Early epidemiological and clinical manifestations of COVID-19 in Japan

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Abstract

Background

Severe acute respiratory syndrome coronaviruses -2 (SARS-COV2) named as COVID-19 had spread worldwide and leading to 1,210,956 confirmed cases and 67,594 deaths

Methods

A data of 1192 confirmed cases and 43 deaths due to COVID-19 in Japan collected from the Ministry of Health, Labour and Welfare of Japan and analysed for different epidemiological parameters and their clinical manifestations. We used Clauset-Newman-Moore (CNM) clustering algorithm to develop web-network of confirmed cases to identified clusters of community transmission.

Results

Out of 1192 confirmed cases, 90.60% were symptomatic and 9.39% were asymptomatic. The prevalence of COVID19 in males was 56.29% and 43.20 % in females. The mean interval (±SD) from symptom onset to diagnosis was 6±22.6 days while mean interval (±SD) from contact to onset of symptoms was 5±19.5 days. People of age range 40-79 were more infected and deaths median age was 80. The main symptoms were fever, dry cough, fatigue and pneumonia. The main infected cities were Tokyo (195/1192, 16.35%), Hokkaido (160/1192 13.42%), Aichi (150/1192, 12.58%) and Osaka (145/1192, 12.16%). Only 2.34% cases had travel history from Wuhan China and Osaka music concert was identify as main cluster for community transmission. While 556 (46.64%) cases were clinically diagnosed and 557 (46.72%) were confirmed by using RT-PCR.

Conclusions

Other than, declare emergency Japan need to change their approach of diagnosing COVID-19, as asymptomatic cases prevalence is high and maybe it is reason for current sudden increase of cases. Screening centre should be establish away from hospitals, which are treating positive cases.

Article activity feed

  1. SciScore for 10.1101/2020.04.17.20070276: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    No key resources detected.


    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. SciScore for 10.1101/2020.04.17.20070276: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.Randomizationnot detected.Blindingnot detected.Power Analysisnot detected.Sex as a biological variableThe prevalence of COVID19 in males was 56.29 % and 43.20 % in females .

    Table 2: Resources


    Results from OddPub: We did not find a statement about open data. We also did not find a statement about open code. Researchers are encouraged to share open data when possible (see Nature blog).


    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore is not a substitute for expert review. SciScore checks for the presence and correctness of RRIDs (research resource identifiers) in the manuscript, and detects sentences that appear to be missing RRIDs. SciScore also checks to make sure that rigor criteria are addressed by authors. It does this by detecting sentences that discuss criteria such as blinding or power analysis. SciScore does not guarantee that the rigor criteria that it detects are appropriate for the particular study. Instead it assists authors, editors, and reviewers by drawing attention to sections of the manuscript that contain or should contain various rigor criteria and key resources. For details on the results shown here, including references cited, please follow this link.