One billion people in 43 countries are at risk of cholera — a “pandemic killing the poor” — despite prevention and treatment being relatively straightforward, the United Nations warned on Friday. The UN branded the outlook bleak, saying it did not have the resources to fight the outbreaks, and the longer it took to start waging the battle, the worse the situation would get. Between the World Health Organisation and the children’s agency Unicef, the UN is seeking $640 million to fight the infectious disease, warning of a “cholera catastrophe” if action is not ramped up immediately.