Newcastle Disease

1 Overview

Newcastle disease, also known as Asian chicken plague, is an acute, highly contagious and severe infectious disease of chickens and turkeys caused by paramyxovirus.

Clinical diagnostic features: depression, loss of appetite, difficulty breathing, green loose stools, and systemic symptoms.

Pathological anatomy: redness, swelling, bleeding, and necrosis of the digestive tract mucosa.

2. Etiological characteristics

(1) Attributes and classifications

Chicken Newcastle disease virus (NDV) belongs to the genus Paramyxovirus in the family Paramyxoviridae.

(2) Form

Mature virus particles are spherical, with a diameter of 100~300nm.

(3) Hemagglutination

NDV contains hemagglutinin, which agglutinates human, chicken, and mouse red blood cells.

(4) Existing parts

The body fluids, secretions, and excretions of poultry tissues and organs contain viruses. Among them, the brain, spleen, and lungs contain the highest amounts of viruses, and they remain in the bone marrow for the longest time.

(5) Proliferation

The virus can proliferate in the chorioallantoic cavity of 9-11-day-old chicken embryos, and can grow and reproduce on chicken embryo fibroblasts and produce cell fission.

(6) Resistance

Inactivates in 30 minutes under sunlight.

                Survival in greenhouse for 1 week

Temperature:     56°C for 30~90 minutes

                Survival at 4℃ for 1 year

                Survival at -20°C for more than ten years

Routine concentrations of conventional disinfectants kill NDV quickly.

3. Epidemiological characteristics

(1) Susceptible animals

Chickens, pigeons, pheasants, turkeys, peacocks, partridges, quails, waterfowl, geese

Conjunctivitis occurs in people after infection.

(2) Source of infection

Virus-carrying poultry

(3) Transmission channels

Respiratory tract and digestive tract infections, excrement, virus-contaminated feed, drinking water, ground, and tools are infected through the digestive tract; virus-carrying dust and droplets enter the respiratory tract.

(4) Pattern of incidence

It occurs all year round, mostly in winter and spring. The morbidity and mortality rates of young poultry are higher than those of older poultry.