Influenza is a viral disease but deaths caused in the patients is mostly due to a bacterium that causes pneumonia. While this is a known concept in medical science, researchers recently threw light on how to influence infection make the patients vulnerable to bacterial pneumonia as well.
A research conducted by Sweden’s Karolinska Institute, now published in the journal PNAS has findings that point to ‘superinfection’ being caused to influenza patients by pneumonia bacteria. Citing the Spanish flu that happened in 1918, an influenza pandemic that wiped 50 million of the world’s population unlike the other pandemics, happened mostly to the young and healthy adults. One important reason that the study holds responsible is the pneumonia-causing bacteria pneumococci. The study also will be helpful for Covid research, the authors said.
Community-acquired Pneumonia is responsible for several global fatalities and it caused by the pneumococcal infection. Often an influenza infection is followed by pneumococcal infection. In the new study, researchers found that influenza causes change in the lower air tract helping in the growth of Pneumococci bacteria in the lungs.
Researchers used an animal model for their findings. During influenza, different antioxidants and nutrients are lost from the blood. This creates a favourable environment for the growth of bacteria. Pneumococci then secrets an enzyme called HtrA to make the inflammatory environment it’s home. HtrA weakens the immune system making bacterial growth easier in influenza affected airways.
According to the principal investigator Brigitta Henriques Normark, when the environment is nutrient-rich with higher levels of antioxidants that happens during viral infection, the pneumonia-causing bacteria finds it suitable to inhabit the lower airways and adapt to the environment inhibiting its further growth and hence lessens its chances of being eradicated from the immune system.
Possible treatment for superinfections
New therapies that would tackle both the viral and the bacterial infection is the need of the hour, suggested the researchers. The use of protease inhibitors has been advised by Vicky Sender, the lead author of the study to prevent the growth of pneumococci in airways. The researchers, however, have not still ascertained if Covid-19 patients are also vulnerable to secondary bacterial infection.