Gastroenteritis ( Norwalk virus )

• causes an acute gastroenteritis with watery diarrhoea, nausea, vomiting and myalgia lasting 24-48 hours. Symptoms develop about 48 hours after infection with Norwalk virus. May also be abdominal cramps and low-grade fever. Patients will feel very unwell for up to 48 hours; however serious complications (and rarely death), in general, only occur if patient is debilitated by a concomitant pathology or patient is elderly and frail.
  
  
• Norwalk virus named after the city in Ohio where the first identified outbreak occurred
  
  
• virus is shed in vomitus and faeces. Transmission is via faecal-oral route via contaminated food, water and infected contacts
  
  
• Management:
  • investigations are rarely necessary because illness resolves spontaneously after about 48 hours
    • U+Es if dehydration suspected
    • stool M,C,S
  • treatment with oral rehydration therapy is generally only intervention that is required
  • anti-diarrhoeal therapies are not recommended
  • prevention of spread - education about mode of transmission, hand washing is essential; disposal of potentially infected material

Reference:

1. GP magazine (17/11/03), 57.