Children with hepatitis C may fight off the infection better than adults can, according to a new study.
Researchers examined 458 children who underwent heart surgery in Germany long before 1991, when that country began screening its blood supply for viruses such as Hepatitis C, a leading cause of liver disease.
The doctors found that 67 of the children -- 15 percent -- had acquired hepatitis C during their operations.
But 20 years later, the infection had cleared on its own in nearly half of the patients. Among those in whom the infection was still present, few had developed liver disease -- even though those few patients also had other risk factors for liver disease, the researchers said.
Only 20 percent of adults who acquire hepatitis C manage to fight off the infection without treatment, said the lead researcher, Dr. Manfred Vogt of the German Heart Center at the Technical University of Munich. And about 30 percent of adults who get the virus develop cirrhosis or other serious liver damage.
"Nobody knows why this is," Vogt said.
The study is published in Thursday's edition of The New England Journal of Medicine.
In an accompanying editorial, Dr. Maureen M. Jonas of the Children's Hospital in Boston noted the reasons behind the "spontaneous clearance" of the infection among the children remain unclear.
"We do not know whether more serious manifestations of liver disease will appear 30 or 40 years after infection," she wrote. "Thus, it is important to screen and follow patients who are at risk for hepatitis C and to do more than simply reassure infected children and their families."
An estimated 2.7 million Americans carry the hepatitis C virus, making it the most common blood-borne infection in the United States. The standard medicines can make all signs of the virus disappear, but it's unclear how long the effect lasts.