Microbial risk assessment of Staphylococcus species in smoked fish from informal markets in Edo State, Nigeria: processing practices and public health implications

Abstract Purpose Staphylococcal contamination of smoked fish represents a public health concern, particularly in informal food markets. This study investigated the microbial risk associated with Staphylococcus-contaminated smoked fish, processing practices, and potential public health implications in Benin City, Nigeria. Structured questionnaires were administered to smoked fish vendors to document processing, handling, and storage practices. Materials and methods Smoked fish samples (Scomber, Meluza, Sese, catfish, and herring) were collected and analyzed using standard culture-based and molecular techniques. Questionnaire data were analyzed using chi-square and correlation analyses. Quantitative Microbial Risk Assessment (QMRA) was conducted to estimate the probability of adverse health outcomes following consumption of contaminated fish, using the exponential dose–response model. Results The results showed that 98% of the smoked fish samples were contaminated with Staphylococcus species, including coagulase-positive strains. Methicillin-resistant Staphylococcus aureus (MRSA) was detected in 37.78% of the samples. Fish stored for more than two days post-smoking exhibited significantly higher bacterial counts (p < 0.05), with marked logarithmic increases observed within 24–48 h after smoking. Scomber and Meluza samples had significantly higher staphylococcal loads than those of other fish species. The use of preservatives, vendors’ awareness of bacterial contamination, and the type of smoking material (wood or sawdust) did not significantly (p > 0.05) influence bacterial loads. QMRA outcomes indicated a high predicted probability (> 90%) of adverse health effects under ambient storage conditions over 2–4 d. Conclusion These findings underscore the need for improved hygiene practices, enhanced consumer and vendor education, better preservation strategies, and stricter regulatory oversight to reduce the risk of staphylococcal foodborne illnesses associated with smoked fish consumption.