Can climatic factors explain the differences in COVID-19 incidence and severity across the Spanish regions?: An ecological study

Abstract

Background Environmental factors play a central role in seasonal epidemics. SARS-CoV-2 infection in Spain has shown a heterogeneous geographical pattern This study aimed to assess the influence of several climatic factors on the infectivity of SARS-CoV-2 and the severity of COVID-19 among the Spanish Autonomous Communities (AA.CC.). Methods Data on coronavirus infectivity and severity of COVID-19 disease, as well as the climatic variables were obtained from official sources (Ministry of Health and Spanish Meteorological Agency, respectively). To assess the possible influence of climate on the development of the disease, data on ultraviolet radiation (UVR) were collected during the months before the start of the pandemic. To analyze its influence on the infectivity of SARS-CoV-2, data on UVR, temperature, and humidity were obtained from the months of highest contagiousness to the peak of the pandemic. Results From October 2019 to January 2020, mean UVR was significantly related not only to SARS-CoV-2 infection (cumulative incidence -previous 14 days- × 105 habitants, rho = − 0.0,666; p = 0.009), but also with COVID-19 severity, assessed as hospital admissions (rho = − 0.626; p = 0.017) and ICU admissions (rho = − 0.565; p = 0.035). Besides, temperature (February: rho = − 0.832; p < 0.001 and March: rho = − 0.904; p < 0.001), was the main climatic factor responsible for the infectivity of the coronavirus and directly contributed to a different spread of SARS-CoV-2 across the Spanish regions. Conclusions Climatic factors may partially explain the differences in COVID-19 incidence and severity across the different Spanish regions. The knowledge of these factors could help to develop preventive and public health actions against upcoming outbreaks of the disease.

Investigating the Potential for Ultraviolet Light to Modulate Morbidity and Mortality From COVID-19: A Narrative Review and Update

“…Benefits for the UVB component of sunlight have also been reported, in which a negative association between the UV Index and COVID-19 deaths were observed in data from 152 countries using modeling that considered other potential effects of local weather (e.g., temperature, humidity) across January–May 2020 ( 49 ). Beneficial inverse associations between COVID-19 severity or death and local ambient UV levels or annual mean sunlight hours were also observed in Spain ( 50 ) and France ( 51 ), respectively, although this French study has been critiqued for the statistical approach undertaken ( 52 ). However, GDP and body mass index, but not mean UV Index (measured across November 2019–April 2020) were significant predictors of COVID-19 deaths (per million) in a multivariate regression analysis across the world ( 53 ).…”

Sea-spray aerosols and SARS-Cov-2: an analysis using AERONET data

“…Transmission of SARS-CoV-2 by aerosol emitted from human respiratory system and its viability have been supported by several recent studies (e.g., Guo et al, 2020;van Doremalen et al, 2020;Chia et al, 2020), but the whole set of parameters in uencing its atmospheric propagation and their role are poorly understood (Sagripanti and Lytle, 2020;Schuit et al, 2020;Ratnesar-Shumat et al, 2020;Cacho et al, 2020), and it is often a speci c combination of them, characterizing speci c atmospheric air masses, that leads to enhanced incidence of infectious diseases (Hochman et al, 2021). The aim of this work was to study the environmental conditions via the role of atmospheric aerosols on SARS-CoV-2 propagation and activity.…”

Altitude and SARS-CoV-2 Infection in the First Pandemic Wave in Spain

“…In the present study, the altitude above sea level was more predictive than any meteorological parameter. In Spain in March, those provinces with a higher altitude had, on average, lower absolute humidity, lower temperature in winter, and less sea influence, and these three factors have been related to increases in respiratory virus transmission [ 2 , 3 , 4 ]. Therefore, the strongest association between higher altitude and SARS-CoV-2 seroprevalence may be explained because this factor combines the effects of absolute humidity, temperature, and proximity to the coast.…”

“…The role of environmental and demographic conditions on SARS-CoV-2 transmission is not well known. Geographical comparisons have associated higher atmospheric temperature and humidity with lower SARS-CoV-2 transmission [ 2 , 3 , 4 , 5 ]. However, these studies may be affected by differences in the completeness of COVID-19 reporting in the first wave, because a high and variable percentage of cases were not confirmed [ 5 ].…”

“…Transmission increased steeply during the first half of March, and the main intervention was a lockdown implemented simultaneously in all Spanish regions on 15 March 2020 [ 15 ]. No other relevant intervention was introduced; therefore, the important geographical differences observed in COVID-19 cumulative incidence in the first pandemic wave were probably related to case reporting, and to environmental and socio-demographical factors [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”