California is in the midst of a significant outbreak of whooping cough, with the number of cases at the highest point in 30 years, leading to at least seven deaths of babies, according to public health officials. As of the end of November, doctors had reported 2,169 cases statewide — roughly triple last year's level, said Celia Woodfill, an epidemiologist with the state Department of Health Services. The figure is significantly higher than estimates officials made earlier in the year. Seven deaths in babies," she added, is "a lot more than usual." More than three hundred cases had been reported...