scholarly journals The incubation period of 2019-nCoV infections among travellers from Wuhan, China

2020 ◽  
Author(s):  
Jantien A. Backer ◽  
Don Klinkenberg ◽  
Jacco Wallinga
Keyword(s):  
Incubation Period ◽  
Symptom Onset ◽  
Viral Pneumonia ◽  
Case Definitions ◽  
Travel History ◽  
The Mean ◽  
Novel Coronavirus ◽  
Epidemiological Characteristics

AbstractCurrently, a novel coronavirus 2019-nCoV causes an outbreak of viral pneumonia in Wuhan, China. Little is known about its epidemiological characteristics. Using the travel history and symptom onset of 88 confirmed cases that were detected outside Wuhan, we estimate the mean incubation period to be 6.4 (5.6 – 7.7, 95% CI) days, ranging from 2.1 to 11.1 days (2.5th to 97.5th percentile). These values help to inform case definitions for 2019-nCoV and appropriate durations for quarantine.

scholarly journals Incubation period of 2019 novel coronavirus (2019-nCoV) infections among travellers from Wuhan, China, 20–28 January 2020

2020 ◽  
Vol 25 (5) ◽  
Author(s):  
Jantien A Backer ◽  
Don Klinkenberg ◽  
Jacco Wallinga
Keyword(s):  
Incubation Period ◽  
Symptom Onset ◽  
Credible Interval ◽  
Viral Pneumonia ◽  
Case Definitions ◽  
Travel History ◽  
The Mean ◽  
Novel Coronavirus

A novel coronavirus (2019-nCoV) is causing an outbreak of viral pneumonia that started in Wuhan, China. Using the travel history and symptom onset of 88 confirmed cases that were detected outside Wuhan in the early outbreak phase, we estimate the mean incubation period to be 6.4 days (95% credible interval: 5.6–7.7), ranging from 2.1 to 11.1 days (2.5th to 97.5th percentile). These values should help inform 2019-nCoV case definitions and appropriate quarantine durations.

scholarly journals Correlation between times to SARS-CoV-2 symptom onset and secondary transmission undermines epidemic control efforts

2021 ◽  
Author(s):  
Natalie M. Linton ◽  
Andrei R. Akhmetzhanov ◽  
Hiroshi Nishiura
Keyword(s):  
Incubation Period ◽  
Symptom Onset ◽  
Focal Point ◽  
Transmission Dynamics ◽  
Generation Interval ◽  
Improve Model ◽  
The Mean ◽  
Two Parameters ◽  
Respiratory Coronavirus ◽  
Epidemiological Characteristics

AbstractSevere acute respiratory coronavirus 2 (SARS-CoV-2) infections have been associated with substantial presymptomatic transmission, which occurs when the generation interval—the time between infection of an individual with a pathogen and transmission of the pathogen to another individual—is shorter than the incubation period—the time between infection and symptom onset. We collected a dataset of 257 SARS-CoV-2 transmission pairs in Japan and jointly estimated the mean generation interval (3.7–5.1 days) and mean incubation period (4.4–5.7 days) as well as measured their dependence (Kendall’s tau of 0.4–0.6), taking into consideration demographic and epidemiological characteristics of the pairs. The positive correlation between the two parameters demonstrates that reliance on isolation of symptomatic COVID-19 cases as a focal point of control efforts is insufficient to address the challenges posed by SARS-CoV-2 transmission dynamics. Accounting for this dependence within SARS-CoV-2 epidemic models can also improve model estimates.

scholarly journals Incubation Period and Other Epidemiological Characteristics of 2019 Novel Coronavirus Infections with Right Truncation: A Statistical Analysis of Publicly Available Case Data

2020 ◽  
Vol 9 (2) ◽  
pp. 538 ◽  
Author(s):  
Natalie Linton ◽  
Tetsuro Kobayashi ◽  
Yichi Yang ◽  
Katsuma Hayashi ◽  
Andrei Akhmetzhanov ◽  
...  
Keyword(s):  
Incubation Period ◽  
Case Fatality ◽  
Illness Onset ◽  
Event Date ◽  
History Of ◽  
Novel Coronavirus ◽  
Case Fatality Risk ◽  
Right Truncation ◽  
Epidemiological Characteristics ◽  
Mean Time

