Mangaluru: 3-year-old girl accidentally falls into well, dies

Bengaluru, Jul 10: With 2,313 more people testing positive for coronavirus in Karnataka in the last 24 hours, its overall tally of patients rose to 33,418 on Friday, health officials said.

57 patients died in Karnataka in the last 24 hours, with majority (27) of them from Bengaluru, taking the state''s death toll to 543, the officials added.

Bengaluru accounted for 1,447 or 63 per cent of the new COVID-19 cases, spiking its tally to 15,329, out of which 11,687 are active cases.

The city alone accounts for 46 per cent of all the cases in the state.

As many as 45 deaths had Severe Acute Respiratory Infection (SARI) as a common symptom.

Among the new cases, excluding Bengaluru, Dakshina Kannada accounted for 139 infections, followed by Vijayapura (89), Ballari (66), Kalaburagi (58), Yadgir and Mysuru (51 each) among others.

On Friday, a record 1,003 patients got discharged, 601 of them in Bengaluru alone with the total number of discharges rising up to 13,836.

Until now, Karnataka has tested 7.79 lakh samples for Covid, out of which 7.28 lakh tested negative.

Despite the record number of discharges, patients in ICU rose to 472.

Of the 33,418 cases, 19,035 are active in the state.

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of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.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