Parasite behind explosive diarrhoea outbreaks reaches food through human waste

The parasite behind outbreaks of severe "explosive diarrhoea" spreads to food primarily through human waste — for example via contaminated irrigation water or infected food-industry workers. Its spread can become a self-perpetuating cycle as contaminated waste re-enters the food chain. Experts warn the pattern makes the parasite particularly difficult to contain once it takes hold.