High temperature slows coronavirus disease 2019 transmission rate: A within and among country analysis

Abstract

Background: The pandemic of coronavirus disease 2019 (COVID-19) is a global issue. The relationships between temperature and incidence, transmission, or survival of many enveloped coronaviruses such as severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS) have been previously widely investigated. However, there has been a lively debate in the literature over whether higher temperatures modulate coronaviruses’ infectivity and spreading, which sets a fertile ground for research on a global scale. In this study, we aimed to investigate the relationship between day-to-day temperature variability and daily COVID-19 incidence rate, as well as the time is taken to reach the total number of 200 confirmed COVID-19 cases within the worst-hit countries by the pandemic. Methods: A within and among countries analysis of the relationship between daily fluctuations in the number of new confirmed COVID-19 cases and temperature for the period starting from 31st December 2019 to 29th March 2020, was conducted. The 46 worst-hit countries by the pandemic were included in the analysis.Results: What emerges from our results is that daily new COVID-19 cases were negatively correlated with daily temperature variation. Moreover, higher temperatures were positively correlated with a longer time to reach a standard number of confirmed COVID-19 cases within countries. Notably, countries with daily average temperatures below 20°C had a faster transmission rate than countries with higher daily average temperatures. Conclusions: Our study provides further insights into the hypothesis that there is an association between temperature and rate of COVID-19 spread within a country.

Winter Is Coming: A Southern Hemisphere Perspective of the Environmental Drivers of SARS-CoV-2 and the Potential Seasonality of COVID-19

“…Another variation to this theme of estimating growth rate-related parameters as an indication of transmissibility is to take rates as time required to progress from the first reported case to 200 cases [ 161 ], or to use the cumulative number of cases reached 28 days after the first reported case [ 162 ]. However, these approaches effectively fit a linear model to case vs. time data, which does not account for the accelerating rate of increase in number of cases.…”