Health experts watching for signs of a malaria outbreak have noticed several cases of the mosquito-borne disease among people traveling back from Haiti, where an earthquake in January killed as many as 300,000 people.
So far, 11 laboratory-confirmed cases of malaria have been reported among emergency responders and those traveling in the United States from Haiti, the U.S. Centers for Disease Control and Prevention said on Thursday.
Haiti already had a problem with malaria, which is spread by mosquitoes that will have more places to breed in the cities and towns wrecked by the giant quake.
Each year, Haiti reports about 30,000 confirmed cases of malaria to the Pan American Health Organization, but the CDC estimates as many as 200,000 may occur each year.
Three cases the CDC cited occurred among Haitian residents traveling to the United States and one case involved a U.S. resident who was visiting Haiti. All are expected to recover fully.