Scientists from the Max F. Perutz Laboratories (MFPL) of the University of Vienna and the Medical University of Vienna have provided insights into how much harm bacteria can cause to the lung of people with the flu. The results could prompt the development of alternative treatments for flu-related bacterial infections, to improve patient outcome and prevent permanent lung damage.
Between 250,000-500,000 people die from influenza every year, with the primary cause actually due to secondary bacterial infections acquired during the weakened immune state from the virus.
One type of bacteria that the immune system usually prevents from spreading and becoming harmful for is called Legionella pneumophila. In some circumstances, such as when infected with influenza virus, Legionella can cause pneumonia, an inflammatory disease of the lung that if left untreated can leave the lung permanently damaged and even cause death.
“In our model system an infection with influenza and Legionella was fatal. We expected that this would be caused by the bacteria growing and spreading like crazy, but what we actually found was that the number of bacteria didn’t change, which was a big surprise”, says Amanda Jamieson, research fellow in the Department of Microbiology, Immunobiology and Genetics of the University of Vienna.
The researchers demonstrated that the damage to the lung tissue caused by a co-infection with flu and Legionella is not properly repaired, as the influenza virus suppresses the body’s ability to repair tissue damage. In case of an additional Legionella infection this may lead to fatal pneumonia.
The study results, published this month in Science Express, indicate that treatment with drugs that activate tissue repair pathways significantly improved the outcome, suggesting that new treatment options to deal with co-infections of flu and bacteria should be explored. “My group will continue to work on tissue repair models and explore different avenues for the treatment of flu/bacterial co-infections,” says Jamieson.
Read the paper at Science Express: Role of tissue protection in lethal respiratory viral-bacterial coinfection.
