Subclinical Clostridium Perfringens Infection and Marek’s Disease in Jordanian Broiler Chickens

Abstract

Subclinical infections are common in the poultry industry such as Clostridium perfringens-induced necrotic enteritis and Marek's disease. This study aims to determine the prevalence of subclinical necrotic enteritis caused by C. perfringens and Marek's disease. For C. Perfringens, 100 blood samples from 20 intensive poultry broiler farms were collected from June 2020 to September 2020 and analyzed. Upon examining intestinal samples, different degrees of intestinal lesions were noticed, which varied from normal to severe necrosis based on a 0 to 3 scoring system. The blood samples were investigated using an ELISA kit to detect the presence of antibodies against C. perfringens. Nonsignificant difference was noticed between the different farms and different lesion scores. The prevalence of C. perfringens in chickens in North Jordan flocks is 14.8%. A significant difference using the chi-square test (P=0.004) was noted between infected and non-infected farms. Certain farms showed limited cases (1-2 cases), while others showed higher infections. The prevalence of Marek's disease was investigated in Amman's municipality slaughterhouse and suspected broiler farms located in the Amman region by histopathology and ELISA. For the subclinical MD investigation, a total of 100 chickens from Amman's municipality slaughterhouse were examined where blood samples were tested for antibody presence by ELISA kit together with histopathology, for the clinical MD investigation, 100 chickens from 10 broiler farms were examined by histopathology and ELISA. Blood samples collected from clinical and subclinical cases and tested by ELISA showed a 70% prevalence of Marek's Disease. Of the tissues collected from the slaughterhouse, 30% of the liver samples (average age of 35 days) showed pathological changes. Microscopic examination of tissues showed pleomorphic cell proliferation in the spleen (23%) and liver (20%). It was concluded that clinical and subclinical forms of C. perfringens infections and Marek's disease is prevalent in Jordan.