THIRUVANANTHAPURAM: Two persons who recently sought treatment at the Sree Chitra Tirunal Institute for Medical Sciences & Technology in Thiruvananthapuram have tested positive for the coronavirus. Following this, 21 persons including 8 doctors have been put under observation. It is learnt that the authorities have not been able to trace the source of infection.

Earlier, the surgery ward of the Medical College hospital was closed after four doctors tested positive for the virus.