What happens if somebody brings swine flu with them to the Haj?

they have heat sensor monitors at all points of entry into Mecca set up. I dont know what they do, supposedly tell if a person has fever or not, but that wont detect those that have the flu, but not showing symptoms yet.. I suppose a lot of people will be wearing masks this year at hajj.. It always happens during this season that a lot of the country get ill.