A second person has died in China from a mysterious SARS-linked virus that has stricken dozens and appeared in two other Asian countries, officials said.

An international team of scientists say they have identified a compound that can fight coronaviruses, responsible for the SARS and MERS outbreaks, which currently have no cure. 

Coronaviruses affected the upper and lower respiratory tracts in humans. They are the reason for up to a third of common colds. 

Three women have contracted the deadly MERS virus in Saudi Arabia, which has been hardest hit by the enigmatic disease, the World Health Organisation said Thursday.

One of the patients is a 67-year-old woman from Riyadh with underlying medical conditions, but who was not known to have come into contact with animals or another sufferer of the virus.

The new respiratory virus that emerged in the Middle East last year appears to make people sicker faster than SARS, but doesn't seem to spread as easily, according to the latest detailed look at about four dozen cases in Saudi Arabia.

Since last September, the World Health Organization has confirmed 90 cases of MERS, the Middle East respiratory syndrome, including 45 deaths. Most cases have been in Saudi Arabia, but the mysterious virus has also been identified in countries including Jordan, Qatar, Britain, France, Germany, Italy and Tunisia. MERS is related to SARS and the two diseases have similar symptoms including a fever, cough and muscle pain.

A deadly new respiratory virus related to SARS has apparently spread from patients to health care workers in eastern Saudi Arabia, health officials said Wednesday.

The Ministry of Health in Saudi Arabia told world health officials that two health care workers became ill this month after being exposed to patients with the virus. One is critically ill.

A "SARS-like" virus that has sparked a health alert by killing nine of the 15 people known to have contracted it infects the body via a docking point in lung cells, a study said Wednesday.

Tests on lab cells have highlighted a key entry point for the new virus and suggest bats may be a natural reservoir for it, investigators said.

A British resident has been diagnosed with a potentially fatal SARS-like virus, British health authorities said on Monday, in the 10th confirmed case worldwide.

The Health Protection Agency said the person, who recently traveled to the Middle East and Pakistan, was being treated at an intensive care unit at a hospital in Manchester, northwest England, after contracting novel coronavirus.

A Saudi man has been cured after he was diagnosed with a mystery illness from the same family as the deadly SARS virus and from which one person died, the kingdom's health ministry said on Sunday.

He was "diagnosed with a coronavirus infection at a hospital in Riyadh," the ministry announced in a statement reported by the official SPA news agency.