The geographic spread of 2019 novel coronavirus (COVID-19) infections from the epicenter of Wuhan, China, has provided an opportunity to study the natural history of the recently emerged virus. Using publicly available event-date data from the ongoing epidemic, the present study investigated the incubation period and other time intervals that govern the epidemiological dynamics of COVID-19 infections. Our results show that the incubation period falls within the range of 2–14 days with 95% confidence and has a mean of around 5 days when approximated using the best-fit lognormal distribution. The mean time from illness onset to hospital admission (for treatment and/or isolation) was estimated at 3–4 days without truncation and at 5–9 days when right truncated. Based on the 95th percentile estimate of the incubation period, we recommend that the length of quarantine should be at least 14 days. The median time delay of 13 days from illness onset to death (17 days with right truncation) should be considered when estimating the COVID-19 case fatality risk.

scholarly journals Reduction in time delay of isolation in COVID-19 cases in South Korea

2020 ◽  
Author(s):  
Sukhyun Ryu ◽  
Cheolsun Jang ◽  
Baekjin Kim
Keyword(s):  
Public Health ◽  
Time Delay ◽  
South Korea ◽  
Symptom Onset ◽  
The Public ◽  
Mean Delay ◽  
Health Authorities ◽  
Public Health Authorities ◽  
The Mean ◽  
Novel Coronavirus

AbstractKorean public health authorities raised the public alert to its highest level on February 23, 2020 to mitigate the 2019 novel coronavirus disease epidemic. We have identified that the mean delay from symptom onset to isolation was reduced to one day after raising the alert. Vigilance can reduce this interval.

scholarly journals Analysis of Epidemiological Characteristics of COVID-19 Patients in Rudan county, Iran

2021 ◽  
Vol 10 (2) ◽  
pp. 51-55
Author(s):  
Mirza Ali Nazarnezhad ◽  
Shokrollah Mohseni ◽  
Mohammad Shamsadiny ◽  
Pirdad Najafi ◽  
Morteza Salemi
Keyword(s):  
Patient Information ◽  
The Elderly ◽  
Underlying Disease ◽  
Cross Sectional Study ◽  
World Health ◽  
Cross Sectional ◽  
Registration System ◽  
The Mean ◽  
Novel Coronavirus ◽  
Epidemiological Characteristics

Background: On March 11, 2020, the World Health Organization (WHO) declared the novel coronavirus disease 2019 (COVID-19) as a global pandemic. The aim of the present study was to analyze the epidemiological characteristics of COVID-19 patients in Rudan county so that regional managers can make timely and effective decisions. Materials and Methods: This is a cross-sectional study performed on all registered patients with confirmed COVID-19 in Rudan county by July 10, 2020. Patient information was extracted from COVID-19 patient information registration system. The collected data included gender, age, mortality, underlying disease, time of infection, occupation, contact history, and hospitalizations. Data were analyzed using SPSS version 22.0. Results: In this study, 614 (56%) of the patients were male and 477 (43%) were female. The mean age of patients was 43 ± 17 years. A total of 136 patients (12.5%) had at least one underlying disease. The majority of patients with underlying diseases (75%) had a history of contact with a patient with confirmed COVID-19. There was no statistically significant relationship between mortality and gender. The mean age of inpatients and outpatients was 56 ± 19 and 40 ± 15 years, respectively. Most deaths occurred among the elderly and housewives, and the highest infection rate also occurred among the latter group. Conclusion: In a situation where the COVID-19 pandemic is a global threat, health systems must demonstrate appropriate and timely responses based on the development and implementation of preventive policies and the care of vulnerable and high-risk patients.

scholarly journals Incubation Period and Other Epidemiological Characteristics of 2019 Novel Coronavirus Infections with Right Truncation: A Statistical Analysis of Publicly Available Case Data

2020 ◽  
Author(s):  
Natalie M. Linton ◽  
Tetsuro Kobayashi ◽  
Yichi Yang ◽  
Katsuma Hayashi ◽  
Andrei R. Akhmetzhanov ◽  
...  
Keyword(s):  
Incubation Period ◽  
Case Fatality ◽  
Illness Onset ◽  
Event Date ◽  
History Of ◽  
Novel Coronavirus ◽  
Case Fatality Risk ◽  
Right Truncation ◽  
Epidemiological Characteristics ◽  
Mean Time

