Conspiracy theories about viruses and vaccines have exploded in recent years. At the same time, something arguably stranger has spiralled…groups online who don’t believe germs which cause disease exist at all. They believe that there’s no such thing as viruses and that all diseases are caused by living an unhealthy life, particularly our diet and environmental toxins. It goes hand in hand with a rejection of vaccines and other forms of conventional medicine. The BBC's health and disinformation reporter Rachel Schraer investigates how germ denial has grown and spread on social media. In South Africa, a small group of germ deniers, influenced by American conspiracy theorists, is awaking painful memories.