Estimating the generation interval for coronavirus disease (COVID-19) based on symptom onset data, March 2020.
基于症状发作数据估计冠状病毒疾病 (新型冠状病毒肺炎) 的产生间隔，2020 年 3 月。
- 作者列表："Ganyani T","Kremer C","Chen D","Torneri A","Faes C","Wallinga J","Hens N
:BackgroundEstimating key infectious disease parameters from the coronavirus disease (COVID-19) outbreak is essential for modelling studies and guiding intervention strategies.AimWe estimate the generation interval, serial interval, proportion of pre-symptomatic transmission and effective reproduction number of COVID-19. We illustrate that reproduction numbers calculated based on serial interval estimates can be biased.MethodsWe used outbreak data from clusters in Singapore and Tianjin, China to estimate the generation interval from symptom onset data while acknowledging uncertainty about the incubation period distribution and the underlying transmission network. From those estimates, we obtained the serial interval, proportions of pre-symptomatic transmission and reproduction numbers.ResultsThe mean generation interval was 5.20 days (95% credible interval (CrI): 3.78-6.78) for Singapore and 3.95 days (95% CrI: 3.01-4.91) for Tianjin. The proportion of pre-symptomatic transmission was 48% (95% CrI: 32-67) for Singapore and 62% (95% CrI: 50-76) for Tianjin. Reproduction number estimates based on the generation interval distribution were slightly higher than those based on the serial interval distribution. Sensitivity analyses showed that estimating these quantities from outbreak data requires detailed contact tracing information.ConclusionHigh estimates of the proportion of pre-symptomatic transmission imply that case finding and contact tracing need to be supplemented by physical distancing measures in order to control the COVID-19 outbreak. Notably, quarantine and other containment measures were already in place at the time of data collection, which may inflate the proportion of infections from pre-symptomatic individuals.
研究背景冠状病毒疾病 (新型冠状病毒肺炎) 爆发的关键传染病参数对建模研究和指导干预策略至关重要。aimWe估计新型冠状病毒肺炎的产生间隔、序列间隔、症状前传播的比例和有效繁殖数。我们说明基于序列间隔估计计算的再现数可能有偏差。方法我们使用来自中国新加坡和天津集群的暴发数据，从症状发作数据中估计产生间隔，同时承认潜伏期分布和潜在传输网络的不确定性。从这些估计中，我们获得了序列间隔、症状前传播的比例和繁殖数。结果新加坡的平均世代间隔为 5.20 天 (95% 可信间隔 (CrI): 3.78-6.78)，天津的平均世代间隔为 3.95 天 (95% CrI: 3.01-4.91)。症状前传播的比例新加坡为 48% (95% CrI: 32-67)，天津为 62% (95% CrI: 50-76)。基于生成间隔分布的再现数估计值略高于基于序列间隔分布的估计值。敏感性分析表明，从疫情数据中估计这些数量需要详细的接触者追踪信息。结论高估计症状前传播的比例意味着病例发现和接触者追踪需要辅以物理距离措施，以控制新型冠状病毒肺炎暴发。值得注意的是，在数据收集时，检疫和其他遏制措施已经到位，这可能会增加有症状前个体的感染比例。
METHODS::Since mid-December of 2019, coronavirus disease 2019 (COVID-19) infection has been spreading from Wuhan, China. The confirmed COVID-19 patients in South Korea are those who came from or visited China. As secondary transmissions have occurred and the speed of transmission is accelerating, there are rising concerns about community infections. The 54-year old male is the third patient diagnosed with COVID-19 infection in Korea. He is a worker for a clothing business and had mild respiratory symptoms and intermittent fever in the beginning of hospitalization, and pneumonia symptoms on chest computerized tomography scan on day 6 of admission. This patient caused one case of secondary transmission and three cases of tertiary transmission. Hereby, we report the clinical findings of the index patient who was the first to cause tertiary transmission outside China. Interestingly, after lopinavir/ritonavir (Kaletra, AbbVie) was administered, β-coronavirus viral loads significantly decreased and no or little coronavirus titers were observed.
METHODS::In December 2019, a novel coronavirus (2019-nCoV) caused an outbreak in Wuhan, China, and soon spread to other parts of the world. It was believed that 2019-nCoV was transmitted through respiratory tract and then induced pneumonia, thus molecular diagnosis based on oral swabs was used for confirmation of this disease. Likewise, patient will be released upon two times of negative detection from oral swabs. However, many coronaviruses can also be transmitted through oral-fecal route by infecting intestines. Whether 2019-nCoV infected patients also carry virus in other organs like intestine need to be tested. We conducted investigation on patients in a local hospital who were infected with this virus. We found the presence of 2019-nCoV in anal swabs and blood as well, and more anal swab positives than oral swab positives in a later stage of infection, suggesting shedding and thereby transmitted through oral-fecal route. We also showed serology test can improve detection positive rate thus should be used in future epidemiology. Our report provides a cautionary warning that 2019-nCoV may be shed through multiple routes.
METHODS::There is a current worldwide outbreak of a new type of coronavirus (2019-nCoV), which originated from Wuhan in China and has now spread to 17 other countries. Governments are under increased pressure to stop the outbreak spiraling into a global health emergency. At this stage, preparedness, transparency, and sharing of information are crucial to risk assessments and beginning outbreak control activities. This information should include reports from outbreak sites and from laboratories supporting the investigation. This paper aggregates and consolidates the virology, epidemiology, clinical management strategies from both English and Chinese literature, official news channels, and other official government documents. In addition, by fitting the number of infections with a single-term exponential model, we report that the infection is spreading at an exponential rate, with a doubling period of 1.8 days.