Methicillin resistant Staphylococcus aureus (MRSA) infection in cystic fibrosis

Abstract

Background-Methicillin resistant Staphylococcus aureus (MRSA) infection is increasingly found in patients with cystic fibrosis (CF).Aims-To determine whether MRSA infection has a deleterious eVect on the clinical status of children with CF. Methods-Children with MRSA in respiratory cultures during a seven year period were identified and compared with controls matched for age, sex, and respiratory function. Respiratory function tests, anthropometric data, ShwachmanKulczycki score, Northern chest x ray score, intravenous and nebulised antibiotic therapy, and steroid therapy were compared one year before and one year after MRSA infection. Results-From a clinic population of 300, 10 children had positive sputum or cough swab cultures for MRSA. Prevalence rose from 0 in 1992-1994 to 7 in 1998. Eighteen controls were identified. Children with MRSA showed significant worsening of height standard deviation scores and required twice as many courses of intravenous antibiotics as controls after one year. They had significantly worse chest x ray scores at the time of the first MRSA isolate and one year later, but showed no increase in the rate of decline in chest x ray appearance. There was a trend towards lower FEV 1 and FEF 25-75 in children with MRSA. There were no significant diVerences between the two groups with respect to change in weight, body mass index, or Shwachman score. There was no significant diVerence in prior use of steroids or nebulised antibiotics. Conclusion-MRSA infection in children with CF does not significantly aVect respiratory function, but may have an adverse eVect on growth. Children with MRSA require significantly more courses of intravenous antibiotics and have a worse chest x ray appearance than controls. (Arch Dis Child 2001;84:160-162)

Clinical Significance of Microbial Infection and Adaptation in Cystic Fibrosis

“…Several small studies did not find an association between MRSA infection and increased mortality or deterioration of lung function in CF patients (208,397,602). Likewise, a retrospective study that evaluated a treatment protocol for eradication of MRSA carriage in 15 CF patients did not find an improvement in pulmonary function in patients who became MRSA free (564).…”

“…In contrast, other studies have found an association between MRSA and worse outcomes. In a retrospective study, Miall and colleagues compared the clinical courses of 10 CF patients with MRSA in their respiratory cultures between 1992 and 1998 to those of 18 controls (some with and some without MSSA) matched for age, sex, and respiratory function (397). After 1 year of follow-up, MRSA was associated with significant worsening of height standard deviation scores and a 2-fold increase in the number of courses of intravenous (i.v.)…”

Challenging and emerging pathogens in cystic fibrosis

“…Several small studies have investigated the effect of mrsa longitudinally. Miall et al conducted a case-control study including 10 children with mrsa and 18 controls, showing no difference in lung function change 89 , whereas Thomas et al studied 23 patients with mrsa and 69 controls and found that lower fev 1 was a risk factor for mrsa acquisition 90 . In this study however, pulmonary function decline was not studied, but there appeared to be no difference in mortality between controls and mrsa positive patients.…”

Early microbial colonization of cystic fibrosis patients identified by neonatal screening, with emphasis on Staphylococcus aureus

“…Os autores concluíram que a infecção por esse tipo de bactéria em crianças com FC não afeta significativamente a função respiratória, mas tem um efeito adverso no crescimento. Os pacientes requerem antibióticos intravenosos em quantidade significativamente maior e têm maiores alterações radiológicas que os controles 23 24 .…”