MRSA infection may be detrimental to children with cystic fibrosis

Among children with cystic fibrosis, those who contract methicillin-resistant Staphylococcus aureus (MRSA) infection appear to have worse respiratory outcomes, including increased antibiotic exposure and breathing obstruction, as reported in a retrospective study.

Researchers used data from the Brazilian CF Patient Registry and electronic medical records. They looked at 32 individuals with cystic fibrosis who had MRSA isolated in cultures from respiratory secretions during the first 5 years of life (MRSA group) and 49 age-matched controls with cystic fibrosis but without MRSA infection (control group).

Outcomes such as nutrition, lung function between 6 and 7 years of age, and the first chest CT scan results were compared between the MRSA and control groups. A linear regression model was used to examine associations between the outcomes and MRSA infection.

Compared with the control group, the MRSA group had greater oral antibiotic exposure but similar hospital admission rates. The MRSA group was less likely to have cultures with methicillin-sensitive S. aureus than the control group (29.4 percent vs 48 percent; p=0.009).

FEV1 values were significantly lower in the MRSA group than in the control group (80.02 percent vs 92.51 percent; p=0.023), while bronchiectasis scores on chest CT scans were substantially higher (1.9 vs 0.38; p=0.031).

Notably, MRSA identification before age 5 years strongly correlated with an average decrease of 10.1 percent (95 percent confidence interval, –19.518 to –0.586; p=0.038) in FEV1.

While the findings cannot establish a cause-and-effect relationship, they provide insight into the associations between early MRSA infection and cystic fibrosis lung disease, according to the researchers.