Objectives We descriptively reviewed a coronavirus disease 2019 (COVID-19) outbreak at a nursing hospital in Gyeonggi Province (South Korea) and assessed the effectiveness of the first dose of the Oxford-AstraZeneca vaccine in a real-world population. Methods: The general process of the epidemiological investigation included a public health intervention. The relative risk (RR) of vaccinated and unvaccinated groups was calculated and compared to confirm the risk of severe acute respiratory syndrome coronavirus-2 (SARSCoV-2) infection, and vaccine effectiveness was evaluated based on the calculated RR. Results: The population at risk was confined to ward E among 8 wards of Hospital X, where the outbreak occurred. This population comprised 55 people, including 39 patients, 12 nurses, and 4 caregivers, and 19 cases were identified. The RR between the vaccinated and unvaccinated groups was 0.04, resulting in a vaccine effectiveness of 95.3%. The vaccination rate of the nonpatients in ward E was the lowest in the entire hospital, whereas the overall vaccination rate of the combined patient and non-patient groups in ward E was the third lowest. Conclusion: The first dose of the Oxford-AstraZeneca vaccine (ChAdOx1-S) was effective in preventing SARS-CoV-2 infection. To prevent COVID-19 outbreaks in medical facilities, it is important to prioritize the vaccination of healthcare providers.
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Preparing for Future Pandemics: Vaccine Effectiveness Against SARS-CoV-2 Variant in a High-Risk Hospital Environment—A Case Study From Vietnam Hien Thi Nguyen, Luong Huy Duong, Thai Quang Pham, Than Huu Dao, Kieu-Anh Thi Nguyen, Huyen Thi Nguyen, Nghia Duy Ngu, Duong Nhu Tran, Kim-Nhung Thi Le, Tung Son Trinh, H. Rogier van Doorn, Florian Vogt, Khanh Cong Nguyen Asia Pacific Journal of Public Health.2025; 37(8): 681. CrossRef
COVID-19 Vaccination in Korea: Past, Present, and the Way Forward Eliel Nham, Joon Young Song, Ji Yun Noh, Hee Jin Cheong, Woo Joo Kim Journal of Korean Medical Science.2022;[Epub] CrossRef
<sec>
<title>Objectives</title>
<p>Investigations into foodborne illness, potentially caused by <italic>Kudoa septempunctata</italic>, has been ongoing in Korea since 2015. However, epidemiological analysis reporting and positive <italic>K septempunctata</italic> detection in feces in Korea has been limited. The aim of this study was to provide epidemiologic data analysis of possible food poisoning caused by <italic>K septempunctata</italic> in Korea.</p></sec>
<sec>
<title>Methods</title>
<p>This study reviewed 16 <italic>Kudoa</italic> outbreak investigation reports, including suspected cases between 2015 and 2016 in Gyeonggi province, Korea. Suspected <italic>Kudoa</italic> foodborne illness outbreak was defined as “evidence of <italic>K septempunctata</italic> in at least one sample.” The time and place of outbreak, patient symptoms and <italic>Kudoa</italic> (+) detection rate in feces was analyzed.</p></sec>
<sec>
<title>Results</title>
<p><italic>Kudoa</italic> foodborne illness outbreaks occurred in most patients in August (22.6%) and in most outbreaks in April (25%). The attack rate was 53.9% and the average attack rate in patients who had consumed olive flounder was 64.7%. The average incubation period was 4.3 hours per outbreak. Diarrhea was the most common symptom which was reported by 91.5% patients. The <italic>Kudoa</italic> (+) detection rate in feces was 69.2% of cases.</p></sec>
<sec>
<title>Conclusion</title>
<p>Monthly distribution of <italic>Kudoa</italic> foodborne illness was different from previous studies. The <italic>Kudoa</italic> (+) detection rate in feces decreased rapidly between 25.5 and 28.5 hours of the time interval from food intake to epidemiologic survey. To identify effective period of time of investigation, we believe additional study with extended number of cases is necessary.</p></sec>
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