PHILADELPHIA - Philadelphia Mayor Jim Kenney is self-isolating for a second time after he says he was exposed to someone who tested positive for the coronavirus.Mayor Kenney previously quarantined for a two week period back in September following a similar exposure.Kenney announced the news during a virtual press briefing Tuesday where he noted that he is not experiencing any coronavirus symptoms and plans on getting tested soon."Like the last time, I mentioned this is not to focus on myself, but to remind everyone that the virus is still here, and we must remain vigilant," Kenney said. "So if you find yourself in a similar situation – exposed to some who tests positive – do the right thing and self-quarantine."Adhering to the CDC's latest.