The CF-Sputum Induction Trial (CF-SpIT) to assess lower airway bacterial sampling in young children with cystic fibrosis: a prospective internally controlled interventional trial

Background Obtaining lower airway specimens is important for guiding therapy in chronic lung infection but is difficult in young children unable to expectorate. While culture‐based studies have assessed the diagnostic accuracy of nasopharyngeal or oropharyngeal specimens for identifying lower airway infection, none have used both together. We compared respiratory bacterial pathogens cultured from nasopharyngeal and oropharyngeal swabs with bronchoalveolar lavage (BAL) cultures as the “gold standard” to better inform the diagnosis of lower airway infection in children with chronic wet cough. Methods Nasopharyngeal and oropharyngeal swabs and BAL fluid specimens were collected concurrently from consecutive children undergoing flexible bronchoscopy for chronic cough and cultured for bacterial pathogens. Results In cultures from 309 children (median age, 2.3 years) with chronic endobronchial suppuration, all main pathogens detected (Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis) were more prevalent in nasopharyngeal than oropharyngeal swabs (37%, 34%, and 23% vs 21%, 6.2%, and 3.2%, respectively). Positive and negative predictive values for lower airway infection by any of these three pathogens were 63% (95% confidence interval [95% CI] 55, 70) and 85% (95% CI, 78, 91) for nasopharyngeal swabs, 65% (95% CI, 54, 75), and 66% (95% CI, 59, 72) for oropharyngeal swabs, and 61% (95% CI, 54,68), and 88% (95% CI, 81, 93) for both swabs, respectively. Conclusions Neither nasopharyngeal nor oropharyngeal swabs, alone or in combination, reliably predicted lower airway infection in children with chronic wet cough. Although upper airway specimens may be useful for bacterial carriage studies and monitoring antimicrobial resistance, their clinical utility in pediatric chronic lung disorders of endobronchial suppuration is limited.

Section: Discussionmentioning

confidence: 99%

Do combined upper airway cultures identify lower airway infections in children with chronic cough?

Hare

Chang

Smith‐Vaughan

et al. 2019

“…Sputum induction using nebulized hypertonic saline is an alternative to obtain lower airway samples with minimal discomfort to the patient . Previous studies have shown that induced sputum samples correlate well with BAL samples with respect to bacterial load and pathogens isolated . In our patient cohort, four children with new NTM isolates had subsequent repeat isolation of these pathogens from BAL samples; one of them had repeat NTM isolation on sputum induction suggesting consistency of microbiological yield from sputum induction.…”

Section: Discussionmentioning

confidence: 53%

Early detection of non‐tuberculous mycobacteria in children with cystic fibrosis using induced sputum at annual review

Ahmed

Kulkarni

Shajpal

et al. 2018

Aim Non‐tuberculous mycobacteria (NTM) have emerged as an important pathogen in cystic fibrosis (CF). Early detection and treatment of NTM can preserve lung function and maintain good lung health. Many children with CF are not regular sputum producers and cough swabs cannot routinely be used to diagnose NTM. We aimed to test the hypothesis that performing sputum induction at routine annual review results in earlier identification of NTM in non‐sputum producing children with CF. Method We conducted a 5‐year prospective observational cohort study involving children with CF aged 5‐17 years who had sputum induction with hypertonic saline for microbiological surveillance including NTM at their annual review. Results Forty‐two children (19 males, mean age 11.4 years ± 3.6, mean FEV1% predicted 94.7 ± 20.6) participated in the study. Forty‐one induced sputum samples from 29 children yielded bacterial pathogens. Six samples from six children (14% of the cohort) yielded NTM never previously isolated from the patient. We also detected three isolates of Pseudomonas aeruginosa and one isolate each of Burkholderia cepacia complex and Meticillin resistant Staphylococcus aureus (MRSA), all of which were first time isolates. Conclusion We conclude that annual induced sputum for microbiological surveillance is useful for early detection of NTM and other important respiratory pathogens, particularly in non‐expectorating children. This may lead to earlier identification and help inform initiation of eradication treatment in children with NTM. Children can also be cohorted earlier, before they potentially infect other children in the clinic.

“…This is of special importance in detection of mycobacteria, which cannot be isolated from OPS. In the prospective CF‐Sputum Induction Trial (CF‐SpIT), pathogen yield from sputum induction was compared with that from OPS, single‐lobe, two‐lobe, and six‐lobe BAL . One hundred twenty‐four children with CF, aged 6 months to 18 years, had 200 sputum induction procedures, of which 84% were successful.…”

Section: Infection Detection and Epidemiologymentioning

confidence: 99%

Cystic fibrosis year in review 2018, part 1

Savant

McColley

2019