In a recent study performed by researchers at the Massachusetts Institute of Technology (MIT) in the United States, it was discovered that regions currently experiencing a monsoon might witness a slowdown in the transmission of the coronavirus due to moderate humidity levels. The information gleaned from this research may prove to be crucial in devising mitigation strategies for tropical countries like India.
Key Findings
The primary takeaway from the MIT study is that approximately 90% of recorded novel coronavirus transmissions have occurred in regions where temperatures range between 3 and 17 degrees Celsius. Furthermore, these regions also shared an average humidity range of 3-9 grams per cubic meter (g/m3). A majority of these regions include parts of the United States and numerous European countries, which currently form the epicenter of COVID-19 infections.
Cases in Warmer and Humid Countries
Interestingly, countries with warmer and more humid climates such as Singapore, Australia, Taiwan, and Qatar have reported significantly fewer infections in comparison. This discrepancy suggests the possibility that warmer temperatures could be instrumental in retarding the spread of the virus.
The Impact of Humidity on Transmission
Supporting this theory are several experimental studies that indicate that coronaviruses are sensitive to humidity levels and show reduced thrive in moderately humid conditions. For example, a comprehensive 2018 study published in Applied and Environmental Microbiology noted that coronaviruses appear to thrive in Relative Humidity (RH) levels exceeding 85% or dropping below 60%. It was found that there is a meaningful decrease in viral infectivity at mid-range RHs between 60 and 85%.
Further Observations
Another experiment aimed at testing the survivability of viruses on stainless steel surfaces provided some additional insights. It was observed that at 4°C, infectious viruses remained viable for as long as 28 days. The slowest rate of viral inactivation took place in environments with low levels of RH. In contrast, at 20°C, inactivation occurred more rapidly across all humidity levels. This suggests that both temperature and humidity play key roles in the survival and spread of the coronavirus.
By observing these patterns and understanding the nuanced effects of weather conditions on the transmission of the virus, scientists and policymakers can better predict the spread of the virus based on regional climates. This can help inform containment strategies and public health decisions, particularly for countries that have not yet seen a significant surge in infections. As our understanding of the virus continues to evolve, this kind of research provides invaluable data for anticipating future trends and managing the ongoing crisis.
