Prevalence of non-typhoidal Salmonella and risk factors on poultry farms in Chitwan, Nepal

Abstract

Background and Aim: Poultry is becoming an increasingly important source of protein in the Nepalese diet. The Chitwan region of Nepal is the hub of the emerging poultry industry. Little is known about the prevalence of non-typhoidal Salmonella (NTS) on poultry farms or the role of farm management practices that may contribute to the presence of NTS on farms. The role of poultry in the transmission of Salmonella enterica to humans is also poorly defined. This descriptive study seeks establish baseline data through estimation of the prevalence of NTS on broiler and layer operations in various farms of the Chitwan district of Nepal. Materials and Methods: Based on district documents on poultry production and meat marketing, a purposive sampling of 18 commercial poultry farms comprising ten broilers farms and eight layers farms was conducted. Environmental samples including water, litter, feces, feed, farm, and eggshell swabs were randomly collected from each farm. Samples were cultured and tested for the presence of NTS; positives were serotyped, and antimicrobial susceptibility determined. A comprehensive farm and practice questionnaire was administered to each farm manager. Results: The farm level point prevalence rate was 55% (10 of 18 farms) for S. enterica. Of the total 288 farm environmental samples collected, 26 samples (9%) were positive. The rate of isolation varied according to the origin of samples: Water (27.5%), feces (10.6%), litter (8.6%), farm swabs (5%), feed (1.8%), and eggshells (0%). Farm management variables/risk factors are summarized and categorized as non-modifiable and modifiable for analysis. Broiler operations were more likely to be positive than layer operations as were poultry houses with two or less open sides. All-in/all-out management style was found to be protective. Due to the small sample size (18 farms), no associations reached statistical significance. Conclusion: Based on environmental sampling results, NTS is highly prevalent on the poultry farms in the Chitwan district of Nepal. Certain risk factors are associated with finding NTS on farms. Our findings are generally in agreement with other studies in similar countries with rapidly emerging poultry industries. The identification of risk factors provides owners, technicians, and veterinarians with some guidance to help reduce the prevalence of NTS on farms. This baseline data are critical to understanding the epidemiology of zoonotic strain of NTS in the region and are necessary for the design of future studies and mitigation plans and underlines the need for a one-health approach to protect public health-related to Salmonella spp. from poultry farms.

Prevalence and antibiotic resistance of Salmonella isolated from poultry and its environment in the Mekong Delta, Vietnam

“…The largely asymptomatic infected animals can spread infections across the poultry supply chain. The prevalence of Salmonella isolated from chicken feces (7.67%) in this study was similar to the previous reports; Alali et al [24] reported that Salmonella was isolated from broiler feces in organic [26]. The prevalence of Salmonella isolated from backyard chickens was 3.5% in Paraguay [27] and 12.7% from free-range chickens in China [15].…”

“…Feeds, especially in the deep litter management systems, can become a potential source of Salmonella contamination [33,34]. Further, the prevalence of Salmonella was reported as 0.26-38.8% in the feed and 0.6-27.5% in the drinking water [4,24,26,35]. Thus, Salmonella can be transmitted back and forth among the chickens through contaminated feed and water.…”

Risk Factors for Persistent Infection of Non-Typhoidal Salmonella in Poultry Farms, North Central Nigeria

“…We confirmed that the odds of NTS infection through feed was slightly high. Other workers [ 44 ] have recently confirmed that the incidence of NTS (S. enterica) in poultry feed and feed ingredients may range from 0 to 78%, and these may serve as a source of infection on poultry farms. Pen odour increased the risk by almost two-fold, which is more an indication of the poor hygiene practices and poor litter management on the farm rather than a risk factor itself.…”

Isolation and antibiotic sensitivity of Salmonella typhimurium isolates from poultry farms and slaughterhouses of Chitwan, Nepal

“…Establishing good antibiotic stewardship, through collaborative education efforts among veterinarians, para-vets, and farmers could help mitigate the resistance of pathogens to antibiotics and improve the efficacy of treatment. Regulatory oversight of water quality, antibiotic sales and use, animal slaughter practices and facility hygiene, along with consumer education about food safety are critical components to control the spillover of drug-resistant strains of Salmonella from poultry to humans (Sharma et al, 2021).…”