3.2-Viral co-infection
Viral co-infection was present in 28.3% (599) of all children, and those with viral co-infection were at a higher risk of severe disease than those with a single virus infection (43.8% vs. 22.7%; aOR, 3.44; 95% CI, 2.74-4.53;P < .001; Table 1). In subgroup analyses for each virus comparing single virus infection and its co-infection; RSV (aOR, 3.70; 95% CI, 2.62-5.23; P < .001), HRV (aOR, 3.50; 95% CI, 2.45-5.02; P < .001), influenza A (aOR, 4.83; 95% CI, 2.37-9.84; P < .001), PIV3 (aOR, 9.03; 95% CI, 3.73-21.90; P < .001), HBoV (aOR, 2.37; 95% CI, 1.27-4.63; P = .01), HAdV (aOR, 3.41; 95% CI, 1.27-9.12;P = .01), and EV (aOR, 5.06; 95% CI, 1.35-18.89; P = .01; Figure 2) co-infections were associated with an increased risk for severe disease.