Scientists are calling for urgent action due to the spread of dangerous free-living amoeba around the world. These microbes are found in soil and water and survive extreme heat, chlorine and modern water systems. An example is the "brain-eating amoeba", which causes fatal infections after contaminated water enters the nose. Amoebae can serve as shelters for dangerous bacteria and viruses, allowing them to avoid disinfection and spread further. These organisms represent a growing global threat to human health.