In Nigeria, the United Nations is warning of a new cholera outbreak in Borno state that’s killed at least 44 people and sickened about 2,300 others. The U.N. says the waterborne disease is spreading rapidly due to squalid conditions in camps for the 1.8 million people who have been displaced by fighting between the Nigerian government and Boko Haram. The new outbreak comes as the World Health Organization says the number of cholera cases in Yemen has reached 700,000, with some 40,000 suspected infections in the last week alone. And health groups warn Haiti could face new cholera cases due to flooding from Hurricanes Irma and Maria.