Influenza gets most of the headlines, but its wicked stepsister spins off regular epidemics among young children every flu season.
From late autumn to early spring, rotavirus infections sweep through homes, play groups, day-care centers, and schools. Rotaviruses are a family of germs named for their wheel-shaped appearance when viewed through a high-power microscope.
Most children catch rotavirus by age 4. It usually means three to eight days of misery for the victims. Children start with a fever and vomiting and continue with 10 to 20 bouts of watery diarrhea a day.
About 3 million cases occur every year among kids under age 5, according to the U. S. Centers for Disease Control and Prevention, making rotavirus the No. 1 cause of severe vomiting and diarrhea in infants and young children.
At least 500,000 kids get badly dehydrated and need a doctor. About 50,000 need hospital treatment. Medical care for rotavirus costs about $300 million a year. Add in the time Mom and Dad lose from work, and other costs, and the national bill for rotavirus infections may top $1 billion.
Thankfully, there are only about 20 deaths a year because of the excellent health care available in the United States.
It's a different story in poor countries in the rest of the world, where rotavirus kills about 450,000 infants and children each year.
Hope for taming rotavirus infections blossomed in 1998, when the first vaccine became available. Although the vaccine was very effective, the manufacturer withdrew it within a year because of reports linking it to a rare but potentially serious side effect called intussusception.
That's a condition in which one part of the intestine slides into another section of intestine, almost like the sections of a collapsible telescope slide into one another. If not diagnosed and treated, it can be life-threatening.
New hope for a vaccine has arisen with the results of huge clinical trials that tested two new rotavirus vaccines on more than 120,000 infants. The vaccines are safe, according to the studies, with no increased risk of the intestinal disorder. Neither vaccine has been approved for general use.
Until a safe vaccine is available, prevention of rotavirus infections rests in the hands of children and adults - quite literally in their hands.
Infected children shed rotavirus in their bowel movements. They may start before any symptoms start, and usually continue shedding it for seven days after symptoms do appear.
The virus spreads to other children by what doctors delicately term the "fecal-oral route." A child touches a dirty diaper and fingers go into the mouth. An adult caregiver changes a diaper, forgets to wash the hands, and touches a pacifier or toy that goes into a child's mouth.
Hands that appear perfectly clean still can carry invisible specks of fecal material that can cause illness.
People who care for young children should wash their own hands often, especially after handling soiled diapers. Wash the child's hands often as well.