Abstract:
Mechanically recovered meat products have been linked to salmonellosis outbreaks in humans. However, no studies have investigated the prevalence and likelihood of mechanically recovered poultry meat (MRPM) imported to South Africa being contaminated with a Salmonella species; despite South Africa being a net importer of MRPM. This study seeks to address this gap by investigating the prevalence and factors associated with the likelihood of importing a Salmonella-contaminated consignment to South Africa. Furthermore, the study identified steps in the value chain likely to impact the levels of this likelihood significantly.
Secondary data of MRPM consignments imported through a South African port entry between 2016 and 2017 was used for this study. Crude and factor-specific proportions of Salmonella positive MRPM consignments and their 95% confidence intervals were calculated for all variables. A logistic regression model was fit to the data to assess the association between country of origin, importer, season, year, month, and MRPM Salmonella status. The likelihood of importing Salmonella-contaminated MRPM consignments was modelled using @Risk software in Microsoft Excel. Spearman’s ranked correlation coefficients were used to assess the correlations between predictors and the likelihood of a consignment being contaminated with Salmonella.
A total of 8127 MRPM consignments were imported over the study period. Seventeen percent (17.18%, 985/5733) of the tested consignments were positive for Salmonella species. Among the 364 isolates that were serotyped, Salmonella Heidelberg (73.90%) was the most common serotype. The odds of consignment testing positive for Salmonella differed based on country of origin, season, and year of importation. The overall likelihood of importing Salmonella-contaminated MRPM consignment to South Africa was calculated as 5.88 x10-4 (5th= 5.886x 10-5--95th=5.73x10-3) which was low. The prevalence of Salmonella in the exporting country (1.00) was significantly correlated with the likelihood of importing Salmonella-contaminated MRPM consignment to South Africa.
Salmonella species have been identified in MRPM consignments imported through a port of entry to South Africa. Among these, Salmonella Heidelberg was the most common. The quantitative risk assessment model suggests that there is likelihood of importing a positive consignment. However, some of the Salmonella serotypes reported in this study have been implicated in foodborne disease outbreaks. Therefore, a risk mitigation strategy must be developed, considering the Salmonella status of the exporting country, the importer, and the season of importation.
