A study conducted by a team of researchers from Nagoya University in Japan has shed new light on the relationship between human behavior and the evolution of SARS-CoV-2, the virus that causes Covid-19. The findings, published in Nature Communications, reveal that human confinement and isolation measures can alter the evolution of the virus in various ways, making it more transmissible earlier in its life cycle.
The study used mathematical models with an artificial intelligence component to analyze previously published clinical data. The researchers found that successful SARS-CoV-2 variants had an earlier and higher peak in viral load, as well as a shorter duration of infection. Additionally, they discovered that the decreased incubation period and higher proportion of asymptomatic infections recorded as the virus mutated also influenced the evolution of the virus.
Professor Shingo Iwami and his team suggest that changes in human behavior designed to limit transmission were increasing selection pressure on the virus. As a result, SARS-CoV-2 was primarily transmitted during the asymptomatic and pre-symptomatic periods, which occur earlier in its infectious cycle. This allowed for more effective spread in the earliest pre-symptomatic stages, leading to a higher viral load peak at this time.
According to scientists, when evaluating public health strategies in response to Covid-19 and potentially pandemic-causing pathogens in the future, it is essential to consider how changes in human behavior may impact virus evolution patterns. The study suggests that new coronavirus strains may have evolved due to a complex interaction between clinical symptoms and human behavior.
Overall, this research highlights the importance of understanding how environmental factors such as human behavior influence disease evolution patterns. By considering these factors when developing adaptive treatments and interventions for infectious diseases like Covid-19, scientists can better predict how viruses will evolve over time and develop more effective strategies for controlling outbreaks.