Scientometrics
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Oct 6, 2020; 8(19): 4431-4442
Published online Oct 6, 2020. doi: 10.12998/wjcc.v8.i19.4431
Global analysis of daily new COVID-19 cases reveals many static-phase countries including the United States potentially with unstoppable epidemic
Cheng Long, Xin-Miao Fu, Zhi-Fu Fu
Cheng Long, Department of Orthopaedics, Sichuan University West China Hospital, Chengdu 610041, Sichuan Province, China
Xin-Miao Fu, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian Province, China
Zhi-Fu Fu, Anxi AIER Eye Hospital (AIER EYE Hospital Group), Anxi 362400, Fujian Province, China
Author contributions: Fu XM conceptually designed the study; Long C organized the data and performed the analyses; Fu ZF drafted the manuscript; and Fu XM made the revision to the manuscript.
Supported by National Natural Science Foundation of China, No. 31972918 and No. 31770830 (to Fu XM).
Conflict-of-interest statement: The authors declare that they have no conflict of interest to disclose.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Zhi-Fu Fu, MD, Chief Doctor, Anxi AIER Eye Hospital (AIER EYE Hospital Group), Anxi County, Anxi 362400, Fujian Province, China. fu_zhifu@163.com
Received: June 15, 2020
Peer-review started: June 15, 2020
First decision: June 19, 2020
Revised: June 20, 2020
Accepted: August 27, 2020
Article in press: August 27, 2020
Published online: October 6, 2020
Abstract
BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic is hitting many countries. It is hypothesized the epidemic is differentially progressing in different countries.

AIM

To investigate how the COVID-19 epidemic is going on in different countries by analyzing representative countries.

METHODS

The status of COVID-19 epidemic in over 60 most affected countries was characterized. The data of daily new cases of each country were collected from Worldometer. The data of daily tests for the United States, Italy, and South Korea were collected from the Website of One World Data. Levels of daily positive COVID-19 tests in the two most affected states of the United States (New York and New Jersey) were collected from the website of the COVID Tracking Project. Statistics were analyzed using Microcal Origin software with ANOVA algorithm, and significance level was set at a P value of 0.05.

RESULTS

The COVID-19 epidemic was differentially progressing in different countries. Comparative analyses of daily new cases as of April 19, 2020 revealed that 61 most affected countries can be classified into four types: Downward (22), upward (20), static-phase (12), and uncertain ones (7). In particular, the 12 static-phase countries including the United States were characterized by largely constant numbers of daily new cases in the past over 14 d. Furthermore, these static-phase countries were overall significantly lower in testing density (P = 0.016) but higher in the level of positive COVID-19 tests than downward countries (P = 0.028). These findings suggested that the testing capacity in static-phase countries was lagging behind the spread of the outbreak, i.e., daily new cases (confirmed) were likely less than daily new infections and the remaining undocumented infections were thus still expanding, resulting in unstoppable epidemic.

CONCLUSION

Increasing the testing capacity and/or reducing the COVID-19 transmission are urgently needed to stop the potentially unstoppable, severing crisis in static-phase countries.

Keywords: COVID-19, SARS-CoV-2, Coronavirus, Pandemic, Testing density

Core Tip: Of the 61 most affected countries by coronavirus disease 2019 (COVID-19), 12 static-phase countries including the United States were characterized by largely constant numbers of daily new cases in the past over 14 d. Furthermore, these static-phase countries were overall significantly lower in testing density but higher in the level of positive COVID-19 tests than downward countries. These findings suggested that daily new cases (confirmed) in these countries were likely less than daily new infections, resulting in an unstoppable epidemic.