Consumption of raw or undercooked freshwater fish and awareness of risks of associated bacterial and parasitic infections in Southeast Asia: an online multicountry cross-sectional survey.

Introduction: Foodborne trematodiases such as clonorchiasis and opisthorchiasis, alongside bacterial infections linked to eating raw or undercooked freshwater fish, pose major public health concerns in Southeast Asia. However, regional data on the prevalence of this dietary practice remains limited. Methods: We conducted a cross-sectional survey of 6021 participants from Cambodia, Lao People's Democratic Republic (PDR), Malaysia, Singapore, Thailand and Vietnam between October 2022 and February 2024. Univariate and multivariable logistic regression analyses were conducted to assess consumption patterns across sociodemographic groups. Results: Raw freshwater fish consumption was most common in Cambodia, Lao PDR, Thailand and Vietnam-between 70% and 90% indicated ever consuming high-risk dishes despite relatively high awareness of associated risks (60%-80%). Younger individuals and male participants generally reported higher consumption. Notably, participants aged 40 and above were significantly less likely to consume high-risk dishes in Cambodia (adjusted OR (AOR): 0.12, 95% CI 0.05 to 0.29), Singapore (AOR: 0.47, 95% CI 0.34 to 0.64), Thailand (AOR: 0.63, 95% CI 0.47 to 0.85) and Vietnam (AOR: 0.40, 95% CI 0.19 to 0.82). In Vietnam, males were more likely to consume high-risk dishes (AOR: 2.16, 95% CI 1.11 to 4.42). Knowledge was protective in Singapore-participants who were unaware of the risks of consumption were 1.6 times more likely to consume high-risk dishes (AOR: 1.62, 95% CI 1.16 to 2.26). Conclusions: Raw freshwater fish consumption remains widespread in Southeast Asia, placing populations at risk of parasitic and bacterial infections. These findings highlight critical gaps in risk communication and can guide targeted interventions to reduce consumption and prevent associated disease outbreaks.