100,000 to 316,000 deaths (the higher figure is from a government estimate widely charged with being deliberately inflated; a figure of about 160,000 is provided in a 2010 University of Michigan study; the 100,000 figure is suggested by the U.S. Geological Survey.)
By 24 January, at least 52 aftershocks measuring 4.5 or greater had been recorded. An estimated three million people were affected by the quake. Death toll estimates range from 100,000 to about 160,000 to Haitian government figures from 220,000 to 316,000; these have been widely characterized as deliberately inflated by the Haitian government. The government of Haiti estimated that 250,000 residences and 30,000 commercial buildings had collapsed or were severely damaged. The nation's history of national debt, prejudicial trade policies by other countries, and foreign intervention into national affairs, contributed to the existing poverty and poor housing conditions that increased the death toll from the disaster.
Many countries responded to appeals for humanitarian aid, pledging funds and dispatching rescue and medical teams, engineers and support personnel. Communication systems, air, land, and sea transport facilities, hospitals, and electrical networks had been damaged by the earthquake, which hampered rescue and aid efforts; confusion over who was in charge, air traffic congestion, and problems with prioritising flights further complicated early relief work. Port-au-Prince's morgues were overwhelmed with tens of thousands of bodies. These had to be buried in mass graves.
As rescues tailed off, supplies, medical care and sanitation became priorities. Delays in aid distribution led to angry appeals from aid workers and survivors, and looting and sporadic violence were observed. On 22 January the United Nations noted that the emergency phase of the relief operation was drawing to a close, and on the following day, the Haitian government officially called off the search for survivors.
Haiti is the poorest country in the Western Hemisphere and is ranked 149th of 182 countries on the Human Development Index. The Australian government's travel advisory site had previously expressed concerns that Haitian emergency services would be unable to cope in the event of a major disaster, and the country is considered "economically vulnerable" by the Food and Agriculture Organization. Haiti is no stranger to natural disasters. In addition to earthquakes, it has been struck frequently by tropical cyclones, which have caused flooding and widespread damage. The most recent cyclones to hit the island before the earthquake were Tropical Storm Fay and Hurricanes Gustav, Hanna and Ike, all in the summer of 2008, causing nearly 800 deaths.