How did the cholera outbreak begin after the 2010 Haiti earthquake?

In October 2010, following the devastating 2010 Haiti earthquake, a cholera outbreak emerged in Haiti’s Artibonite province. The disease was introduced when the Artibonite River—a primary source of drinking water—was contaminated with fecal matter carrying a South Asian strain of the bacteria.12

Investigations identified United Nations peacekeeping forces from Nepal, stationed near the river, as the source of the outbreak. This conclusion was supported by the fact that cholera had not been detected in Haiti for over a century, and a parallel outbreak was occurring in Kathmandu, the city from which the troops had recently departed.21

The epidemic spread rapidly, reaching the tent cities of Port-au-Prince by November 2010 and eventually affecting all of Haiti’s provinces. The crisis highlighted the severe vulnerability of the population, as many households lacked access to safe water and adequate sanitation, conditions that were further exacerbated by the widespread destruction caused by the earthquake.123