Evaluation of rapid immunochromatographic tests for norovirus in neonatal and infant faecal specimens.

Objectives To compare the diagnostic performance of two norovirus rapid immunochromatographic kits (QuickNavi (R)-Norovirus [QN] and QuickNavi (R)-Norovirus 2 [QN2]; Denka Seiken, Niigata, Japan) for neonatal and infant faecal specimens. Methods Monthly faecal samples were collected from infants from birth to 12 months of age, and tested for norovirus using QN and QN2. Real-time reverse transcription polymerase chain reaction (RT-PCR) was used as the gold standard for norovirus detection. The diagnostic performance of the kits was calculated. Results A total of 343 specimens from 81 infants were analysed. In all samples, the specificity of QN and QN2 was 80% (275/343) and 99% (339/343), respectively. In infants aged <1 month, the specificity of QN was 33% (23/70), increasing to 93% at 4 months of age. Specificity of QN2 was 94% in infants between 0 and 12 months of age. Conclusions QN2 offers improved performance and is more useful than QN for the diagnosis of norovirus infection in the neonatal and infant period.