Physician assistants Scott Fillman (left) and Andrew Hunadi get ready to see patients with flu symptoms, in a tent erected just outside the emergency entrance at the Lehigh Valley Hospital in Allentown, Pa.
Four-year-old Gabriella Diaz gets a flu shot at the Whittier Street Health Center in Boston, Mass., on Wednesday, the same day the city declared a public health emergency.
Charles Krupa/ASSOCIATED PRESS
Chickens are under quarantine in Tepatitlan, Jalisco State, Mexico. The Mexican government declared a national animal health emergency July 2 in the face of an aggressive bird flu epidemic that has infected nearly 1.7 million poultry.
Hector Guerrero/AFP/Getty Images