Table 3.

Actual Versus Expected Coinfections by Age Group

Coinfection	Age Group
	All Ages	<2 y	2–4 y	5–9 y	10–14 y
RSV-IA
Samples	3017	991	865	780	381
Actual coinfections	33	9	10	10	4
Expected coinfections	116	32	44	23	11
P value	<.0001	<.0001	<.0001	.0005	.0052
RSV-IB
Samples	1458	465	373	412	208
Actual coinfections	10	0	1	7	2
Expected coinfections	37	5	12	12	5
P value	<.0001	.0151	<.0001	.103	.0664
RSV-hMPV
Samples	2813	985	834	669	325
Actual coinfections	23	12	5	3	3
Expected coinfections	45	19	19	6	3
P value	.0002	.0722	.0002	.1613	.7253a
RSV-HCoV
Samples	4067	1452	1189	974	452
Actual coinfections	42	25	9	6	2
Expected coinfections	44	23	14	6	2
P value	.6934	.7198	.0862	.9989	1a

Total samples include samples collected during weeks where both pathogens of interest were circulating. Pearson χ² and Fisher exact tests were used to compare the observed and expected distributions of coinfections.

Abbreviations: HCoV, human coronaviruses (OC43, 229E, NL63, HKU1); hMPV, human metapneumovirus; IA, influenza A; IB, influenza B; RSV, respiratory syncytial virus.

^aIf observed counts <5.