NEW YORK (AP) — U.S. health officials are now looking into more than 100 possible cases of a mysterious and severe liver disease in children, including five deaths. About two dozen states and Puerto Rico have reported such illnesses to the Centers for Disease Control and Prevention. The count reported Friday includes cases that date back to October, all in children under 10. Eight received liver transplants. What’s causing the illnesses isn’t clear. Adenovirus was detected in half the children but CDC officials say they don’t know if that’s the cause. This week, the World Health Organization said it had reports of almost 300 probable cases in 20 countries.