Amid a surge in Covid-19 cases, Karnataka Health Minister Dr K Sudhakar on January 4 said that the Covid infection rate has doubled in the past few days. “In the first and second waves of Covid-19, the infection rate used to double once in 15 days and 8-10 days, respectively. But now, this is doubling in 1-2 days. We need to be cautious,” Sudhakar added.