The US national measles count reached 2,231 confirmed cases across 42 states by 9 July1, on pace to pass last year's 2,289 cases, the worst tally since 1991, before September. The count has climbed through the first half of the year in a country that recorded near-elimination levels only a decade ago.
The Philadelphia airport exposure and the retracted Delaware County scare both sit inside that national picture, part of a hemispheric surge in measles tracked across the Americas ahead of the World Cup. Falling childhood vaccination rates in pockets of the US have let a disease declared eliminated there in 2000 re-establish chains of transmission, particularly around mass-gathering travel.
