After two consecutivedays of zero cases, three people tested positive for COVID-19 in Kerala on Tuesday while 37 people are undergoing treatment in various hospitals for the infection, Chief Minister Pinarayi Vijayan said.A truck driver, who had gone to Chennai's Koyambedumarket, a hotspot, and later tested positive for the virus, had infected his mother, wife and the cleaner's son, Vijayan told reporters here, adding that all the three cases were from Wayanad district.Meanwhile, the governmenthas decided to appoint 980 doctors for three months."Those who have completed house surgency will be given appointment for 90 days to strengthen our health sector as we have to receive the expatriates who would return to the state.Along with that the monsoon is also fast approaching," Vijayan said.He said 502 people have been infected with the virus and presently 37 are undergoing treatment in various hospitals.Over 21,000 people are under surveillance, including 308 in various hospitals.Another relief was that there were no new hotspots in the state and no positive cases reported in four districts, he said."As of now, Kannur has the highest number of patients, 18, followed by Kottayam with six and Wayanad with four patients.Kollam and Kasaragod have got three patients each," Vijayan said.When asked about certain confusion prevailing on the inter-state travel of stranded people, Vijayan said the travellers would require pass from the state from which the journey begins and the destination state."But it seems like some states which are en route are also seeking their pass during transit.We will bring this to the attention of the Centre," he said.Meanwhile, the Kerala Police Tuesday registered 3,397 cases and recorded arrests of 3,519 people for violating lockdown protocol and travelling.