In the midst of one of the worst flu epidemics in America, a new study published Thursday has shown that the flu can be spread simply by breathing.
The study, published in the Proceedings of the National Academy of Sciences, found that viral influenza particles are present not only in the lower respiratory tract — which includes the lungs — but also the upper airways, which includes the nose.
According to Jovan Pantelic, an assistant professional researcher at the campus’s Center for the Built Environment, one person with influenza can exhale enough viral particles within 30 minutes to infect 1,000 people.
These findings, Pantelic said, have particular implications for crowded environments such as BART trains and college campuses, which he called “perfect” for transmitting diseases. Since college dorm rooms are usually only ventilated by windows, students are more likely to catch something during the winter when they open the windows less, Pantelic said.
“I hope in the future we’ll pay more attention to the design of environments where people live in really close proximity,” Pantelic said.
To campus epidemiology professor Arthur Reingold, the study mostly reinforces prior knowledge of the flu. While he found some findings interesting — such as the fact that those who were previously vaccinated could potentially spread more viral particles — he doesn’t believe that many people in public health would find them very surprising.
Campus clinical professor emeritus John Swartzberg said he shared this opinion, saying that the study’s findings wouldn’t change flu prevention advice already given by the Centers for Disease Control and Prevention and other specialists. Although there has been some debate about the effectiveness of the flu vaccine in recent years, Swartzberg said, a vaccination can still help prevent illness or modify the severity of the illness.
According to Lisa Polley, nurse manager for the campus’s University Health Services, the Tang Center has administered about 3,730 flu shots so far for the 2017-18 school year. Forty students have been treated by the Tang Center for influenza this month — an increase from 31 students treated in January 2017.
Flu season has hit the country particularly hard this year, with 30 children already dead and 32 states reporting severe flu activity. The influenza A strain — H3N2 — has been responsible for a majority of the flu cases.
“What (the study) basically says is we need a better flu vaccine,” Reingold said. “It certainly suggests that people may be infectious even when they’re not coughing or sneezing, but how much of a factor is that when it’s transmitting from person to person — I don’t think the study answers that.”