Influenza and Bacterial Superinfection: Illuminating the Immunologic Mechanisms of Disease

Abstract

cSeasonal influenza virus infection presents a major strain on the health care system. Influenza virus infection has pandemic potential, which was repeatedly observed during the last century. Severe disease may occur in the young, in the elderly, in those with preexisting lung disease, and in previously healthy individuals. A common cause of severe influenza pathogenesis is superinfection with bacterial pathogens, namely, Staphylococcus aureus and Streptococcus pneumoniae. A great deal of recent research has focused on the immune pathways involved in influenza-induced susceptibility to secondary bacterial pneumonia. Both innate and adaptive antibacterial host defenses are impaired in the context of preceding influenza virus infection. The goal of this minireview is to highlight these findings and synthesize these data into a shared central theme of pathogenesis.

Severe pneumococcal pneumonia following Measles- Mumps- Rubella vaccination / Pneumonie pneumococică severă dezvoltată ca urmare a vaccinării Rujeolă-Oreion-Rubeolă

“…AIDS (16,17). A recently published review summarized the role of impaired immune pathways in influenza virus infection, which induces susceptibility to secondary bacterial pneumonia (20). In this case, the presence of a viral or fungal respiratory tract coinfection was also supposed, but as presented earlier, the laboratory diagnosis revealed no viral pathogen.…”

“…The Vaccine Adverse Event Reporting System (VAERS) has summarized higher rates of severe adverse events only in patients over the age of 60 for the yellow fever vaccine, another live attenuated vaccine (20,21).…”

Staphylococcus aureus colonization and non-influenza respiratory viruses: Interactions and synergism mechanisms

“…While clinical and mechanistic aspects of the synergism between S. aureus and influenza virus have been deeply studied, the interactions between this bacterium and other common respiratory viruses were only partially investigated [10]. Literature still lacks more data about the relations between S. aureus carriage and non-influenza respiratory virus infections, as well as deeper insights into mechanisms of interactions between these different pathogens.…”

“…Influenza virus is known to promote staphylococcal superinfection by alteration of the host immune system via increased production of pro-inflammatory cytokines and interferons (IFNs), impairment of phagocytic cell functions and suppression of type 17 immunity [9,10]. In addition, influenza virus has been shown to promote S. aureus adhesion and internalization within non-professional phagocytic cells through at least two distinct mechanisms: binding of bacteria to the membrane-associated hemagglutinin of influenza-infected cells, and binding of bacteria to free virions, followed by internalization of virus-coated bacteria into non-infected cells [44].…”

“…The role of interactions between viruses and bacteria in the pathogenesis of respiratory infections have been extensively studied in the literature and notably those between influenza viruses and S. aureus or S. pneumoniae [5–10]. However, interactions between S. aureus and non-influenza respiratory viruses were not reviewed recently.…”