Influenza-like illness is associated with high pneumococcal carriage density in Malawian children

Area of Science:

• Microbiology
• Immunology
• Epidemiology

Background:

• High pneumococcal carriage density is a known risk factor for invasive pneumococcal disease (IPD) and transmission.
• Factors influencing pneumococcal carriage density remain incompletely understood.
• Understanding these factors is crucial for developing effective prevention strategies.

Purpose of the Study:

• To investigate the relationship between influenza-like illness (ILI) and pneumococcal carriage density.
• To compare microbial composition, cytokine levels, and pneumococcal carriage densities in children with ILI versus healthy controls (HC).

Main Methods:

• A cross-sectional study was conducted.
• Samples from children with ILI and asymptomatic HC were analyzed for microbial composition and cytokine levels.
• Pneumococcal carriage densities were quantified in all participants.

Main Results:

• Children with ILI had a higher prevalence of viral organisms and a greater number of co-infecting microbes compared to HC.
• ILI patients exhibited elevated IL-8 levels in nasal aspirates.
• Significantly higher pneumococcal carriage densities were observed in children with ILI compared to HC (RR 4.2, p < 0.0001).

Conclusions:

• Children experiencing ILI demonstrate an increased propensity for high pneumococcal carriage density.
• This heightened carriage may contribute to increased susceptibility to IPD.
• The findings suggest ILI could play a role in the community transmission of pneumococcus.