After weeks of many Americans failing to heed face mask and social distancing guidelines, health officials in some states are reporting an increase in younger populations testing positive -- saying those individuals are often asymptomatic but could be infecting others. And public health measures meant to control infection aren't quite up to speed -- a problem the country has consistently faced in past months. "As you reopen ... you expect to see more cases. But what we're hearing, in terms of the public health model -- of testing people, through contact tracing, and then isolation and quarantine -- it doesn't sound like it's working as well as it really needs to," says former acting director of the US Centers for Disease Control and Prevention, Dr. Richard Besser.