Temperature plays an important role in the onset of infectious diseases. Transmission of the coronavirus causing SARS in 2003 was thus favored in areas where the temperature was close to 22-25 ° C.
Due to the current events related to SARS-CoV-2, thousands of worries assail us and make us wonder what this virus is. How is it transmitted? What can we do to avoid getting infected? It is also possible that we ask ourselves the following question: what promotes the activity of viruses, cold or heat?
In 2003, a coronavirus outbreak took place in Hong Kong and spread to many countries. Scientists then studied how climatic factors affected its transmission.
We will, throughout this article, tell you about how temperature affects virus activity, among other interesting data.
Temperature and organisms
Temperature is the most important environmental factor affecting the health of all organisms, as its effects impact the growth and development of pathogenesis immediately.
Changes in temperature can affect the biology of the host as well as that of the parasite (virus). In fact, the impact of climate change is linked to many infectious diseases.
Some of the deadliest outbreaks of viral-type infectious diseases are Ebola, HIV, and the coronavirus, which causes SARS (severe acute respiratory syndrome).
Effects of temperature
Viruses are heat labile, which means that they destroy themselves when they reach a high temperature. This is why if they are applied at a temperature between 50-65 ° C for half an hour, the majority of viruses are inactivated.
This is explained by the fact that high temperatures cause the denaturalization of the proteins that make up the capsid (protein structure that envelops and protects the genetic material).
However, there are exceptions. For example, hepatitis B viruses are inactivated when they are at 120 ° C for half an hour. Or when given 15 lbs of pressure, used as a disinfectant, or by applying activated glutaraldehyde at 2 ° C.
Viruses are stable at low temperatures. So at -75 ° C they stay on for months, and at -196 ° C they can stay on for years.
We will now explain to you how temperature affects the survival of certain viruses that cause infectious diseases.
The case of the coronavirus
SARS-CoV was an emerging disease associated with severe pneumonia, caused by the coronavirus, which spread to 20 countries across 5 continents, in 2003. It arose in Amoy Garden, Hong Kong , in a block apartments where more than 300 residents have been infected.
Its mortality was 9% and the elderly were the most affected. The number of cases has increased in the hospital environment due to contact between patients, healthcare professionals and fomites (inert objects that transmit pathogens in hospitals, such as stethoscopes, masks, sheets, etc.) .
Temperature and SARS
The main route of transmission of SARS-CoV infection is through respiratory droplets. These are spread through the air by coughing or sneezing. They are more commonly known as “Flugge droplets”.
In a study published in the journal Applied and Environmental Microbiology, this virus was found on smooth surfaces and hospital objects, where it remained for up to 28 days at temperatures between 22 and 25 ° C. However, it deactivated when a temperature of 40 ° C was applied to it.