Introduction: Food safety is an important public health concern globally. Risk communication is one of crucial element to manage food safety. While current food safety studies have focused on contamination of hazards or risk factors, limited research exists on consumer concerns, knowledge and perception about the actual risk food poses to their health. This study aimed to assess and compare the knowledge and perceptions regarding food safety, and the information needed and trusted by pork consumers in Northern Vietnam.Methods: A total of 225 consumers recruited from three different market types: modern urban, traditional urban and traditional rural, were interviewed using a questionnaire between November to December 2019.Results: The majority of participants (81.8%) were female and consumers interviewed at modern urban retail were younger than those interviewed at traditional retail settings (p < 0.01). Sixty-five percent of participants across the three retail types agreed that microbes were the most common hazards which can make them sick, but the adverse health effect due to chemical hazards was ranked higher than that of biological hazards. Most participants often received food safety information that was about animal diseases (such as African swine fever most recently), chemical contamination and the unknown origin of food rather than about food poisoning and measures to prevent it. Food safety messages from television and professional experts were the most trusted sources and consumer preference was for information about the origin of food (traceability) and how to choose safe food. Participants were willing to receive food safety information daily to weekly. A lack of perception and awareness about animal welfare related to pig farming or slaughtering was reported by most respondents (84.3%).Discussion: These findings provide insight on Vietnamese consumer knowledge gaps, information demand and communication channels for food safety, so that risk communicators and managers can implement better food safety awareness campaigns and communication to consumers.

Trichinellosis and cysticercosis remain challenges to human health and animal productivity worldwide, especially in developing countries. While information on the occurrence of both diseases is infrequent, they are endemic in parts of Vietnam and mainly related to indigenous pigs kept by ethnic minorities. This study aimed to determine the seroprevalence and risk factors of both diseases in indigenous pigs and explore the perception and awareness of both human and pig trichinellosis and cysticercosis of pig farmers. A total of 352 pig sera samples from 131 holdings were collected and analyzed using ELISA antibody tests in six communes in the Da Bac districts of Hoa Binh province, Vietnam. A survey was conducted with representatives from these households to understand the knowledge and perspective on food-borne parasitic diseases. Overall, the seroprevalence of trichinellosis and T. solium cysticercosis was 13.6% (95% CI 10.2–17.7) and 1.7% (95% CI 0.6–3.7), respectively. The seroprevalence of trichinellosis was significantly higher in female and older pigs. Risk perception and knowledge of interviewed people on both human and pig trichinellosis and cysticercosis of pig farmers was poor. Risky practices, including free roaming of pigs and eating undercooked or fermented pork, were observed. Educational and awareness campaigns aligned with further research on feasible practice changes are critical to addressing these issues.

Foodborne diseases linked with pork consumption remain a major public health concern in low- and middle- income countries, where traditional supply chains dominate, food safety controls are limited, and interventions are under-explored. This thesis tested and evaluated food safety interventions in pig slaughterhouses and traditional markets, using a One Health approach that integrates microbiological, behavioural, economic, and socio-cultural perspectives. Two intervention studies were conducted across five provinces in the north, central, and south of Vietnam. At 16 slaughterhouses, a controlled trial evaluated a technique-based (low-cost equipment and hygiene training) and an incentive-based (performance-based inspection with financial rewards) intervention. At 68 traditional markets, a randomised controlled trial assessed interventions including vendor training, inspection and public disclosure, equipment provision, and a consumer awareness campaign. A total of 192 samples from slaughterhouses (pig carcasses and workers’ hand swabs) and 814 samples from markets (cut pork and cutting board swabs) were analysed for total bacterial count, Salmonella, coliforms, and Escherichia coli, alongside pre- and post- intervention observations and interviews (486 participants each round). Baseline findings demonstrated high microbiological contamination and poor hygiene practices at both slaughterhouses and markets. Interventions improved knowledge, hygiene practices, equipment availability, and additionally at the market level, increased vendor revenues. Microbiological reductions were observed for certain indicators at slaughterhouses but remained consistently high at markets, indicating the influence of interacting factors, including hygienic practice, infrastructure, environmental conditions, and socio-economic dynamics along the supply chain. Consumer awareness and risk perception exhibited a limited response to the consumer campaign, and purchasing behaviour remained unchanged. This thesis contributes to the evidence based on intervention effectiveness under real-world conditions, suggesting that future strategies should emphasise consumers as active drivers of demand for safe food, combined with coordinated structural and regulatory improvements across the supply chain.