Gujarat BJP MP Liladhar Vaghela recuperating in ICU after attack by Gau Mata

Bengaluru, Jul 23: Karnataka on Thursday recorded a biggest single-day surge of over 5,000 cases and 97 related fatalities, taking the total number of people who tested positive for the virus to 80,863, the health department said. 

The day also saw a record 2,071 patients getting discharged after recovery.

Out of 5,030 fresh cases reported, a whopping 2,207 cases were from Bengaluru urban alone.

As of July 23 evening, cumulatively 80,863 Covid-19 positive cases have been confirmed in the state, which includes 1,616 deaths and 29,310 discharges, the health department said in its bulletin.

It said, out of 49,931 active cases, 49,291 patients are in isolation at designated hospitals and are stable, while 640 are in ICU. Out of the 97 deaths reported on Thursday 48 are from Bengaluru urban, followed by Mysuru 8, Dakshina Kannada 7 and others.

Most of the dead are either with a history of Severe Acute Respiratory Infection (SARI) or Influenza-like illness (ILI).

Among the districts where the new cases were reported, Bengaluru urban accounts for 2,207, followed by Raichur 258, Kalaburagi 229, Dakshina Kannada 218, and others.

Bengaluru urban district tops the list of positive cases, with a total of 39,200 infections, followed by Dakshina Kannada 4,209 and Kalaburagi 3,370. 

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of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.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