Researchers from University of Verona-Italy, the Provincial Agency for Social and Sanitary Services (APSS), Trento- Italy and the Cincinnati Children’s Hospital Medical Center-USA have in a new study found that the SARS-CoV-2 coronavirus has evolved to withstand higher temperatures.
The study findings suggest that the strong evolutive pressure placed on SARS-CoV-2 over time may have fostered the accumulation of mutations that have contributed to evolve and adapt the virus to circulate even at high temperatures, thus calling for reinforcing preventive measures and healthcare preparedness even during the warmest periods of the year.
The study findings were published on a preprint server: Research Square and are currently being peer reviewed. https://www.researchsquare.com/article/rs-1907627/v1
The results of this analysis suggest that the strong evolutive pressure placed on SARS-CoV-2 over time may have fostered the accumulation of mutations that have contributed to evolve and adapt the virus to circulate even at high temperatures, as in July 2022 in Verona.
Alternatively, the impact of temperature on viral transmissibility may be relatively constant but offset by the significant increase in infectivity with continued viral mutation over time. Higher daily average temperatures leading to more indoor activities and/or increased community transmission in light of decreased preventative health measures may also be contributing factors to our observations.
Regardless the cause, these findings have paramount public health consequences, in that some effective preventive measures for preventing SARS-CoV-2 infection (social distancing, use of face masks, hand hygiene) should not be abandoned even during the warmest periods of the year, whilst healthcare administrators and policymakers shall also consider that the number of SARS-CoV-2 infections needing hospitalization may no longer decay during the hot season.
Background: Since SARS-CoV-2 has undergone a considerable genetic evolution over time, we investigated its infectivity in the province of Verona (Italy), during the month of July of the first three pandemic years (i.e., 2020, 2021 and 2022).
Methods: The daily number of new COVID-19 diagnoses in the province of Verona between July 1-27 of the years 2020, 2021 and 2022 was retrieved from the database of the Regional Healthcare Service, whilst the mean daily air temperature during the same period in the same area was downloaded from an official Italian meteorological website.
Results: The mean July air temperature in Verona was 24±2°C in 2020, 25±2°C in 2021 and 28±2°C in 2022. The daily number of new COVID-19 diagnoses in the province of Verona increased from 2.5±5.7 in July 2020, to 106.0±71.8 in July 2021, up to 1287.4±509.9 in July 2022. The number of new COVID-19 diagnoses made in the province of Verona in July 2022 has increased by 519- and 12-fold in 2022 compared to the same month of the previous two years, despite the fact that the mean air temperature also notably increased by 18% and 15% compared to the years 2020 and 2021, respectively.
