THIRUVANANTHAPURAM: The district on Sunday recorded 322 new cases and 248 recovered cases of Covid-19. A total of 3,536 positive cases are currently under treatment. Those who were infected on the day included 246 contact cases and three health workers. Three deaths were confirmed as due to the virus. A total of 21,808 people are under house surveillance and 76 people are under institutional quarantine in the district now.