Page updated 30 September 2007
Food Poisoning - Acute Diarrhoea Caused by Viruses
Introduction
Acute diarrhoea is acquired by eating undercooked shellfish or by the faecal-oral route. Generally very infectious and easily transmitted from person-to-person. Outbreaks often occur in nurseries and in hospitals (especially care of the elderly wards) where hygiene is deficient.
Symptoms
Incubation period a day or two depending on the virus. Preceded by a cold-like symptoms (hence the term "gastric 'flu), the first GI symptom is usually vomiting, often unexpected and projectile- hence the infectivity. Proceeds to major watery diarrhoea usually without blood and pus.
Specific Viruses
- Rotavirus: resistant to disinfectants and survive well on fomites. Replicates and destroys intestinal epithelium. Common in infants and the elderly.
- Norovirus: Norwalk and other Small Round Structured Viruses (SRSV). Acute gastroenteritis, extremely infectious.
- Caliciviruses probably obtained from animals. Some explosive outbreaks. High secondary attack rate.
Diagnosis
- Electron Microscopy
- ELISA capture antibodies(monoclonal) detect VP6 core protein of type A rotavirus
- Latex agglutination (Some false positives)
- Polyacrylamide gel electrophoresis
 |
 |