The (Covid) situation demands a fresh mindset where the approach to development is human-centric

The asymptomatic spread of Sars-CoV-2 virus could be a major challenge as India eases curbs on buses and metro rail

NEW DELHI: One Covid-19 infected person passed on the virus to 23 of 67 passengers on a bus, a new study published this week determined, showing the pathogen can spread readily in a closed, small setting like public transport.

The findings are significant for India as it enters the fourth phase of the Unlock plan, with more public transport – including buses and metro trains – being allowed to run soon.

According to the report in JAMA Internal Medicine, a journal of the American Medical Association, the spread happened in one of two buses that carried a group of 128 people who visited a worship event in eastern China. “Those who rode a bus with air recirculation and with a patient with Covid-19 had an increased risk of SARS-CoV-2 infection compared with those who rode a different bus,” said the authors, who studied the spread that took place on January 19 in Zhejiang province.

The super-spreader, whose gender was not specified, had no symptoms such as a fever or cough at the time of travel, said the study, and this was a period before wearing of masks was made mandatory in China. Passenger mapping that the sickest people were in the front and back of the bus, outside the perimeter of 1-2 metres (threesix feet) that infectious droplets are believed to travel.

A similar investigation of a outbreak cluster in the southern Chinese city of Guangzhou, SarsCoV-2 was found to have spread between diners’ tables more than one metre apart at a restaurant in, where three families dined on January 24.

An experimental study published in NEJM in April had demonstrated that the virus remains viable in aerosols for 3 hours or longer, but epidemiological evidence from actual community transmission among people was missing.