ABSTRACT
Objective:To analyze the epidemiological characteristics of 8 clusters of coronavirus disease 2019 （COVID-19） in Chenzhou City， and provide scientific basis for epidemic prevention and control. Methods:Descriptive epidemiological analysis was conducted for 8 COVID-19 clusters， comparing and analyzing the differences of infection rates among close contacts within and outside the family， and emphatically describing two typical cases. Results:8 COVID-19 clusters were reported in Chenzhou with a total of 31 cases from January to February， 2020. The main source of infection of the family index cases was Hubei Province. Cough symptoms were observed in 67.74% of the cases， followed by fever （54.84%）. The infection rate of close contacts within the family （55.00%） was higher than that outside the family （2.56%）， and the difference was statistically significant （χ2=28.177， P<0.001）. The infection rate of spouse of the family index cases was 85.71%， higher than that of parents （77.78%）， other family members （44.44%） and children （40.00%）， and the difference was not statistically significant （χ2=6.004， P=0.120）. Two typical cases suggested that both COVID-19 pre-symptomatic and asymptomatic patients have the potential to excrete the virus from the body and become sources of infection. Conclusion:Effective family prevention and control measures and early sampling and screening of people in key epidemic areas are conducive to early detection， early isolation and early treatment of infected people， so as to avoid the occurrence and spread of family clusters.
ABSTRACT
Objective To identify the epidemiological features of COVID-19 epidemic in Chenzhou City, Hunan province so as to provide scientific evidence for effective containment of the COVID-19 epidemic. Methods Descriptive epidemiological method was used to retrospectively characterize the confirmed COVID-19 cases and asymptomatic cases in Chenzhou City from January 23 through March 10, 2020. Results A total of 39 confirmed COVID-19 cases and 6 asymptomatic cases infection were documented in the city, with no death.We identified 8 clusters of COVID-19, which were all familial transmission.There was statistical difference between the sources of different types of epidemic (χ2=15.996, P < 0.001), in which all the local COVID-19 cases were the secondary cases in the clusters.As the epidemic expanded, the trend shifted from imported-case-centered to local-case-centered.The epidemic has covered 81.81% of the city area; in each area, the first COVID-19 cases were all imported. Conclusion The COVID-19 epidemic has been effectively controlled.At present, we focus on the quarantine in the entry and exit to prevent the imported epidemic.
ABSTRACT
Objective@#To conduct an epidemiological investigation on a cluster of overseas imported cases of coronavirus disease 2019(COVID-19)in Qingtian County, Lishui,so as to provide reference for the prevention and control of COVID-19 imported from abroad. @*Methods@#According to the COVID-19 Prevention and Control Program (FiFth Edition) issued by National Health Commission of China,a field investigation was employed and the close contacts of the case were tracked down ;the real-time reverse transcription polymerase chain reaction (RT-PCR) assay was performed to detect the nucleic acid of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from the sputum specimens or throat swabs of cases;the epidemiological characteristics,source of infection,route of transmission and disposal of the cluster were analyzed. @*Results@#From March 1 to March 6,2020,eight confirmed cases and one asymptomatic case of COVID-19 were reported. Their median age was 33 years old. The nine cases all had no fever,no decrease in leukocyte and lymphocyte levels,and the clinical symptoms of seven cases were not obvious. The asymptomatic case had been tested negative for SARS-CoV-2 for six times,but had been weakly positive for IgM antibody and strongly positive for IgG antibody. Nine cases were all the employees of the same restaurant in Begamo,Italy. They lived in three independent villas and usually had lunch and dinner in the restaurant where they worked. Begamo had COVID-19 epidemic,but the staff of the restaurant did not take any protective measures such as wearing masks and environmental disinfection. Eight cases reported to have cold symptoms in Italy during mid February. Through a closed-loop management of“all people,all sites,all chains ”,such as treatment of current cases,screening and isolation of close contacts and health education,totally 372 close contacts were traced back,yet no fever or respiratory symptoms have been found. @*Conclusions @# It was a cluster of COVID-19 cases imported from abroad. The clinical symptoms of the cases were not obvious. Qingtian County adopted the closed-loop management in time,and effectively controlled the spread of the epidemic. No second-generation cases have been found.