Emergence of Riemerella anatipestifer Infection in Domestic Ducks in Assam, India

Abstract

Duck farming is an important component of poultry production in India, contributing substantially to both egg and meat production. According to the 2019 livestock census, Assam's total duck population is approximately 12.04 million. In Assam and the northeastern region of India, ducks are primarily raised by marginal farmers. With the growing changing pattern of climate around the world, there is outbreak of new diseases of poultry in many areas. Riemerella anatipestifer (RA) infection, a bacterial disease that is becoming prevalent in Assam and causing considerable economic losses for duck farmers. The present study was aimed to conduct an epidemiological study on the outbreak of RA infection in Assam. Samples of both nasal and throat swabs were collected from both sick and ailing ducks across various organized and unorganized duck farms throughout Assam. Twenty six out of 40 samples showed cultural characteristics were tentatively identified as RA. The infection was confirmed using polymerase chain reaction (PCR) targeting the Z gene, which yielded an amplicon of 546 base pairs (bp). The highest prevalence of PCR positivity was detected in pharyngeal swabs (73.33%), followed by ocular swabs (63.00%). This study concludes that RA infection is an emerging endemic infection among the duck population of Assam.