A new deadly respiratory virus related to SARS has killed half the people known to be infected and is a "threat to the entire world," according to the United Nations' World Health Organization.
The worldwide death toll has hit 23 out of 44 people known to have been infected with the new virus. The 23rd victim was a French patient who died Tuesday of the disease.
The novel coronavirus is related to SARS, which killed some 800 people in a global epidemic in 2003. Dr. Margaret Chan, head of the World Health Organization, singled out the illness in a speech on Monday in Geneva.
"We understand too little about this virus when viewed against the magnitude of its potential threat," Chan said at the annual WHO meeting. "We do not know where the virus hides in nature. We do not know how people are getting infected. Until we answer these questions, we are empty-handed when it comes to prevention. These are alarm bells. And we must respond."
Most of those infected since the virus was identified last year had traveled to Qatar, Saudi Arabia, Jordan or Pakistan. There also have been cases in Britain and Germany.
The ministry said the Frenchman, whose illness was identified May 8, had recently returned from a visit to the United Arab Emirates. His hospital roommate also tested positive for the illness.
Meanwhile, the Saudi Health Ministry reported five new cases of the virus. All the patients were in their 70s or older.
Symptoms of the new virus resemble those of a common cold and include fever, cough, which can then lead to pneumonia and kidney failure. Gastrointestinal symptoms such as diarrhea have also been reported, according to the WHO.
Based on reporting by The Associated Press.