About Rota

Rotavirus is an infection that causes diarrhea. It's the most common cause of diarrhea in infants and children worldwide, according to the Centers for Disease Control and Prevention. Before the development of a vaccine, most children in the United States had at least one bout with rotavirus by age 5.

Although rotavirus infections are unpleasant, you can usually treat this infection at home with extra fluids to prevent dehydration. Occasionally, severe dehydration requires intravenous fluids in the hospital. Dehydration is a serious complication of rotavirus and a major cause of childhood deaths in developing countries.

Vaccination can help prevent rotavirus infection in your infant. For older children and adults — who aren't as likely to develop serious symptoms of rotavirus — frequent hand-washing is the best line of defense.

Symptoms

A rotavirus infection usually starts within two days of exposure to the virus. Initial symptoms are a fever and vomiting, followed by three to seven days of watery diarrhea. The infection can cause abdominal pain as well.

In adults who are otherwise healthy, a rotavirus infection may cause only mild signs and symptoms or none at all.

When to see a doctor

Call your child's doctor if your child:

• Has diarrhea for more than 24 hours
• Has frequent episodes of vomiting
• Has black or tarry stool or stool containing blood or pus
• Has a temperature of 104 F (40 C) or higher
• Seems lethargic, irritable or in pain
• Has signs or symptoms of dehydration, including dry mouth, crying without tears, little or no urination, unusual sleepiness, or unresponsiveness

If you're an adult, call your doctor if you:

• Can't keep liquids down for 24 hours
• Have diarrhea for more than two days
• Have blood in your vomit or bowel movements
• Have a temperature higher than 103 F (39.4 C)
• Have signs or symptoms of dehydration, including excessive thirst, dry mouth, little or no urination, severe weakness, dizziness on standing, or lightheadedness

Causes

Rotavirus is present in an infected person's stool several days before symptoms appear and for up to 10 days after symptoms subside. The virus spreads easily through hand-to-mouth contact throughout this time — even if the infected person doesn't have symptoms.

If you have rotavirus and you don't wash your hands after using the toilet — or your child has rotavirus and you don't wash your hands after changing your child's diaper or helping your child use the toilet — the virus can spread to anything you touch, including food, toys and utensils. If another person touches your unwashed hands or a contaminated object and then touches his or her mouth, an infection may follow. The virus can remain infectious on surfaces for weeks or longer if the area isn't disinfected.

Because there are many types of rotavirus, it's possible to be infected more than once, even if you've been vaccinated. However, repeat infections are typically less severe.

Risk factors

Rotavirus infections are common in children ages 3 to 35 months — particularly those who spend time in child care settings. Older adults and adults caring for young children have an increased risk of infection as well.

In the United States, the risk of rotavirus is highest in winter and spring.

Complications

Severe diarrhea can lead to dehydration, particularly in young children. Left untreated, dehydration can become a life-threatening condition regardless of its cause.

Prevention

To reduce the spread of rotavirus, wash your hands thoroughly and often — especially after you use the toilet, change your child's diaper or help your child use the toilet. But even strict hand-washing doesn't offer any guarantees.

There are two vaccines offered against rotavirus:

• RotaTeq. This vaccine is given by mouth in three doses, often at ages 2 months, 4 months and 6 months. The vaccine is not approved for use in older children or adults.

Although a few cases of intussusception — a rare but life-threatening form of intestinal blockage — were reported after vaccination with RotaTeq, the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) found that the number of cases in vaccinated children was similar to the number of cases in unvaccinated children and concluded that the vaccine didn't increase a child's risk of intussusception. A similar anti-rotavirus vaccine (RotaShield) was pulled from the market in 1999 because of an association with intussusception.

If after vaccination your child has stomach pain, vomiting, diarrhea, blood in his or her stool, or a change in bowel movements, contact your doctor immediately.

• Rotarix. This vaccine is a liquid given in two doses to infants at ages 2 months and 4 months. Clinical trials of the vaccine detected no increased risk of intussusception.