Winter Rise in Covid-19 Cases
- 20 Jul 2020
- 3 min read
Why in News
According to a recent study, “The Covid-19 Spread in India and Its Dependence on Temperature and Relative Humidity”, the spread of Covid-19 may pick up the pace during peak monsoon and winter with a fall in the temperature.
- The study was conducted by the School of Earth, Ocean and Climate Sciences of the IIT, Bhubaneswar and the Department of Microbiology of the AIIMS, Bhubaneswar.
- It took into account the pattern of the coronavirus outbreak and the number of such cases in all of the states between April and June 2020.
- The respiratory viral pandemics of the 21st century (SARS in 2003, Swine Flu in 2009) have revealed that seasonality in environmental factors plays an important role in the dynamics of their spread.
- Researchers tried to observe the state-level relationship between environmental factors such as temperature, relative humidity, specific humidity and solar radiation on the Covid-19 spread over the Indian region.
- The rainfall, decrease in temperatures and cooling of the atmosphere coupled with progression towards winter may environmentally favour the spread of Covid-19 in the country.
- Temperature and relative humidity have a significant impact on the disease growth rate and doubling time and the rise in temperatures leads to a decline in the transmission of the virus.
- Correlation with Covid-19:
- A one-degree-Celsius rise in temperature leads to a 0.99% decrease in cases and increases the doubling time by 1.13 days, implying a slowdown of the virus spread.
- An increase of 10% in relative humidity tends to decrease the growth rate and doubling time of coronavirus cases by 1.18 days.
- The study also carried out an analysis of the impact of solar radiation on the spread of Covid-19.
- A higher surface-reaching solar radiation leads to a reduction in the number of infections and an increase in the doubling time of cases, similar to that of temperatures.
- The mean difference of as high as seven degrees Celsius between summer and winter points to a possibility for greater potential spread of Covid-19 in winter.
- The progression of the season towards monsoon, post-monsoon, and after that winter with a continuous reduction in temperature will prove a significant challenge for health workers and policymakers attempting to enforce mitigation and control measures.
- Policymakers should take targeted decisions that may also include environmental information to slow the spread.
- The actual spread will eventually depend on human intervention, such as strict enforcement of universal masking, physical distancing and improved hand hygiene and possible commencement of herd immunity.