Challenges Caused by Imported Cases Abroad for the Prevention and Control of COVID-19 in China

Abstract

Background: Overseas imported cases of COVID-19 continue to increase in China, so we conducted this study to review the epidemiological characteristics of these patients.Methods: From February 26 to April 4, 2020, the imported cases from abroad were enrolled in this study. The effect of prevention countermeasures in curbing the spread of COVID-19 was assessed in this study. Moreover, we defined incubation period and confirmed time as from the date of leaving the epicenter to date of symptom onset and date of final diagnosed, respectively, and the interval of symptom onset to final diagnosed time was defined as diagnostic time. Categorical variables were summarized as numbers and percentages, and the difference among the variables were analyzed.Results: For 670 cases imported from abroad, 555 were Chinese and 115 were foreigners. Apparently, confirmed cases had significantly decreased after China was compelled to temporarily suspend the entry of foreign passport holders with valid visas or residence permits; 6 days after implement of controlled measures, the daily new confirmed cases were reduced to 13 cases. Moreover, about 84.3% of patients (166/197) presented symptoms 1 week after leaving the epicenter, and notably seven patients (3.6%) had symptoms 2 weeks after leaving the epicenter. The median incubation period was 3.0 days (inter quartile range, 1.0 to 6.0), the 95th percentile was 11.6 days. Additionally, most of cases (92.9%) were detected positively of nucleic acid after symptom onset with 4 days, the median diagnostic time was 2.0 days (interquartile range, 1.0 to 3.0), and the 95th percentile of the distribution was 5.0 days. Finally, about 5.8% of patients were healthy carriers, and the median confirmed time of asymptomatic patients was 4.0 days (interquartile range, 2.0 to 9.0). The following variables might be associated with confirmed time: symptom type (P = 0.005), exported regions (P < 0.001), and symptom onset time (P < 0.001).Conclusions: The prevention countermeasures for imported cases implemented by the Chinese government played an indispensable role in curbing the spread of COVID-19; the time of departure from epicenter could provide an estimate of the incubation period; and a confirmed time, 2-week quarantine period might need to be prolonged, while asymptomatic patients should be closely monitored.

Incubation Period of COVID-19 Caused by Unique SARS-CoV-2 Strains

“…We identified 5012 records through PubMed, EMBASE, and Science Direct database searches, and documented the study selection process in a flowchart and showed the total numbers of retrieved references and the numbers of included and excluded studies (Figure 1). Based on the inclusion and exclusion criteria, 142 articles (8112 patients) were selected for analysis …”

Changes in Incidence of Notifiable Infectious Diseases in China Under the Prevention and Control Measures of COVID-19

“…China has strengthened control over people living abroad following the COVID-19 outbreak, which also limited the spread of imported diseases such as dengue fever and malaria. At the same time, the country forbids the consumption of live wild animals, and people's awareness of protection is enhanced, which also reduces the possibility of cross-border transmission of infectious diseases to a certain extent (29). The year-on-year increase in the incidence of brucellosis was related to the "Lanzhou Event" in China in 2020, which led to the outbreak of brucellosis, the increase in detection quantity, and the increase in the number of reported cases (30).…”

Psychological Health and Sleep Quality of Medical Graduates During the Second Wave of COVID-19 Pandemic in Post-epidemic Era

“…As a result, on March 15, 2020, the World Health Organization (WHO) declared the COVID-19 outbreak as a global pandemic ( 3 ). With the reversal of the epidemic at home and abroad, China was faced intense pressure due to imported cases ( 4 ).…”