Aam Aadmi' inaugurates AAP district office in Mangalore

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of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.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

Mangaluru, July 8: Dakshina Kannada on Wednesday recorded its highest single-day spike in Covid-19 cases with 183 cases reported in the district, while Udupi reported 31 new cases.

DK also recorded two more fatalities – both patients with co-morbid conditions — taking the total death toll in the district to 28. Udupi has recorded three Covid-19 deaths.

The fresh spike saw total positive cases in DK shoot up to 1,542 and active cases to 819. As many as 12 patients were discharged from hospital on Wednesday. The positivity rate in the district now stands at 0.07 %. Health authorities as on date have received 22,181 samples and 20,153 out of 21,695 samples tested have turned out negative.

MLA’s gunman tests positive

The gunman assigned to former minister U T Khader tested positive on Wednesday and three others who were with him in the escort vehicle have been quarantined, said city police commissioner Vikash Kumar Vikash. A section of police commissioner’s office was shut for sanitisation as per protocol after staff working there were treated as primary contacts. The office per se has not been sealed contrary to ‘reports’ doing rounds in social media, he said.

Deputy commissioner Sindhu B Rupesh said the district reported two deaths — one late on Tuesday and the other during the day. The victims are a 57-year-old man and 32-year-old youth. Two of the 183 cases were secondary contacts, 25 were cases of influenza like illness, four cases of SARI, one a case of inter district travel, two with interstate travel, five with international travel history, 22 random samples and five pre-surgery samples.

Udupi district recorded 31 new cases taking the total positive cases recorded as on date to 1,421. Discharge of 1,189 patients meant that Udupi has 229 active cases.

Meanwhile, Kota Shrinivas Poojari, minister for fisheries on Wednesday inaugurated the Covid-19 lab at district hospital in Udupi. Karkala MLA Sunil Kumar inaugurated ambulance monitoring system to ensure expeditious transfer of infected patients to designated treatment centres.