Anatomopathological and Seroepidemiological Surveys of Avian Pseudo-Plague (Newcastle Disease) and Its Socioeconomic Impact on Family Poultry Sector in Abéché, Ouadda？ Province, Eastern Chad

This study investigates the epidemiological and socioeconomic impact of Newcastle disease (ND) on family poultry in Abéché, Chad. Using anatomo pathological surveys, serological testing and stakeholder interview and the authors determined an average serological prevalence of 15.3%. The study identified local perceptions of the disease, its seasonal peak, and significant economic losses for producer, collectors and merchants, which lead to high-risk behaviors like panic selling of sick birds. Newcastle disease is locally recognized forms with distinct clinical presentations. These are different manifestations of the same disease: the peracute form (N？ma) with general symptoms and petechiae, and the acute form with respiratory (Amzirnekh), digestive (Ammisserine), and nervous (Ammarara) tropisms. Salient clinical symptoms characterized by profuse greenish diarrhea (33.5%), high-pitched cry (13.4%), dizziness (11.7%) and serous oronasal serosities (10.5%) and the main lesions dominated by congestions and membrane petechiae of proventriculus. Newcastle disease resurfaces in the cold dry season in the form of a pathological complex often associated with infectious Coryza (Ab-iyené) in 10% and with fowl pox (djederi ab-rièsse) in 15% of poultry farms as opposed to the hot dry season, when it is linked to external argas parasitoses (dalam) and lice (Gamoul). Its annual evolution showed two epizootic peaks in December and March. The average serological prevalence rate of the province estimated at 15.3%. However, there were observable variations with significant differences (P < 0.05) between the peri-urban area of Abeché (15.15%) and rural areas in the rural West area (7.7%) and rural East area of Abéché (23.07%). Furthermore, the average annual direct costs of chicken mortality were 53.371 francs CFA (81.37 €) (n = 19), 317.520 CFA francs (484.09 €) (n = 112) and 184.275 francs CFA (280.94 €) (n = 65) respectively for the production, sales and collection systems with significant differences (P < 0.05). The low prevalence rates obtained could likely reflect both a form of adaptation of local chickens to an endemic and less virulent avian viral strain of Newcastle disease. These vulnerability factors can compromise the profitability and sustainable development of the family poultry sector. Promoting comminuted-based biosecurity training or establishing designated safe-slaughter points.