The problem of bacterial complications post respiratory viral infections

Every person over the course of their lifetime is repeatedly infected by a variety of respiratory viruses that represent risk factors for the development of bacterial complications. The most dangerous among the etiological factors of acute respiratory viral diseases is the influenza A virus. This virus is capable of causing catastrophic pandemics with high mortality mainly due to secondary bacterial pneumonia. As has been shown in numerous recent studies, the main mechanism of provoking bacterial infections irrespective of the type of respiratory virus is the imbalanced response of the antiviral innate immunity – excessive interferon response and uncontrolled inflammation. The probability of severe bacterial complications in the course of acute respiratory viral infections is determined by both the virulence of the virus itself and by the composition of the respiratory microbiota at the time of the viral infection as well as by the genetic characteristics of the organism. The occurrence of severe bacterial complications is also affected by the chronic diseases that have an impact on the regulation of the innate immune response. This review summarizes the current concept of the mechanisms of the development of post viral bacterial complications as well as the potential prevention strategies for these complications