Based on electron microscopic (EM) imagery, this illustration provides a three-dimensional (3D) graphical representation of a number of norovirus virions, set against a white background.
It is winter, and a new strain of norovirus called GII.17[P17] is spreading across the U.S. including the northeast.
MedStar Health Urgent Care in our region is experiencing an uptick in norovirus across its 33 clinics, says its spokesperson. Norovirus is highly contagious, spreading easily from person to person on contaminated surfaces, in food and water, and can be airborne.
The CDC reports that most norovirus outbreaks occur because people do not wash their hands after going to the bathroom. Also, the CDC reports that foods commonly involved in norovirus outbreaks are leafy greens, fresh fruits, and shellfish (such as oysters).
See https://www.cdc.gov/norovirus/outbreak-basics/ to learn more about norovirus the geographical source of certain oysters that the FDA is currently warning restaurants and retailers about not serving or selling and consumers not eating.
The virus can cause sudden and severe vomiting and diarrhea, known as "acute gastroenteritis." While not everyone who presents with symptoms is tested, MedStar Health Urgent Care data shows norovirus cases are up 5-10 percent over last year as of Jan. 13, according to its spokesperson.
Jon Gonella, a MedStar physician's assistant, has 25 years of experience treating patients with vomiting and diarrhea and diagnosing and managing viral illnesses, particularly norovirus.
Gonella shared details about the incubation period for norovirus, symptoms, duration, virus transmission, and how to prevent exposure. This is important because hand sanitizer alone will not prevent norovirus from spreading. It lives on "fomites," inanimate objects that can transmit disease-causing viruses and germs from one person to another. Examples are doorknobs, countertops, furniture, school desks, phones, clothing, toys and eating utensils.
Gonella explained that norovirus most commonly spreads to these surfaces through the fecal-oral route."An infected person sheds the virus through their feces," Gonella said. "An example would be someone who has the virus and uses the bathroom, then touches the door on their way out of the bathroom. The next person who comes in touches that door or touches a counter where the virus is, and then they acquire it that way. Then that whole process starts over again."
Norovirus can be airborne to some degree. Gonella said that when an infected person is vomiting, the viral particles can spread through the air. For example, a parent holds the basin for the child to vomit. Understanding the airborne spread is important because only a tiny viral particle burden is necessary to transmit the virus.
According to Gonella, the concern with norovirus, or any of the viruses that cause vomiting, is dehydration. The impact can differ among age groups, with children and older people more susceptible to dehydration.
Any changes in mental status, such as the patient becoming lethargic or less alert, are red flags to take the sick person to a medical office or emergency care. "If someone's had repeated vomiting or diarrhea, they may become more pale, more what we call pallor. Their skin color may change," said Gonella.
Asked how people clean up the vomiting and diarrhea mess, Gonella said, "Norovirus is somewhat resistant to our typical alcohol-or chlorine-based sanitizer. A lot of the hand sanitizers that we use are alcohol-based, and norovirus is resistant to that. We recommend washing hands with good old soap and water. We recommend a chlorine bleach water mix to clean up a norovirus vomiting episode." He added that contaminated surfaces should be disinfected with bleach, 5-25 tablespoons of household bleach per gallon of water.
He added the virus's incubation period, is 24 to 48 hours, and symptoms typically last 2 to 4 days. There is no antiviral treatment for norovirus, and the focus should be maintaining hydration and a bland diet.
Gonella emphasizes the importance of washing fruits and vegetables to prevent norovirus transmission, as well as hand washing.
Individuals suspected of having norovirus should not prepare food for others until at least two days after their symptoms resolve.
The CDC reports infecting someone can take as few as 10 viral particles. Norovirus causes an average of 900 deaths annually mostly among older adults, 109,000 hospitalizations, and 19 million to 21 million cases in the U.S. each year.