Newcastle Disease Virus (NDV) Current situation in Egypt

The Newcastle Disease Virus (NDV) is still a concern in Egypt’s poultry industry. The virus is still evolving, which puts a massive negative Impact on Poultry industry.

1. Poultry Industry in Egypt

Egypt’s poultry industry is among the biggest in the Middle East. The average amount of poultry meat consumed per person in 2023 was 19.0 kg, while the output of chicken meat reached roughly 1.85 million metric tons in 2023/2024. The anticipated amount of eggs consumed per person was 3.69 kg. Both large integrated commercial enterprises and small-scale producers are part of this industry.

2. Newcastle Disease Virus (NDV) Brief

In 1948, Newcastle Disease was first detected in Egypt. Since then, it has been one of the most significant and continuous threats to the poultry Industry.

During outbreaks, long-life flocks may have a 50% decrease in egg production. In unvaccinated birds, mortality can reach 80–100% and morbidity is about 100%.

The three main pathotypes of Newcastle Disease Virus (NDV) strains in birds are lentogenic (low virulence, mild/no symptoms), mesogenic (moderate virulence), and velogenic (very pathogenic, causing severe respiratory/nervous manifestations and significant mortality).

• Etiology: The disease is caused by virulent strains of Avian Orthoavulavirus 1, family Paramyxoviridae (formerly known as Avian Paramyxovirus 1 or APMV-1). It is an enveloped, single-stranded, negative-sense RNA virus.
• Transmission: The virus spreads via inhalation or ingestion of contaminated secretions. Migratory birds act to introduce new strains into local poultry populations.
• Clinical Signs: Infected birds shows severe respiratory distress, greenish diarrhea, and neurological signs, as torticollis and leg paralysis.
• Pathology: Postmortem examinations typically shows proventricular, cecal tonsils, and intestinal lymphoid patches hemorrhages, in addition to catarrhal tracheitis

The amino acid motif at the viral Fusion (F) protein’s cleavage site is the main factor that determines NDV pathogenicity.

Current Situation of Newcastle Disease in Egypt

Newcastle Disease (ND) is considered one of the most destructive viral infections impacting the Egyptian poultry industry. Despite decades of extensive vaccination programs, the disease remains highly prevalent due to continuous virus mutations that lead to new genotypes capable of causing epidemics even in immunized birds.

• Dominant Genotype: Currently, Genotype VII (NDV GVII) is the most prevalent strain and the primary source of recent epidemics in Egyptian poultry farms.
• Circulating Strains: In addition to Genotype VII, Genotypes II and VI are also actively circulating in the field.
• National Prevalence: A six-year cohort study reported a national prevalence rate of 52.4% in domestic poultry (chickens and turkeys).
• Reservoirs and Risks: Wild birds (such as cattle egrets and sparrows) and apparently healthy ducks in backyard systems serve as significant reservoirs for virulent strains. Because ducks can carry the virus without showing symptoms, the research recommends prohibiting contact between different poultry species in Egyptian backyard systems.

Prevalence of NDV by Governorate

The following table summarizes the prevalence rates across various governorates reported in the two primary surveillance studies .

3. Most Prevalent Genotypes and Recent Outbreaks

Historically, genotype II strains circulated, but since around 2011, virulent genotype VII viruses have predominated. Nationwide outbreaks are common, particularly in areas with high chicken populations.

4. Control, Recommendations, and Vaccination

In Egypt, vaccination plays a major role in the control of Newcastle disease. Both live attenuated and inactivated oil-emulsion vaccines, such as those based on genotype II and genotype VII, are commonly utilized.

In order to reduce the effects of ND, we must emphasize Improved vaccination strategies, particularly a greater use of genotype-matched NDV vaccines (live/inactivated) on all farms; scheduling optimization and cold-chain integrity; biosecurity enforcement, including improving farm-to-farm movement control, managing live markets, and raising standards on small farms (training, incentives); Improved surveillance: systematic observation to identify new epidemics early.