The Current Situation of Newcastle Disease (NDV) in Algeria

1. Poultry Industry in Algeria

Algeria’s poultry sector is a key component of the country’s agricultural economy and the main source of affordable animal protein.

• Population and Production Capacity: About 500,000 jobs are directly and indirectly supported by Algeria’s poultry industry, which employs about 20,000 farmers. Over 4.8 billion table eggs and 340,000 tons of white meat are produced annually.
• Per Capita Consumption: Algeria shows a rising reliance on chicken products. About 6 to 8 kg of white meat are consumed annually per person, however when it comes to egg consumption Algeria is ranked seventh in Africa, which is estimated to be 6.35 kilograms per capita annually.

2. Newcastle Disease Virus (NDV) Brief

Newcastle is Currently widely spread in Algeria and posing a concerning threat to the industry, Newcastle Disease Virus (NDV) is a highly contagious viral disease affecting both domestic and wild avian species. The causative agent is avian paramyxovirus-1 (APMV-1), an enveloped, single-stranded, negative-sense RNA virus belonging to the family Paramyxoviridae.

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).

• 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. The multi-basic amino acid sequence of virulent strains enables the protein to be cleaved by widespread host proteases present throughout the body, resulting in systemic, multi-organ infection.

3. Most Prevalent Genotypes and Recent Outbreaks

While traditional Genotype II strains were associated with past outbreaks in Algeria, Genotype VII has become the predominant, highly velogenic lineage spreading across Algerian poultry farms. This is consistent with the wider epidemiological pattern seen in the Middle East and North Africa.

Recent Outbreaks and Field Data

• Algeria’s ND epidemiological history is marked by ongoing field difficulties that might periodically escalate into widespread epizootics:
•  The 2014 Epizootic Wave: After a twelve-year period of relative quiescence, broiler operations in the northeastern governorates, such as Bordj Bou Arreridj, Sétif, and Tébessa, experienced a huge comeback of ND. Over 416,000 birds were impacted by this wave, which resulted in sharp increases in mortality, with the characteristic viscerotropic velogenic form of the disease killing over 60% of afflicted flocks.

4. 4. Control, Recommendations, and Vaccination

Live lentogenic vaccines (mostly Clone 30, LaSota, or VG/GA strains), often given as bivalent formulae in addition to Infectious Bronchitis (IB) vaccinations, are the foundation of Algerian poultry defense. Even with these procedures, vaccination failures are still common. Field data indicates that:

• Vulnerability is significantly higher in farms that fail to administer essential booster shots.
• The foundation of conventional live vaccinations is Genotype II. Although these successfully reduce severe clinical death, they are unable to offer homologous protection against the field strains of Genotype VII that are now in circulation, which permits the wild virus to multiply and spread undetected into the environment.

• Inadequate biosecurity cannot be made up for by vaccination alone. Vaccine failures are directly correlated with high bird density and poor farm hygiene, according to regional field data. Upgrading housing, improving the habitat, and tailoring the vaccination to the particular circulating field genotype are all essential components of a cohesive strategy for long-term field protection.