ABSTRACT
With the spread of COVID-19 in the world, the medical protective clothing has becoming more and more important. However, there have been few reports on the analysis of the current protective clothing standards. This paper summarizes the current standards of medical protective clothing at home and abroad systematically. Furthermore, the main standards of medical protective clothing (GB19082-2009, ISO 16603-2004, ISO 16604-2004, NFPA1999-2018, EN14126-2003) are compared. Through the analysis, the protection requirements of various standards are compared in detail, the shortcomings of the standards of surgical clothing are pointed out, and lastly suggestions for improvement are put forward.
ABSTRACT
With the further spread of COVID-19, the market trend the protective mask industry presents new changes, which is both an opportunity and a challenge for the development of China's textile industry. This paper reviews the origin and development of masks and expounds the internal structure and protective mechanism of masks. Masks are an important line of defense against respiratory infections and can reduce the risk of novel coronavirus infection. Masks can not only prevent the patient from spraying droplets, reduce the amount and speed of droplets, but also block the virus containing droplets nucleus, preventing the wearer from inhaling. There are many types of face masks on the market, and different types of face masks have different application ranges. Different types of face masks follow different standards. The author investigated the application scope and relevant standards of masks in various countries, sorted out the classification, standards and evaluation indicators, etc., in order to provide help for medical personnel and the public. Through analysis, the new surgical mask with high antibacterial, high viral resistance and comfortable wearing is an important development direction in the future.
ABSTRACT
Objective: To describe the basic characteristics of clusters of coronavirus diseases 2019 (COVID-19) cases in Ningbo, Zhejiang province, and evaluate the generation time (Tg) and basic reproduction number (R(0)) of COVID-19. Methods: The basic information and onset times of the clusters of COVID-19 cases in Ningbo were investigated, the inter-generational interval of the cases were fitted by using gamma distribution, and the R(0) was calculated based on the SEIR model. Results: In the 15 clusters of COVID-19 cases, a total of 52 confirmed cases, 5 cases of nucleic acid-positive asymptomatic cases. The cases occurred from January 23 to February 4, the cases were mainly women. The incubation period was (6.11±3.38) days, and the median was 5 days. The Tg was (6.93±3.70) days. There were no significant differences in Tg between age group<60 years and age group 60 years and above, and between men and women (P=0.551). According to the Tg calculated in this paper, the R(0) of COVID-19 in Ningbo was 3.06 (95%CI: 2.64- 3.51); according to the reported case transmission interval of 7.5 days in the literature, the R(0) was 3.32 (95%CI: 2.51-9.38). Conclusion: There is no age and gender specific differences in the Tg of clusters of COVID-19 cases in Ningbo, and COVID-19 has high infectivity and spreading power in early phase.
Subject(s)
COVID-19 , COVID-19/epidemiology , China/epidemiology , Female , Humans , Male , Middle Aged , SARS-CoV-2ABSTRACT
Objective: To investigate a cluster epidemic of COVID-19 after a mass gathering activity in Ningbo of Zhejiang province and analyze the transmission chain and status of infection cases of different generations. Methods: The tracking of all the close contacts of the first COVID-19 case and epidemiological investigation were conducted on January 29, 2020 after a cluster epidemic of COVID-19 related with a Buddhism rally on January 19 (the 1.19 rally) in Ningbo occurred. The swabs of nose/throat of the cases and close contacts were collected and tested for nucleic acids by real-time fluorescence quantitative RT-PCR. Results: From January 26 to February 20, 2020, a total of 67 COVID-19 cases and 15 asymptomatic infection cases related with the 1.19 rally were reported in Ningbo. The initial case was the infection source who infected 29 second generation cases and 4 asymptomatic infection cases, in whom 23 second generation cases and 3 asymptomatic infection cases once took bus with the initial case, the attack rate was 33.82% (23/68) and the infection rate was 38.24% (26/68). The risks of suffering from COVID-19 and being infected were 28.91 times and 26.01 times higher in rally participants taking bus with initial case compared with those taking no bus with initial case. In this epidemic, 37 third+generation cases and 11 related asymptomatic infection cases occurred, the attack rate was 2.88% (37/1 283) and the infection rate was 4.76% (48/1 008). The main transmission routes included vehicle sharing and family transmission. Conclusion: It was a cluster epidemic of COVID-19 caused by a super spreader in a massive rally. The epidemic has been under effective control.