Institute and Institut Pasteur concluded the strain of cholera originated in eastern Africa and was carried to Yemen by migrants. Morbidity and mortality Yemen authorities announced the cholera outbreak on October 7, 2016. By the end of that year, there were 96 deaths. Following the October 2016 outbreak, the rate of spread in most areas declined by the end of February 2017, and by mid-March 2017, the outbreak was in decline after a wave of cold weather. A total of 25,827 suspected cases, including 129 deaths, were reported by 26 April 2017. The number of cholera cases resurged in a second wave that began on 27 April 2017. According to Qadri, Islam and Clemens, writing in The New England Journal of Medicine, the dramatic April 2017 resurgence was "coincident with heavy rains that may have contaminated drinking water sources, and was amplified by war-related destruction of municipal water and sewage systems". During May 2017, 74,311 suspected cases, including 605 deaths, were reported. By June, UNICEF and WHO estimated that 5,000 new cases per day were occurring, and that the total number of cases in the country since the outbreak began in October had exceeded 200,000, with 1,300 deaths. The two agencies stated that it was then "the worst cholera outbreak in the world". By 4 July 2017, there were 269,608 cases and the death toll was at 1,614 with a case fatality rate of 0.6%. On 14 August 2017 the WHO updated the number of suspected cholera cases to 500,000. Oxfam said in 2017 the outbreak would become the largest epidemic since record-keeping began, overtaking the 754,373 cases of cholera recorded after the 2010 Haiti earthquake. In six months, more people were ill with cholera in Yemen than in seven years after the earthquake in Haiti, and the situation in Yemen was made worse by hunger and malnutrition. On 22 December 2017, WHO reported the number of suspected cholera cases in Yemen had surpassed one million. By October 2018, there were more than 1.2 million cases reported, and more than 2,500 people—58% children—have died in the Yemen cholera outbreak, which is the worst epidemic in recorded history and was, according to the United Nations (UN), the worst humanitarian crisis in the world. Between 1 January 2018 to 31 May 2020, the cumulative total number of suspected cases was 1,371,819 with 1566 associated deaths. The case fatality rate for the outbreak