Two years ago, a 7.0 earthquake struck Haiti, killing 300,000 Haitians and leaving 1.5 million homeless. Nine months later, a cholera epidemic began — its first victim a 28-year-old man who bathed in and drank from a river that was likely contaminated by raw sewage from an encampment of UN peacekeepers from Nepal. Half a million people have been stricken by cholera since then, and 7,000 have died. New cases are being reported at a rate of roughly 200 per day.

Cholera is also spreading in the Dominican Republic, which shaires the island of Hispaniola with Haiti. Officials from CDC, UNICEF, and the Pan-American Health organization have pledged to join the two countries’ governments to eradicate the disease from the island by investing in clean water and sanitation. Their amibitious goal is to reach two-thirds of the Haitian population by 2015, at an estimated cost of $1.1 billion.

Vindushi Sinha of Voice of America notes that cholera is not the only disease afflicting Haitians who lack sufficient access to clean water and sanitation: More than one million Haitian children under age five are killed by diarrheal diseases every year.