Severe Pneumococcal Pneumonia in Previously Healthy Children: The Role of Preceding Influenza Infection

Abstract

An outbreak of severe pneumococcal pneumonia among children occurred in Iowa from November 1995 through January 1996. An associated outbreak of influenza disease was predominantly caused by influenza A (H1N1) for the first time since 1989. We conducted a case-control study to determine whether preceding influenza infection was directly associated with pneumococcal illness. We identified 13 children with severe pneumococcal pneumonia. Patients were more likely than control subjects to report experiencing an influenza-like illness in the 7-28 days preceding admission (matched odds ratio [OR], 12.4; 95% confidence interval [CI], 1.7-306). Likewise, family members of patients were more likely than those of control subjects to report experiencing an influenza-like illness in the 28 days preceding their admission date (OR, 2.6; 95% CI, 1.0-6. 3). Patients were more likely than control subjects to have a positive influenza A (H1N1) convalescent serology (matched OR, 3.7; 95% CI, 1.0-18.1). This study provides direct and indirect evidence that influenza infection led to severe pneumococcal pneumonia among these children. Prevention of pneumococcal disease should be included among the potential benefits of influenza vaccination.

Influenza virus and proteolytic bacteria co-infection in respiratory tract from individuals presenting respiratory manifestations

“…These studies were continued over twenty decades 11 , demonstrating the lethal synergism between influenza virus and Streptococcus pneumoniae that led to 100% of mortality in mice used as an experimental model. This finding has been related not only in animal models; a synergism between bacteria-influenza virus has been reported, and also observed in children with pneumococcal pneumonia that preceded influenza infection 14 Based on our data and the other reports cited, it may be concluded that co-infection between these microorganisms exacerbates respiratory infections. This situation may be aggravated in hospitalized individuals with immune depression, such as in some patients evaluated in this work.…”

IL-10 Is an Important Mediator of the Enhanced Susceptibility to Pneumococcal Pneumonia after Influenza Infection

“…Bacteria such as Staphylococcus aureus and Haemophilus influenzae are known to cause postinfluenza pneumonia, but Streptococcus pneumoniae is the most prominent pathogen causing secondary bacterial pneumonia in recent decades (1). Primary infection with this pathogen is usually less severe than secondary infection (5).…”

Addressing Parents’ Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant’s Immune System?

“…For example, patients with pneumococcal pneumonia are more likely to have had a recent influenza infection than matched controls. 62 Similarly, varicella infection increases susceptibility to group A ␤-hemolytic streptococcal infections such as necrotizing fasciitis, toxic shock syndrome, and bacteremia. 63 …”