Fred Unger

Dr. Fred Unger


Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 February 2017 in Infectious Diseases of Poverty
Verified
Journal Article
Open access
PDF file
HNHung Nguyen-Viet
Hung Nguyen-Viet
TTTuyet-Hanh Thi Tran Thi
Tuyet-Hanh Thi Tran Thi
FUFred Unger
Fred Unger
SDSinh Dang
Sinh Dang
Delia GraceDelia Grace
Delia Grace
Food-borne diseases are attracting a lot of attention in Vietnam as a result of repeated episodes of adulterated and unsafe food. In this paper, we provide some perspectives on food safety in Vietnam from the point of view of an international research institution working on food safety with partners in the country. We argue that one of the key issues of food safety in Vietnam is that certain food value chain stakeholders lack ethics, which leads to the production and trading of unsafe foods in order to make profits irrespective of adverse health effects on consumers. In turn, the shortfall in ethical behaviours around food can be attributed to a lack of incentives or motivating factors. Although food safety causes panic in the population, it is unclear how much contaminated food contributes to the burden of food-borne diseases and food poisonings in Vietnam. However, globally, the biggest health problem associated with food are infections from consuming food contaminated with viruses, bacteria or parasites. A major food safety challenge is the inappropriate way of communicating food risks to the public. Another key constraint is the inherent difficulty in managing food in wet markets and from smallholder production. On the other hand, local foods, and local food production and processing are an important cultural asset as well as being essential to food safety, and these aspects can be put at risk if food safety concerns motivate consumers to purchase more imported foods. In this paper, we also discuss good experiences in food safety management from other countries and draw lessons learnt for Vietnam on how to better deal with the current food safety situation.

4 May 2021 in Pathogens
Verified
Journal Article
Open access
PDF file
Rortana CheaRortana Chea
Rortana Chea
HNHung Nguyen-Viet
Hung Nguyen-Viet
STSothyra Tum
Sothyra Tum
FUFred Unger
Fred Unger
SBSofia Anna Boqvist
Sofia Anna Boqvist
Johanna LindahlJohanna Lindahl
Johanna Lindahl
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.

1 February 2019 in International Journal of Food Microbiology
Verified
Journal Article
Closed access
SDSinh Dang
Sinh Dang
HNHung Nguyen-Viet
Hung Nguyen-Viet
PPPhuc Pham-Duc
Phuc Pham-Duc
FUFred Unger
Fred Unger
NTNgan Tran-Thi
Ngan Tran-Thi
KMKohei Makita
Kohei Makita

SDSinh Dang
Sinh Dang
HNHung Nguyen-Viet
Hung Nguyen-Viet
PPPhuc Pham-Duc
Phuc Pham-Duc
Delia GraceDelia Grace
Delia Grace
FUFred Unger
Fred Unger
KMKohei Makita
Kohei Makita
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.

10 May 2021 in Pathogens
Verified
Journal Article
Open access
PDF file
EHEllinor Henriksson
Ellinor Henriksson
RSRebecca Söderberg
Rebecca Söderberg
GHGunilla Ström Hallenberg
Gunilla Ström Hallenberg
Kroesna KangKroesna Kang
Kroesna Kang
Sokong LySokong Ly
Sokong Ly
Johanna LindahlJohanna Lindahl
Johanna Lindahl
Japanese encephalitis (JE) is endemic in Cambodia, but circulation of JE virus (JEV) among domestic pigs has previously only been studied in the southern part of the country. The main purpose of this study was to determine the seroprevalence of JEV antibodies in smallholder pigs held in rural areas of Kampong Thom, Preah Vihear, Ratanakiri, and Stung Treng provinces, northeastern Cambodia. Another purpose was to identify possible associations between serologic status and other factors, such as reproductive disorders, and to investigate the farmers’ knowledge of mosquito-borne diseases and use of preventive measures. In October 2019, 139 households were visited throughout the study area, and 242 pigs were sampled for blood. The sera were analysed with ELISA for JEV antibodies. Household representatives were interviewed, and data were recorded for each sampled pig. The apparent seroprevalence was 89.1% in pigs between 3 and 6 months of age, and 100% in pigs over 6 months of age. In total, 93.0% of the pigs tested positive. Province appeared to be the only factor significantly associated with serologic status (p < 0.001). Almost all (97.8%) respondents knew that mosquitos could transmit diseases, and 70.5% had heard of JE. However, only one respondent knew that JEV is transmitted to people through mosquito bites. Very few respondents knew that pigs can become infected with JEV, and no one knew that mosquitos transmit the virus. All families used some sort of mosquito protection for themselves, but only 15.1% protected their pigs from mosquito bites. The children were vaccinated against JE in 93 households, while adults only were vaccinated in eight households. The results suggest that JEV transmission is intense in northeastern Cambodia, and that people’s knowledge about the transmission route of JEV and the role of pigs in the transmission cycle is low. Fortunately, people are well aware of mosquito-borne diseases in general and use mosquito protection, and many children are vaccinated against JE. Nonetheless, it is important that national vaccination is continued, and that people—especially in rural areas where pigs are commonly kept—are educated on the ecology and transmission of JEV.

Chalita JainontheeChalita Jainonthee
Chalita Jainonthee
SDSinh Dang
Sinh Dang
HNHung Nguyen-Viet
Hung Nguyen-Viet
FUFred Unger
Fred Unger
WCWarangkhana Chaisowwong
Warangkhana Chaisowwong
The COVID-19 pandemic affected the food supply chain, retailers, and consumers owing to infection awareness. This study evaluated the impacts COVID-19 on ASF retailers’ businesses and consumers’ livelihoods, as well as their knowledge toward the disease, attitudes, and food safety practices to prevent infections. The study includes a cross-sectional component that was conducted in urban/peri-urban (U/PU) and rural areas in Chiang Mai province. In another part of the study, a structured questionnaire was developed for animal source food (ASF) retailers and consumers, with three primary parts for data analysis: general information, COVID-19 impacts, and knowledge, attitudes, and practices (KAP) assessment. Data corresponding to three periods of interest (before the COVID-19 outbreak, during partial lockdown, and present) were gathered and analyzed. In this study, 155 retailers and 150 consumers participated, of which the majority of the respondents were female (70.3% and 82.7%, respectively) with average ages of 47.4 and 44.9 years, respectively. The most noticeable effect of COVID-19 was a decline in income for retailers and consumers. The KAP scores of consumers in both areas were not significantly different, whereas the retailer attitudes toward COVID-19 prevention and food safety practices scored more highly in rural areas than in U/PU. During the partial lockdown, food safety practices significantly improved relative to the time preceding the outbreak, and these practices have remained constant to the present day. The results revealed that gender, age group, business type, and type of ASF retailers were associated with the KAP of the retailers, whereas gender, age group, education, number of family members, and occupation were associated with the KAP of the consumers. Our findings provide in-depth information about the effects of COVID-19 on ASF retailers and consumers, as well as their KAP regarding the outbreak and food safety, which may serve as support in developing policies for improved health and food safety.