AbstractThe geographic spread of 2019 novel coronavirus (COVID-19) infections from the epicenter of Wuhan, China, has provided an opportunity to study the natural history of the recently emerged virus. Using publicly available event-date data from the ongoing epidemic, the present study investigated the incubation period and other time intervals that govern the epidemiological dynamics of COVID-19 infections. Our results show that the incubation period falls within the range of 2–14 days with 95% confidence and has a mean of around 5 days when approximated using the best-fit lognormal distribution. The mean time from illness onset to hospital admission (for treatment and/or isolation) was estimated at 3–4 days without truncation and at 5–9 days when right truncated. Based on the 95th percentile estimate of the incubation period, we recommend that the length of quarantine should be at least 14 days. The median time delay of 13 days from illness onset to death (17 days with right truncation) should be considered when estimating the COVID-19 case fatality risk.

scholarly journals Novel Coronavirus Outbreak in Wuhan, China, 2020: Intense Surveillance Is Vital for Preventing Sustained Transmission in New Locations

2020 ◽  
Vol 9 (2) ◽  
pp. 498 ◽  
Author(s):  
Robin N. Thompson
Keyword(s):  
Symptom Onset ◽  
Credible Interval ◽  
Imported Case ◽  
Global Pandemic ◽  
New Locations ◽  
Current Outbreak ◽  
The Mean ◽  
The Times ◽  
Novel Coronavirus ◽  
Mean Time

The outbreak of pneumonia originating in Wuhan, China, has generated 24,500 confirmed cases, including 492 deaths, as of 5 February 2020. The virus (2019-nCoV) has spread elsewhere in China and to 24 countries, including South Korea, Thailand, Japan and USA. Fortunately, there has only been limited human-to-human transmission outside of China. Here, we assess the risk of sustained transmission whenever the coronavirus arrives in other countries. Data describing the times from symptom onset to hospitalisation for 47 patients infected early in the current outbreak are used to generate an estimate for the probability that an imported case is followed by sustained human-to-human transmission. Under the assumptions that the imported case is representative of the patients in China, and that the 2019-nCoV is similarly transmissible to the SARS coronavirus, the probability that an imported case is followed by sustained human-to-human transmission is 0.41 (credible interval [0.27, 0.55]). However, if the mean time from symptom onset to hospitalisation can be halved by intense surveillance, then the probability that an imported case leads to sustained transmission is only 0.012 (credible interval [0, 0.099]). This emphasises the importance of current surveillance efforts in countries around the world, to ensure that the ongoing outbreak will not become a global pandemic.

scholarly journals Transmission characteristics of the COVID-19 outbreak in China: a study driven by data

2020 ◽  
Author(s):  
Meili Li ◽  
Pian Chen ◽  
Qianqian Yuan ◽  
Baojun Song ◽  
Junling Ma
Keyword(s):  
Public Health ◽  
Incubation Period ◽  
Symptom Onset ◽  
Generation Time ◽  
Reproduction Number ◽  
Contact Tracing ◽  
Transmission Characteristics ◽  
Public Health Threat ◽  
The Mean ◽  
The Basic Reproduction Number

The COVID-19 outbreak has been a serious public health threat worldwide. We use individually documented case descriptions of COVID-19 from China (excluding Hubei Province) to estimate the distributions of the generation time, incubation period, and periods from symptom onset to isolation and to diagnosis. The recommended 14-day quarantine period may lead to a 6.7% failure for quarantine. We recommend a 22-day quarantine period. The mean generation time is 3.3 days and the mean incubation period is 7.2 days. It took 3.7 days to isolate and 6.6 days to diagnose a patient after his/her symptom onset. Patients may become infectious on average 3.9 days before showing major symptoms. This makes contact tracing and quarantine ineffective. The basic reproduction number is estimated to be 1.54 with contact tracing, quarantine and isolation, mostly driven by super spreaders.

scholarly journals Challenges Caused by Imported Cases Abroad for the Prevention and Control of COVID-19 in China

2021 ◽  
Vol 8 ◽  
Author(s):  
Jianfei Zhu ◽  
Qingqing Zhang ◽  
Chenghui Jia ◽  
Shuonan Xu ◽  
Jie Lei ◽  
...  
Keyword(s):  
Incubation Period ◽  
Symptom Onset ◽  
Onset Time ◽  
Interquartile Range ◽  
Categorical Variables ◽  
Chinese Government ◽  
Asymptomatic Patients ◽  
Diagnostic Time ◽  
Imported Cases ◽  
Epidemiological Characteristics

