Table 2.

Prevalences of respiratory viruses in infants with URTI, with rhinitis or infants without nasal symptoms at 6, 12, 18 and 24 months of age

	n	Any virus detected (%)	Rhino‐virus (%)	RSV (%)	Corona‐virus (%)	PIV (%)*	Influenza‐virus (%)†	CMV (%)	Other viruses‡ (%)
URTI
6 months	33	19 (58)	9 (27)	6 (18)	7 (21)	2 (6)	2 (6)	1 (3)¶	2 (6)**
12 months	14	11 (79)	6 (43)	3 (21)	0 (0)*	2 (14)	1 (7)	0 (0)**	0 (0)**
18 months	28	20 (71)	15 (54)	3 (11)¶	1 (4)¶	0 (0)¶	1 (4)¶	0 (0)¶	2 (7)¶
24 months	5	4 (80)	3 (60)	2 (40)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
Rhinitis
6 months	46	25 (54)	19 (41)	1 (2)¶	3 (7)¶	3 (7)¶	0 (0)¶	3 (7)¶	1 (2)¶
12 months	33	19 (58)	17 (52)	1 (3)¶	1 (3)¶	0 (0)¶	0 (0)¶	0 (0)¶	1 (3)¶
18 months	29	10 (34)	9 (31)	1 (3)**	0 (0)¶	0 (0)¶	0 (0)¶	2 (7)**	1 (3)¶
24 months	25	13 (52)	12 (48)	1 (4)¶	1 (4)¶	0 (0)¶	0 (0)¶	0 (0)¶	0 (0)¶
Nasal‐symptom‐free
6 months	70	23 (33)	12 (17)	2 (3)**	3 (4)**	1 (1)¶	1 (1)¶	9 (13)§	2 (3)¶
12 months	64	20 (31)	18 (28)	0 (0)¶	0 (0)¶	0 (0)¶	0 (0)¶	3 (5)¶	1 (2)¶
18 months	38	12 (32)	10 (26)	0 (0)¶	0 (0)¶	0 (0)¶	0 (0)¶	2 (5)**	0 (0)¶
24 months	49	8 (16)	7 (14)	0 (0)**	1 (2)	0 (0)**	0 (0)**	0 (0)**	0 (0)**

Prevalences were calculated as a percentage of total numbers of infants (n) per age and symptom group.

RSV: respiratory syncytial virus; PIV: parainfluenzavirus; CMV: cytomegalovirus.

^* One PIV1, 2 PIV2 and 5 PIV3 infections.

^† Four influenza virus A and 1 influenza B infection.

^‡ Adenovirus and enterovirus.

^§ p < 0.01 CMV vs. PIV and vs. influenza virus, p < 0.05 vs. ‘other viruses’.

^¶ p < 0.01 vs. rhinovirus.

^** p < 0.05 vs. rhinovirus.