Temperature Significantly Change COVID-19 Transmission in 429 cities

Abstract

Background There is no evidence supporting that temperature changes COVID-19 transmission. Methods We collected the cumulative number of confirmed cases of all cities and regions affected by COVID-19 in the world from January 20 to February 4, 2020, and calculated the daily means of the average, minimum and maximum temperatures in January. Then, restricted cubic spline function and generalized linear mixture model were used to analyze the relationships. Results There were in total 24,232 confirmed cases in China and 26 overseas countries. In total, 16,480 cases (68.01%) were from Hubei Province. The lgN rose as the average temperature went up to a peak of 8.72℃ and then slowly declined. The apexes of the minimum temperature and the maximum temperature were 6.70℃ and 12.42℃ respectively. The curves shared similar shapes. Under the circumstance of lower temperature, every 1℃ increase in average, minimum and maximum temperatures led to an increase of the cumulative number of cases by 0.83, 0.82 and 0.83 respectively. In the single-factor model of the higher-temperature group, every 1℃ increase in the minimum temperature led to a decrease of the cumulative number of cases by 0.86. Conclusion The study found that, to certain extent, temperature could significant change COVID-19 transmission, and there might be a best temperature for the viral transmission, which may partly explain why it first broke out in Wuhan. It is suggested that countries and regions with a lower temperature in the world adopt the strictest control measures to prevent future reversal.

Is temperature reducing the transmission of COVID-19 ?

“…Thus, the arrival of summer could reduce the transmission of the COVID-19. Our result agreed with those already reported in other geographical locations, showing how the number of diagnosed cases increase below a maximum temperature of 10 ºC and linearly decreasing afterward (Triplett 2000;Wang et al, 2020b). However, these are cross-sectional studies at the country scale, which might have some measurement error due to high spatial variability when estimating a fixed temperature exposure for large geographic areas (Soares et al, 2012).…”

“…A previous study in the four major Chinese cities suggested that the SARS outbreak was significantly associated with the temperature, increasing the daily incidence rate with lower temperatures (Tan et al, 2005). Recent preprint studies using national data from countries affected by COVID-19 reported that low temperature is beneficial to the viral transmission (Triplett 2020;Wang et al, 2020a;Wang et al, 2020b). However, these should be taken with caution since have not yet been peer reviewed.…”

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.…”

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

“…Some evidence of a faster spreading of diseases in high humidity levels has been reported, 16 namely for the Legionella disease, although this infection is not caused by a virus. Few papers have been written since mid-February on this topic [17][18][19][20] even though the relationship is not perfectly established and more research is required.…”