Police wearing surgical masks stand outside a store closed as part of the city's regulations to combat influenza A (H1N1) in downtown Mexico city May 5, 2009. The flu outbreak in Mexico could knock as much as half a percentage point off the country's economic growth this year, the government said on Tuesday, as it promised tax relief and emergency financing to affected companies. REUTERS/Daniel Aguilar (MEXICO HEALTH)
REUTERS/DANIEL AGUILAR