Background: Overseas imported cases of COVID-19 continue to increase in China, so we conducted this study to review the epidemiological characteristics of these patients.Methods: From February 26 to April 4, 2020, the imported cases from abroad were enrolled in this study. The effect of prevention countermeasures in curbing the spread of COVID-19 was assessed in this study. Moreover, we defined incubation period and confirmed time as from the date of leaving the epicenter to date of symptom onset and date of final diagnosed, respectively, and the interval of symptom onset to final diagnosed time was defined as diagnostic time. Categorical variables were summarized as numbers and percentages, and the difference among the variables were analyzed.Results: For 670 cases imported from abroad, 555 were Chinese and 115 were foreigners. Apparently, confirmed cases had significantly decreased after China was compelled to temporarily suspend the entry of foreign passport holders with valid visas or residence permits; 6 days after implement of controlled measures, the daily new confirmed cases were reduced to 13 cases. Moreover, about 84.3% of patients (166/197) presented symptoms 1 week after leaving the epicenter, and notably seven patients (3.6%) had symptoms 2 weeks after leaving the epicenter. The median incubation period was 3.0 days (inter quartile range, 1.0 to 6.0), the 95th percentile was 11.6 days. Additionally, most of cases (92.9%) were detected positively of nucleic acid after symptom onset with 4 days, the median diagnostic time was 2.0 days (interquartile range, 1.0 to 3.0), and the 95th percentile of the distribution was 5.0 days. Finally, about 5.8% of patients were healthy carriers, and the median confirmed time of asymptomatic patients was 4.0 days (interquartile range, 2.0 to 9.0). The following variables might be associated with confirmed time: symptom type (P = 0.005), exported regions (P < 0.001), and symptom onset time (P < 0.001).Conclusions: The prevention countermeasures for imported cases implemented by the Chinese government played an indispensable role in curbing the spread of COVID-19; the time of departure from epicenter could provide an estimate of the incubation period; and a confirmed time, 2-week quarantine period might need to be prolonged, while asymptomatic patients should be closely monitored.

scholarly journals Nosocomial outbreak of COVID-19 pneumonia in Wuhan, China

2020 ◽  
Vol 55 (6) ◽  
pp. 2000544 ◽  
Author(s):  
Xiaorong Wang ◽  
Qiong Zhou ◽  
Yukun He ◽  
Lingbo Liu ◽  
Xinqian Ma ◽  
...  
Keyword(s):  
Nosocomial Infections ◽  
Healthcare Workers ◽  
Initial Period ◽  
Family Members ◽  
Virus Shedding ◽  
Clinical Onset ◽  
Short Period ◽  
The Mean ◽  
Novel Coronavirus ◽  
Epidemiological Characteristics

BackgroundThe novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), infected over 3300 healthcare workers in early 2020 in China. Little information is known about nosocomial infections of healthcare workers in the initial period. We analysed data from healthcare workers with nosocomial infections in Wuhan Union Hospital (Wuhan, China) and their family members.MethodsWe collected and analysed data on exposure history, illness timelines and epidemiological characteristics from 25 healthcare workers with laboratory-confirmed coronavirus disease 2019 (COVID-19) and two healthcare workers in whom COVID-19 was highly suspected, as well as 10 of their family members with COVID-19, between 5 January and 12 February 2020. The demographics and clinical features of the 35 laboratory-confirmed cases were investigated and viral RNA of 12 cases was sequenced and analysed.ResultsNine clusters were found among the patients. All patients showed mild to moderate clinical manifestation and recovered without deterioration. The mean period of incubation was 4.5 days, the mean±sd clinical onset serial interval (COSI) was 5.2±3.2 days, and the median virus shedding time was 18.5 days. Complete genomic sequences of 12 different coronavirus strains demonstrated that the viral structure, with small irrelevant mutations, was stable in the transmission chains and showed remarkable traits of infectious traceability.ConclusionsSARS-CoV-2 can be rapidly transmitted from person to person, regardless of whether they have symptoms, in both hospital settings and social activities, based on the short period of incubation and COSI. The public health service should take practical measures to curb the spread, including isolation of cases, tracing close contacts, and containment of severe epidemic areas. Besides this, healthcare workers should be alert during the epidemic and self-quarantine if self-suspected of infection.

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