The General Administration of Customs has recently taken heightened precautions against imported cases of acute hepatitis of unknown origin in children, China Central Television reported on Monday.

The administration has required local customs authorities to strengthen health monitoring and medical checks of incoming travelers arriving from countries that have reported the disease.

People — especially children — who have reported or have shown symptoms such as abdominal pain, diarrhea, vomiting and jaundice should undergo medical screening, it said.

Those who are suspected of contracting acute hepatitis will be transferred to designated hospitals for further diagnosis and treatment, the administration added.

As of May 1, 20 countries have registered at least 228 confirmed infections of the disease, along with 50 suspected cases, according to the World Health Organization.

Most infections were found in children age 1 to 16, it said.