Diseases that cause diarrhea with or without vomiting are called gastroenteritis. Gastroenteritis means inflammation of the stomach and intestines. Gastroenteritis is an infection caused by a variety of germs that results in vomiting or diarrhea. It is often called the “stomach flu,” although it is not related to the flu (a respiratory illness caused by the influenza virus).

Viral gastroenteritis is an infection of your intestines that typically causes watery diarrhea, pain or cramping in your abdomen, nausea or vomiting, and sometimes fever.

Viral gastroenteritis is caused by viruses. Viruses invade normal cells in your body. Many viruses cause infections that can be spread from person to person.

People commonly call viral gastroenteritis “stomach flu,” but the term is not medically correct. Viral gastroenteritis is an infection of the intestines, not the stomach, and it is not caused by influenza (flu) viruses. The flu vaccine does not protect against viral gastroenteritis.

Viral gastroenteritis is acute, meaning it happens suddenly and lasts a short time. Most cases of viral gastroenteritis last less than a week, and most people get better on their own without medical treatment. In some cases, viral gastroenteritis may cause severe symptoms or may lead to dehydration.

Many different germs can cause gastroenteritis, including viruses (such as rotaviruses, noroviruses [Norwalk virus]), bacteria (such as Salmonella or Shigella), and parasites (such as Giardia). Medications and certain medical conditions can also cause similar symptoms. A doctor can determine if the diarrhea is caused by a germ or by something else.

These germs are found in the stool or vomit of infected people and on surfaces that have been touched by ill people. They are also found in animals, and can be present on raw meat, poultry and eggs. Outbreaks occur more often where there are more people in a small area, such as nursing homes, mass evacuation centers, restaurants, catered events, child care centers, and cruise ships.

Why can the germs that cause diarrhea and vomiting be associated with evacuation centers?

Close living quarters increase the amount of contact between people. In addition, toilet facilities are shared and new shelter arrivals may bring the germs to other residents and staff.

People can become infected with the germs by:

• Eating food or drinking liquids contaminated with germs
• Touching surfaces or objects contaminated with the germs and then touching their own mouth, nose, or eyes
• Having close contact with a sick person
  • while they are vomiting
  • by sharing food or eating from the same utensils
  • while caring for a sick person
  • by shaking hands
• Not washing hands after using the bathroom or changing diapers and before eating or preparing food.

The main symptoms of diarrheal diseases caused by viruses are watery diarrhea and vomiting. The sick person may also have headache, fever, muscle aches, and abdominal cramps (“stomach ache”). In general, the symptoms begin 1 to 2 days following infection, and lasts for 1 to 10 days, depending on which virus causes the illness. Norovirus gastroenteritis usually lasts about 1-2 days.

Gastroenteritis caused by bacteria is similar, but often also includes fever, and diarrhea may be either watery or bloody. Bloody diarrhea, also called dysentery, indicates damage to the wall of the intestine by the bacteria. Bloody diarrhea, or dysentery, is not caused by viruses.

For most people, they are not serious illnesses. People who get diarrhea and/or vomiting almost always recover completely without any long-term problems. Diarrhea and/or vomiting can cause serious dehydration and a loss of minerals (e.g., salt and potassium) if sick people are unable to drink enough fluids to replace what they lose through vomiting or diarrhea. Infants, young children, and persons who are unable to care for themselves, such as the disabled or elderly, are at risk for dehydration from loss of fluids. Immunocompromised persons also are at risk for dehydration because they may have more vomiting or diarrhea. Some people may need to be treated at a medical center or hospitalized for treatment to correct or prevent dehydration and/or loss of minerals (e.g., salt and potassium).

• Advise the evacuation center staff of your illness.
• Drink plenty of fluids.
• Wash hands with soap and water often for 15-20 seconds, or use an alcohol hand gel if soap and water are unavailable.
• Use toilets set aside for persons with diarrhea.
• Use plastic bags to catch vomit when you are not in the toilet.
• Clean up spills of vomit and stool quickly using a disinfectant.
• Do not help prepare or serve food

• Ensure food is stored, cooked, prepared and served in a hygienic manner.
• Wash hands often. Wash hands after using the bathroom or changing diapers and before eating or preparing food. Wash hands more often when helping someone who has diarrhea or vomiting.
• Avoid shaking hands during outbreaks.
• Use alcohol-based hand rubs when soap and water are not nearby.
• For those who are ill, move with your family to an area of the evacuation center set apart for those who are ill and their immediate families. This decreases the chance of infecting other people.