To answer this concern, Rodó and his team initially examined the association of temperature and humidity in the preliminary stage of SARS-CoV-2 spread in 162 nations across 5 continents, before changes in human behavior and public health policies were put into place. The outcomes show a negative relationship in between the transmission rate (R0) and both temperature and humidity at the worldwide scale: greater transmission rates were associated with lower temperatures and humidity.
Once again, they discovered a strong unfavorable association for short time windows in between disease (number of cases) and environment (temperature and humidity), with constant patterns throughout the very first, 2nd, and 3rd waves of the pandemic at various spatial scales: worldwide, countries, down to individual areas within highly affected countries (Lombardy, Thüringen, and Catalonia) and even to the city level (Barcelona).
The first epidemic waves waned as temperature level and humidity increased, and the 2nd wave increased as temperature levels and humidity fell.
The group then examined how this association between environment and disease progressed over time, and whether it corresponded at different geographical scales. For this, they utilized a statistical technique that was specifically developed to identify similar patterns of variation (i.e. a pattern-recognition tool) at different windows of time. Once again, they found a strong unfavorable association for short time windows between disease (number of cases) and climate (temperature and humidity), with constant patterns throughout the very first, second, and 3rd waves of the pandemic at different spatial scales: worldwide, nations, down to specific regions within extremely impacted countries (Lombardy, Thüringen, and Catalonia) and even to the city level (Barcelona).
The very first epidemic waves waned as temperature level and humidity increased, and the second wave increased as temperature levels and humidity fell. this pattern was broken during summertime in all continents. “This could be discussed by numerous factors, including mass gatherings of young individuals, tourist, and air conditioning, to name a few,” describes Alejandro Fontal, scientist at ISGlobal and first author of the research study..
When adjusting the design to analyze short-term connections at all scales in nations in the Southern Hemisphere, where the infection got here later on, the exact same negative connection was observed. The environment results were most evident at temperatures between 12o and 18oC and humidity levels in between 4 and 12 g/m3, although the authors caution that these varieties are still a sign, provided the short records readily available..
Finally, utilizing an epidemiological design, the research study group revealed that incorporating temperature level into the transmission rate works much better for predicting the fluctuate of the different waves, especially the first and third ones in Europe. “Altogether, our findings support the view of COVID-19 as a true seasonal low-temperature infection, similar to influenza and to the more benign flowing coronaviruses,” states Rodó.
This seasonality could contribute importantly to the transmission of SARS-CoV-2, considering that low humidity conditions have been shown to minimize the size of aerosols, and thus increase airborne transmission of seasonal viruses such as influenza. “This link warrants an emphasis on air health through enhanced indoor ventilation as aerosols are capable to continue suspended for longer times,” states Rodó, and highlights the need to include meteorological criteria in the examination and preparation of control steps..
Recommendation: “Climatic signatures in the different COVID-19 pandemic waves across both hemispheres” by Fontal A, Bouma MJ, San José A, Lopez L, Pascual M, Rodó X, 21 October 2021, Nature Computational Science.DOI: 10.1038/ s43588-021-00136-6.
New research study supplies strong proof that COVID-19 is a seasonal infection linked to low temperatures and humidity, similar to seasonal influenza.
A new study led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by “la Caixa” Foundation, supplies robust proof that COVID-19 is a seasonal infection connected to low temperatures and humidity, similar to seasonal influenza. The outcomes, published in Nature Computational Science, also support the substantial contribution of air-borne SARS-CoV-2 transmission and the requirement to move to steps that promote “air health.”
An essential concern concerning SARS-CoV-2 is whether it is acting, or will behave, as a seasonal infection like influenza, or whether it will be equally sent during at any time of the year. A very first theoretical modeling study recommended that environment was not a driver in COVID-19 transmission, provided the high variety of prone people without any immunity to the virus. However, some observations suggested that the initial propagation of COVID-19 in China happened in a latitude in between 30 and 50o N, with low humidity levels and low temperatures (in between 5o and 11 o C)..
” The concern of whether COVID-19 is an authentic seasonal illness ends up being progressively central, with implications for identifying effective intervention steps,” describes Xavier Rodó, director of the Climate and Health program at ISGlobal and planner of the research study. To address this question, Rodó and his group first analyzed the association of temperature level and humidity in the initial stage of SARS-CoV-2 spread in 162 countries throughout 5 continents, before modifications in human habits and public health policies were taken into location. The results reveal a negative relationship between the transmission rate (R0) and both temperature level and humidity at the global scale: higher transmission rates were associated with lower temperatures and humidity.
