Infectious Disease Compendium

Norovirus

Microbiology

A virus. (NEJM Review)

Epidemiologic Risks

Eating and drinking contaminated food and water; cruise ships have had outbreaks. Oysters are a good source as they concentrate the virus and the virus is not killed by either freezing or the quick cooking required for a good oyster.

"It is likely that the time and temperature of cooking required to inactivate norovirus in oysters may render the food unpalatable to consumers" (PubMed).

Don't think bottled water is protective; in Spain it was the source of norovirus (PubMed).

10% of hospitalizations for diarrhea will be due to noro (PubMed).

Some strains cause more severe disease.

It is much harder for blood group B to get disease.

The immunoincompetant (transplant, hematologic malignancy) can have prolonged, chronic diarrhea (PubMed).

Different strain have variable morbidity and mortaility with Genogroup 2 Genotype 4 more likely to cause hospitalization and death (PubMed).

And it can be found in harbor porpoises (PubMed). So avoid porpoise sushi.

New strains for which there is no herd immunity pop up, or maybe poop up, from to time to cause new epidemics/pandemics. Just like influenza.

Syndromes

Diarrhea nausea and vomiting, fevers not uncommon. Asymptomatic shedders are not important for spread of disease (PubMed).

Treatment

Supportive.

Notes

After an outbreak of norovirus, those affected have increased incidence of dyspepsia, constipation, and GERD (PubMed).