Original ArticleMicrobiological yield from induced sputum compared to oropharyngeal swab in young children with cystic fibrosis

BackgroundStandard respiratory sampling in young children with cystic fibrosis (CF) is by oropharyngeal swab (OPS) as they cannot spontaneously expectorate. Sputum induction (IS) has been poorly investigated in this population. We aimed to compare the bacteriological yield of OPS vs. IS in young children with CF.MethodsSequentially paired OPS followed by IS samples was collected in children < 5 years of age attending a CF clinic in Cape Town, South Africa.ResultsIS was successfully paired with OPS in 98/113 (85%) attempts in 32 children (mean ± SD 19 ± 16 months), with no serious adverse events. IS culture yield for any CF-associated bacteria from IS was 46% vs. 28% from OPS (p = 0.01). The sensitivity, specificity, PPV and NPV of OPS compared to IS in isolating CF-associated bacteria were 56%, 96%, 93%, and 72% respectively.ConclusionSputum induction is feasible, safe and superior to OPS for detecting CF-associated bacteria in young children with CF.