Seasonality of acquisition of respiratory bacterial pathogens in young children with cystic fibrosis

BMC Infect Dis. 2017 Jun 9;17(1):411. doi: 10.1186/s12879-017-2511-9.

Abstract

Background: Seasonal variations are often observed for respiratory tract infections; however, limited information is available regarding seasonal patterns of acquisition of common cystic fibrosis (CF)-related respiratory pathogens. We previously reported differential seasonal acquisition of Pseudomonas aeruginosa in young children with CF and no such variation for methicillin-susceptible Staphylococcus aureus acquisition. The purpose of this study was to describe and compare the seasonal incidence of acquisition of other respiratory bacterial pathogens in young children with CF.

Methods: We conducted a retrospective study to describe and compare the seasonal incidence of methicillin-resistant Staphylococcus aureus (MRSA), Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Haemophilus influenzae acquisition in young CF patients residing in the U.S. using the Cystic Fibrosis Foundation National Patient Registry, 2003-2009. Log-linear overdispersed Poisson regression was used to evaluate seasonal acquisition of each of these pathogens.

Results: A total of 4552 children met inclusion criteria. During follow-up 910 (20%), 1161 (26%), 228 (5%), and 2148 (47%) children acquired MRSA, S. maltophilia, A. xylosoxidans and H. influenzae, respectively. Compared to winter season, MRSA was less frequently acquired in spring (Incidence Rate Ratio [IRR]: 0.79; 95% Confidence Interval [CI]: 0.65, 0.96) and summer (IRR: 0.69; 95% CI: 0.57, 0.84) seasons. Similarly, a lower rate of A. xylosoxidans acquisition was observed in spring (IRR: 0.59; 95% CI: 0.39, 0.89). For H. influenzae, summer (IRR: 0.88; 95% CI: 0.78, 0.99) and autumn (IRR: 0.78; 95% CI: 0.69, 0.88) seasons were associated with lower acquisition rates compared to winter. No seasonal variation was observed for S. maltophilia acquisition.

Conclusion: Acquisition of CF-related respiratory pathogens displays seasonal variation in young children with CF, with the highest rate of acquisition for most pathogens occurring in the winter. Investigation of factors underlying these observed associations may contribute to our understanding of the aetiology of these infections and guide future infection control strategies.

Keywords: Achromobacter xylosoxidans, Haemophilus influenzae; Cystic fibrosis; MRSA; Seasonality; Stenotrophomonas maltophilia.

MeSH terms

  • Achromobacter denitrificans / isolation & purification
  • Achromobacter denitrificans / pathogenicity
  • Child, Preschool
  • Climate
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / microbiology*
  • Female
  • Haemophilus Infections / epidemiology
  • Haemophilus Infections / microbiology
  • Haemophilus influenzae / isolation & purification
  • Haemophilus influenzae / pathogenicity
  • Humans
  • Male
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Methicillin-Resistant Staphylococcus aureus / pathogenicity
  • Pseudomonas Infections / epidemiology
  • Pseudomonas Infections / microbiology
  • Pseudomonas aeruginosa / isolation & purification
  • Pseudomonas aeruginosa / pathogenicity
  • Respiratory Tract Infections / epidemiology*
  • Respiratory Tract Infections / microbiology*
  • Retrospective Studies
  • Seasons
  • Staphylococcal Infections / epidemiology
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / isolation & purification
  • Staphylococcus aureus / pathogenicity
  • Stenotrophomonas maltophilia / isolation & purification
  • Stenotrophomonas maltophilia / pathogenicity
  • United States