Table 3.

RSV-associated complications leading to intubation in Danish children aged 0–17 years

			Children with no risk factors		Children with risk factors
			2016–17 to 2019–20 (n=27)*	2021–22 (n=19)†	2016–17 to 2019–20 (n=52)*	2021–22 (n=35)†
Classic bronchiolitis only			6 (22%)	0	41 (79%)	28 (80%)
Other complications			21 (78%)	19 (100%)	11 (21%)	7 (20%)
Adjacent respiratory complications
	Any		9 (33%)	14 (74%)	5 (10%)	1 (3%)
		Wheeze responsive to salbutamol	3 (11%)	7 (37%)	0	0
		Severe bacterial co-infection	3 (11%)	3 (16%)	5 (10%)	0
		Pneumothorax	2 (7%)	3 (16%)	0	1 (3%)
		Stridor	1 (4%)	1 (5%)	0	0
		Acute respiratory arrest due to secretion	0	1 (5%)	0	0
Neurological complications
	Any		12 (44%)	4 (21%)	2 (4%)	5 (14%)
		Prolonged or complex febrile convulsions	10 (37%)	3 (16%)	2 (4%)	3 (9%)
		Acute encephalopathy or encephalitis	2 (7%)	1 (5%)	0	1 (3%)
		Convulsions due to hyponatremia	0	0	0	1 (3%)
Cardiac complications			0	1 (5%)	4 (8%)	1 (3%)
Median duration of mechanical ventilation, days (IQR)			3 (2–5)	3 (2–6)	4 (3–6)	2 (1–7)
RSV-associated death			1 (4%)	0	4 (8%)	3 (9%)

Data are n (%), unless otherwise stated. Risk factors for severe RSV disease were defined as age younger than 3 months, prematurity (gestational age <32 weeks), and chronic medical conditions, including lung and heart disease, neuromuscular diseases, inborn errors of metabolism, inborn errors of immunity, and immunosuppressive therapy. RSV=respiratory syncytial virus.

^*79 children received mechanical ventilation during the four pre-COVID RSV-epidemic winter seasons (2016–17 to 2019–20), as identified through prospective nationwide data collection.

^†54 children received mechanical ventilation in the 2021–22 winter season, as identified through prospective nationwide data collection.