Norovirus

Infection with norovirus leads to abrupt onset of vomiting and diarrhea after a 12-48 hour incubation. Multiple daily attacks of gastrointestinal distress often occur without warning until spontaneous resolution occurs after 72 hours of misery. Antibiotics only worsen the condition. At present symptomatic treatment of norovirus infection with adequate fluids and calories remains the generally accepted therapy.

Unfortunately the infectious dose is only 20 viral particles but vomit and diarrhea contain millions of virons. Worse yet aerosolization from vomiting or flushing the toilet spreads the virus up to 25 feet. Norovirus particles survive for days to weeks on countertops, doorknobs, light switches, faucets and keyboards.

Infection occurs when the virus gains access to the mouth by way of fingers harboring norovirus particles. This fecal-oral transmission route together with inhaling particles or consuming them on food contaminated anywhere from the field to the kitchen results in more than 20 million cases a year just in the United States.