Some common disease-causing bacteria can stay alive in the air for up to 45 minutes after someone coughs or sneezes, according to researchers from Queensland University of Technology in Australia.
"Most research in this area to date has focused on laboratory-generated bio-aerosols, or airborne droplets, which are different from natural respiratory droplets generated by humans," said Lidia Morawska, PhD, a professor at QUT. "We developed a novel technique to target the short-term and long-term ageing of bio-aerosols from people, without contamination from the ambient air."
Using the new method, Dr. Morawska and her team tested cough droplets from two patients who had cystic fibrosis and chronic Pseudomonas aeruginosa infection.
They found some Pseudomonas aeruginosa bacteria are resistant to normal biological decay that occurs and had a half life of more than 10 minutes. Therefore, some bacteria "remain viable in the air long enough to form an airborne infection risk, especially to people with respiratory problems such as patients with cystic fibrosis," Dr. Morawska said.
This could be because droplets originate in different parts of the respiratory tract and therefore carry different amounts of bacteria.
Dr. Morawska said her findings could have implications for infection control in hospitals.