Abstract:
This study aimed at determine prevalence and concentration of Streptococcus suis contamination in pork production chains as well as evaluate the health risk attributable to S. suis serotype 2 from pork consumption in Thailand. In total, 492 pig-to-pork and 480 environmental samples were collected from 4 pork production chains in Bangkok. Besides, total 1,036 pork samples were also collected from traditional and modern trades in Chiangmai, Phayao, Nan, Khonkaen, Mukdahan, Saraburi, Nakhonpathom, and Phang-nga provinces. All samples were enumerated using plate count method. S. suis isolates were confirmed by detecting cps2-j gene, followed by Quellung reaction. A stochastic risk assessment model was constructed using the available information together with the results from this study. Total 11.4% (56/492) of pig-to-pork samples and 5.2% (25/480) of environmental samples from Bangkok were positive to S. suis. Total 1% (10/1,036) of pork samples from both traditional and modern trades were positive to S. suis, with an average concentration of 4.22 log cfu/g. There was no S. suis serotype 2 detected from all pork samples. The estimated daily risk of S. suis serotype 2 illness from pork consumption was 1.3 x 10-7 or equilvalent to 4.6 cases per 100,000 persons, annually. A sensitivity analysis revealed that exposure dose, bacterial concentration at consumption and storage time at home greatly impacted the risk estimate.
