[Waterborne and Foodborne Disease Outbreaks in the Republic of Korea, 2023]

The Korea Disease Control and Prevention Agency (KDCA) is strengthening its management system by conducting nationwide epidemiological investigations and risk assessments for water and foodborne diseases. In addition, the KDCA operates the "Enhanced Surveillance of Water and Foodborne Disease Outbreaks" during high-risk periods from May to September every year. In 2023, 600 outbreaks were reported, including 329 large-scale and 271 small-scale incidents. Most outbreaks occurred in April (59, 9.8%), February (56, 9.3%), and December (55, 9.2%), with no significant increase during summer. Outbreaks were most frequent in restaurants (275, 45.8%), educational facilities (217, 36.2%), and group-living facilities (41, 6.8%), in that order. Most outbreaks occurred in educational facilities in March and September, coinciding with school opening, with 42 (7.0%) in elementary schools and 38 (6.3%) in kindergartens. The presumed source of infection was mainly "unknown" (373, 62.2%), followed by "carriers" (human-to-human transmission, food service employees, etc. [84, 14.0%]). "Norovirus" was the most commonly suspected pathogen (204, 34.0%), followed by "unknown" (182, 30.3%) and "Salmonella" (48, 8.0%). Notably, 76.5% of outbreaks suspected of "Norovirus" were presumed to involve human-to-human transmission. As a analysis of water and foodborne disease outbreak in 2023, to prevent the spread of these diseases, it is essential to maintain an annual surveillance system, provide ongoing education for managers and workers in educational facilities, and promote personal hygiene education. Additionally, establishing surveillance systems to block transmission routes based on infection source characteristics is critical.