Organism Isolation Outcomes
Among all cultures obtained, only 617 cultures (17.2%) demonstrated
organism isolation, with 751 total organisms identified (22 unique
species). Unadjusted analysis demonstrated that cultures of children
with ARI had higher odds of any organism isolation compared with those
from children without ARI (24.3% vs 14.8%, p<0.01,Figure 1(a) ); unadjusted odds ratio(OR) 1.83 (95% Confidence
Interval(CI) 1.67-2.01, Table 2 ). The most prevalent organisms
isolated in both children with and without ARI were Pseudomonas
aeruginosa , Staphylococcus aureus (29% methicillin-resistant),Haemophilus influenzae , and Moraxella catarrhalis(Figure 1(b) ). On unadjusted analysis, all 4 of these organisms
were significantly more frequently isolated with ARI diagnosis compared
with no ARI diagnosis (Figure 1(b) ).
On adjusted analysis, ARI diagnosis continued to demonstrate increased
odds of organism isolation (aOR 1.29; 95%CI 1.16-1.44, Table
2 ). ARI was not associated with P. aeruginosa or S.
aureus isolation on adjusted analysis, but P. aeruginosa was
associated with bARI diagnosis. Using multinomial adjusted analysis
examining for the comprehensive outcome of each organism isolation, ARI
diagnosis was associated with isolation of 4 organisms, H.
influenzae (aOR 2.09), M. catarrhalis (aOR 1.76), S.
pyogenes (aOR 1.92), and Streptococcus pneumoniae (aOR 4.04,Table 3 ), as compared with no organism isolation. Isolation of
all other organisms, including P. aeruginosa and S.
aureus , were not associated with ARI diagnosis at the time of culture
collection.