13 more coronavirus cases in Karnataka; total 101 now

The current physical distancing guidelines provided by the World Health Organisation (WHO) and by the US Centers for Disease Control and Prevention (CDC) may not be adequate to curb the coronavirus spread, according to a research which says the gas cloud from a cough or sneeze may help virus particles travel up to 8 metres. The research, published in the Journal of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.

Study author, MIT associate professor Lydia Bourouiba, warned that droplets of all sizes can travel 23 to 27 feet, or 7-8 metres, carrying the pathogen.

According to Bourouiba, the current guidelines are based on "arbitrary" assumptions of droplet size, "overly simplified", and "may limit the effectiveness of the proposed interventions" against the deadly pandemic.

 She explained that the old guidelines assume droplets to be one of two categories, small or large, taking short-range semi-ballistic trajectories when a person exhales, coughs, or sneezes.

However based on more recent discoveries, the MIT scientist said, sneezes and coughs are made of a puff cloud that carries ambient air, transporting within it clusters of droplets of a wide range of sizes.

Bourouiba warned that this puff cloud, with ambient air entrapped in it, can offer the droplets moisture and warmth that can prevent it from evaporation in the outer environment.

"The locally moist and warm atmosphere within the turbulent gas cloud allows the contained droplets to evade evaporation for much longer than occurs with isolated droplets," she said.

"Under these conditions, the lifetime of a droplet could be considerably extended by a factor of up to 1000, from a fraction of a second to minutes," the researcher explained in the study.

The MIT scientist, who has researched the dynamics of coughs and sneezes for years, added that these droplets settle along the trajectory of a cough or sneeze contaminating surfaces, with their residues staying suspended in the air for hours.

"Even when maximum containment policies were enforced, the rapid international spread of COVID-19 suggests that using arbitrary droplet size cutoffs may not accurately reflect what actually occurs with respiratory emissions, possibly contributing to the ineffectiveness of some procedures used to limit the spread of respiratory disease," Bourouiba wrote in the study

Bengaluru, Mar 2: The Karnataka Department of Public Instruction has directed the School heads across the State to grant leave to students and staff suffering from fever, cold, cough and other respiratory infections.

As precautionary measure following the COVID-19 (known as coronavirus) outbreak at the global level, the department issued a circular in this regard here on Monday.

If any student, teacher or staff is suffering from respiratory infections, they should be granted leave. They should be allowed to come back to school only after confirming from the doctor that they are cured, the circular added.

Mangaluru, May 11: Hundreds of migrant labourers today gathered at a service bus stand in Mangaluru to return to Uttar Pradesh and Jharkhand.

They were working in different parts of Dakshina Kannada and remained stranded without a job after the announcement of lockdown.

Labourers said that they have not registered with Seva Sindhu portal to avail pass for travelling outside the state.

Though all the people who gathered wore a mask, the physical distancing norm was not followed.

Already three Shramik trains from Mangaluru had left for Jharkhand, Uttar Pradesh and Bihar with nearly 3,500 stranded labourers in the last two days.

The gathered labourers are anticipating that they would be allowed to travel to their destinations in the Shramik trains that will leave in the evening from Mangaluru.

The doctors and paramedical staff who have arrived the spot are checking the health of the labourers before allowing them to travel to the railway station.

The cost of a ticket to Uttar Pradesh is Rs 1,040 per person (which includes bus fare from service bus stand to railway station, food and water bottle).