ABSTRACT
Background: An outbreak of pneumonia associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan city and then spread to other cities. It is very urgent to delineate the epidemiological and clinical characteristics of these affected patients. Methods: To investigate the epidemiological characteristics of the COVID-19, we describe a case series of 473 patients with confirmed COVID-19 in Wenzhou of China from January 27 to March 2, 2020.Results: The median age of all patients was 47.6 years, 48.4% of which were female. 33.8% of the patients had a history of residence in Wuhan. Fever (71.7%) and cough (43.1%) were the most common symptoms. In addition, three kinds of unconventional cases were observed, namely 4.9% asymptomatic patients, 7.6% confirmed patients who had no link to Wuhan city but contact with individuals from Wuhan without any symptoms at the time of contact, and 12.9% confirmed patients who had an unknown source of transmission. We estimated that the basic reproductive number (R0) was 2.75 (95%CI: 2.37-3.23). The effective reproduction number (Rt) fluctuated within the range of 2.50 to 3.74 from January 11 to January 16 while gradually reached the peak of 3.74 on January 16. Rt gradually decreased after January 16 and decreased to 1.00 on January 30. Rt continually decreased and reached the lowest point (0.03) on February 21, 2020.Conclusion: Our findings presented the possibility of asymptomatic carriers affected with SARS-CoV-2, and this phenomenon suggested that chances of uncontrollable transmission in the larger population might be higher than formerly estimated, and transmission by these three kinds of unconventional patients in Wenzhou may be an important characteristic of infection in other mid-sized cities in the world. This study evaluated the epidemic characteristics of Wenzhou after having cases imported from Hubei Province and the effects after adopting a series of strict prevention and control strategy.
Subject(s)
COVID-19 , Fever , PneumoniaABSTRACT
Coronavirus infection has exerted a severe disease burden on the world, especially the newly emerged SARS-CoV-2 that has caused worldwide pandemic. It is possible meteorological factors can influence the transmission of coronavirus. The aim of this study was to evaluate the effect of meteorological factors on COVID-19 and SARS, and to provide evidence for disease control and prevention. Data of COVID-19 and SARS cases and daily mean temperature, relative humidity and other meteorological factors in Guangzhou in 2003 and 2020 were collected. Using a distributed lag non-linear model approach, we assessed the relationship between ambient temperature, relative humidity and the risks of COVID-19 and SARS. The numbers of cases for COVID-19 and SARS during the study period were 347 and 1072, respectively. There was a dome-shaped relation between mean temperature and COVID-19, with a threshold of 14.50°C (RR=1.48, 95%CI: 1.01, 2.16) and the optimal range was 12.40-16.40°C. A similar association was found between mean temperature and SARS occurrence, with a threshold of 18.40°C (RR=1.02, 95%CI: 1.00, 1.04), and the optimal range was 15.30-19.30°C. Besides, there were non-linear negative relationships between both RH and COVID-19, SARS. In addition, the largest overall effect of RH on COVID-19 and SARS were obtained at 52% and 45%, yielding relative risk of 7.47 (95%CI: 1.66, 33.55) and 47.56 (95%CI: 11.49, 196.95), respectively. The optimal ranges were below 77.00% and below 82.70%, respectively. Meteorological parameters should be taken into consideration while developing early warning systems and risk strategies for controlling and preventing coronavirus infection.
Subject(s)
COVID-19 , Coronavirus InfectionsABSTRACT
Background: An outbreak of pneumonia associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan city and then to other city. It is very urgent to delineate the epidemiological and clinical characteristics of these affected patients. Methods: To investigate the epidemiological characteristics of the COVID-19, we describe a case series of 459 patients with confirmed COVID-19 in WZ of China from January 27 to February 12, 2020.Results: The median age of all patients was 48.0 years, and 46.8% were females. 37.5% of patients had a history of residence in Wuhan. Fever (72.1%) and cough (43.6%) were the most frequent symptoms. In addition, three kinds of unconventional cases were observed, in which included 4.4% confirmed virus carrier who were asymptomatic, 7.8% confirmed patients who had no link to Wuhan city but contact with individuals from Wuhan without any symptoms at the time of contact, and 10.7% confirmed patients who had no link to Wuhan city nor a history of intimate contact with patients or individuals from Wuhan without any symptoms, respectively.Conclusion: Our findings presented the possibility of asymptomatic carriers affected with SARS-CoV-2, and this phenomenon suggested that chances of uncontrollable transmission in the larger population might be higher than formerly estimated, and transmission by these three kinds of unconventional patients in WZ may be one of the characteristics of infection in other Chinese cities outside the Wuhan epidemic area.