Analysis on a Typical COVID-19 Outbreak Spread by Tourist Groups

Background Novel coronavirus disease (SARS COV-2 infection or COVID-19) is a respiratory tract infection which has been linked with severe acute respiratory syndrome transmitted particularly through touching and respiration. The purpose of this study is to understand the epidemiological characteristics of the COVID-19 cases in a typical tourist-related outbreak and explore the possible route for its transmission. Methods All data and epidemiological survey reports of COVID-19 cases in the outbreak were reported by provincial and urban (county) Centers for Disease Control and Prevention and Health Commissions nationwide from October 16 to November 5, 2021. The epidemiological survey reports included information on gender, age, source of infection (imported from other provinces or locally acquired), daily life track and itinerary, date of symptom onset and date of diagnosis. The data were analyzed using descriptive statistical methods, one-way analysis of variance, independent t-test, and Chi-square tests. Histograms and percentage stacked area plots were used to describe the epidemiological characteristics of the outbreaks. Results The COVID-19 outbreak associated with the tourist groups has involved 551 COVID-19 cases, with a median age of 44 years (interquartile range: 30-59 years), gradually spreading from the northwestern region to the national level across 15 provinces of China. Fifth cases (16.0%) had traveled to ejin banner, resulting in 68 second-generation cases. The outbreak involved 11 flights and 19 trains, with a total of 27 confirmed cases. An amount of 42 related outbreaks were clustered, of which 21 outbreaks (50.0%) occurred in households and 10 outbreaks (23.81%) in restaurants. About 106 confirmed cases were related to the restaurant gathering. The median incubation period for this COVID-19 outbreak was 7 days (inter-quartile range: 5-10 days). Conclusions The survey results indicated that this COVID-19 outbreak originated in Ejina Banner and spread by tourist groups, which was a typical infection outbreak promoted by travel. Our results further confirmed that travel need to be more strictly weighed in pandemic like COVID-19, and people need to pay more attention to the prevention against infectious diseases particularly when traveling in a tourist group.