Thanh Nguyen-Tien

Bio: Thanh Nguyen-Tien is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 12 citations.

Simulating Cross-Contamination of Cooked Pork with Salmonella enterica from Raw Pork through Home Kitchen Preparation in Vietnam.

Abstract: Pork is the most commonly consumed meat in Vietnam, and Salmonella enterica is a common contaminant. This study aimed to assess potential S. enterica cross-contamination between raw and cooked pork in Vietnamese households. Different scenarios for cross-contamination were constructed based on a household survey of pork handling practices (416 households). Overall, 71% of people used the same knife and cutting board for both raw and cooked pork; however, all washed their hands and utensils between handling raw and cooked pork. The different scenarios were experimentally tested. First, S. enterica was inoculated on raw pork and surfaces (hands, knives and cutting boards); next, water used for washing and pork were sampled to identify the presence and concentration of S. enterica during different scenarios of food preparation. Bootstrapping techniques were applied to simulate transfer rates of S. enterica cross-contamination. No cross-contamination to cooked pork was observed in the scenario of using the same hands with new cutting boards and knives. The probability of re-contamination in the scenarios involving re-using the cutting board after washing was significantly higher compared to the scenarios which used a new cutting board. Stochastic simulation found a high risk of cross-contamination from raw to cooked pork when the same hands, knives and cutting boards were used for handling raw and cooked pork (78%); when the same cutting board but a different knife was used, cross-contamination was still high (67%). Cross-contamination between was not seen when different cutting boards and knives were used for cutting raw and cooked pork. This study provided an insight into cross-contamination of S. enterica, given common food handling practices in Vietnamese households and can be used for risk assessment of pork consumption.

Food safety in low- and middle-income countries: What works, what doesn't and why

Abstract: Evidence on foodborne disease (FBD) in low and middle income countries (LMICs) is still limited, but important studies in recent years have broadened our understanding. These suggest that developing country consumers are concerned about FBD; that most of the known burden of FBD disease comes from biological hazards; and, that most FBD is the result of consumption of fresh, perishable foods sold in informal markets. FBD is likely to increase in LMICs as the result of massive increases in the consumption of risky foods (livestock and fish products and produce) and lengthening and broadening value chains. Although intensification of agricultural production is a strong trend, so far agro-industrial production and modern retail have not demonstrated clear advantages in food safety and disease control. There is limited evidence on effective, sustainable and scalable interventions to improve food safety in domestic markets. Training farmers on input use and good practices often benefits those farmers trained, but has not been scalable or sustainable, except where good practices are linked to eligibility for export. Training informal value chain actors who receive business benefits from being trained has been more successful. New technologies, growing public concern and increased emphasis on food system governance can also improve food safety.

Food safety practices of food handlers at home engaged in online food businesses during COVID-19 Pandemic in the Philippines

Abstract: This study was conducted to assess the self-reported and observed food safety practices (FSP) of food handlers, who deliver food products that are prepared and cooked at home during the COVID-19 pandemic in the Philippines. 751 participated in the online survey who were selected using criterion sampling. A questionnaire developed by the researcher was used to gather data with Cronbach Alpha of 0.91. t-test, ANOVA, and Fleiss kappa were performed to treat data. There were no significant differences between self-reported FSP in four dimensions and demographic characteristics, except for age, where a significant difference exists between the FSP of the four age groups along food preparation (F ​= ​4.530, ρ x ¯ and σ of 1.72 ​± ​0.69 which is interpreted as Sometimes Practiced. The food handlers at home inadequately and inappropriately practiced the protocols in keeping the food safe to eat. The observed reports showed that the food handlers at home do not meet food safety standards as indicated in the weighted x ¯ and σ in the four dimensions 1.63 ± 0.11, with a description of Sometimes Practiced. Observed practices further show very poor adherence to guidelines. Test for inter-rater reliability yielded almost perfect agreement (κ ​= ​0.81, ρ ρ ρ ρ ρ

Prevalence of Salmonella spp. and Staphylococcus aureus in Chicken Meat and Pork from Cambodian Markets.

Abstract: Salmonella spp. and Staphylococcus aureus are two of the most common foodborne bacteria in animal-source foods (ASF) that cause illness worldwide. This study aimed to determine the prevalence of Salmonella spp. and S. aureus in chicken meat and pork in markets in Cambodia. Sampling was done in 52 traditional markets and 6 supermarkets in 25 provinces of Cambodia between October 2018 and August 2019. In total, 532 samples were obtained: chicken meat and pork (n = 408, 204 of each), chicken and pork cutting board swabs (n = 124, 62 of each). All samples were analyzed for the presence of Salmonella spp. and S. aureus; colony-forming units per gram (CFU/g) of coagulase-positive Staphylococci (CPS) were counted, and a subset of samples was also analyzed for the most probable number (MPN, n = 136) of Salmonella. The overall prevalence of Salmonella spp. and S. aureus were 42.1% (224/532) and 29.1% (155/532), respectively, with 14.7% (78/532) of samples containing both bacteria. The prevalence of Salmonella spp. in chicken meat was 42.6%, on chicken cutting board it was 41.9%, on pork it was 45.1%, and the pork cutting board 30.6%. Chicken meat had a significantly (p-value < 0.05) higher prevalence of S. aureus, 38.2%, compared to the chicken cutting board, 17.7%, pork 28.9%, and pork cutting board 11.3%. Mean MPN-Salmonella was 10.6 MPN/g in chicken and 11.1 MPN/g in pork samples. Average Log CFU/g of CPS in chicken and pork samples were 2.6 and 2.5, respectively. The results indicate that chicken meat and pork in Cambodia were highly contaminated with Salmonella spp. and S. aureus, posing risks to consumers' health. Urgent interventions are necessary to improve hygiene for safer meat in Cambodian markets.