Newcastle disease

What is it?

Newcastle disease is a highly contagious viral infection that affects chickens, turkeys and other birds. It can cause significant losses in Tunisian poultry farms due to its rapid spread. It is closely monitored because certain strains can also affect humans slightly.

Commonly observed signs

These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.

Causes and risk factors

The disease is caused by a virus from the avian paramyxovirus family, called Newcastle virus. This virus comes in several strains, some of which are more dangerous than others. It multiplies rapidly in the respiratory and digestive tracts of infected birds.

Farms with a high density of birds, a lack of hygiene or an absence of vaccination are more exposed to the disease. Contact with wild birds or new, uncontrolled poultry also increases the risk. A weakened immune system in young birds also favors infection.

Transmission

The virus is transmitted mainly by direct contact with infected birds or their respiratory secretions and droppings. It can also be spread through contaminated equipment, clothing or water. Transmission to humans is rare and generally limited to mild conjunctivitis in people in close contact with sick poultry.

Diagnosis and care

Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.

Prevention

References

WOAH — Organisation mondiale de la santé animale (ex-OIE)

MSD Veterinary Manual

Content reviewed by the TunisieVet editorial team · Updated 18 August 2026