Hong Kong hospitals raised alert levels Sunday as a woman diagnosed with the deadly H7N9 avian flu virus was in a critical condition.

The 68-year-old woman was hospitalised on December 25 after returning from the southern Chinese city of Shenzhen almost two weeks earlier, although it has not been confirmed where or how she contracted the virus.

Swiss pharmaceutical company Novartis said Friday it has won approval to market its Cosentyx psoriasis treatment in Japan, making it the first country to authorize commercialization of the drug.

The Japanese decision allows Novartis to sell secukinumab, sold under the name Cosentyx, to adult patients suffering psoriasis vulgaris and psoriatic arthritis, and who aren't responding to other medication.

A brain-dead pregnant woman was taken off life support Friday after a court ruled that her 18-week-old fetus was doomed to die — a case that exposed fear and confusion among doctors over how to apply Ireland's strict ban on abortion in an age of medical innovation.

The three-judge Dublin High Court said that all artificial support for the woman should end more than three weeks after she was declared clinically dead. Her relatives gathered at a hospital in the Irish Midlands to bid farewell to the unidentified woman, who was in her late 20s and had two young children.

The death toll from the Ebola outbreak in west Africa has risen to 7,693 out of 19,695 cases recorded, the World Health Organization said Friday.

The previous toll released December 22 stood at 7,518 fatalities out of 19,340 infected in Sierra Leone, Liberia and Guinea.

Europe will be "vulnerable" if it does not regard viruses as a "national security issue" like the United States, the microbiologist who discovered Ebola said in an interview published Friday.

"It's time the UK and Europe had a well-trained corps of people who are globally experienced and deployable," Peter Piot told the British daily The Independent.

Queen Elizabeth II will pay tribute in her annual Christmas Day broadcast on Thursday to the "selflessness" of medical staff and aid workers fighting the Ebola epidemic.

She will say how "deeply touched" she was by the volunteers who have gone to work in areas affected by the deadly virus, according to extracts released ahead of the broadcast.

Sierra Leone's government has declared a five-day lockdown in the country's north to step up efforts to contain the Ebola epidemic, while making an exception for Christmas.

"Muslims and Christians are not allowed to hold services in mosques and churches throughout the lockdown except for Christians on Christmas Day (Thursday)," Alie Kamara, resident minister for the Northern Region, told Agence France Presse.

British scientists said Wednesday they had discovered 12 genes linked to developmental disorders in children that can cause heart defects, seizures and intellectual disability.

The genes were found in a trawl of the genomes of 1,133 children with severe, undiagnosed disorders and their parents, said the authors of a study published in the journal Nature.

A lab worker may have been exposed to a live sample of the deadly Ebola virus, the U.S. Centers for Disease Control and Prevention said Wednesday, adding the accident is under investigation.

The technician is not currently showing any symptoms of the hemorrhagic fever, which has killed more than 7,500 people in an outbreak in West Africa. 

A lawyer representing a 17-week-old fetus living inside the clinically dead body of its mother says the unborn child's right to life trumps the woman's right to a dignified death.

Conor Dignam made his closing arguments Wednesday to three Dublin High Court judges who must decide whether Ireland's anti-abortion laws permit the woman's life support machines to be turned off. Their judgment is expected Friday.