A confirmed infectious traveller passed through Philadelphia International Airport terminals A, B and C on Saturday 4 July, between 07:30 and 11:15, during the July 4 travel peak 1. The Philadelphia Department of Public Health (PDPH) issued a public alert on 11 July and asked anyone unvaccinated in those terminals to watch for symptoms through 25 July.
Health commissioner Dr Palak Raval-Nelson said there was "no broad threat to the general public" from the transit case 2. measles is among the most contagious pathogens known, able to linger in the air of an enclosed space for up to two hours after an infected person leaves, which is why a single airport transit can put an unvaccinated traveller at risk. The confirmed airport case is the genuine exposure that late June's Chester County measles scare, near the city's World Cup venues, had only hinted at .
