The UN refugee agency is to start an emergency airlift of tents to the West African nation of Benin this week, amid the worst flooding there in decades. Some 3,000 tents will be flown in from Denmark to provide shelter for some of the estimated 680,000 people affected.Two-thirds of Benin has suffered from months of heavy rain, and about 800 cases of cholera have been reported. It is the worst flooding to hit the country – one of the poorest in the world – since 1963.The flooding has sparked major health concerns, with drinking and bathing water contaminated by human waste.