Washington, Sep 8 (IANS): A respiratory virus has hit the US state of Missouri, sending hundreds of children to hospital, a media report said Monday.

Virologists were looking into the unusually high number of hospitalisations caused by enterovirus, and at least 10 other states -- Colorado, North Carolina, Georgia, Ohio, Iowa, Illinois, Missouri, Kansas, Oklahoma and Kentucky -- have contacted the Centers for Disease Control and Prevention (CDC) for assistance, CNN reported.

Although enterovirus infections are quite common and affect millions of people worldwide each year, it was the high number of hospitalisations that was worrying experts.

"We're in the middle of looking into this... We don't have all the answers yet," a CDC official was quoted as saying.

In Kansas City, about 475 children were recently treated at Children's Mercy Hospital, and at least 60 of them received intensive hospitalisation, spokesperson Jake Jacobson said.

Colorado, Illinois and Ohio also reported cases with similar symptoms and were awaiting testing results.

Enterovirus infections are associated with symptoms including mild respiratory illness, hand, foot and mouth disease and acute hemorrhagic conjunctivitis.