Home Self-Collection of Nasal Swabs for Diagnosis of Acute Respiratory Virus Infections in Children With Cystic Fibrosis

Background. Understanding the importance of respiratory viruses in children with cystic fibrosis (CF) has been limited because of challenges using clinic- or hospital-based diagnostic testing. We conducted a pilot study to assess feasibility of home self- (or parent-) collection of nasal swabs (NS). Methods. Cystic fibrosis patients aged 6–18 years with new respiratory illness participated. In clinic, a deep nasal flocked swab was collected by research staff and compared with an anterior foam NS obtained after instillation of saline spray. At home, up to 2 self-collections of paired foam NS (with and without saline) were collected and mailed for real-time polymerase chain reaction (PCR) testing. Results. Paired swabs were collected from 28 patients: 18 sets in clinic (deep nasal vs saline foam NS) and 43 sets at home (saline vs dry foam NS) with 9 (50%) and 35 (81%) virus detections, respectively. Home-collected NS were obtained closer to illness onset, with a mean difference in symptom days of −2.3 between home and clinic collections (95 % confidence interval [CI] −3.5, −1.2; P <.001). Rhinovirus comprised 73 % of virus detections; the difference in mean PCR cycle threshold values for rhinovirus between swabs collected at home versus clinic was −3.8 (95 % CI −6.8, −0.9; P =.014), indicating significantly higher viral load for home-collected swabs. Conclusions. Home-collected foam NS had a higher positivity rate compared with clinic-collected swabs