An acute gastroenteritis outbreak is affecting members of the U.S. swim team at Worlds. Here’s what it means, what causes it, ...

But these symptoms can come on in different ways. Viral gastroenteritis, such as with norovirus, usually causes symptoms 24–48 hours after exposure, which can last for one to two days.

It is not yet clear whether noroviruses are transmissible to immunocompetent adults from patients with chronic viral shedding, the latter having been proposed as a possible reservoir of novel ...