Investigation of sheep anthrax outbreak in Madurai district of Tamil Nadu, India

Abstract

Anthrax is an acute bacterial disease primarily affecting the herbivores and is transmissible to humans. There was a history of sudden death of five adult sheep at T. Kallupatti, Madurai district of Tamil Nadu during the month of January 2020. The disease investigation was carried out. External examination of the carcasses revealed that there was an unclotted blood near the nostrils, at anal orifice and on the floor. Blood smears were prepared from blood from ear vein of all the five dead animals for staining and one blood sample was collected in an EDTA vial from the fresh carcass for molecular diagnosis. Clinical examination of carcasses, positive M'Fadyean reaction and positive polymerase chain reaction amplification of B. anthracis protective antigen (596 bp) and capsule (846 bp) confirmed the anthrax outbreak in sheep flock. The outbreak was successfully controlled by using bio security measures and anthrax vaccination of the animal population at risk. Regular surveillance and periodic anthrax vaccination of domestic animals will be useful to control the disease in animals and humans.