What is Norovirus (Diarrhea and Vomiting Bug)? How to Use Norovirus Rapid Test Kit?

Norovirus (NoV), also known as “stomach flu” or “stomach bug”, is an exceptionally infectious virus that causes vomiting and diarrhea. It is more common in winter, although you can catch it at any time of the year. Even a few norovirus particles are enough to infect. Read along to learn more about noroviruses, important symptoms that need to be followed up, different methods of testing, and how to prevent Norovirus.

What is Norovirus?

Noroviruses belong to the family Caliciviridae. They are a group of non-enveloped viruses with single-stranded RNA that primarily may cause acute gastroenteritis. Noroviruses can be classified into ten genogroups (GI-GX) and 48 genotypes.

Norovirus can be persistent to keep itself alive but usually clears up by itself in a couple of days.  It can be spread by feces, direct contact with the person who carries it, nutrients contaminated by norovirus, and touching your hand to your mouth after touching surfaces contaminated by norovirus. Hospitals, military, cruise ships, and resorts, schools are places where norovirus can be seen commonly.

What are the symptoms of a Norovirus infection?

The most frequent symptoms at initial diagnosis are diarrhea, vomiting, and abdominal pain. As rare symptoms, low-grade fever, chills, headache, muscle aches, and fatigue can be seen.

In a study (Robilotti et al., 2015) involving 179 patients infected by Norovirus, diarrhea occurred in 87.5%, vomiting occurred in 25.5% of patients, while 4.4% complained of abdominal pain and 2.2% had a fever. Symptoms were seen for 2.1 ± 1.5 days, with a range of 1.2 to 2.8 days; 86.4% of patients had symptom substitution within 1 to 3 days.

What Are Test Techniques to Detect Norovirus?

Until the cloning and sequencing of the Norwalk virus genome in 1990 (Jiang et al., 1990), followed by the development and application of the first RT-PCR assays for norovirus, electron microscopy (EM) was the only method to detect the virus. In the following years, as rapid diagnostic systems gained importance in the context of low cost, detection speed, ease, and sensitivity, immunochromatographic (ICG) lateral flow assays began to be used to evaluate the presence of norovirus.

How to Use the Norovirus Rapid Test Kit?

Rapid test kits intended for the detection of Norovirus usually use fecal samples such as our RapidFor^™ Norovirus Rapid Test Kit. A small amount of liquid or solid fecal sample (about 50mg) must be collected as a first step of the procedure. Following the collection of a specified amount of feces, the collected specimen should be mixed thoroughly with the provided extraction buffer and stand for 2 minutes. After that, the test cassette should be removed from the pouch and placed on a clean and dry surface. Finally, 3-4 drops of the processed sample are added to the sample well of the test cassette. Both red T (Test line) and C (Control line) appear on the membrane, which says the test is positive. However, only the purplish control band appears on the membrane. The absence of a test band shows a negative result. If the control band is not seen, it means the test is invalid. Repeat the test using a new test cassette/strip.

How Can You Protect Yourself Against Norovirus?

It is important that we wash our hands properly after using the toilet or changing diapers, before touching the foods we are about to eat or prepare, before giving someone else medicine, or when we take medication that can easily protect us from Norovirus.

Additionally, washing fruits and vegetables well, cooking oysters and other shellfish to an internal temperature of 62 °C (about 145 °F) at least, and routinely disinfecting/cleaning our kitchen utensils, counters, and surfaces can be protective.

It should not be forgotten that Noroviruses are relatively resistant to heat. They can survive to 62 °C (about 145 °F). Therefore, quick steaming processes cannot create enough heat to kill noroviruses.

REFERENCES

Jiang, X., Graham, D. Y., Wang, K., & Estes, M. K. (1990). Norwalk Virus Genome Cloning and Characterization. Science, 250(4987), 1580–1583. https://doi.org/10.1126/science.2177224

Jung, J. J., Grant, T., Thomas, D., Diehnelt, C. W., Grigorieff, N., & Joshua-Tor, L. (2019). High-resolution cryo-EM structures of outbreak strain human norovirus shells reveal size variations. Proceedings of the National Academy of Sciences of the United States of America, 116(26), 12828–12832. https://doi.org/10.1073/pnas.1903562116

Meštrović, T. (2021, May 19). Norovirus Classification. News-Medical.net. https://www.news-medical.net/health/Norovirus-Classification.aspx

Norovirus. (2023, February 13). NHS Inform. Retrieved May 24, 2023, from https://www.nhsinform.scot/illnesses-and-conditions/infections-and-poisoning/norovirus

Novakovic, A. (2023, April 24). What to know about norovirus. https://www.medicalnewstoday.com/articles/179107#what-is-norovirus

Robilotti, E., Deresinski, S., & Pinsky, B. A. (2015). Norovirus. Clinical Microbiology Reviews, 28(1), 134–164. https://doi.org/10.1128/cmr.00075-14