Persistent methicillin-resistant Staphylococcus aureus and rate of FEV1 decline in cystic fibrosis

Am J Respir Crit Care Med. 2008 Oct 15;178(8):814-21. doi: 10.1164/rccm.200802-327OC. Epub 2008 Jul 31.


Rationale: The prevalence in cystic fibrosis (CF) of respiratory cultures with methicillin-resistant Staphylococcus aureus (MRSA) has dramatically increased over the last 10 years, but the effect of MRSA on FEV(1) decline in CF is unknown.

Objectives: To determine the association between MRSA respiratory infection and FEV(1) decline in children and adults with CF.

Methods: This was a 10-year cohort study using the Cystic Fibrosis Foundation patient registry from 1996-2005. We studied individuals who developed new MRSA respiratory tract infection. Repeated-measures regression was used to assess the association between MRSA and FEV(1) decline, adjusted for confounders, in individuals aged 8-21 years and adults (aged 22-45 yr). Two different statistical models were used to assess robustness of results.

Measurements and main results: The study cohort included 17,357 patients with an average follow-up of 5.3 years. During the study period, 1,732 individuals developed new persistent MRSA infection (> or =3 MRSA cultures; average, 6.8 positive cultures) and were subsequently followed for an average of 3.5 years. Even after adjustment for confounders, rate of FEV(1) decline in individuals aged 8-21 years with persistent MRSA was more rapid in both statistical models. Their average FEV(1) decline of 2.06% predicted/year was 43% more rapid than the 1.44% predicted/year in those without MRSA (difference, -0.62% predicted/yr; 95% confidence interval, -0.70 to -0.54; P < 0.001). Effect of MRSA on FEV(1) decline in adults was not clinically significant.

Conclusions: Persistent infection with MRSA in individuals with CF between the ages of 8 and 21 years is associated with a more rapid rate of decline in lung function.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / physiopathology*
  • Female
  • Follow-Up Studies
  • Forced Expiratory Volume / physiology*
  • Humans
  • Male
  • Methicillin Resistance*
  • Middle Aged
  • Prevalence
  • Prognosis
  • Retrospective Studies
  • Staphylococcal Infections / complications*
  • Staphylococcal Infections / epidemiology
  • Staphylococcal Infections / physiopathology
  • Staphylococcus aureus / isolation & purification*
  • Time Factors
  • United States