Household hygiene practices and foodborne pathogen contamination in traditional fermented fish from northeastern Thailand: a One Health cross-sectional study

Background and Aim: Traditional fermented fish (pla-som) is widely consumed in Northeastern Thailand and contributes substantially to household nutrition and rural livelihoods. However, production is commonly conducted at the household level under limited sanitary control, increasing the risk of foodborne pathogen contamination. From a One Health perspective, human hygiene behavior, environmental sanitation, and food safety are closely interconnected. This study aimed to assess the prevalence of major foodborne bacterial pathogens in household-produced fermented fish and to determine their associations with hygiene practices. Materials and Methods: A cross-sectional analytical study was conducted between May and October 2020 in Kalasin Province, Northeastern Thailand. A total of 144 fermented fish samples were collected from 23 registered household production sites. Microbiological analyses were performed to detect Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Salmonella spp. using standard bacteriological methods. Hygiene conditions were evaluated using a structured checklist based on national Good Manufacturing Practice (GMP) criteria covering six domains: location and building, equipment and utensils, production process control, sanitation, maintenance and cleaning, and personal hygiene. Binary logistic regression was used to identify associations between hygiene factors and bacterial contamination. Results: S. aureus was the most prevalent contaminant (72.92%), followed by Salmonella spp. (57.64%), E. coli (40.28%), and B. cereus (12.50%). E. coli contamination was significantly associated with poor equipment and utensil hygiene (Adjusted odds ratio [AOR] = 16.61; 95% CI: 3.43–80.46; p < 0.001) and inadequate building conditions (AOR = 0.11; 95% CI: 0.02–0.50; p = 0.005). S. aureus contamination was strongly linked to substandard sanitation (AOR = 0.15; 95% CI: 0.06–0.38; p < 0.001) and poor personal hygiene (AOR = 12.00; 95% CI: 2.52–57.09; p = 0.002). Salmonella spp. contamination was associated with inadequate sanitation, maintenance and cleaning, and personal hygiene, whereas no hygiene-related factors were significantly associated with B. cereus contamination. Conclusion: Household-level fermented fish production in Northeastern Thailand is characterized by high levels of foodborne pathogen contamination, strongly linked to modifiable hygiene practices. Strengthening GMP- and Water, sanitation, and hygiene-based hygiene training for small-scale producers—particularly targeting equipment cleanliness, sanitation, and personal hygiene—can substantially reduce contamination risks and support safer traditional food production within a One Health framework. Keywords: food safety, fermented fish, household hygiene, One Health, Salmonella, Staphylococcus aureus, traditional food production, water sanitation.