Role of temperature and humidity in the modulation of the doubling time of COVID-19 cases

Abstract

COVID-19 is having a great impact on public health, mortality and economy worldwide, in spite of the efforts to prevent its epidemy. The SARS-CoV-2 genome is different from that of MERS-CoV and SARS-CoV, although also expected to spread differently according to meteorological conditions. Our main goal is to investigate the role of some meteorological variables on the expansion of this outbreak.In this study, an exponential model relating the number of accumulated confirmed cases and time was considered. The rate of COVID-19 spread, using as criterion the doubling time of the number of confirmed cases, was used as dependent variable in a linear model that took four independent meteorological variables: temperature, humidity, precipitation and wind speed. Only China cases were considered, to control both cultural aspects and containment policies. Confirmed cases and the 4 meteorological variables were gathered between January 23 and March 1 (39 days) for the 31 provinces of Mainland China. Several periods of time were sampled for each province, obtaining more than one value for the rate of disease progression.Two different periods of time were tested, of 12 and 15 days, along with 3 and 5 different starting points in time, randomly chosen. The median value for each meteorological variable was computed, using the same time period; models with > 0.75 were selected. The rate of progression and doubling time were computed and used to fit a linear regression model. Models were evaluated using = 0.05.. CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not peer-reviewed)The copyright holder for this preprint . https: //doi.org/10.1101//doi.org/10. /2020 Results indicate that the doubling time correlates positively with temperature and inversely with humidity, suggesting that a decrease in the rate of progression of COVID-19 with the arrival of spring and summer in the north hemisphere. A 20ºC increase is expected to delay the doubling time in 1.8 days. Those variables explain 18% of the variation in disease doubling time; the remaining 82% may be related to containment measures, general health policies, population density, transportation or cultural aspects.

Multivariate Analysis of Factors Affecting COVID-19 Case and Death Rate in U.S. Counties: The Significant Effects of Black Race and Temperature

“…Several recent reports have also linked higher temperature to decreased virus spread, while others have found no significant effects. [9][10][11][12][13][14] Here, we demonstrate an independent effect of temperature that results in reduced COVID-19 cases, but not mortality, across U.S. counties. If warmer temperatures do, in fact, play a role in mitigating disease spread, it is reasonable to expect a potential seasonal trend in global cases and mortality.…”

“…Recent work has primarily focused on patient demographics, underlying health comorbidities, social disparities in healthcare access and quality, and environmental variables such as pollution to identify potential risk factors and vulnerable populations. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] However, while these previous studies have examined the effects of these domains on COVID-19 spread independently, some do not control for the potentially confounding interactions between variables. In this study, we sought to investigate COVID-19 prevalence and mortality in all U.S. counties through a more comprehensive framework that accounts for effects of county-level macroeconomic, demographic, environmental, health status, and healthcare access variables.…”

“…Developing new therapies, identifying risk factors, and minimizing spread through social distancing remain top priorities in the fight against COVID-19. 4,5 Previous studies have examined the effects of various risk factors on spread of COVID-19 including patient demographics, 6,7 social determinants of health, 8 environmental variables, [9][10][11][12][13][14][15] housing, 16,17 and underlying health conditions. [18][19][20] Identifying risk factors allows public health officials to determine populations at greater risk and development targeted public health interventions.…”

Effects of temperature variation and humidity on the mortality of COVID-19 in Wuhan

“…All analyses were conducted using R software (version 3.5.3) with the GAM fitted by the "mgcv" package (version 1. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. The effect estimates were expressed as the percentage changes and their 95% confidence intervals (CIs) in daily mortality of COVID-19 associated with per 1 unit increase in weather variables.…”

Effects of temperature variation and humidity on the death of COVID-19 in Wuhan, China

“…A study demonstrated that absolute humidity had significant correlations with influenza viral survival and transmission rates (Metz and Finn, 2015). Few studies reported that the COVID-19 was related to the meteorological factors, which decreased with the temperature increasing (Oliveiros et al, 2020;, but their effects on the mortality have not been reported. Therefore, we assume that the weather conditions might also contributed to the mortality of COVID-19.…”