Ahn Seonhee, Son Tae Jong, Jang Yoonsuk, Choi Jihyun, Park Young Joon, Seong Jiseon, Kwon Hyun Hee, Kim Muk Ju, Kwon Donghyok
Division of Infectious Disease Response, Gyeongbuk Regional Disease Response Center, Korea Disease Control and Prevention Agency, Daegu, Republic of Korea.
Epidemiological Investigation Team, Korea Disease Control and Prevention Agency, Cheongju, Republic of Korea.
Osong Public Health Res Perspect. 2023 Jun;14(3):188-196. doi: 10.24171/j.phrp.2023.0066. Epub 2023 Jun 8.
Healthcare facilities are high-risk sites for infection. This study analyzed the epidemiological characteristics of a coronavirus disease 2019 (COVID-19) outbreak in a tertiary hospital after COVID-19 vaccination had been introduced in Republic of Korea. Vaccine effectiveness (VE) and shared anti-infection strategies are also assessed.
The risk levels for 4,074 contacts were evaluated. The epidemiological characteristics of confirmed cases were evaluated using the chi-square test. The "1 minus relative risk" method was used to determine VE in preventing infection, progression to severe disease, and death. In the largest affected area (the 8th floor), a separate relative risk analysis was conducted. A multivariate logistic regression analysis (with 95% confidence interval [CIs]) was used to identify transmission risk factors with a significance level <10% via the backward elimination method.
In total, 181 cases of COVID-19 were confirmed, with an attack rate of 4.4%. Of those cases, 12.7% progressed to severe disease, and 8.3% died. In the cohort isolation area on the 8th floor, where 79.0% of the confirmed cases occurred, the adjusted odds ratio was 6.55 (95% CI, 2.99-14.33) and 2.19 (95% CI, 1.24-3.88) for caregivers and the unvaccinated group, respectively. VE analysis revealed that 85.8% of the cases that progressed to severe disease and 78.6% of the deaths could be prevented by administering a second vaccine.
Caregiver training for infection prevention and control is necessary to reduce infection risk. Vaccination is an important intervention to reduce the risk of progression to severe disease and death.
医疗机构是感染的高风险场所。本研究分析了韩国引入2019冠状病毒病（COVID-19）疫苗后，一家三级医院发生的COVID-19疫情的流行病学特征。同时评估了疫苗效力（VE）和共享的抗感染策略。
评估了4074名接触者的风险水平。使用卡方检验评估确诊病例的流行病学特征。采用“1减去相对风险”方法确定疫苗在预防感染、进展为重症疾病和死亡方面的效力。在受影响最大的区域（8楼）进行了单独的相对风险分析。采用多因素逻辑回归分析（95%置信区间[CI]），通过向后排除法确定显著性水平<10%的传播风险因素。
共确诊181例COVID-19病例，感染率为4.4%。其中，12.7%进展为重症疾病，8.3%死亡。在8楼的队列隔离区，79.0%的确诊病例发生在此处，护理人员和未接种疫苗组的调整优势比分别为6.55（95%CI，2.99-14.33）和2.19（95%CI，1.24-3.88）。疫苗效力分析显示，接种第二剂疫苗可预防85.8%进展为重症疾病的病例和78.6%的死亡病例。
为降低感染风险，有必要对护理人员进行感染预防和控制培训。接种疫苗是降低进展为重症疾病和死亡风险的重要干预措施。
