Keywords : Avian influenza

Diagnosis and histopathological study of avian influenza virus-H5 (AIV-H5) in broiler farms

Fanar A. Isihak; Hana Kh. Ismail; Abed Alwaheed A. Wahid

Iraqi Journal of Veterinary Sciences, 2020, Volume 34, Issue 1, Pages 101-107
DOI: 10.33899/ijvs.2019.125646.1120

This study was conducted for diagnosis and description of the pathological changes of AIV-H5 as the causative pathogen in Iraqi broiler farms. The current study was carried out on 84 broiler farms. Infected birds were tested for detection of the AIV infection from the tracheal swabs by rapid chromatographic AIV type A and H5 test kits. In RRT-PCR 8 samples (8 farms) of Trachea were selected to be tested by this assay. Samples of trachea, lung, and spleen from the dead birds with natural AIV-H5 infection were submitted for histopathological examination. seventy-two out of 84 farms tested for AIV-Type A gave positive results, and 58 out of 72 positives for type A-AIV gave a positive result for H5 antigen in a rapid chromatographic strip. The main gross lesions in the trachea of infected birds were severe congestion and hemorrhage. In the RRT-PCR assay, 8 out of 8 samples gave a distinct positive result for this test. The microscopic histopathological examination of infected tracheas showed obvious desquamation of lining epithelium with complete loss of cilia associated with congestion of blood vessels in lamina properia. Infected lungs revealed diffuse alveolar damage and severe multifocal vascular congestion. There was deposition of fibrinous material in the splenic tissue associated with the disappearance of the germinal centers. Thus, we concluded that AIV-H5 infection causes severe pathological and histopathological changes as a result of systemic infection. The RRT-PCR assay was highly sensitive and specific for the detection of highly pathogenic avian influenza virus subtypes.

Toxicological and neurobehavioral effects of chlorpyrifos and deltamethrin insecticides in mice

Khaerea A. Mustafa; Banan Kh. Al-Baggou

Iraqi Journal of Veterinary Sciences, 2020, Volume 34, Issue 1, Pages 189-196
DOI: 10.33899/ijvs.2019.125738.1144

The aim of the present study was to determine the acute toxicity of chlorpyrifos and deltamethrin in mice separately and to study their toxic and neurobehavioral effects. Median Lethal Doses (LD50) of chlorpyrifos and deltamethrin were determined depending on up and down method. The oral LD50 of chlorpyrifos was 193.05 mg/kg and of deltamethrin was 15.71 mg/kg in mice. The oral administration of chlorpyrifos 155 mg/kg and deltamethrin 12.56 mg/kg represent 80% of LD50 resulted in acute signs of poisoning that manifested by dyspnea, salivation and lacrimation at 100%, piloerection, straub tail, tremors, convulsions and death at 70% for chlorpyrifos and 60% for deltamethrin and writhing reflex at 20% for chlorpyrifos. Oral administration of chlorpyrifos 310 mg/kg and deltamethrin 24 mg/kg increased severity of toxicosis signs as a percentage of piloerection, straub tail, tremors, seizures and death 100%. As well as decrease the onset of tremors, convulsions and death, writhing reflex which appears at 20% for chlorpyrifos and 10% for deltamethrin. After three hours of chlorpyrifos and deltamethrin oral administration at doses represent 20% and 10% of LD50 there are significantly hypoactivation in open-field activity, significantly increased in the duration of negative geotaxis performance, significantly decreased in head pocking and swimming scores compared to control group. In conclusion we found that deltamethrin was more toxic than chlorpyrifos this is based on the LD50 value. However, the signs of toxicosis and neurobehavioral effects produced by both toxicants were not differential and could not be associated with the toxic level.