The Novel Coronavirus, 2019-nCoV, is Highly Contagious and More Infectious Than Initially Estimated

Abstract

124 Main text including references and figure captions: 3,945 All rights reserved. No reuse allowed without permission. author/funder, who has granted medRxiv a license to display the preprint in perpetuity. AbstractThe novel coronavirus (2019-nCoV) is a recently emerged human pathogen that has spread widely since January 2020. Initially, the basic reproductive number, R0, was estimated to be 2.2 to 2.7. Here we provide a new estimate of this quantity. We collected extensive individual case reports and estimated key epidemiology parameters, including the incubation period. Integrating these estimates and high-resolution real-time human travel and infection data with mathematical models, we estimated that the number of infected individuals during early epidemic double every 2.4 days, and the R0 value is likely to be between 4.7 and 6.6. We further show that quarantine and contact tracing of symptomatic individuals alone may not be effective and early, strong control measures are needed to stop transmission of the virus.

Transmission potential of the novel coronavirus (COVID-19) onboard the diamond Princess Cruises Ship, 2020

“…unfolded aboard the Diamond Princess Ship, January-February 2020. The overall mean reproduction number in the confined setting reached values as high as ~11, which is higher than mean estimates reported from community-level transmission dynamics in China and Singapore in the range 1.1-7[10][11][12][13][14][15][16]. However, following the implementation of the quarantine period, the overall R t decreased substantially compared to values estimated during the early stage, but it exhibited fluctuations around the epidemic threshold, which likely prolonged the outbreak.Our results indicate that R t declined following the quarantine measures implemented by the Japanese government on February 5 relative to values during the early phase of the outbreak[3].…”

Potential impact of seasonal forcing on a SARS-CoV-2 pandemic

“…richard.neher@unibas.ch (2.2 with 90% high density interval 1.4-3.8 (Riou and Althaus, 2020) or 2.7 with a 95% CrI of 2.47-2.86 (Wu et al, 2020)). Higher estimates have also been reported (Sanche et al, 2020;Yang et al, 2020). Importantly, R 0 is not a biological constant for a pathogen, but is affected by factors such as environmental conditions and the behaviour of infected individuals.…”

A simple model to assess Wuhan lock-down effect and region efforts during COVID-19 epidemic in China Mainland

“…SARS-CoV-2 is highly contagious, Wang et al (2020) projected that without any control measure the infected population would exceed 200,000 in Wuhan by the end of February. As for Steven et al (2020) and Read et al (2020), the estimated number was 233,400 (CI: 38,278) by the end of January and 191,529 (CI: 132,649) by February 4, respectively. Up to February 27, the confirmed cases are 48,137.…”

“…SARS-CoV-2 has diversity transmission approaches, including respiratory (mouth foam) and contact routes which have been confirmed, as well as aerosol and digestive (fecal-oral) routes which cannot be ruled out (National Health Commission of China, 2020). It is also highly concealed according to the recent report of transmission of the virus from asymptomatic and mild individuals (Zhang et al, 2020;Sanche et al, 2020).…”

“…(which was not certified by peer review) diagnosis. The latest estimated value of R0 and the control reproductive number is 4.7-6.6 (Steven et al, 2020) and 6.47 (CI: 5.71-7.23) (Tang et al, 2020), respectively. SARS-CoV-2 is highly contagious, Wang et al (2020) projected that without any control measure the infected population would exceed 200,000 in Wuhan by the end of February.…”