TOKYO -- Researchers in Japan have found that children younger than 10 are prone to infection with cold viruses amid the coronavirus pandemic, with the risk of rhinovirus infections double that of an average year.
The discovery was made by a research team led by virology professor Yoshihiro Kawaoka at the University of Tokyo's Institute of Medical Science. Countermeasures against the coronavirus, which have reduced influenza infections, are thought to have played a part in this.
Rhinoviruses can cause common colds, triggering inflammation in the upper airways including the nose and throat. The virus can aggravate symptoms with complications such as pneumonia.
The team analyzed specimens collected from 2,244 respiratory disease patients, among whom 1,119 were younger than 10, excluding COVID-19 patients, at a medical institute in the city of Yokohama between January 2018 and September 2020, and looked into viruses that cause respiratory diseases.
As a result, though the flu virus has rarely been detected in children younger than 10 since the first coronavirus infection was confirmed in Yokohama in February 2020, the rhinovirus detection rate was more than twice as high as that of an average year. Both flu virus and rhinovirus detection rates among people aged 10 or older declined.
In general, when people get infected with a virus, their immune system is activated, blocking other viruses. Therefore, there tend to be few rhinovirus infections during flu season. Team member Emi Takashita, a senior research scientist specializing in virology at the National Institute of Infectious Diseases, commented, "The spread of influenza has been inhibited by countermeasures against the coronavirus, and as a result, the environment has become such that rhinoviruses can spread easily. Young children in particular aren't immune to rhinoviruses, so they are prone to infection."
Takashita explained that while antiseptic solutions such as alcohol can deactivate the coronavirus and influenza viruses by destroying their fatty membranes, known as the "envelope," alcohol does not effectively work for the rhinovirus because it does not have the envelope. She added, "Washing hands with soap is effective against the rhinovirus, too. To protect children from infections, we want people to wash their hands adequately in addition to disinfecting them with alcohol."
(Japanese original by Ayumu Iwasaki, Science & Environment News Department)