target for biosecurity and import quarantine.

Transmission

Spread by the respiratory and digestive routes and by direct contact; the virus can spread rapidly through air, droplets, droppings and contaminated equipment, and is highly pathogenic and highly contagious.

Main impact

Causes nervous signs (torticollis, circling), difficulty breathing and greenish diarrhoea with a very high mortality rate; an outbreak can cause major losses in a loft. It is a notifiable disease.

Why testing matters

Rapid confirmation of Newcastle disease and differentiation from adenovirus, paramyxovirus and other agents, guiding emergency vaccination and biosecurity isolation; it is a core item for loft disease control and import quarantine.

Common symptoms

• ◆ Nervous signs, torticollis
• ◆ Difficulty breathing
• ◆ Greenish diarrhoea
• ◆ Drop in egg production, high mortality

Differential diagnosis

Must be differentiated from adenovirus, paramyxovirus and other agents; Newcastle disease is characterised by nervous signs, difficulty breathing, greenish diarrhoea and high mortality, and is a notifiable disease.

Incubation period

Incubation period 2–15 days, usually 5–6 days; the course varies greatly with the virulence of the strain.

Diagnostic methods

Collect throat and cloacal swabs for qPCR detection of viral nucleic acid for confirmation, interpreted together with the nervous and respiratory signs.

Management and treatment

There is no specific treatment. Management centres on isolation, culling of high-risk birds, vaccination and biosecurity control, under veterinary and official guidance.

Prevention

Vaccinate on schedule, strengthen biosecurity, and report and isolate promptly when disease is suspected.