Risk of Water and Food-Borne Communicable Diseases in Travelers Entering Korea

OBJECTIVES: It was supposed to analyze status and affecting factors in water and food-borne communicable disease by screening entrants with diarrhea symptom at the point of entry in Korea METHODS: Symptomatic travelers with water and food-borne communicable diseases who entered Korea were diagnosed by a health declaration and detection of causative agents in water and food using laboratory tests. Among those entered in 2017, the affecting factors in the incidence of communicable diseases among those who had diarrhea at the entry into Korea, were analyzed, with frequency and chi-square test. RESULTS: The number of travel entrants with gastrointestinal communicable diseases increased by 40.19% from 2013 to 2017. The percentage of causative agents of water and food-borne communicable diseases was the highest at 69.2% from July to September. The rate of detection of causative agents of communicable disease pathogens in travelers from Southeast Asia entering Korea was 70.2%, which was higher than people arriving from East Asia and Central Asia (57.5%; p < 0.001). CONCLUSION: The positive ratio of causative agents of water and food-borne communicable diseases was high among travelers that had entered Korea from July to September, with a high number among entrants from Southeast Asia. Based on the positive detection of causative agents, the entry period and countries visited were statistically significant affecting factors (p < 0.001).

Distribution of Pathogenic Vibrio Species in the Coastal Seawater of South Korea (2017–2018)

OBJECTIVES: Pathogenic Vibrio species are widely distributed in warm estuarine and coastal environments, and can infect humans through the consumption of raw or mishandled contaminated seafood and seawater. For this reason, the distribution of these bacteria in South Korea was investigated.METHODS: Seawater samples were collected from 145 coastal area points in the aquatic environment in which Vibrio species live. Environmental data (i.e., water temperature, salinity, turbidity, and atmospheric temperature) was collected which may help predict the distribution of the species (data not shown). Seawater samples were filtered, and incubated overnight in alkaline peptone water, at 37°C. Using species-specific polymerase chain reaction methods, screening tests were performed for the hlyA, ctxA, vvhA, and tlh genes. Clones of pathogenic Vibrio species were isolated using 3 selective plating media.RESULTS: In 2017, total seawater isolation rates for Vibrio vulnificus, Vibrio cholerae (non-pathogenic, non-O1, non-O139 serogroups), and Vibrio parahaemolyticus were 15.82%, 13.18%, 65.80%, respectively. However, in 2018 isolation rates for each were 21.81%, 19.40%, and 70.05%, respectively.CONCLUSION: The isolation rates of pathogenic Vibrio species positively correlated with the temperature of seawater and atmosphere, but negatively correlated with salinity and turbidity. From 2017 to 2018, the most frequent seawater-isolated Vibrio species were V. parahaemolyticus (68.10 %), V. vulnificus (16.54%), and non-toxigenic V. cholerae (19.58%). Comprehensive monitoring, prevention, and control efforts are needed to protect the public from pathogenic Vibrio species.