Outbreak investigation and identification of risk factors associated with the occurrence of foot and mouth disease in Punjab, Pakistan

Foot-and-mouth disease (FMD) is a highly contagious viral disease of domesticated and wild ruminants and pigs that causes enormous economic losses through morbidity, mortality, and trade restrictions. Although the disease is endemic in Pakistan, seasonal outbreaks occur every year throughout the country. This study aimed to investigate FMD outbreaks and to identify the risk factors associated with FMD outbreaks between January and April 2019 in the Punjab province. We performed outbreak investigations (n = 64) for FMD in nine districts of the Punjab province through Divisional Disease Diagnostic Laboratories, Livestock and Dairy Development Department Punjab. Subsequently, we conducted a case-control study including 128 livestock farms (case to control ratio = 1). The data on various plausibly associated factors were collected using a structured questionnaire from each farm. The FMD outbreaks started during the month of January, culminated in February (n = 36, 56.25%) and stopped during the month of April 2019. The most common serotype was O (45.83%), followed by Asia1 (29.17%) and A (13.89%); however, some case farms had mixed infection with serotypes A and O (9.72%) and serotypes O and Asia1 (1.39%). Multivariable analysis revealed that the history of introducing a new animal with unknown FMD vaccination status in the herd (OR =11.51, 95% CI = 3.28 – 40.47), not practicing regular vaccination against FMD (OR = 20.81, 95% CI = 4.59 – 94.35), history of the visit of an animal broker (OR = 9.06, 95% CI = 2.31 – 35.61), distance of the farm to a nearby livestock farm (OR = 6.13, 95% CI = 1.39 – 27.01) and large herd size (OR = 20.79, 95% CI = 2.45 – 176.27) were significantly associated with the occurrence of FMD outbreaks in Punjab province during 2019. In conclusion, improving biosecurity measures, avoiding the introduction of animals without FMD vaccination history and regular vaccination against FMD can significantly reduce the occurrence of the disease on livestock farms in Pakistan.