Table 1 Inclusion criteria for the ROC analysis reference groups

Reference

positive 1

1. IID

2. Norovirus detected by electron microscopy

3. Norovirus infection confirmed by RT-PCR

Reference

positive 2

1. IID

2. Norovirus detected by electron microscopy

3. Norovirus infection confirmed by RT-PCR

Or

1. IID

2. Electron microscopy negative

3. Norovirus detected by RT-PCR

4. No other pathogen detected

5. Specimen collected within 3 days of symptom onset

Reference

positive 3

1. IID

2. Norovirus detected by electron microscopy and/or RT-PCR

3. Negative for Campylobacter spp., Salmonella spp. and Shigella spp. by bacterial culture and Cryptosporidiumspp. by light microscopy

(and rotavirus A by ELISA in children aged less than five years only)

Reference

negative 1

1. No history of IID in previous 3 weeks

2. Norovirus detected by RT-PCR

Reference

negative 2

1. IID

2. Norovirus detected by RT-PCR

3. Infection with Salmonella spp., Campylobacter spp. or Shigella spp. detected by bacterial culture or Cryptosporidium spp. detected by light microscopy

(or rotavirus A by ELISA in children aged less than five years only)