'Don't know what will happen after one year'

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of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.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

Udupi, May 24: As many as 23 people tested positive for coronavirus in Udupi in past 24 hours, according to the latest bulletin released by the health and family welfare department.

While 18 were tested positive till noon, five more tested postive by evening.

With this the total number of covid-19 cases in the district rose to 76 including a death. Three have recovered. There 72 active cases.

Among 23 fresh cases, many had reportedly come from Maharashtra. A 44-year-old woman had returned from UAE. A 26-year-old man returned from Telangana.

Bengaluru, Jul 9: Karnataka Chief Minister B S Yediyurappa on Thursday said the Covid-19 situation was “getting out of control a little” in some parts of the state, but assured citizens that authorities were taking necessary steps. 

“In some districts, it’s getting out of control a little. But the district administration and police are working day and night,” Yediyurappa said before the Cabinet meeting where the Covid-19 situation will be discussed. 

Speculation is rife that the government might consider stricter measures to curb the movement of people to try arresting the rising number of Covid-19 cases. 

Later in the day, Yediyurappa is slated to inspect the Bengaluru International Exhibition Centre, which has been converted into a Covid Care Centre with 10,000 beds. The chief minister said he had ordered “immediate” arrangement of more ambulances for Bengaluru, where cases are rapidly shooting up. 

“A team from the Centre had come. They’ve made some observations and they also appreciated us for some of the things we’ve done,” he added. 

On Friday, Yediyurappa has convened a meeting of all Bengaluru ministers, legislators, MPs and councillors to discuss the Covid-19 pandemic in the city.