cholera

A South Asian strain of cholera that was introduced into Haiti three years ago this month has now spread to this continent's mainland.

Mexico is the fourth Western Hemisphere country to experience the cholera outbreak. It's a disease that's very hard to stamp out once it gets into an area with poor water and sanitation.

Human rights activists are suing the United Nations on behalf of five Haitian families afflicted by cholera — a disease many believe U.N. peacekeeping troops brought to Haiti in the aftermath of the devastating 2010 earthquake there.