There is No ‘Stomach Flu’

January 25, 2013 | 3:32pm

Some people call it the “stomach flu” but, in fact there is no stomach flu.

It is actually norovirus, not influenza, that is making many San Diegans sick to their stomach.

“Norovirus has been around for years,” said Wilma Wooten, M.D., M.P.H., County public health officer. “The so-called ‘stomach flu’ is not really the flu at all.”

Each year in the United States, noroviruses cause about 21 million illnesses and contribute to about 70,000 hospitalizations and 800 deaths, according to the Centers for Disease Control and Prevention (CDC).

Norovirus inflames the linings of the stomach and large intestine (gastroenteritis) which can cause nausea, vomiting (more often in children), watery diarrhea (more often in adults), and stomach cramps.

Other norovirus symptoms include low-grade fever, chills, headache, muscle aches, and fatigue.  These symptoms are like the flu, which is why many people confuse the two illnesses.

Most of these symptoms aren't serious, but frequent diarrhea and vomiting can deplete your body of fluids and you can become dehydrated. Children, the elderly, and people with other medical conditions are most susceptible to dehydration.

You can get infected with a norovirus when you eat food or drink liquids that have been contaminated or by touching an object or surface that has been infected with the virus and then touching your nose, mouth or eyes.

Noroviruses typically thrive on cruise ships— the reason some people call it the cruise-ship virus—as well as in day-care centers, restaurants, nursing homes, work sites and other close quarters.

Once someone is infected with a norovirus, it can quickly pass from person to person through shared food or utensils, door handles, shaking hands or through other close contact. People who have a weakened immune system are particularly susceptible to catching noroviruses and having more severe symptoms.

Norovirus was first reported in 1972 in the town of Norwalk, Ohio. Since then, several other strains have been detected, including the recently discovered Sydney strain, which has been associated with increased rates of hospitalization and death compared to other strains.

In this fiscal year, which started July 1, 2012, there been 23 outbreaks reported in San Diego involving 628 people. Some of the outbreaks have been caused by the new Sydney strain.

“This is a not an unexpected number of outbreaks,” said Wooten adding that there have been 26 to 43 outbreaks reported each of the past six years.

Norovirus is only reportable when it is identified or suspected in an outbreak, so the actual number of cases in the county is much higher. Since individual cases of norovirus are not reportable to local health officials, there is no way to determine the number of people who have suffered from a norovirus.

An elevated number of diarrheal illnesses were being seen in local emergency departments during the first two weeks in January, but they could have been due to bacteria and viruses including norovirus. The numbers are now back to normal. 

So what can you do to avoid getting norovirus?

Good hygiene is the key to preventing norovirus, especially when you are around many people. You should:

  • Wash your hands often with soap and water or use an alcohol-based hand sanitizer, especially after going to the bathroom or changing a baby's diaper, and before you prepare or eat food
  • Wash raw fruits and vegetables thoroughly. Cook oysters and other shellfish before eating them
  • Clean and disinfect surfaces with a mixture of detergent and chlorine bleach after someone is sick
  • If you have norovirus, don't prepare food for at least two to three days after you feel better
  • Try not to eat food that has been prepared by someone else who is sick

“If people have the symptoms, they should stay at home, rest and drink plenty of fluids,” Wooten said. “If you are very sick, you should see your doctor, especially if you feel dehydrated.”

For more information about norovirus, please visit the CDC website.