Norovirus infection resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Twinkle Singh, M.B.B.S. [2]

Definition

Norovirus is one of the extremely contagious viruses leading to 50% of the gastroenteritis outbreaks worldwide. An outbreak of norovirus is defined as an occurrence of 2 or more similar illnesses resulting from a common exposure that is either suspected or laboratory-confirmed to be caused by norovirus.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Life threatening cause 1
• Life threatening cause 2
• Life threatening cause 3

Common Causes

• Common cause 1
• Common cause 2
• Common cause 3
• Common cause 4
• Common cause 5

Management

Shown below is an algorithm summarizing the approach to norovirus infection outbreak.

Characterize the symptoms ❑ Non bloody diarrhea ❑ Vomiting ❑ Nausea ❑ Abdominal cramps ❑ Low grade fever ❑ Body aches ❑ Necrotising enterocolitis (in neonates) ❑ Chronic diarrhea (in immunosuppressed) ❑ Irritable bowel syndrome

Collect samples

❑ Whole stool sample Collection: ❑ Within 48 to 72 hrs after onset ❑ From at least 5 ill patients ❑ 10-50 ml of whole stool sample in a stool cup is preferred. Storage: ❑ If testing done < 3 weeks ❑ Refrigerate samples at 39 F ❑ If testing done > 3 weeks ❑ Refrigerate samples at - 4 F Transportation: ❑ Bagged, sealed and transported on ice packs in an insulated and waterproof container.

❑ Vomitus sample ❑ Collected, stored and transported in same ways as mentioned above for stool sample.

❑ Environmental samples: ❑ Water sample ❑ Shellfish samples ❑ Environmental surface swabs (Pursued in consultation with CDC)

Diagnostic tests: ❑ Enzyme immunoassays ❑ Reverse transcription-polymerase chain reaction ❑ Geno-typing

Norovirus positive

Norovirus negative

❑ Take measures to prevent and control outbreak (see below) ❑ Treat acute gastroenteritis

❑ Treat as acute diarrhea

Treatment of acute gastroenteritis

Do's

• Settings prone to outbreaks:
  

❑ Health care settings
❑ Restraunts
❑ Cruise ships
❑ Schools and other institutional settings