'Diluted' anti-superstition bill gets State Cabinet nod

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of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.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, Jun 29: Bengaluru continued to see a sharp spike in covid- 19 cases as 738 more people tested positive on Monday that took the city's tally to 4052 of which 3427 is active.

The surge in Bengaluru pushed up the number of positive cases to 1105 across Karnataka. The total number of cases in Karnataka now stands at 14,295 of which 6382 are active.

The death toll stood at 230 as 19 more people died in the 24 hours till 5 pm on Monday.

Karnataka, particularly Bengaluru, has seen a sharp rise in cases over the last two weeks indicating the possibility of community transmission and further rise in cases.

Estimates by government authorities project that Karnataka will have around 25,000 cases by mid-August.

R.Ashok, the revenue minister incharge of covid- 19 in Bengaluru on Monday told doctors that they would have to dedicate another six months to contain the virus indicating that authorities were expecting the case count to rise in subsequent days and months.

The city reported over 3,200 cases since 19 June as against 844 cases between 8 March and 18 June.

There are around 500 containment zones in Bengaluru that is likely to have an impact of business and activities in the state's growth capital and its efforts to revive the economy.

The state government on Monday held meetings with private hospitals to increase the number of beds available for treatment of covid- 19.

The number of people in intensive careunits (ICU) jumped to 268.