Norovirus is the official genus name for Norwalk-like viruses or Norwalk agent. These are the single-stranded RNA that cause stomach flu or acute gastroenteritis in human commonly in adults and older children. Norovirus is the leading cause of food poisoning in US. Cruise ships and hospitals are some of the ideal environments for the norovirus spreading specially in the winter. Noroviruses are transmitted though the facel-oral route, so they can spread from person to person or though contaminated food (mostly shellfish) and/or water (stored in cruise ship, swimming pool and lake) or by touching a contaminated surface. And, noroviruses are highly contagious as a few viral particles may be sufficient to infect an individual.
People of all ages are at risk for norovirus infection, and who exposed to infection develop signs and symptoms of norovirus between 24 and 48 hours, but in outbreaks this incubation period of norovirus changes to 33 to 36 hours. It lasts only for 2 to 3 days and self treated. People of all ages with weakened immune systems are at risk to develop complications of norovirus because of dehydration.Only these cases require immediate hospitalization.
Immunity to norovirus is not stable and lasts only for a few months. It seems that immunity may be strain-specific so, individuals are likely to be infected many times though their lifetime.Hence, its better to take proper prevention measures during the norovirus spreading can prevent outbreaks.
