The U.S. Food and Drug Administration (FDA) has cleared the first test for the preliminary identification of norovirus that cause the “stomach flu,” or gastroenteritis.

Norovirus contamination usually occurs in settings where there is close group contact, such as cruise ships, hospitals, long-term care facilities, and schools or child-care centers. The viruses are transmitted by faecally contaminated food or water, by person-to-person contact. The most common symptoms of acute gastroenteritis are diarrhea, vomiting, and stomach pain.

Manufactured by Germany-based R-Biopharm AG, the Ridascreen Norovirus 3rd Generation EIA assay is for use when a number of people have simultaneously contracted gastroenteritis and there is a clear avenue for virus transmission, such as a shared location or food.

The test is not sensitive enough for use when only a single person has symptoms and should not be used for diagnosing individual patients, says the U.S. health regulator. The test identifies norovirus across samples about two-thirds of the time it was present.

“This test provides an avenue for early identification of norovirus,” said Jeffrey Shuren, M.D., J.D., director of the FDA’s Center for Devices and Radiological Health. “Early intervention can halt the spread of an outbreak.”