A recent study found that influenza infection can enhance the ability of Streptococcus pneumoniae to cause ear and throat infections.
The results of the study, published in Infection and Immunity, showed that influenza infection in mice enhanced the ability of the bacterium to colonize the nasopharynx and infect the middle ear, which is normally sterile, ScienceDaily reports.
"We learned that once influenza virus is introduced, all of the 'rules' regarding phase variants are out the window," W. Edward Swords, a corresponding author of the study from Wake Forest University, said, according to ScienceDaily. "Phase variation refers to the fact that the colonizing bacteria have transparent cell surfaces, while those that spread within the host have opaque surfaces."
Recent research also revealed that influenza interferes with innate immunity and allows pneumococci to rapidly develop. The study showed that the interference manifested as increased inflammatory responses of the mucosal surface in influenza-infected mice, including in the middle ear and nasopharynx.
"As with most pneumococcal infections, it should be appreciated that localized nonlethal infections are much more common than the rapidly lethal presentations," Sword said, ScienceDaily reports. "For example, influenza is a contributing factor in otitis media (middle ear infections) in children."
Sword said a better understanding of why and how viral infection causes the bacteria to colonize could help to improve preventative and therapeutic treatments, according to ScienceDaily.