Studies on the effect of different adjuvants and inactivators on the immune response of chickens vaccinated with inactivated NDV, AIV (H5N1) vaccines and their bivalent forms

Abstract

The present study was designed to spot the light on the epidemiological status of AIV in the Egyptian commercial poultry farms during 2016 - 2017 and to determine the most prevalent AIV subtype circulating in Egypt via field investigation of different outbreaks suspected to be infected with HPAIV. Thirty-one different broiler chicken flocks of different ages located in 7 governorates (Sharkia, Elfayoum, Monofia, Kalyobia, Giza, Ismailia, Menia) in Egypt were examined. The preliminary diagnosis of suspected HPAIV outbreaks was adopted on the basis of the flock history, the clinical examination and PM examination. Three hundred and ten tracheal swabs were collected from moribund and freshly dead birds (Ten samples / flock considered as one sample). The prepared samples were inoculated into 10 days old SPF-ECEs for isolation of HPAIV. The allantoic fluid of inoculated SPF-ECEs was collected and subjected for rapid HA test. Real time PCR was conducted for detection of HPAIV (H5) subtype then samples were examined for presence or absence of mixed infection with NDV and or AIV (H9&H7) by RRT- PCR. The results revealed that, all the examined flocks were found to be suffered from various clinical signs including dullness, depression, off food, off water and ruffled feather to cyanosis of comb and wattle with facial edema, ecchymosis on the shanks and feet and respiratory and nervous signs. PM lesions appeared as hemorrhagic lesion in internal organ and the skin