Climate and COVID-19 pandemic: effect of heat and humidity on the incidence and mortality in world's top ten hottest and top ten coldest countries
Authors: A A Alomar
S A Meo
A S Meo
I Z Al-Beeshi
K M Shafi
A Alhowikan
A M Usmani
A A Abukhalaf
J Akram
Journal: European Review for Medical and Pharmacological Sciences (2020)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: COVID-19 pandemic; heat; humidity; incidence; mortality
Affiliations: Department of Physiology, Strategic Centre for Diabetes Research, College of Medicine, King Saud University, Riyadh, Saudi Arabia. .

Abstract:  Objective: The COVID-19 pandemic has caused a global public health crisis with social, psychological and long-lasting economical damages. Weather-related dynamics have an impact on the pattern of human health and disease. The present study aimed to investigate the impact of heat and humidity on daily basis incidence and mortality due to COVID-19 pandemic in ten of the world's hottest countries compared to ten of the coldest ones. Materials and methods: Worldwide, we selected 20 countries; 10 hottest countries with the highest temperatures and 10 coldest countries with the lowest temperature. The selection of the countries was based on the daily basis mean temperature from the date of appearance of the initial cases of COVID-19, Dec 29, 2019 to May 12, 2020. In the world's 10 hottest countries, the mean temperature was (26.31±1.51) and humidity (44.67±4.97). However, in the world's 10 coldest countries the mean temperature was (6.19±1.61) and humidity (57.26±2.35). The data on the global outbreak of COVID-19, daily new cases and deaths were recorded from World Health Organization, and daily information on temperature and humidity was obtained from metrological web "Time and Date". Results: In countries with high temperatures and low humidity, the mean daily cases incidence were (407.12±24.33); cumulative cases (9094.34±708.29); and cumulative deaths (452.84±43.30) were significantly low compared to countries with low temperatures and high humidity: daily cases (1876.72±207.37); cumulative cases (44232.38±5875.11); and cumulative deaths (2008.29±310.13). Moreover, COVID-19 cases and deaths per million population were significantly low in countries with high temperatures (cases 711.23, and deaths 16.27) compared to countries with low temperatures (cases 1685.99; and deaths 86.40). Furthermore, in hottest countries, a 1% increase in humidity reduced number of cases and deaths by (β = -5.40, p&lt;0.001) and (β = -0.187, p=0.004) respectively. A similar trend was seen with a 1°C increase in temperature, reducing the number of deaths by (β = -1.35. p&lt;0.001). Conclusions: The results revealed a significant decrease in incidence of daily cases and deaths in countries with high temperatures and low humidity (warmest countries), compared to those countries with low temperatures and high humidity (coldest countries). The findings could be of interest to the policymakers and the health officials on the epidemiological trends of COVID-19 pandemic and weather changes. 

Retracted: No

PubPeer comments:
 *[below]* Fig 6A.  Representative images of subcutaneous tumor xenografts from groups agomir-432 and agomir-NC . *[above]* Fig 8A from [Situ et al (2020)] .  DU145 cells transfected with either agomir-939 or agomir-NC were subcutaneously inoculated into nude mice. Images of the tumor xenografts at the end of the experiment are shown . ![file] The tumors appear to be identical (slightly rotated). At right, contrast adjusted for easier comparison of the markings and scratches on the rulers. They also seem to be the same ruler, although there is no obvious connection between the research teams or their institutions. How did this happen? , 
 Four flow-cytometry plots share most of their points in common, suggesting that they come from the same raw data file (differently gated and filtered). I have adjusted contrast and aspect ratios for ease of comparison. ![file] Here in context. The right-hand panel is from Figs 2C, 4C, 5D. ![file] Figs 2C, 4B, 5F from [Li et al (2019a)] . ![file] Figs 2C, 4C, 5C from [Li et al (2019b)] . ![file] , 
 September 29, 2021 Situ J, Zhang H, Jin Z, Li K, Mao Y, Huang W. Onco Targets Ther. 2020;13:4257u20134270. The Editor and Publisher of OncoTargets and Therapy wish to retract the published article. Concerns were raised over alleged image duplication in Figure 8A with similar images from unrelated articles, specifically: Figure 8A appears to have been duplicated with a similar image in Figure 6A from Chen et al, 2019 (https: doi.org 10.3892 ijmm.2019.4429 The authors did not respond to our queries and the Editor determined the findings of the study were no longer valid and advised for the article to be retracted. Our decision-making was informed by our policy on publishing ethics and integrity and the COPE guidelines on retraction. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as u201cRetractedu201d. ,