COVID-19: Rising temperatures can curb the spread
COVID-19: Rising temperatures can curb the spread. Analysis of 429 cities shows that rising temperatures can curb the spread of new coronavirus.
With the warmth of spring, will the COVID-19 epidemic gradually ease? Recently, a study published by Wang Mao’s team from the Department of Occupational and Environmental Hygiene of the School of Public Health, Sun Yat-sen University found on the Medrxiv website that temperature is related to the spread of the virus. The spread of the virus is the strongest in a certain temperature range, and the subsequent rise in temperature may inhibit the virus. spread.
The article pointed out that in order to deal with the outbreak of the new coronavirus, we need to understand its biological characteristics under natural environmental conditions. Depending on the climate and temperature, the virus has different effects on people in different parts of the world. We have discovered the first generation of patients infected with the virus since the beginning of January, and the third and fourth generations of transmission were discovered on February 4, but it is still unclear about the optimal transmission temperature of the new coronavirus and the spread range affected by this.
There are many epidemics that show a close relationship with temperature. In temperate regions, May to September in the southern hemisphere and November to March in the northern hemisphere are the seasons for influenza. Laboratory tests have found that the environmental infection rate of swine flu viruses is 75%-100% in a low temperature environment of 5°C, and the infection rate is 0 when the temperature rises to 30°C.
The 2003 SARS study showed that during the SARS outbreak, the temperature was low, and the daily incidence rate increased with different cities. This virus can survive for 5 days on a smooth surface at a temperature of 22-25°C and a relative humidity of 40%-50%, but when the temperature rises to 38°C and the relative humidity reaches 95%, the virus quickly Lost activity.
This may provide us with a clue to study the new coronavirus. We speculate that certain temperatures are most suitable for the spread of viruses, and an increase or a low temperature can inhibit the virus. Therefore, we collect data from urban areas affected by the virus around the world, and explore the specific connection between it and the virus based on their average, minimum and maximum temperature values.
The research team collected data from 24,139 confirmed cases in 429 cities in 34 provinces (including municipalities and autonomous regions) and 26 overseas countries in China. Among them, 16,480 cases (68.01%) were from Hubei Province. Guangdong, Zhejiang, Henan, Jiangxi and Hunan were 931, 947, 801, 550 and 619 respectively. Their average temperatures were 5.23, 17.30, 9.36, and 2.64, respectively. 2.90°C, 6.52°C.
When the daily maximum temperature is 12.42℃, the cumulative case parameter is 12.37, which is the highest value.
The peaks of the two curves are consistent with the recent temperature range values of Hubei Province, especially Wuhan City (average temperature 4.28-6.18℃, maximum temperature 6.46-11.84℃). At the same time, we can see that as the temperature rises, the curve shows a downward trend.
Data analysis found that when the temperature is low, the cumulative case parameters increase by 0.83, 0.82, and 0.83 for every 1°C increase in the average temperature, minimum temperature and maximum temperature. In the high temperature group model, the cumulative number of cases will decrease by 0.86 every time the minimum temperature increases by 1°C. Once the temperature rises to 30°C, the cumulative cases decrease to the lowest point.
Therefore, to a certain extent, temperature can significantly change the spread of COVID-19, and there may be an optimal temperature for virus transmission, which may be part of the reason for the first outbreak of the virus in Wuhan.
The authors concluded that there is an optimal dose-response relationship between temperature and the spread of the virus, and temperature may have played a role in the outbreak of the virus in Wuhan and surrounding areas. Rising temperatures may have a restraining effect on the development of the epidemic, but for some countries and regions with lower temperatures, we must be vigilant and take strict precautions to prevent the epidemic from breaking out quickly after entering a suitable temperature range.