Haiti has been plagued by pestilence and natural disasters since a catastrophic earthquake a year ago killed more than 220,000 people. Here is a chronology of the main events:

January 12, 2010:

- The 7.0-magnitude quake shakes Haiti at 4:53 pm (2153 GMT). Towns like Leogane and Jacmel are flattened along with large parts of the capital Port-au-Prince, where the presidential palace and key ministries collapse.

- January 14-15: After almost two days cut off from the outside world, the first international aid flights land at Port-au-Prince's badly-damaged international airport. More than 15,000 corpses have already been collected.

- January 16: US President Barack Obama calls predecessors George W. Bush and Bill Clinton to the White House and charges them with gathering funds for the mammoth reconstruction task that lies ahead.

- January 18: As fears over widespread looting and general lawlessness grow, the United States deploys up to 10,000 soldiers to maintain security and oversee the aid effort.

- January 19: US Marines descend by helicopter to take control of the ruined presidential palace as the aid effort gathers pace and supplies begin to reach those most in need.

- January 20: Elisabeth, a 23-day-old baby, is rescued from the ruins of a house in the devastated town of Jacmel in southern Haiti after spending seven days trapped with nothing to eat or drink.

- January 30: Ten American missionaries are arrested attempting to take 33 Haitian children across the border into the neighboring Dominican Republic without the necessary paperwork.

- February 27: Flooding kills at least 10 people in the southwest of the country, which was largely spared from the earthquake's devastation.

- March: A week of heavy rain causes widespread flooding in the tent cities that have sprung up around the capital to house an estimated 1.3 million people left homeless by the quake.

- March 31: UN member states and international partners pledge 5.3 billion dollars for the next 18 months to begin Haiti's path to long-term recovery and almost 10 billion dollars overall.

- May 17: Capping a 108-day ordeal, a judge frees the head US missionary accused of trying to smuggle out the 33 Haitian children.

- June 1: The US military ends major relief operations in Haiti.

- October 18: Floods submerge much of Port-au-Prince, leaving 13 dead.

- Mid-October: The country's first cholera epidemic in more than a century erupts in a central river valley. By the end of the year more than 3,300 people will have died from the disease.

- November 5: Hurricane Tomas leaves a trail of destruction in the west of the country, killing 21 people and worsening the cholera epidemic.

- November 15-17: Three people are killed in riots targeting UN peacekeepers blamed for bringing cholera into the country.

- November 28: Haitians vote to choose a successor to President Rene Preval, who has served his maximum term and is widely unpopular due to slow pace of recovery since the quake.

- December 7: Protests erupt when preliminary results reveal Preval's handpicked protege has made it through to a run-off ahead of a popular opposition candidate -- at least five people are killed.

- December 9: The electoral commission agrees to recount tally sheets, but weeks later Haitians still await final results and no decision has been made on who will contest the indefinitely delayed run-off.

- December 22: Authorities say at least 45 people accused of spreading cholera, several of them voodoo practitioners, have been killed by angry mobs since the epidemic began.