The toll in China from the novel coronavirus rose to 1,483 on Friday, AFP reported. However, the number of new infections in the Hubei province, the worst-hit, recorded a fall, with 4,823 new cases.

The province’s health commission reported 116 more deaths. It said most of these deaths involved “clinically diagnosed” patients.

Meanwhile, the China National Biotech Group announced on Thursday evening that virus-neutralising antibodies had been detected in the plasma of patients who have recovered from the illness, the South China Morning Post reported. The company said that research shows these antibodies can kill the virus.

The company said it had successfully prepared the plasma for clinical treatment. It has been used to treat 11 patients, with significant results, the China National Biotech Group said.

A United States’ cruise ship which was denied access to several Asian ports over fears of coronavirus docked at a Cambodian pier in Sihanoukville on Thursday, AFP reported. The ship has 1,455 passengers on board.

It was supposed to take its passengers on a 14-day cruise around East Asia, beginning in Hong Kong on February 1 and disembarking on Saturday in Yokohama, Japan. However, Japan, Guam, the Philippines, Taiwan and Thailand all refused to let the ship dock at their ports. The cruise operator, Holland America, has claimed that there are no cases of the coronavirus on board.

“Thank you Cambodia! You believed in us when no one would!” passenger Lydia Miller tweeted. “We promise to spend lots of money in your country.”

However, Sihanoukville Provincial Governor Kuoch Chamroeun said that the passengers will have to stay on board the ship until flights are arranged for them. “The arrangement of the planes to take them from [Sihanoukville] Airport to Phnom Penh Airport is underway,” he said.

On Thursday, health officials conducted medical checkups of all passengers. The samples of 20 passengers on board who were sick were sent to the Pasteur Institute in Phnom Penh for testing for the coronavirus.

Global authorities attempt to identify ‘patient zero’

The virus spread from a sales meeting of Servomex company, a gas metre firm in Singapore in January, Reuters reported. Someone who was part of the meeting first spread the coronavirus to others.

“We do feel uncomfortable obviously when we diagnose a patient with the illness and we can’t work out where it came from...the containment activities are less effective,” said Dale Fisher, chairperson of the Global Outbreak Alert and Response Network coordinated by the World Health Organization. Health authorities said identifying “patient zero” is important for tracing all those potentially exposed to infection and containing the outbreak.

The virus has officially been named COVID-19. Infection symptoms include fever, cough, and shortness of breath. It causes respiratory illness, and is similar to the Severe Acute Respiratory Syndrome, or SARS, which had also emerged from China in 2002. SARS killed 774 people around the world.