Norovirus is a gastrointestinal illness that can cause vomiting, diarrhea, and stomach pain. Other symptoms include headache, chill, and fever. Onset of vomiting can be sudden and extreme resulting in excessive fluid loss. Death is uncommon but is still a risk especially in highly susceptible populations.
Incubation usually takes 12 to 48 hours. Recovery generally happens in one or two days. Mild symptoms can linger for up to a week.
Noroviruses are quite resilient and can exist in a variety of conditions. They can withstand freezing as well as temperatures of up to 140 °F. Viral particles can survive for long periods on surfaces and are resistant to chlorine in concentrations up to 10 ppm, which far exceeds the average concentration of chlorine in Austin drinking water.
Transmission
Noroviruses are highly contagious and 10-100 viral particles are enough to infect an individual. Infected persons can shed billions of particles over the course of their illness. Primary transmission is through the fecal-oral route, either by consuming contaminated food/water, or by spreading directly from person to person. Aerosolized vomit containing a high viral load can contaminate surfaces or infect people directly. Because of this, enclosed spaces with a high density of people are at a much higher risk for transmission.
Immunity may only last a few months and is strain-specific. There is no vaccine to prevent norovirus and no cure if it is contracted.
Outbreaks
Any food item may become contaminated if handled by infected person or if washed with contaminated water. Norovirus infections spread rapidly in community settings like hospitals, schools, cruises, and assisted living facilities. Food managers are required to immediately contact EHS at (512) 471-3511 if an employee tests positive for norovirus or if an outbreak from any food event is suspected.
Preventive measures
- Proper hand washing for a minimum of 20 seconds after using the bathroom/toilet. Hands should be washed often while handling foods. It is recommended to use extra safety measures such as double handwashing, hand sanitizer, and gloves.
- Isolation of sick patients and avoiding group activities;
- Careful environmental cleaning and disinfection of public places
- Wear masks/gloves when cleaning any areas exposed to contamination
- Avoid food handling when having gastrointestinal symptoms and staying away for at least 48 hours after the symptoms subside. Food establishments must receive approval from EHS before any employee that tested positive can return to work.