A surge in internet searches about gut ailments is helping researchers predict the next Covid-19 hotspots, a study has revealed. Massachusetts General Hospital found areas where there was a spike in Google queries relating to diarrhoea and loss of appetite frequently reported a sharp rise in cases of coronavirus three to four weeks later. Other markers included a loss of taste, nausea and abdominal pain. A link between Covid-19 and gut ailments was first identified in China earlier this year, with about a third of sufferers reporting gastrointestinal rather than respiratory sickness. Other patients complained of suffering from both.