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Beijing, May 25: China has reported 51 new coronavirus cases including 40 asymptomatic infections, majority of them in the contagion's first epicentre Wuhan, where over six million tests have been conducted in the last 10 days, health officials said on Monday.

The country's National Health Commission (NHC) said that 11 new imported cases were reported on Sunday.

While no new domestically-transmitted COVID-19 cases were reported in China on Sunday, 11 imported cases including 10 in the Inner Mongolia Autonomous Region and one in Sichuan province were reported, the NHC said in its daily report.

Out of the 40 new asymptomatic cases, 38 were reported in Wuhan, which is currently undergoing mass testing of its over 11.2 million people after a spike in the asymptomatic cases.

Currently, 396 people with asymptomatic symptoms are under medical observation in China, including 326 in Wuhan, according to the health authority.

Asymptomatic cases refer to the patients who have tested COVID-19 positive but develop no symptoms such as fever, cough or sore throat. However, they pose a risk of spreading the disease to others.

Wuhan, which earlier had over 50,000 cases between January and March, started a campaign on May 14 to expand the nucleic acid testing in order to better know the number of asymptomatic cases or people who show no clear symptoms despite carrying the virus.

According to the latest figures released by the Wuhan municipal health commission, the city conducted more than 6 million nucleic acid tests between May 14 and 23.

On Saturday, the city carried out nearly 1.15 million tests, state-run Xinhua news agency reported on Monday.

Nucleic acid testing is a molecular technique for screening blood donations to reduce the risk of transfusion transmitted infections.

As of Sunday, a total of 82,985 confirmed COVID-19 cases have been reported in China with 4,634 fatalities, the NHC added.

Beijing, Feb 19: The death count from China's new coronavirus epidemic jumped to 2,000 on Wednesday after 132 more people died in Hubei province, the hard-hit epicentre of the outbreak.

In its daily update, the province's health commission also reported 1,693 new cases of people infected with the virus.

This brings the total number of cases in mainland China past 74,000.

Most of the cases are in Hubei, where the virus first emerged in December before spiralling into a nationwide epidemic.

Wednesday's jump in the death count was an increase on Tuesday's figures, although the number of new cases reported in Hubei were the lowest for a week.

A study released by Chinese officials claimed most patients have mild cases of the illness.

Outside of hardest-hit Hubei, which has been effectively locked down to try to contain the virus, the number of new cases has been slowing and China's national health authority has said this is a sign the outbreak is under control.

President Xi Jinping, in a phone call with the British prime minister, said China's measures were achieving "visible progress", according to state media Tuesday.

However, the World Health Organization has cautioned that it was too early to tell if the decline would continue.

On Tuesday the director of a hospital in the central Hubei city of Wuhan became the seventh medical worker to succumb to the COVID-19 illness.

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.