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Stijn Jonckheerea,b, Nadine Botteldoornc, Patricia Vandecandelaereb, Johan Fransd, Wim Laffute,
Guy Coppensf, Anne Vankeerberghena, Hans De Beenhouwera, on behalf of the BILULU study group
a OLV Hospital, Aalst; b Jan Yperman Hospital, Ieper; c National Reference Center for Norovirus, WIV-ISP, Brussel; d Imelda Hospital,
Bonheiden; e HH Hospital, Lier; f Hospital Oost-Limburg, Genk (all located in Belgium)
Correspondence: stijn.jonckheere@yperman.net
Background
Noroviruses are the leading cause of nonbacterial acute
gastroenteritis in both children and adults and cause both
sporadic cases and outbreaks of gastroenteritis. Rapid
laboratory diagnosis is essential to implement measures to
prevent and control the outbreaks. Recently, the RIDA® QUICK
Norovirus (R-Biopharm) was revised and additional antibodies
were included for a broad range of detection (article number
N1402 instead of the former N1403). Also, the antibodies are
dissolved in the reagent, instead of dried on the membrane,
converting the test from a two-step flow through
immunochromatographic test to a one-step lateral flow assay,
thereby reducing the turn-around-time and increasing the ease-
of-use. We present a prospective, multicenter study evaluating
the performance of the RIDA® QUICK Norovirus N1402 on
stool samples.
Test cassette of the
RIDA QUICK (N1402)
Material/methods:
This prospective, multicenter clinical trial was conducted from
November 2014 through April 2015 at five study sites in
Belgium. A total of 771 samples were tested with the RIDA®
QUICK and the RIDA® GENE Norovirus I & II real-time reverse
transcriptase (RT-rt)PCR (R-Biopharm). RIDA® QUICK
positive samples that were not confirmed by the RIDA® GENE
Norovirus I & II RT-rtPCR were further tested by additional PCR
testing (in-house SYBR®Green RT-rtPCR with melting peak
analysis). A sample was considered positive if one of the RT-
rtPCR’s was positive. All positive samples were further
characterized to genotype level by partial sequencing of the
polymerase and capsid regions.
Multicenter evaluation of the revised RIDA® QUICK test (N1402)
for rapid detection of norovirus in a diagnostic laboratory setting
Results
The overall positivity rate of norovirus was 16.2% (125/771)
(norovirus GI: 0.6% (5/771) and GII: 15.6% (120/771)), although
marked local difference was noticed (range: 7.3% – 26%).
Multivariate logistic regression showed that age was the only
parameter that was independently correlated with a positive result
for norovirus (b = -0.016, p < 0.001). The relative high inclusion
rate of children in Jan Yperman probably explains the high
positivity rate compared to other centers.
Overall sensitivity and specificity of the RIDA® QUICK for
detection of norovirus compared to PCR as gold standard was
72.8% and 99.5%, respectively. The RIDA® GENE, that was used
as first line RT-rtPCR test, detected 110 positive samples. Another
15 were only detected by the in-house SYBR®Green RT-rtPCR.
By doing a more in depth molecular analysis it was discovered
that the false negative results by the RIDA® GENE RT-rtPCR
were caused by a deletion in the ORF1-ORF2 junction region
which prevented amplification by the RIDA® GENE RT-rtPCR, but
not by the in-house RT-rtPCR. Genotyping revealed that the most
frequently detected norovirus genotypes in this study were
norovirus GII.P4 and GII.4.
Conclusions
The updated RIDA® QUICK N1402 can be used as a reliable
test for rapid detection of norovirus in stool samples with less
hands-on time compared to the former N1403 assay. However,
a negative result does not exclude norovirus infection, although
it was shown in this study that RT-rtPCR testing can also
suffer from a suboptimal sensitivity.
Abstract number: 6011
95
96,8
99,5
72,8
50 60 70 80 90 100
NPV (%)
PPV (%)
Specificity (%)
Sensitivity (%)
RIDA QUICK (n=771, all study sites included)
16,2
15
7,3
18,4
7,7
26
010 20 30
Total (n=771)
ZOL, Genk (n=80)
HH Hospital, Lier (n=96)
Imelda Hospital, Bonheiden (n141)
OLV Hospital, Aalst (n=208)
Jan Yperman, Ieper (n=246)
Positivity rate of norovirus (%) for different study sites
