A senior California health official said on Thursday the source of a measles outbreak that has sickened 119 people in the state may never be identified, despite a finding that the same strain of virus had led to a wave of illness in the Philippines. More than 150 people across the United States have been diagnosed with measles, many linked to an outbreak that authorities believe began when an infected international traveler visited Disneyland in late December. California Department of Public Health researchers who genotyped specimens from 30 of the state's measles patients found all were of the same strain that caused an outbreak in the Philippines.
