Can throat swab after physiotherapy replace sputum for identification of microbial pathogens in children with cystic fibrosis?

OBJECTIVE

To compare cultures throat swab after physiotherapy with results of sputum culture in identification of lower airway pathogens in children with cystic fibrosis.

METHODS

387 samples of sputum cough swabs, throat swab and throat swab after physiotherapy were collected from 48 patients of cystic fibrosis and cultured for aerobic bacteria. The results of cultures of cough swabs, throat swab and throat swab after physiotherapy were compared with results of sputum culture.

RESULTS

There was good concordance between culture results of sputum and other methods. Over all concordance was 70%, 81% and 92% with cough swab, throat swab and throat swab after physiotherapy. Sensitivity for isolation of Pseudomonas aeruginosa by throat swab, cough swab and throat swab after physiotherapy was 40%, 42% and 82% respectively. Specificity for isolation of Pseudomonas by throat swab, cough swab and throat swab after physiotherapy was 99%, 100% and 99% respectively. Sensitivity for isolation of Staphylococcus aureus by throat swab, cough swab and throat swab after physiotherapy was 57%, 50% and 100% respectively. Specificity for isolation of Staphylococcus by throat swab, cough swab and throat swab after physiotherapy was 99% for all these methods.

CONCLUSION

It is concluded that throat swab after physiotherapy in a child with CF can be used reliably for identification of lower airway pathogens.