Effect of coinfection with influenza virus and bacteria on host damage.

Abstract

BACKGROUND: Influenza virus infection is often complicated by a bacterial infection, with this coinfection causing severe pneumonia. If not timely treated, the disease can cause death. OBJECTIVE: To demonstrate, in animal models, that coinfection with influenza virus and bacteria that affect the respiratory tract causes multisystemic damage. METHOD: Six groups of mice were formed: a control group, one infected with the influenza virus, two infected with bacteria: Haemophilus influenzae and Streptococcus pneumoniae, respectively; and two co-infected with influenza virus and Haemophilus influenzae or Streptococcus pneumoniae, respectively. RESULTS: Of the six groups of mice, only the group co-infected with influenza virus and Streptococcus pneumoniae showed damage to thoracic and abdominal organs. A decrease in serum cytokine levels was found in all study groups, which was more pronounced in the co-infected mice. CONCLUSIONS: The groups of mice infected with Streptococcus pneumoniae or influenza virus alone showed no damage, which indicates that coexistence of these infections caused the damage in the group of co-infected mice.