Prevalence of Campylobacter and Non-typhoidal Salmonella in Chicken and Chicken Products in South and Southeast Asia: A Systematic Review and Meta-analysis

Abstract

This systematic literature review and meta-analysis took the very first attempt to assess the prevalence of Campylobacter and non-typhoidal Salmonella in chicken samples and chicken eggs in south and south-east Asia along with the associated risk factors. A computerized literature search was performed targeting publications from 2000 to 2020 on PubMed, ProQuest, Embase, Web of Science and Google Scholar. A total of 60 Campylobacter articles and 121 non-typhoidal Salmonella articles were selected for this meta-analysis after title, abstract and full-text screening. The overall estimated random effect pool prevalence of Campylobacter in chicken in south and south-east Asia at sample unit was 42.4% (95% Confidence Interval: 36.1% to 48.7%) and farm unit was 58.4% (95% CI: 42.4% to 74.4%). On the other hand, overall random-effect non-typhoidal Salmonella prevalence in chicken samples was 26.1% (95% CI: 22.5% to 29.8%) and egg samples was 9% (95% CI: 4.7% to 13.3%) in this region. Metaregression results suggested that both Campylobacter [Co-efficient: 23.5 (95% Confidence interval: 9.2 to 37.7); p=0.001] and non-typhoidal Salmonella [Coefficient: 22.5 (95% CI: 13.3 to 31.7); p=<0.001] were most prevalent among samples from Thailand. Samples collected from live bird markets showed the highest prevalence [Co-efficient: 17.6 (95% CI: 3.5 to 31.7); p=0.01] for Campylobacter while nontyphoidal Salmonella was most prevalent in retail outlets [Co-efficient: 28.1 (95% CI: 11.0 to 45.1]. Non-typhoidal Salmonella was detected more in carcass [Co-efficient: 38.4 (95% CI: 22.4 to 54.3), p<0.001] and raw meat [Co-efficient: 17.6 (95% CI: 6.5 to 29.0); p=0.002] samples. Egg shells [Co-efficient: 15 (95% CI: 2.2 to 27.7); p=0.02] significantly contained more non-typhoidal Salmonella than egg content. C. jejuni [79.9%; 95% CI: 78.2% to 81.4%] and C. coli [17.1%; 95% CI: 15.6% to 18.6%] were the predominant Campylobacter species. Salmonella enterica serovar Enteritidis (30.3%; 95% CI: 27.7% to 33.1%) was the most commonly identified in chicken samples and Salmonella enterica serovar Typhimurium (62.5%; 95% CI: 48.5% to 75.1%) was most common in egg samples. Installment of surveillance system, proper training of the workers of live bird markets and retail outlets to maintain hygiene and avoiding raw and undercooked meat and egg is recommended to prevent and control these pathogens.