ABSTRACT
OBJECTIVE: To identify factors associated with culture-proven serious bacterial infection (SBI) and positive emergency department septic screening (EDSS) tests in children with bronchiolitis and to identify factors associated with the performance of EDSS. METHODS: We reviewed an existing study database of patients with bronchiolitis. We defined a positive EDSS as urine with >/=10 WBC per high power field or cerebrospinal fluid (CSF) with >/=10 WBC per high power field (>25 WBC in neonates), or if organisms were identified on gram stain. We defined SBI as significant growth of an accepted pathogen in blood, urine or CSF. Our composite endpoint was positive if either of these was positive. The decision to perform testing was modeled using modified Poisson regression; the presence of the combined outcome was modeled using logistic regression modified for rare events. RESULTS: We studied 640 children. Testing was performed in 199/640 (31.1%). These tended to be younger than two months RR 2.69 (95% CI 2.11, 3.44), febrile RR 2.01 (95% CI 1.58, 2.55), more dehydrated RR 1.50 (95% CI 1.28, 1.75) and had more severe chest wall retractions RR 1.54 (95% CI 1.22, 1.94). Only 11/640(1.7%) had a positive EDSS or SBI. Younger age (OR 0.67 per month; 95% CI 0.45, 0.99) and a negative RSV antigen test (OR 6.22; 95% CI 1.30, 29.85) were associated with the composite endpoint. CONCLUSION: Testing was more likely to be performed in children younger than two months of age, and in those who were febrile, dehydrated, and had more severe chest wall retractions. A positive EDSS or SBI was rare occurring in younger infants with non-RSV bronchiolitis.
ABSTRACT
BACKGROUND: The clinical presentation of Bordetella pertussis can overlap with that of respiratory syncytial virus (RSV); however, management differs. HYPOTHESIS: First, the prevalence of B. pertussis is less than 2% among patients screened for RSV, and second the prevalence of B. parapertussis is also less than 2% among these patients. METHODS: Nasal washings submitted to a clinical laboratory for RSV screening were tested for B. pertussis and B. parapertussis, using species-specific real-time polymerase chain reaction (PCR) assays. These were optimized to target conserved regions within a complement gene and the CarB gene, respectively. A Bordetella spp. genus-specific real-time PCR assay was designed to detect the Bhur gene of B. pertussis, B. parapertussis, and B. bronchiseptica. RSV A and B subtypes were tested by reverse transcription-PCR. RESULTS: Four hundred and eighty-nine clinical samples were tested. There was insufficient material to complete testing for one B. pertussis, 10 RSV subtype A, and four RSV subtype B assays. Bordetella pertussis was detected in 3/488 (0.6%) (95% CI 0.1% to 1.8%), while B. parapertussis was detected in 5/489 (1.0%) (95% CI 0.3% to 2.4%). Dual infection of B. pertussis with RSV and of B. parapertussis with RSV occurred in two and in three cases respectively. RSV was detected by PCR in 127 (26.5%). CONCLUSION: The prevalence of B. pertussis in nasal washings submitted for RSV screening was less than 2%. The prevalence of parapertussis may be higher than 2%. RSV with B. pertussis and RSV with B. parapertussis coinfection do occur.
