The COVID-19 pandemic really does have the habit of sending the scientific community into a tizzy. Either the virus is too difficult to comprehend or scientists are just not able to identify some crucial information that the virus holds about itself. New facts and complications come up almost every day, which experts debunk the next day. Just take the case of asymptomatic people. They were initially thought to be the silent spreaders of the disease. Then just recently the World Health Organisation issued a statement saying that it was rare for asymptomatic people to spread the virus. And, then, about 24 hours later, the premier organization retracted their statement and said that around 40 per cent of the cases are spread by these silent carriers. This is just one example.
Another example is the widely held belief that sunlight can kill the virus. Many scientists believe that high temperatures can kill the virus. Experts translated this to mean that exposure to sunlight may also be able to do the same. But now, according to a new study, while greater heat and humidity can slow the spread of Covid-19, longer hours of sunlight is associated with a higher incidence of the disease. The journal Geographical Analysis published this study.
Influence of climate on COVID-19
Many earlier studies show that pathogens like the influenza and SARS thrive in lower temperatures and less humidity. But not much was know how SARS-CoV2, the agent that causes COVID-19, behaves in such conditions. It was mostly assumptions made by experts and laymen alike. According to researchers from University of Canada, there is a lot of pressure to reopen the economy, and many people want to know if it will be safer to do so in the summer months. Restrictions in movement, which is now slowly being lifted, hinge in part on how SARS-CoV2 will be affected by a change in season. This new study tried to find some answers.
More sun means greater spread of virus
For the purpose of the study, researchers investigated climate factors in the spread of COVID-19 in several provinces in Spain, one of the countries hardest hit by the pandemic. They combined and analysed data on reported cases of the disease and meteorological information over a period of 30 days that began immediately before a state-of-emergency was declared. They saw that, at higher levels of heat and humidity, for every percentage increase, there was a three per cent decline in the incidence of COVID-19. This may be because warmer temperatures curtail the viability of the virus.
The opposite was true for hours of sunshine: More sun meant greater spread. According to scientists, this may also be because people tend to be more unruly under lockdown on sunny days.
Elderly population and sun exposure
The researchers found one surprising this while conducting this study. They saw that rates of transmission dropped among more dense populations and in areas with more older adults. This may be due to the fact that those populations regard themselves as being at greater risk, and so are more likely to adhere to lockdown guidance. While older adults are more vulnerable to the disease, researchers believe they are less likely overall to contribute to the spread of the disease because they are more apt to be isolated from others because of health or mobility issues.
Discipline is important
The researchers stressed that models such as this one show that contagion of COVID-19 declines as a lockdown progresses, possibly to the vanishing point – an argument for maintaining discipline despite the approach of pleasant weather. Earlier this month, another study published in the journal Transboundary and Emerging Diseases, reveal that COVID-19 could be a seasonal illness with a higher risk in winter. The study found an association between lower humidity and an increase in locally acquired positive cases.