World Health Organisation's Director-General Tedros Adhanom Ghebreyesus has lauded the Aarogya Setu App, India's contact tracing app, and said that it helped city public health departments identify COVID-19 hotspots and take steps to tackle it. 'Aarogya Setu app from India has been downloaded by 150 million users and has helped city public health departments to identify areas where clusters could be anticipated & expand testing in a targeted way,' he said. The WHO chief also named other apps developed in other nations to say that digital technologies have helped track the spread of the infection. The WHO chief also spoke on the few instances of Covid reinfection and warned that a large number of people still remain at risk of contracting the virus. 'We are only beginning to understand the long term health impacts among people with Covid-19,' the WHO chief said. He added since the virus transmits mainly between close contacts and causes outbreaks it can be controlled by implementing targeted measures. Watch the full video for all the details.