In the 1970s, several research groups set out to find out how many children died each year from diarrhoea-related illness. While their initial estimates were imprecise – ranging from three million to 12 million deaths per year – their scale focused medical and public health attention on the deadly impact that diarrhoea has on child survival.
Back then, a causative agent could be identified in fewer than 15% of diarrhoeal episodes. These included the bacteria that cause cholera and salmonella, several parasites and various environmental toxins.
But advances in electron microscopy soon began to open a window on the plethora of other pathogens infecting children’s guts and making them unwell. One of them was a beautiful but deadly wheel-shaped virus isolated from the small intestines of children with gastroenteritis. It was named rotavirus.