The New Norovirus From Down Under
By Danielle Torres // June 4, 2014
RESPONSIBLE FOR 20 MILLION HIGHLY CONTAGIOUS 'STOMACH BUGS' IN U.S. ANNUALLY
ABOVE VIDEO: ABC’s Chief Medical Editor and expert on viruses and epidemics, Dr. Richard Besser, discusses how to avoid the highly contagious norovirus.
BREVARD COUNTY • MELBOURNE, FLORIDA — At one time or another, most people have experienced the 24-hour “stomach bug,” more appropriately termed gastroenteritis. Though there are other viruses responsible for viral gastroenteritis, 70-75 percent of adult cases are caused by norovirus.
The most common cause of acute gastroenteritis and food borne disease outbreaks in the United States, norovirus, according to the Center for Disease Control and Prevention (CDC), is responsible for 19-20 million illnesses, leads to 1.7–1.9 million outpatient visits and 400,000 emergency department visits, primarily in young children, and contributes to 56,000-71,000 hospitalizations and 570-800 deaths annually in America.
The virus causes acute inflammation of the stomach and intestines leading to abdominal pain, nausea, vomiting and diarrhea, which usually last 1-3 days. Patients can also remain contagious for up to 3 days after the acute symptoms resolve.
It is possible to develop immunity to specific norovirus strains, but it is not known how long immunity lasts.
Anyone can be affected by the norovirus, and, since there are many different types of noroviruses, it is possible to have multiple bouts of norovirus gastroenteritis during a lifetime. Although usually self-limiting, it can be serious, especially for young children and older adults.
HIGHLY CONTAGIOUS NEW STRAIN FROM AUSTRALIA
Like other viruses, norovirus mutates constantly, creating new strains every few years, the newest of which was discovered in 2012 in Australia and was termed GII.4 Sydney.
The norovirus can be diagnosed with PCR testing of a stool sample with high accuracy. Diagnostic testing is done in the hospital setting to rule out other more serious illnesses such as appendicitis or pancreatitis. However, making a formal diagnosis of norovirus in an outpatient setting is not usually necessary because of its self-limiting nature.
Though not particularly more dangerous than previous strains, GII.4 has been spreading rampantly throughout the United States in the past two years causing violent bouts of nausea, vomiting, and diarrhea, and resulting in some cases of severe dehydration.
KNOW THE SIGNS AND SYMPTOMS OF DEHYDRATION
Dehydration is one of the main concerns for patients infected with norovirus, so knowing the signs and symptoms of dehydration is important. Mild to moderate dehydration may result in dry mouth and throat, decreased urination and dizziness.
Severe dehydration, which is a concern with prolonged multiple bouts of diarrhea, may cause acute weight loss, lethargy or apathetic behavior, loss of consciousness, inability to drink, increased heart rate (or in the most severe cases, the heart rate drops), weakened pulse, deepened breathing, sunken eyes, absent tears, and cold, cyanotic extremities.
TREATMENT FOCUSED ON FLUID AND ELECTROLYTE REPLACEMENT
There is no specific medicine to treat people with norovirus illness. Norovirus infection cannot be treated with antibiotics because it is a viral (not a bacterial) infection.
Rehydration is the best way to treat the fluid loss from the vomiting and diarrhea of norovirus. Pedialyte, an over the counter oral electrolyte solution manufactured by Abbot Laboratories that is designed to replace fluids and minerals lost when a child has vomiting and diarrhea, or a similar product is recommended to rehydrate both children and adults. It is perfectly balanced in fluid, calories, carbohydrates, and electrolytes.
Though enticing, using products such as ginger ale, apple juice, and Gatorade should be limited due to the high sugar and radical electrolyte differences.
If there are signs of severe dehydration, medical evaluation should be sought immediately for possible hospitalization and intravenous infusion of fluids and electrolytes.
DILIGENTLY HAND WASH WITH SOAP AND WATER
Norovirus can spread quickly in closed places like daycare centers, nursing homes, schools, and, as we all know through wide media coverage, cruise ships.
Once in a household, norovirus is easily transmitted between the patient and caretaker, so diligent precautions must be taken to prevent its spread. Gloves, masks, aerosols, bleach, diligent laundry washing, and carpet cleaning can be helpful to decrease transmission.
Unfortunately alcohol is ineffective with this type of virus so hand sanitizers will not work against it. Using traditional techniques of meticulous hand washing with soap and water, and keeping hands away from the face and mouth area are fundamental to preventing spreading the virus. If you do contract the virus, stay inside and quarantined from others, and stay hydrated!
For more information on norovirus go to: CDC.gov/norovirus/about/index.html
ABOUT THE AUTHOR
Danielle Torres is a Doctor of Pharmacy candidate scheduled to graduate from the University of Florida, College of Pharmacy in May of 2015. She has gained community and hospital experience through internships in the central Florida area, and is currently on her Adult Medicine rotation at Holmes Regional Medical Center.