The number of cases of Covid patients having the new mutated strain of the virus, first detected in the UK last year, rose to four with a recent returnee also found to have it, officials said on Friday.The new case was detected in Jaipur on Thursday night.The 18-year-old woman had returned from the UK in December and was staying in isolation at her home here. Her samples were sent to Delhi for further testing after she tested Covid positive.Soon after, a medical team reached her residence and shifted her to hospital.The other three members of her family were also tested but were negative.Earlier, three residents - a couple and their son - of the state's Sriganganagar had tested positive for the new mutant strain.Rajasthan's total active cases, till Thursday evening, were 7,468 while the cumulative positive cases were 3,11,620. There have been 2,727 deaths so far.