Khan, Qadri march to Parliament inside Islamabad's 'Red Zone'

London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.

Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.

In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.

"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.

According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.

They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.

These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.

In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.

The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.

Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.

The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.

"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.

However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.

They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.

This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.

Geneva, Jul 11: The World Health Organization said Friday that it is still possible to bring coronavirus outbreaks under control, even though case numbers have more than doubled in the past six weeks.

WHO chief Tedros Adhanom Ghebreyesus said the examples of Italy, Spain, South Korea and India's biggest slum showed that however bad a outbreak was, the virus could still be reined in through aggressive action.

"In the last six weeks cases have more than doubled," Tedros told a virtual press conference in Geneva.

However, "there are many examples from around the world that have shown that even if the outbreak is very intense, it can still be brought back under control," said Tedros.

"And some of these examples are Italy, Spain and South Korea, and even in Dharavi -- a densely packed area in the megacity of Mumbai -- a strong focus on community engagement and the basics of testing, tracing, isolating and treating all those that are sick is key to breaking the chains of transmission and suppressing the virus."

The novel coronavirus has killed at least 555,000 people worldwide since the outbreak emerged in China last December, according to a tally from official sources compiled by AFP on Friday.

Nearly 12.3 million cases have been registered in 196 countries and territories.

"Across all walks of life, we are all being tested to the limit," Tedros said, "from countries where there is exponential growth, to places that are loosening restrictions and now starting to see cases rise.

"Only aggressive action combined with national unity and global solidarity can turn this pandemic around."

Beijing/Zurich, Mar 4: China has approved the use of Swiss drugmaker Roche's anti-inflammation drug Actemra for patients who develop severe complications from the coronavirus as it urgently hunts for new ways to combat the deadly infection that is spreading worldwide.

China is hoping that some older drugs could stop severe cytokine release syndrome (CRS), or cytokine storms, an overreaction of the immune system which is considered a major factor behind catastrophic organ failure and death in some coronavirus patients.

Actemra, a biologic drug approved in 2010 in the United States for rheumatoid arthritis (RA), inhibits high Interleukin 6 (IL-6) protein levels that drive some inflammatory diseases.

China's National Health Commission said in treatment guidelines published online on Wednesday that Actemra can now be used to treat coronavirus patients with serious lung damage and high IL-6 levels.

Separately, researchers in the country are testing Actemra, known generically as tocilizumab, in a clinical trial expected to include 188 coronavirus patients and running until May 10.

Roche, which donated 14 million yuan ($2.02 million) worth of Actemra during February, said the trial was initiated independently by a third party with the aim of exploring the efficacy and safety of the drug in coronavirus patients with CRS.

It added that there was currently no published clinical trial data on the drug's safety or efficacy against the virus.

More than 3,000 people have died and 93,000 have been infected by the novel coronavirus thought to have originated in Wuhan, China, before spreading to around 90 countries including the United States, Italy, Switzerland, France and Germany.

The Swiss company, for which China is its No. 2 market behind the United States, also makes diagnostic gear to detect the coronavirus.

Since Actemra's approval a decade ago, it has become a go-to drug against other inflammatory conditions, including cytokine storms in cancer patients receiving cell therapies from Novartis and Gilead Sciences.

In 2012 it helped save the life of a young U.S. girl, the first child to be treated for leukaemia with Novatis' Kymriah, from a post-treatment rush of IL-6.

Priced at between $20-30,000 annually for RA according to SSR Health, Roche's medicine is also used for rare juvenile arthritis and giant cell arteritis, or inflammation of the blood vessels.