High temperature, humidity reduce coronavirus transmission: Study


High temperature and humidity can reduce the transmission of the novel coronavirus or COVID-19, which has so far affected 162 countries and territories including Bangladesh, according to a new study by Chinese researchers.

Jingyuan Wang, Kai Feng and Weifeng Lv from the School of Computer Science and Engineering at Beihang University and Ke Tang from the School of Social Sciences at Tsinghua University, jointly conducted the research from January 21 to 23.

They said their finding is consistent with the fact that high temperature and high humidity significantly reduce the transmission of influenza, reports UNB.

“It indicates that the arrival of summer and rainy season in the northern hemisphere can effectively reduce the transmission of the COVID-19,” they wrote in the 19-page research that appeared online on March 10 and was later revised again on March 14.

After estimating serial interval of COVID-19 from 105 pairs of the virus carriers and the infected, researchers calculated the daily effective reproductive number, R, for each of all 100 Chinese cities with more than 40 cases.

Using R values as proxies of non-intervened transmission intensity, researchers found that under a linear regression framework, high temperature and high relative humidity significantly reduce the transmission of COVID-19.

The study also shows that one degree Celsius increase in temperature and one percent increase in relative humidity lower R by 0.0383 and 0.0224, respectively.

Meanwhile, a German virologist, an Indian infectious disease specialist, an epidemiology expert of Johns Hopkins University, and a pathology professor of the University of Hong Kong also mentioned about natural decrease of coronavirus transmission thanks to high temperature, humidity and sunlight.

Thomas Pietschmann, a virologist from Germany's Centre for Experimental and Clinical Infection Research, said coronavirus is "not very heat-resistant, which means that it quickly breaks down when temperatures rise", reports Deutsche Welle.

Chennai-based Dr Abdul Ghafur said heat and humidity in India "could be one of the reasons" why coronavirus is not spreading faster, as weather limits the virus from travelling "longer or faster", reports Al Jazeera.

Dr Stefan Baral, an epidemiology expert at Johns Hopkins University, said he expects "a natural decrease" of the disease as the US moves into warmer weather, according to the Boston Herald.

AccuWeather, the US-based forecaster, quoted Dr John Nicholls, a pathology professor at the University of Hong Kong, as saying that there are three things coronavirus does not like: Sunlight, Temperature and Humidity.

"Sunlight will cut the virus's ability to grow in half, so the half-life will be 2.5 minutes, and in the dark it's about 13 to 20 [minutes]. Sunlight is really good at killing viruses," Nicholls said.

Coronavirus or COVID-19 pandemic claimed 7,164 lives globally as of Tuesday. The disease has so far infected 182,550 people around the world, according to worldometer.

Bangladesh has so far confirmed eight cases. Four of these patients had come from Europe. The country announced detection of three new patients, including two children, on Monday and confirmed that the virus has started transmitting locally.