Relief for spouses of H-1B visa holders: US delays decision on work authorisation for H-4 visa programme

Feb 22: A 20-year-old Chinese woman from Wuhan, the epicentre of the coronavirus outbreak, travelled 400 miles(675 km) north to Anyang where she infected five relatives, without ever showing signs of infection, Chinese scientists reported on Friday, offering new evidence that the virus can be spread asymptomatically.

The case study, published in the Journal of the American Medical Association, offered clues about how the coronavirus is spreading, and suggested why it may be difficult to stop.

"Scientists have been asking if you can have this infection and not be ill? The answer is apparently, yes," said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, who was not involved in the study.

China has reported a total of 75,567 cases of the virus known as COVID-19 to the World Health Organization (WHO) including 2,239 deaths, and the virus has already spread to 26 countries and territories outside of mainland China.

Researchers have reported sporadic accounts of individuals without any symptoms spreading the virus. What's different in this study is that it offers a natural lab experiment of sorts, Schaffner said.

"You had this patient from Wuhan where the virus is, travelling to where the virus wasn't. She remained asymptomatic and infected a bunch of family members and you had a group of physicians who immediately seized on the moment and tested everyone."

According to the report by Dr Meiyun Wang of the People's Hospital of Zhengzhou University and colleagues, the woman travelled from Wuhan to Anyang on Jan. 10 and visited several relatives. When they started getting sick, doctors isolated the woman and tested her for coronavirus. Initially, the young woman tested negative for the virus, but a follow-up test was positive.

All five of her relatives developed COVID-19 pneumonia, but as of Feb. 11, the young woman still had not developed any symptoms, her chest CT remained normal and she had no fever, stomach or respiratory symptoms, such as cough or sore throat.

Scientists in the study said if the findings are replicated, "the prevention of COVID-19 infection could prove challenging."

Key questions now, Schaffner said, are how often does this kind of transmission occur and when during the asymptomatic period does a person test positive for the virus.

Beijing, Jun 16: The coronavirus situation in China's capital is "extremely severe", a city official warned Tuesday, as 27 new infections were reported from Beijing where a new cluster has sparked a huge trace-and-test programme.

The COVID-19 resurgence -- believed to have started at the sprawling Xinfadi wholesale food market in the capital -- has sparked alarm as China had largely brought its outbreak under control through mass testing and lockdowns imposed earlier in the year.

The new cases took the number of confirmed infections in Beijing over the past five days to 106, as authorities locked down almost 30 communities in the city and tested tens of thousands of people.

"The epidemic situation in the capital is extremely severe," Beijing city spokesman Xu Hejian warned at a press conference.

The World Health Organization had already expressed concern about the cluster, pointing to Beijing's size and connectivity.

Officials in the capital have said they will test stall owners and managers at all of the city's food markets, restaurants and government canteens.

Beijing's coronavirus testing capacity has been expanded to 90,000 a day, according to China's official news agency Xinhua.

On Tuesday, the capital's transport commission banned taxi- and ride-hailing services from driving out of the city, Xinhua reported, in another move to try and contain the new outbreak.

All indoor sports and entertainment venues in Beijing were ordered to shut on Monday, and some other cities across China warned they would quarantine those arriving from the capital.

The National Health Commission also reported four new domestic infections in Hebei province, which surrounds Beijing, and a case reported in southwestern Sichuan province was linked to the Beijing cluster.

Authorities were also racing to track people from Beijing who had travelled to other parts of China, and those who visited the capital have been encouraged to get tested.

Beijing spokesman Xu said: "High-risk people who have left Beijing must inform local authorities immediately."

Market inspections

Authorities shut down another market on Tuesday -- Tiantaohonglian in the central Xicheng district -- after one employee there was diagnosed with COVID-19, state broadcaster CCTV reported.

Seven residential estates surrounding that market were also locked down.

In total, Beijing officials said Tuesday they have disinfected 276 agricultural markets, closed 11 markets, and disinfected more than 33,000 food and beverage businesses in a bid to stamp out the new cluster.

Officials had warned Sunday that since May 30, 200,000 people had visited the Xinfadi market -- the original site of the new outbreak.

More than 8,000 workers from Xinfadi have been tested and sent to centralised quarantine facilities.

Until this recent outbreak, most of China's cases in recent months were nationals returning home as the pandemic spread to other countries.

China's Center for Disease Control and Prevention said Monday that the virus strain found in the Beijing outbreak was a "major epidemic strain in the European countries".

While the virus was detected on chopping boards used to handle imported salmon at Xinfadi, "it does not clearly or definitely indicate it's from imported seafood", Wu Zunyou, the body's chief epidemiologist, said in an interview with state broadcaster CCTV.

"Ever since new cases suddenly emerged in Beijing, we have tried to figure out the reasons for the outbreak since there were no COVID-19 cases found over the past two months," Wu Zunyou said.

"We came up with several possibilities, and the most likely one is that the carrier of the novel coronavirus comes from outside China or other parts of China and brought it here."

On Tuesday, another eight imported cases were reported.

Melbourne, Apr 10: Scientists have identified six drug candidates from more than 10,000 compounds that may help treat COVID-19.

The research, published in the journal Nature, tested the efficacy of approved drugs, drug candidates in clinical trials and other compounds.

"Currently there are no targeted therapeutics or effective treatment options for COVID-19," said Professor Luke Guddat from the University of Queensland in Australia.

"In order to rapidly discover lead compounds for clinical use, we initiated a programme of high-throughput drug screening, both in laboratories and also using the latest computer software to predict how different drugs bind to the virus," Guddat said.

The project targeted the main COVID-19 virus enzyme, known as the main protease or Mpro, which plays a pivotal role in mediating viral replication, the researchers said.

This makes it an attractive drug target for this virus, and as people don't naturally have this enzyme, compounds that target it are likely to have low toxicity, they said.

"We add the drugs directly to the enzyme or to cell cultures growing the virus and assess how much of each compound is required to stop the enzyme from working or to kill the virus. If the amount is small, then we have a promising compound for further studies," said Guddat.

After assaying thousands of drugs, researchers found of the six that appear to be effective in inhibiting the enzyme, one is of particular interest.

"We're particularly looking at several leads that have been subjected to clinical trials including for the prevention and treatment of various disorders such as cardiovascular diseases, arthritis, stroke, atherosclerosis and cancer," Guddat said.

Researchers said compounds that are already along the pipeline to drug discovery are preferred, as they can be further tested as antivirals at an accelerated rate compared to new drug leads that would have to go through this process from scratch.

"With continued and up-scaled efforts we are optimistic that new candidates can enter the COVID-19 drug discovery pipeline in the near future," Guddat said.