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

1. Introduction

Punjab is one of the most progressive state of Northern region of India. The economically dependent to livestock growths that contribute to the livelihood of farmer of the state. Punjab accounts 2.2% of poultry and 2.5% of cattle and buffalo population in India while its contributions to milk, egg, and meat production are 7%, 5%, and 3.4%, respectively [1]. Livestock supplies 16% of the revenue to small farm households [2]. The most economic loss of small farm owners of bovine due to outbreaks of infectious diseases in the farm. Among infectious disease of bovine FMD is one of the most contagious diseases affecting cattle and buffalo. Create a severe economic impact in the nations that report the disease to the World Organization for Animal Health (WOAH), with an estimated global economic loss of USD 6.5 and 21 billion [3, 4]. To control FMD, several strategies have been put into place, such as vaccination, diagnostics, culling and surveillance [5]. In India the National Animal Disease Control Programme for FMD is to control FMD by 2025 with vaccination and its eventual eradication by 2030 [6]. Nationwide efforts to control FMD have adopted a comprehensive strategy that includes biannual vaccinations, sero-monitoring, and sero-surveillance. However, the elevated viral mutation rate, transient immunity to vaccination, susceptibility to different hosts, and intricate socioecological processes have presented significant obstacles to disease control [7]. In India the virus mainly spreads due to unrestricted animal movement [10]. In carrier animals, virus persists in the soft palate, pharynx, and tonsils for 2 years [8, 9]. Virus enters mainly by the respiratory route, oral route or through conjunctiva, genital route and virus initially multiplies in the epithelium [11]. Viremia sets elevated body temperature and blister formation, mainly on the mouth, tongue. Sick animals the clinical presentation involved feet hydropic degeneration and necrosis of the infected cells are hallmarks of FMD's. Blisters can cause lameness, appetite loss, and weight loss [12]. In young animals the virus tends to localized in the heart muscles and produces severe myocarditis [13]. FMD virus are seven serotypes O (Oise valley in Franch), A (Allemagne in France), C (Germany) Asia-1(Pakistan) and SAT1, SAT2 & SAT3 (South African Territories) and serotype O is also termed as Pan Asia strain [14]. All the serotypes of FMD virus are antigenically distinct and no cross protection occur and each serotype has many subtypes [15]. FMD virus is sensitive to heat, acid and alkali [16]. Currently, disease outbreaks in farm animals in India are caused by three serotypes (O, A, and Asia-1) and result in significant economic losses as well as trade restrictions [10].The experts from Animal Disease Research Centre (ADRC) along with Scientist from Veterinary Medicine of University recently conducted disease investigations on suspected outbreaks of FMD and septicemia with respiratory involvement in various districts of Punjab Ludhiana, Barnala, Gurdaspur, Bhatinda, Faridkot, Mansa and Amritsar. The outbreak notice in these areas was due to change climate that favor to viral transmission. In Mansa and Gurdaspur districts outbreak was reported due to introduction of newly purchased animals in the farm from affected area. Scientists examined the animals, recorded history of disease, mortality, morbidity as per information received from Veterinary Officers and owners of affected animals through direct interview. The aim of present study to investigate the recent FMD outbreaks in Punjab, viral etiology, and identify the serotype of virus circulating strain in this area. The present study was reported that potential causative agents of the disease outbreaks and need to prevent the further disease transmission of circulating strain in Punjab.

2. Materials and Methods

2.1. Disease History and outbreak investigation

In October 2023 the telephonic call received from village Badowal, District Ludhiana, through owner. The University expert team visited village farm and collected data through direct interview and observation of clinical sign and lesions of the disease in sick animals. Likewise, other outbreak data was collected and observation recoded. The predominant clinical findings included oral vesicular lesions, lameness, respiratory distress, fever, and decreased feed intake. The outbreak investigation period was from October 2023 to April 2024 and the peak period was in the month of February 2024. Higher mortality rate was observed among calves and heifers. The study encompassed 13 outbreaks involving cattle and buffalo on organized farms across seven districts in Punjab. Higher morbidity and mortality rates were noted in farms and villages without a recent history of vaccination against FMD. Out of a total population of 3,810 animals in the investigation area, 692 animals were affected or suspected of having FMD based on observed clinical signs (Figure 1) and lesions.