Washington (AFP) – The US Centers for Disease Control and Prevention is investigating 109 childhood cases of a mysterious form of hepatitis, including five reported deaths, the agency said Friday. “Investigators both here and abroad and around the globe are working hard to determine the cause,” said Jay Butler, deputy director for infectious diseases for the CDC. Ninety percent of the cases have involved hospitalization, with 14 percent requiring liver transplants. The majority fully recovered. The CDC issued a health alert last week notifying doctors and public health authorities to be on the…