Anxiety continued to mount in the State capital with four of the nine people who tested positive for SARS-CoV-2 on Thursday contracting the infection from unknown sources.
The four patients, none of who has a history of travel, include a 25-year-old graduate trainee of the Vikram Sarabhai Space Centre (VSSC) hailing from Vazhuthoor, near Neyyattinkara.
He has been associated with the Small Satellite Launch Vehicle (SSLV) project in the project complex on the 70-acre area on the VSSC premises. Over 15 people have been asked to go in quarantine.
Official sources say many more, including secondary contacts, will be quarantined.
The trainee, who used to travel for work in a VSSC bus, also used to frequent other wings, including the Thumba Equatorial Rocket Launching Station (TERLS), Veli research centre, and the rocket fabrication facility.
He is known to have last attended office on June 24. The VSSC campus will be disinfected on Friday, official sources said.
A technician in the electrical section of the VSSC and a retired employee of the Liquid Propulsion Systems Centre had been diagnosed with COVID-19 on June 26. It is not known whether the trainee had come in contact with any of the duo.
Shopping complex staff
The other COVID-19 cases classified with unknown sources of transmission include a 24-year old Assam native, who worked at a garment store in Saphalyam Complex in Palayam, a 45-year-old Kunnumpuram native who used to sell lottery tickets, and a 47-year-old man hailing from Aluvila, near Balaramapuram.
Five imported cases were also reported on the day. They include a 45-year-old Pongumoodu woman who came from Kuwait on June 18, a 20-year old Kattakada native who came from Pune via Kochi on June 23, a two-year-old girl from Channankara who came from Kuwait on June 26, a 47-year-old Kunnukuzhy native who came from Abu Dhabi via Kochi on July 1, and a 65-year-old man who came from Oman via Kochi.