Test Code NORO Norovirus Real-time RT-PCR
Clinical Indications
Noroviruses are a major cause of nonbacterial acute
gastroenteritis, accounting for as many as 50% of viral
gastroenteritis cases. Symptoms include acute diarrhea,
vomiting,
abdominal cramps, headache, nausea, fatigue, and low-grade
fever.
Most cases are self-limiting, but complications can occur,
particularly in the young, the elderly, and immunocompromised
individuals. In immunocompromised patients, norovirus infection
can
cause life-threatening gastroenteritis after hematopoietic stem
cell transplantation and should always be considered in the
differential diagnosis of gut GVHD.
Real-time reverse-transcriptase PCR has
been shown to be a sensitive, specific method for early
assessment
of norovirus infections, contributing to positive clinical
outcomes.
Additional Test Codes
Epic Order Name: NOROVIRUS
PCR,
FECES
Sunquest Order Code: NORO
Epic Px Code: LAB2958
Specimen Collection Type
Random stool collected in a sterile container (e.g. culture
cup)
Minimum Collection Volume
Size of pea, or 2 mL liquid stool
Reference Range
Detected/Not Detected
Critical Value
N/A
Interpretation
Qualitative result (Detected/Not Detected). The assay
differentiates between Norovirus Group I and Group II.
This assay demonstrates no cross-reactivity with other known
gastroenteritis pathogens. Genogroup I and Gengroup II assays
show
slight cross-reactivity with high titers of Norovirus Genogroup
IV
RNA.
Detection of norovirus RNA in the stool
does not definitively indicate that norovirus is the causative
agent of gastrointestinal disease. Asymptomatic shedding of
norovirus, especially in immunocompromised patients, has been
reported in peer reviewed scientific literature. Results should
be
used in conjunction with clinical findings, and should not form
the
sole basis for a diagnosis or treatment decision.
Rejection Criteria
Fecal specimens that have been stored at ambient temperature
for
>96 hrs. If storage longer than 96 hours is needed, fecal
samples should be frozen at -20°C or colder.
Specimen Availability for Add-on Testing
1 Day
Specimen Stability
Ambient (preferred): 4 days
Refrigerated: 4 days
Frozen: 7 days
Day(s) Performed
Monday through Saturday
Performing Lab- Department
TUKHS-BH-Mail Outs
CPT Code
87799
LOINC Code
N/A
Test Alias
Nororvirus RNA, RT-PCR
Norovirus I and II PCR
Norovirus RNA
Norwalk Virus
Human Calcivirus
Additional Information / Notes
Turnaround time: Same day (within 8 – 12 hours from
receipt of specimen)