KOCHI: A total of 716 people tested positive for Covid-19 in the district on Tuesday. Of them, 521 contracted the virus through the local transmission and 12 people returned from abroad and other states. Ten health workers, 20 INHS officers and a police officer are also among the infected. The sources of infection of 173 people remain unknown. The district also recorded 914 recoveries on the day. A total of 11,575 people are undergoing treatment in the district. The health authorities have sent 5,550 samples for testing on Tuesday. A total of 29,905 are currently under observation in the district.