London, March 7 : The world is facing the biggest surge in cholera for at least 20 years, as economic crises, climate change and the aftermath of the Covid-19 pandemic see deadly outbreaks flourish, experts say. At least 30 countries have seen flare-ups of the water-borne infection, long associated with poverty, inadequate hygiene and poor sanitation, including several which have not seen the disease for years, The Telegraph reported. The combination of the number and scale of the outbreak is thought to be the worst in decades and comes after many countries had made progress cutting deaths from the infection. The World Health Organization (WHO) has warned that flooding from the storm season in Southern Africa risks further fuelling outbreaks, even as the weekly case tally in the continent appears to dip. Philippe Barboza, the WHO lead for cholera emergencies, said patchy historic data made it difficult to compare this year's outbreaks with the past, but they were the biggest seen in two decades. "I would say the number of countries with these large outbreaks occurring at the same time, we have not seen it in at least 20 years," he told The Telegraph. Health services that had been overwhelmed by Covid in the past three years were struggling to stop outbreaks or protect people when they were underway. Public health efforts to prevent cholera had often been put on hold during the pandemic. Malawi has been battling its worst outbreak since records began in the 1970s and had seen 1,564 deaths by the end of February. A new storm and flooding season is now battering Southern Africa and may make outbreaks worse. Mozambique reports cases have been growing exponentially since December 2022 and are cropping up in areas where it has not been seen for more than five years, The Telegraph reported. Barboza said climate change was thought to be adding to the problem. He said: "Most of the major outbreaks we are looking at are all driven by major, unusual climate events." The worrying spread of the outbreaks is underlined by the return of cases to countries where the disease is no longer endemic and has not been seen for decades, he said. Lebanon has been dealing with its first outbreak in 30 years while the country endures an economic collapse described by the World Bank as one of the worst in the past 150 years, The Telegraph reported. /IANS