Clinical and Antigen Serotype O Confirmation of Foot and Mouth Disease (FMD) Virus Outbreak in Punjab Spillover from Domestic Livestock

Foot and Mouth Disease (FMD) is one of the most highly contagious viral diseases affecting cloven-hoofed domestic and wild animals. This study described clinical investigations of FMD outbreaks (n=13) with serotype O confirmation in seven districts of Punjab from October 2023 to April 2024. Samples from sick animals and post-mortem examinations were collected from FMD suspected animals for laboratory diagnosis. The investigation included clinical signs and lesions, blood profiles, presence of other infectious pathogens, differential diagnosis, and the cause of death in the area. A total of 13 outbreaks in farm ruminants were confirmed, detecting FMDV serotype O. Outbreaks were reported in Ludhiana, Barnala, Gurdaspur, Bathinda, Faridkot, Mansa, and Amritsar districts. Animals were diagnosed to be positive for FMDV antigen using Sandwich ELISA. A total of 692 animals, including both cattle and buffalo, were affected in these districts, with a mortality rate of 24.42% (169/692) in young animals and heifers. The most severely affected districts were Bathinda, Barnala, and Faridkot, that experienced high mortality rates, leading to significant economic losses in these areas. Histopathologically samples revealed muscle degeneration and diffuse lymphocytic infiltration, and lymphocytic myocarditis in the heart, which is characteristic of the cardiac form of FMD. Serotype O FMDV, primarily circulating in the study area, was identified as the cause of the outbreaks in farm ruminants under investigation. The local animal health authorities should take steps to minimize the spread of the disease by being prepared for risk factors, particularly animal movement and human activities linked to an outbreak and the need for improved vaccination coverage and enhanced biosecurity measures to control the spread of FMD in the region.