Jan, 2001. Eradication of early pseudomonas aeruginosa infection [online]. Seacroft and St James's University Hospitals, UK. Available from http://www.cysticfibrosismedicine.com

In the early stages of cystic fibrosis there may be little to find clinically but bronchoscopy studies have documented the presence of infection and inflammation in the lungs of some clinically well CF infants (Armstrong et al, 1995; Armstrong et al, 1996; Kahn et al, 1995). Viral and bacterial infections, with Staphylococcus aureus and Haemophilus influenzae, predominate in younger patients while chronic colonisation with Pseudomonas aeruginosa is usual in most patients by their late teens. This can now be prevented, or at least substantially delayed by intensive treatment of the first Pseudomonas aeruginosa isolate (Littlewood et al, 1985; Valerius et al, 1991; Vazquez et al, 1993; Frederiksen et al, 1997). It is critically important to offer all patients this "eradication regimen" because chronic P. aeruginosa infection results in worse clinical status; lower respiratory function, lower weight, height and BMI, more hospital admissions (Konstan et al, 1999).

In the majority of patients with CF chronic infection with P. aeruginosa is with the mucoid form of the bacteria. This defends itself against ingestion and destruction by the white blood cells by producing large amounts of a protective film/mucus called alginate. The huge numbers of peripheral blood white cells which congregate in the lung in an attempt to kill these bacteria release powerful enzymes, directed at the bacteria but also damaging to the lung itself. These fuel a continuing inflammatory process in the lungs, the end result of which is destruction of lung tissue (Venaille et al, 1998). Following repeated respiratory tract infections it is the body’s response to P. aeruginosa infection which is largely responsible for causing lung damage (Heeckeren et al, 1997).

When Pseudomonas aeruginosa is first isolated from respiratory cultures, treatment with 3 weeks oral ciprofloxacin and nebulised colistin (2 mega units two to three times daily) will eradicate the organism for prolonged periods of time in over 80% of patients (Valerius et al, 1991; Frederiksen et al, 1997). Similar success has been achieved using ciprofloxacin and nebulised tobramycin (Vazquez et al, 1993). Thus, in many CF patients, chronic pseudomonas infection can now be delayed. It is the Leeds policy to treat the first isolate and all subsequent intermittent isolates with three months of oral ciprofloxacin 25-50 mg/kg/day, and nebulised colistin 2 megaunits two to three times a day (Frederiksen et al, 1997). If this treatment fails or is deemed inappropriate, intravenous anti-pseudomonal antibiotic therapy is recommended in combination with nebulised colistin (started at the time of intravenous antibiotic therapy).

For more details see CF (UK) Trust antibiotic consensus section

References

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Armstrong DS, Grimwood K, Carlin JB, Carzino A, Phelan PD. Bronchoalveolar lavage and oropharyngeal cultures to identify lower respiratory pathogens in infants with cystic fibrosis. Pediatr Pulmonol 1996; 21: 267-275

Frederiksen B, Koch C, Hoiby N. Antibiotic treatment at time of initial colonisation with Pseudomonas aeruginosa postpones chronic infection and prevents deterioration in pulmonary function in patients with cystic fibrosis. Pediatr Pulmonol 1997; 23: 330-335

Heeckeren A, Walenga R, Konstan MW, Bonfield T, Davis PB, Ferkol T. Excessive inflammatory response of cystic fibrosis mice to bronchopulmonary infection with Pseudomonas aeruginosa. J Clin Invest 1997; 100: 2810-2815

Kahn TZ, Wagener JS, Bost T, Martinez J, Accurso FJ, Richer DWH. Early pulmonary inflammation in infants with cystic fibrosis. Am J Respir Crit Care Med 1995; 151: 1075-1082

Konstan MW, Butler SM, Schidlow DV, Morgan WJ, Julius JR, Johnson CA et al. Patterns of medical practice in cystic fibrosis. Pediatr Pulmonol 1999; 28: 242-247

Littlewood JM, Miller MG, Ghoneim AT, Ramsden CH. Nebulised colomycin for early pseudomonas colonisation in cystic fibrosis. Lancet 1985; i: 865

Valerius NH, Koch C, Hoiby N. Prevention of chronic Pseudomonas aeruginosa infection in cystic fibrosis by early treatment. Lancet 1991; 338: 725-726

Vazquez C, Municio M, Corera M, Gaztelurrutia L, Sojo A, Vitoria JC. Early treatment of Pseudomonas aeruginosa colonisation in cystic fibrosis. Acta Paediatrica 1993; 82: 308--309

Venaille TJ, Ryan G, Robinson BW. Epithelial cell damage is induced by neutrophil-derived, not pseudomonas-derived, proteases in cystic fibrosis sputum. Respir Med 1998; 92: 233-240

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