Norovirus, the most common cause of vomiting in young children, leads to more than 1 million medical visits costing $273 million each year in the U.S., according to a study that highlights the need for a vaccine to prevent it.
By the time children are 5 years old, 1 in 278 in the U.S. will have been hospitalized for the vomiting and diarrhea bug, and 1 in 6 will be treated by a doctor or nurse for it, according to a report released by the New England Journal of Medicine.
The figures are surprisingly high, said Daniel Payne, lead author of the study and a researcher at the U.S. Centers for Disease Control and Prevention. The virus, sometimes called the stomach flu, easily spreads through food, water and close contact when microscopic amounts of fecal matter are ingested. Since a vaccine that could help stop the spread is likely years away, hand washing is the best defense, said Payne.
"This study very strongly suggests that person-to-person transmission of norovirus is a very big deal," Payne said. "This is a significant health care burden among U.S. children under 5."
Since the introduction of vaccines that prevent rotavirus, another gastrointestinal germ, norovirus has become the leading cause of stomach illness among children younger than 5. There were about twice as many cases of norovirus than rotavirus detected in the study, researchers found. This is one of the only large-scale studies to look at the prevalence of norovirus in young children because doctors don't typically test for it, Payne said.
Takeda Pharmaceutical Co. is the furthest along in developing a norovirus vaccine, Payne said.
More than 600,000 American children younger than 5 visit their doctor each year because of the virus, about 281,000 go to the emergency room and 14,000 are hospitalized, the study found. The average cost for hospitalization is about $4,000.
The virus causes severe dehydration from vomiting and diarrhea, particularly in infants and the elderly, which can be deadly if not treated.
In the study, researchers looked at fecal samples from 1,295 children at medical centers in New York, Tennessee, and Ohio who had symptoms of gastroenteritis over two years and 493 healthy children in a control group. Norovirus was detected in 21 percent of the children with gastroenteritis symptoms.