Salhi Omar, Messaï Chafik Redha, Ouchene Nassim, Boussaadi Iman, Kentouche Hassiba, Kaidi Rachid, Khelef Djamel
Biotechnology Laboratory of Animal Reproduction, Institute of Veterinary Sciences, Blida, Algeria.
Laboratory of Research Health and Animal Production, High National Veterinary School, Algiers, Algeria.
Vet World. 2021 Jan;14(1):182-189. doi: 10.14202/vetworld.2021.182-189. Epub 2021 Jan 22.
Since 2017, there have been epidemics with respiratory disorders in the laying hen farms in Algeria, as signs and lesions, respiratory difficulties, and hemorrhagic tracheitis, which closely like laryngotracheitis. This study aimed to analyze the epidemiological, serological, and clinical indicators, as well as the risk factors, of infectious laryngotracheitis (ILT) in layer hen flocks in Algeria.
A total of 1728 layer hens were sampled randomly from 48 poultry houses. Blood samples were collected from each hen at the wing vein area, and an indirect enzyme-linked immunosorbent assay was done using an IDvet kit.
The flocks showed 56.25% seroprevalence. Clinical signs and gross lesions of ILT suspect cases included respiratory signs characterized by hemorrhagic tracheitis and sinusitis; conjunctivitis; egg drop; and a low mortality rate varying from 5% to 20%. Statistical analyses showed the effect of risk factors on the seropositivity for ILT in 48 layer flocks. When the vaccination was not applied, flocks were significantly more seropositive by 54% (odds ratio OR=1.54, p=0.01) compared to vaccinated flocks. Furthermore, flocks with poor hygiene were more seropositive by 68% (OR=1.68, p=0.002) compared to those with good hygiene. Finally, flocks with decreased egg production between 10% and 30% were significantly more seropositive by 42% (OR=1.42, p=0.04) than those with egg production >30%.
The serological survey revealed anti-ILT virus antibodies, signifying the circulation of this virus in layer hen farms in Algeria. Correct vaccination protocol, strict biosecurity measures, rapid diagnosis, and detection of latent carriers are necessary to control and eradicate the disease from layer farms.
自2017年以来，阿尔及利亚的蛋鸡养殖场出现了呼吸道疾病疫情，表现为呼吸道症状和病变、呼吸困难以及出血性气管炎，与喉气管炎极为相似。本研究旨在分析阿尔及利亚蛋鸡群中传染性喉气管炎（ILT）的流行病学、血清学和临床指标以及危险因素。
从48个禽舍中随机抽取了1728只蛋鸡。在每只鸡的翅静脉区域采集血样，并使用IDvet试剂盒进行间接酶联免疫吸附试验。
鸡群的血清阳性率为56.25%。ILT疑似病例的临床症状和大体病变包括以出血性气管炎和鼻窦炎为特征的呼吸道症状；结膜炎；产蛋下降；死亡率较低，在5%至20%之间。统计分析显示了危险因素对48个蛋鸡群中ILT血清阳性的影响。未接种疫苗的鸡群血清阳性率比接种疫苗的鸡群显著高54%（优势比OR = 1.54，p = 0.01）。此外，卫生条件差的鸡群血清阳性率比卫生条件好的鸡群高68%（OR = 1.68，p = 0.002）。最后，产蛋量下降10%至30%的鸡群血清阳性率比产蛋量>30%的鸡群显著高42%（OR = 1.42，p = 0.04）。
血清学调查显示存在抗ILT病毒抗体，表明该病毒在阿尔及利亚的蛋鸡养殖场中传播。正确的疫苗接种方案、严格的生物安全措施、快速诊断以及检测潜在携带者对于控制和根除蛋鸡养殖场的疾病是必要的。
