What is Newcastle Disease (ND)?

About Newcastle Disease (ND):

• It is a highly contagious and often severe disease found worldwide that affects birds, including domestic poultry.
• It is caused by a virus in the family of paramyxoviruses.
• It attacks their respiratory, nervous, and digestive systems.
• ND only affects birds, particularly poultry, such as chickens.
• It can cause illness and death in large numbers of birds quickly.
• Transmission:
  • ND is transmitted most often by direct contact with diseased or carrier birds.
  • Infected birds may shed the virus in their feces, contaminating the environment.
  • Transmission can then occur by direct contact with feces and respiratory discharges or by contaminated food, water, equipment, and human clothing.
  • ND viruses can survive for several weeks in the environment, especially in cool weather.
• The disease is very contagious. When the virus is introduced into a susceptible flock, virtually all the birds will be infected within two to six days.
• Symptoms: Infected birds may show signs of:
  • loss of appetite, coughing, gasping, nasal discharge, watery eyes, bright green diarrhoea, and nervous signs such as paralysis and convulsions
  • combs and wattles may look swollen, enlarged, and discoloured (purple or blue)
  • reduced egg production, and the few eggs that are produced may be soft shelled and malformed.
• Treatment:
  • There is no treatment for ND, and, in many countries, infected and susceptible birds in the vicinity of an outbreak are culled to contain transmission of the disease.
  • Prevention is accomplished through vaccination and strict biosecurity.

Q1: What is a Virus?

A virus is an infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat. A virus cannot replicate alone; instead, it must infect cells and use components of the host cell to make copies of itself. Often, a virus ends up killing the host cell in the process, causing damage to the host organism. Well-known examples of viruses causing human disease include AIDS, COVID-19, measles and smallpox.

Source: Brazil declares animal health emergency after Newcastle disease case