What you need to know.

During the COVID-19 Pandemic (it really is not over yet), foodborne illness outbreaks were down, and I said a few days ago, they are back – CDC Report: We are back to “Bad Normal” with foodborne illnesses as COVID wanes.  Well, if the recent rash of norovirus outbreaks on cruise ships is any indication, norovirus and cruise ships are also back.  Here is the lates from the CDC:

The Centers for Disease Control and Prevention (CDC) estimates that noroviruses cause nearly 21 million cases of acute gastroenteritis annually, making noroviruses the leading cause of gastroenteritis in adults in the United States. Of the viruses, only the common cold is reported more often than a norovirus infection—also referred to as viral gastroenteritis.

Humans are the only host of norovirus. Norovirus causes nearly 60% of all foodborne illness outbreaks. Norovirus is transmitted primarily through the fecal-oral route, with fewer than 100 norovirus particles needed to cause infection.  Moreover, the viruses can spread quickly, especially in places where people are in proximity, such as cruise ships and airline flights, even those of short duration. Common settings for norovirus outbreaks include restaurants and events with catered meals (36%), nursing homes (23%), schools (13%), and vacation settings or cruise ships (10%).

Outbreaks of norovirus infections have become synonymous with cruise ships. Healthcare facilities also experience a high incidence of norovirus outbreaks. The CDC has published information regarding the prevention of norovirus outbreaks on cruise ships and in healthcare facilities on its website. Once a case has occurred, even more stringent hygienic measures than normal are required to prevent an outbreak, particularly on an enclosed space such as a cruise ship.

Norovirus illness usually develops 24 to 48 hours after ingestion of contaminated food or water. Symptoms typically last a relatively short amount of time, approximately 24 to 48 hours. Symptoms of norovirus include nausea, vomiting, diarrhea, and abdominal pain. Headache and low-grade fever may also accompany this illness. People infected with norovirus usually recover in two to three days without serious or long-term health effects.

Although symptoms usually only last one to two days in healthy individuals, norovirus infection can become quite serious in children, the elderly, and immune-compromised individuals. In some cases, severe dehydration, malnutrition, and even death can result from norovirus infection, especially among children and among older and immune-compromised adults in hospitals and nursing homes. Recently, there have been reports of some long-term effects associated with norovirus, including necrotizing entercolitis, chronic diarrhea, and post-infectious irritable bowel syndrome.


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