An experiment by a team of French scientists reveals that the coronavirus can survive long period of exposure to high temperatures.
Upon the publication of the French paper "Evaluation of heating and chemical protocols for inactivating SARS-CoV-2" published on bioRxiv on Saturday, previous theories about warmer weather killing the virus have now been further discredited.
60-degree, 60-minute rule
Professor Remi Charrel and colleagues at the Aix-Marseille University in southern France detailed that the SARS-CoV-2 under the heat of 60 degrees Celsius or 140 Fahrenheit for an hour can still have surviving strains that were still able to replicate.
According to South China Morning Post, this 60-degree, 60-minute rule has been adopted by many laboratories to suppress fatal viruses including Ebola.
The scientists revealed on their paper that they had to bring the temperature up to 92 degrees to kill the virus. These results have implications for the safety of health workers especially those lab technicians working with the virus.
As African green monkey kidney cells is a standard host material being used for viral activity tests, the French scientists injected it with a strain from a patient in Berlin, Germany. They put the cells inside a tube that represents two types of environment -the "clean" environment, and the "dirty" environment- together with animal proteins to mimic biological contamination in real-life samples just like in an oral swab.
The viral strains in the clean environment were thoroughly disabled, while some strains in the dirty environment survived after the heating process. Although the heating process resulted in a clear drop in infectivity, enough strains still live that can cause another round of infection, according to the paper.
A danger to lab technicians
The news outlet emphasized that there is a growing demand to perform tests on the novel coronavirus. However, some of the experiments are needed to be done in laboratories with lower protection standards. This puts the lab technicians directly exposed to the sample, requiring the COVID-19 samples to be destroyed before further processing.
The authors of the study highlighted that the findings of their research should help to choose the best-suited protocol for inactivation to prevent exposure of laboratory technicians in charge of the direct and indirect detection of SARS-CoV-2 in diagnosing patients.
Evidence of Seasonality
The National Academies of Science published a report last week directed to the White House that explained that the warm weather in summer would have little impact on the spread of the novel coronavirus in the United States which currently leads the most number of confirmed COVID-19 cases in the world.
Although there is some evidence that suggests that the coronavirus may transmit less efficiently in warmer temperatures, it will still be rendered insignificant given the lack of host immunity on a global scale.
The "evidence of seasonality" is also not found in other types of coronaviruses such as the Middle East Respiratory Syndrome (MERS) and the Severe Acute Respiratory Syndrome (SARS).
