CHINA has reported no new cases of the deadly coronavirus in Hubei Province, where it all started for a fourth consecutive day.

The rate of infection in China has been on  a downward curve for weeks while the rest of the world steps up measures to try and battle the pandemic. 

Chinese authorities say 46 new cases were confirmed in China on Saturday, bringing the total in the country to 81,054.

The authorities say 45 of the new cases are people who entered China from other countries.

They say six more people have died - one less than the previous 24 hours. China's death toll now stands at 3,261.

Wuhan must go 14 straight days without a new case for draconian travel restrictions to be lifted, but already, a special train returned more than 1,000 car factory employees for the first time since the outbreak.

Parks and other public gathering places are reopening in China as people return to work and businesses resume.

The World Health Organization on Friday praised China's success in controlling the outbreak in the central city of Wuhan, where the virus first emerged late last year.

When China announced it was shutting down Wuhan, the centre of the coronavirus outbreak, in a bid to prevent further spread of the disease, the world was stunned and some experts were sceptical.

The authorities have been assisted by strong measures such as the introduction of a surveillance app for mobile phones.  It assigns citizens a colour depending on their health, with the result determining if they could travel.

Called Alipay Health Code it assigns individuals the colour green, yellow or red, depending on whether they should be allowed into public spaces or quarantined at home.

It uses big data to identify potential virus carriers, according to its developer Ant Financial. 

It assigns individuals base on time spent in outbreak hotspots and exposure to potential carriers of the virus. The software, used in more than 100 cities, will soon allow people to heck the colours of other residents when their ID numbers are entered.

There has been criticism of the country for taking advantage of the nation's surveillance and big data networks and huge questions about civil liberties.

HeraldScotland: China coronavirus outbreak

But a group of Oxford scientists say the idea of using common smartphone features during such a crisis may still have merit.

As the novel coronavirus continues to spread globally, a team of University of Oxford-linked scientists have suggested a centralized smartphone app could feasibly be designed to alert people that they had been in close proximity to a person who later tested positive for the respiratory disease.

The university experts — epidemiologist Prof. Christophe Fraser, clinical scientist David Bonsall and ethicist Prof. Michael Parker—acknowledged in their findings that China's tool, integrated into the WeChat app, was scrutinized for "data protection and privacy" concerns, and said they sought to create a "broadly acceptable version."

They said that if rapidly and widely deployed, the infectious disease experts believe such an app could significantly help to contain the spread of coronavirus.

They said most Covid-19 cases so far have been identified by testing people with symptoms, but noted tracing for additional victims is often based on memory, which is unreliable and time consuming.

This is where a mobile app could prove worthwhile - if handled with care, they said. It would have to be a centralized system, built with an option to request a Covid-19 test and log the result.

The Oxford University team recommended that the mobile application should form part of an integrated coronavirus control strategy that identifies infected people and their recent contacts using digital technology.

Their paper states: "An alternative [to China's version] could be implemented with an algorithm that is so simple... yet is shown mathematically to feasibly contain epidemics. The core functionality is to replace a weeks' work of manual contact tracing with an instantaneous signal transmitted to and from a central [computer] server."

"The application is in green mode during normal times. The app is the central hub of access to all Covid-19 health services, information and instructions, [it is] the mechanism to request tests if a user is symptomatic [and it is] a mechanism to request food deliveries during self-isolation (code red.)"

The paper continues: "A positive test result is instantly communicated to the server, and enacts quarantine and social distancing measures in those known to be possible contacts."

Dr David Bonsall researcher at Oxford's Nuffield Department of Medicine and clinician at Oxford's John Radcliffe Hospital said: "Our findings confirm that not everybody has to use the mobile app for it to work. If with the help of the app the majority of individuals self-isolate on showing symptoms, and the majority of their contacts can be traced, we stand a chance of stopping the epidemic. To work, this approach needs to be integrated into a national programme, not taken on by independent app developers. If we can securely deploy this technology, the more people that opt-in, the faster the epidemic will stop, and the more lives can be saved."

Dr Bonsall explains why the current contact tracing strategy is no longer viable, adding: "At the current stage of the epidemic, contact tracing can no longer be performed effectively by public health officials in the UK, and many countries across Europe, as coronavirus is spreading too rapidly. Our research of early data from other countries shows that patient histories are incomplete - we don't know the details of the person we sat next to on the bus. We need an instantaneous and anonymous digital solution to confirm our person-to-person contact history."

The data findings, published on GitHub, have not yet been peer-reviewed, Mr Fraser tweeted yesterday. He said the paper was released early because it "seems appropriate to have a wider debate given the general question of app-based approaches and ongoing feasibility studies."

Singapore has said it has launched a contact-tracing smartphone app to allow authorities to identify those who have been exposed to people infected with coronavirus as part of efforts to curb the spread of the disease.

The TraceTogether app will work by exchanging short distance Bluetooth signals between phones to detect other participating users in close proximity of 2 meters.

Records of the encounters will be stored locally on each phone with the app, developed by Singapore’s Government Technology Agency (GovTech) and the health ministry.

Users will need to send their logs when requested by the health ministry, which will otherwise not have any knowledge of the data, according to an official statement.