The cardiac surgeon had unknowingly spread a staph infection from the rash on his hand to the hearts of at least five patients by the time Los Angeles County health investigators learned of the outbreak. The doctor had operated on more than 60 others in recent months, and county officials feared those patients could be struck with the same dangerous infection. Investigators didn't ultimately tie any deaths to the 2012 outbreak, but four patients needed additional surgery because of the infection. The only public mention of the case came a year later in a little-noticed appendix to the health department's...