Flu activity has held steady in many states but risen in others, with the highest test positivity levels seen in northeast, south-central and mountain states, according to the CDC’s latest FluView report.  Eight CDC updates:  1. Of all specimens tested in a clinical lab, 8.9 percent were positive for the flu for the week ending April 16, up slightly from 8.4 percent the week prior.  2. For the week ending April 16, 3,243 lab-confirmed flu patients were hospitalized, up from 3,170 the week before.