Journalist Gauri Lankesh, who led crusade against communalism, shot dead

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of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.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

Bengalur, May 2: Two people died of COVID-19 in Karnataka on Saturday taking the toll in the state to 25, whereas nine more tested positive for the virus, pushing the tally to 598, the health department said. Two deaths were reported in Bidar and Bengaluru urban, the health department said in a statement.

An 82-year-old person with a history of Severe Acute Respiratory Illness died in Bidar. While the second fatality was a 62-year-old man with a history of diabetes, hyper-tension, renal failture and was on multiple myeloma on chemotherapy, in Bengaluru. He too had complained of breathlessness on April 30 and died on Saturday at the designated hospital.

Among the nine new cases, two each are from Tumakuru, Vijayapura, one each from Bidar, Chikkaballapura, Belagavi, Bagalkot and Bengaluru urban. Cumulatively, 598 COVID-19 positive cases have been confirmed in the state and it includes 25 deaths.

Paris, Mar 2: A global agency says the spreading new virus could make the world economy shrink this quarter, for the first time since the international financial crisis more than a decade ago.

The Organization for Economic Cooperation and Development says Monday in a special report on the impact of the virus that the world economy is still expected to grow overall this year and rebound next year.

But it lowered its forecasts for global growth in 2020 by half a percentage point, to 2.4 per cent, and said the figure could go as low as 1.5 per cent if the virus lasts long and spreads widely.

The last time world GDP shrank on a quarter-on-quarter basis was at the end of 2008, during the depths of the financial crisis. On a full-year basis, it last shrank in 2009.

The OECD said China's reduced production is hitting Asia particularly hard but also companies around the world that depend on its goods.

It urged governments to act fast to prevent contagion and restore consumer confidence.

The Paris-based OECD, which advises developed economies on policy, said the impact of this virus is much higher than past outbreaks because "the global economy has become substantially more interconnected, and China plays a far greater role in global output, trade, tourism and commodity markets."