Researchers at Nord University in Bodø have easily explained how sick people became this spring in the 20 most corona-affected countries – with the weather in the same countries.
Studies have previously shown that common cold viruses spread more easily in cool weather and dry air, as is often the case in winter.
The coronavirus is very similar to cold viruses in size and shape. Then it seems likely that this virus will also spread more easily in autumn and winter.
Examined meteorological patterns
– We made a model where we tried to find meteorological patterns in the spread of the coronavirus, says Samuel Asumadu Sarkodie to forskning.no.
– This is how we clearly confirmed that with higher temperatures, the spread of infection is reduced.
– If the temperature drops to around the 0 point, it leads to increased spread of infection and to more people being affected by covid-19.
Sarcodie and research colleague Phebe Asantewaa Owusu believe this may help explain why the coronavirus is so widespread in sub-Saharan Africa.
South Africa is an exception. More than 700,000 people have been infected here. But the infection peaked in June – when it was winter in South Africa.
Wind and humidity also affect
– We also found connections between wind and corona spread, Sarkodie says to forskning.no.
– More wind increases the spread of the virus. One possible connection is that the wind helps the virus to move more easily from one person to another.
Another connection the researchers see is that with high relative humidity, the spread of the virus is reduced. If, on the other hand, the air is dry – as it is more often in the winter – the virus thrives better.
Sarkodie and Owusu are both economists and they have used models from the subject to bring together health data and weather data. The study is published in the latest issue of the journal Environmental Research.
Refrigerator temperature perfect for the virus
- Laboratory experiments have also shown that SARS coronavirus does not thrive with high temperature and high humidity.
- At normal room temperature, however, the virus can survive for several days. If you put coronavirus in a refrigerator where it is 4 ℃ and dry, it can last for a whole month.
- There have been several reports of widespread outbreaks of coronary heart disease among slaughterhouse workers. Here the employees work in just such temperatures.
Kilde: Lisa M. Casanova m.fl: «Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces», Applied and Environmental Microbiology, 2010
The researchers used corona data from John Hopkins University in the USA and compared these with global weather data from NASA. The study runs from January to April this year and includes a total of 1940 cases of infection in 20 countries.
The infected people stayed in temperatures ranging from −42 ° С in Russia to +35.5 ° С in India. Also the average temperatures varied a lot. The same went for wind and other weather conditions in the various countries.
Most precipitation was in corona-affected Peru in South America.
Infectious diseases spread in winter
Previously, several studies have found connections between weather conditions and the spread of infectious diseases.
Both in Norway and other countries in the northern hemisphere, the flu and common cold spread more in the winter than in the summer.
This may be due to lower temperatures. But another contributing factor is certainly that people in the winter stay more indoors.
Several international studies
The connection between the new coronavirus and weather conditions has also been investigated by other researchers.
A study conducted in Bangladesh finds, like the study from Nord University, that there is a clear connection between lower temperatures and increased corona spread.
A collective study conducted by researchers at Pará University in Belem, Brazil, has brought together results from a total of 17 studies in several countries, all of which have looked at weather conditions and the spread of the coronavirus. The researchers conclude that the results are fairly consistent in demonstrating a link between cool weather and the spread of the virus.
At the same time, the Brazilian researchers conclude that weather conditions are not the most important explanation behind the spread of the virus. They state that infection control measures or lack of infection control measures implemented by the health authorities are more important.
References and sources:
Asumadu Sarkodie Phebe og Asantewaa Owusu: «Impact of meteorological factors on COVID-19 pandemic: Evidence from top 20 countries with confirmed cases», Environmental Research, desember 2020. Artikkelen.
Abu Reza Md. Towfiqul Islam m.fl: «Effect of meteorological factors on COVID-19 cases in Bangladesh», Environment, Development and Sustainability, 8. oktober 2020.
Paulo Mecenas m. fl: «Effects of temperature and humidity on the spread of COVID-19: A systematic review», Plos One, 18. september 2020.
Sara Pith: «Does coronavirus spread more easily in cold temperatures? Here’s what we know», The Conversation, 29. oktober 2020.
The article was first published by forskning.no.