Diagnosing norovirus-associated infectious intestinal disease using viral load

BMC Infectious Diseases

Table 2 Ct values in genogroup II norovirus positive IID cases and healthy controls.

Method of norovirus detection	IID Cases			Controls			Rank-sum test p-value comparing cases to controls
	Median Ct value	Ct value IQR	Sample size	Median Ct value	Ct value IQR	Sample size
All ages
All	34	25–37	589	38	35–39	159	<0.0001
Electron microscopy	24	21–27.5	92				<0.0001
RT-PCR (Electron microscopy negative)	35	29–38	497				<0.0001
< 5 years
All	34	26–37	253	37	34–38	92	<0.0001
Electron microscopy	23	21–25	48				<0.0001
RT-PCR (Electron microscopy negative)	35	32–37	205				0.0001
5 years +
All	34	25–38	334	38	36–39	67	<0.0001
Electron microscopy	25	22–28.5	44				<0.0001
RT-PCR (Electron microscopy negative)	35	27–38	290				<0.0001

The rank-sum tests for electron microscopy and RT-PCR positive IID cases compare them to all controls. Age was not recorded for two IID cases. IQR is the interquartile range.

ISSN: 1471-2334