key: cord-0854758-d0vr45ws
authors: Biggerstaff, Matthew; Cowling, Benjamin J.; Cucunubá, Zulma M.; Dinh, Linh; Ferguson, Neil M.; Gao, Huizhi; Hill, Verity; Imai, Natsuko; Johansson, Michael A.; Kada, Sarah; Morgan, Oliver; Pastore y Piontti, Ana; Polonsky, Jonathan A.; Prasad, Pragati Venkata; Quandelacy, Talia M.; Rambaut, Andrew; Tappero, Jordan W.; Vandemaele, Katelijn A.; Vespignani, Alessandro; Warmbrod, K. Lane; Wong, Jessica Y.
title: Early Insights from Statistical and Mathematical Modeling of Key Epidemiologic Parameters of COVID-19
date: 2020-11-03
journal: Emerg Infect Dis
DOI: 10.3201/eid2611.201074
sha: d4c728e53bfa06d25e033c8c0eb017e293a45806
doc_id: 854758
cord_uid: d0vr45ws

We report key epidemiologic parameter estimates for coronavirus disease identified in peer-reviewed publications, preprint articles, and online reports. Range estimates for incubation period were 1.8–6.9 days, serial interval 4.0–7.5 days, and doubling time 2.3–7.4 days. The effective reproductive number varied widely, with reductions attributable to interventions. Case burden and infection fatality ratios increased with patient age. Implementation of combined interventions could reduce cases and delay epidemic peak up to 1 month. These parameters for transmission, disease severity, and intervention effectiveness are critical for guiding policy decisions. Estimates will likely change as new information becomes available.

. Search terms in study of modeling of key epidemiologic parameters of COVID-19 Topic Search terms "nCoV," "2019-nCoV," "nCoV-2019," "COVID," "COVID-19," "novel coronavirus," "SARS-CoV-2" AND "evolution*" or "phylogenetics" Incubation period

In PubMed, medRxiv, bioRxiv and arXiv: #1: "incubation period" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND #2 In SSRN: #1: "incubation period" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND search within each of the term in #2 In research square, Virological, and Wellcome Open Research: #1: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" Then read through all the papers Serial interval In PubMed: #1: "serial interval" OR "generation interval" OR "generation time" OR "serial distribution" OR "secondary infections" OR "secondary cases" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND #2 In medRxiv, bioRxiv, and arXiv: #1: "serial interval" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND #2 In SSRN: #1: "serial interval" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND search within each of the term in #2 In research square, Virological, and Wellcome Open Research: #1: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" Then read through all the papers Generation interval

In PubMed and arXiv: #1: "generation interval" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND #2 In medRxiv and bioRxiv: Topic Search terms "generation interval" for full text or abstract or title (match whole all) In SSRN: #1: "generation interval" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND search within each of the term in #2 In research square, Virological, and Wellcome Open Research: #1: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" Then read through all the papers Doubling time

In PubMed, medRxiv, bioRxiv and arXiv: #1: "doubling time" OR "growth rate" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND #2 In SSRN: #1: "doubling time" OR "growth rate" #2: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" #3: #1 AND search within each of the term in #2 In research square, Virological, and Wellcome Open Research: #1: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" Then read through all the papers CFR In PubMed: In biorXiv and medrXiv: for title "coronavirus fatality" (match all words) and abstract or title "coronavirus fatality" (match all words) and posted between "01 Jan 2020 and 07 Mar 2020" In arXiv: Query: order: -announced_date_first; size: 50; date_range: from 2020-01-01 to 2020-03-07; include_cross_list: True; terms: AND abstract = coronavirus; AND abstract = fatality In ResearchSquare: SARS-CoV-2 Preprints In Wellcome Research: Query: "coronavirus" In WHO Global Research Database: Query: "sever*" Cited by WHO: Imperial College London, IDO Nonpharmaceutical interventions In all databases: "coronavirus" OR "nCoV" OR "COVID" OR "COVID-19" OR "2019-nCoV" OR "nCoV-2019" OR "SARS-CoV-2" 

Incubation period of 2019 novel coronavirus (2019-nCoV) infections among travellers from Wuhan, China

The effect of travel restrictions on the spread of the 2019 novel coronavirus (COVID-19) outbreak

Risk for transportation of 2019 novel coronavirus disease from Wuhan to other cities in China

Serial interval of COVID-19 among publicly reported confirmed cases

Estimating the generation interval for coronavirus disease (COVID-19) based on symptom onset data

Real-time estimation of the risk of death from novel coronavirus (COVID-19) infection: inference using exported cases

The difference in the incubation period of 2019 novel coronavirus (SARS-CoV-2) infection between travelers to Hubei and nontravelers: the need for a longer quarantine period

Early transmission dynamics in Wuhan, China, of novel coronavirus-infected pneumonia

Incubation period and other epidemiological characteristics of 2019 novel coronavirus infections with right truncation: a statistical analysis of publicly available case data

Serial interval of novel coronavirus (COVID-19) infections

High contagiousness and rapid spread of severe acute respiratory syndrome coronavirus 2

Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study

Evolving epidemiology and transmission dynamics of coronavirus disease 2019 outside Hubei province, China: a descriptive and modelling study

Appendix Table 6 . Types of nonpharmaceutical interventions that could be implemented at the individual and community level Type Nonpharmaceutical intervention Individual interventions Voluntary home isolation: separation of persons ill with contagious diseases from noninfected persons Voluntary home quarantine: restriction of persons who are presumed to have been exposed to a contagious disease but are not ill, either because they did not become infected or because they are still in the incubation period Community level School closure (closure of day care facilities, schools, and higher education) Workplace closure (closure of nonessential services) Cancel or postpone large public gatherings Appendix Table 7 . Definition of nonpharmaceutical intervention search keywords* Topic Definition Case detection, case detected Detection of cases imported from an affected area Case isolation and contact tracing Isolation of an identified positive case. Travel screening'Screening of passengers at port of exit/entry Travel reduction, reduced travel, airline suspension Mobility reduction of persons, intra-or inter-city/country. School closure Closing schools to prevent further transmission Cancellation of events and mass gatherings, lockdown Cancellation of events and mass gatherings to prevent further transmission. Community response Population's psychological and behavioral responses during an outbreak *This table gives a short definition of the search keywords related to nonpharmaceutical intervention we are interested in. Because there are no specific terms to describe these interventions, or there are different terms to describe the same kind of intervention, we considered them to be equivalent.