tetano
Editor, Senior Moderator
J Med Internet Res
. 2020 Aug 27.
doi: 10.2196/19994. Online ahead of print.
Epidemiological parameters of coronavirus disease 2019: a case series study
Shujuan Ma[SUP] 1 [/SUP], Jiayue Zhang[SUP] 1 [/SUP], Minyan Zeng[SUP] 2 [/SUP], Qingping Yun[SUP] 3 [/SUP], Wei Guo[SUP] 1 [/SUP], Yixiang Zheng[SUP] 4 [/SUP], Shi Zhao[SUP] 5 [/SUP], Maggie H Wang[SUP] 5 [/SUP], Zuyao Yang[SUP] 5 [/SUP]
Affiliations
Abstract
Background: The outbreak of coronavirus disease 2019 (COVID-19) has been declared a pandemic by the World Health Organization, while the estimates of several key epidemiological parameters of the disease by many studies were based on small sample sizes or inaccurate due to various issues.
Objective: This study aimed to obtain more robust estimates of the incubation period, serial interval, frequency of pre-symptomatic transmission, and basic reproduction number (R0) of COVID-19.
Methods: We systematically retrieved and screened 20658 reports of laboratory confirmed COVID-19 cases released by the health authorities of China, Japan, and Singapore and 9942 publications retrieved from PubMed and CNKI through April 8, 2020. To be eligible, a report had to contain individual data that allowed for accurate estimation of at least one parameter. Widely used models such as gamma distributions were fitted to the data sets and the results with best-fitting values were presented.
Results: In total, 1591 cases were included for the final analysis. The mean and standard deviation were estimated to be 7.04 days and 4.27 days, respectively, for incubation period (n=687), and 6.49 days and 4.90 days, respectively, for serial interval (n=1015 pairs). In 40 (5.82%) cases, the incubation period was longer than 14 days. In 32 (3.15%) infector-infectee pairs, infectees' symptom onsets occurred before those of infectors. Pre-symptomatic transmission occurred in 129 (43.58%) infector-infectee pairs (n=296 pairs). R0 was estimated to be 1.85 (95% CI: 1.37, 2.60).
Conclusions: This study provides robust estimates of several epidemiological parameters of COVID-19. The findings support current practice of 14-day quarantine of persons with potential exposure, but also suggest the need for additional measures. Pre-symptomatic transmission together with the asymptomatic transmission reported by previous studies highlight the importance of adequate testing, strict quarantine, and social distancing.
. 2020 Aug 27.
doi: 10.2196/19994. Online ahead of print.
Epidemiological parameters of coronavirus disease 2019: a case series study
Shujuan Ma[SUP] 1 [/SUP], Jiayue Zhang[SUP] 1 [/SUP], Minyan Zeng[SUP] 2 [/SUP], Qingping Yun[SUP] 3 [/SUP], Wei Guo[SUP] 1 [/SUP], Yixiang Zheng[SUP] 4 [/SUP], Shi Zhao[SUP] 5 [/SUP], Maggie H Wang[SUP] 5 [/SUP], Zuyao Yang[SUP] 5 [/SUP]
Affiliations
- PMID: 33001833
- DOI: 10.2196/19994
Abstract
Background: The outbreak of coronavirus disease 2019 (COVID-19) has been declared a pandemic by the World Health Organization, while the estimates of several key epidemiological parameters of the disease by many studies were based on small sample sizes or inaccurate due to various issues.
Objective: This study aimed to obtain more robust estimates of the incubation period, serial interval, frequency of pre-symptomatic transmission, and basic reproduction number (R0) of COVID-19.
Methods: We systematically retrieved and screened 20658 reports of laboratory confirmed COVID-19 cases released by the health authorities of China, Japan, and Singapore and 9942 publications retrieved from PubMed and CNKI through April 8, 2020. To be eligible, a report had to contain individual data that allowed for accurate estimation of at least one parameter. Widely used models such as gamma distributions were fitted to the data sets and the results with best-fitting values were presented.
Results: In total, 1591 cases were included for the final analysis. The mean and standard deviation were estimated to be 7.04 days and 4.27 days, respectively, for incubation period (n=687), and 6.49 days and 4.90 days, respectively, for serial interval (n=1015 pairs). In 40 (5.82%) cases, the incubation period was longer than 14 days. In 32 (3.15%) infector-infectee pairs, infectees' symptom onsets occurred before those of infectors. Pre-symptomatic transmission occurred in 129 (43.58%) infector-infectee pairs (n=296 pairs). R0 was estimated to be 1.85 (95% CI: 1.37, 2.60).
Conclusions: This study provides robust estimates of several epidemiological parameters of COVID-19. The findings support current practice of 14-day quarantine of persons with potential exposure, but also suggest the need for additional measures. Pre-symptomatic transmission together with the asymptomatic transmission reported by previous studies highlight the importance of adequate testing, strict quarantine, and social distancing.