Two people who died in Jordan in April have been found to have been infected with the new virus from the same family as SARS which sparked a global alert in September, the World Health Organization (WHO) said on Friday.
The coronavirus, previously unknown in humans, has now been confirmed in a total of nine people in three countries in the Middle East region, including a Saudi who had severe acute respiratory illness last month, the United Nations agency said.
But the two fatal cases in Jordan, confirmed in samples just retested by a WHO collaborating laboratory in Egypt, do not change WHO's assessment that the virus does not appear to spread easily between people, if at all, spokesman Gregory Hartl said.
"These Jordan cases don't change our risk assessment at the moment. We haven't seen any new pattern. These are old cases," Hartl told Reuters.
In a statement, the Geneva-based WHO said: "Two fatal cases in Jordan have been reported to WHO today, bringing the total of laboratory-confirmed cases to nine."
Initially, the samples had tested negative for known coronaviruses and other respiratory viruses in April.
"As the novel coronavirus had not yet been discovered, no specific tests for it were available," the agency said.
The new virus shares some of the symptoms of SARS, or Severe Acute Respiratory Syndrome, which emerged in China in 2002, spread easily among people and killed around a tenth of the 8,000 people it infected worldwide.
"Based on current information, it does not appear to transmit easily between people, unlike the SARS virus," WHO said.
The new virus can appear to be pneumonia and acute kidney failure has occurred in five cases, the WHO said.
In all, five cases of the new virus, including three deaths have been confirmed in Saudi Arabia, including three patients in one family, it said. Two cases have been confirmed in Qatar, and both are recovering, while both cases in Jordan were fatal.
The Jordan cases were among a total of 12 cases of severe acute respiratory illness that erupted last April linked to a hospital in Zarqa some 40 kilometers (24 miles) outside Amman, Hartl said. Most were health workers, he added.
"The link is the hospital. It could be some environmental thing or human-to-human transmission," he said.
"The main thing is the fact that even if it were human-to-human transmission, which we don't know, it doesn't seem to spread very well or efficiently," Hartl said.
The two so-called "clusters" of cases, in Saudi Arabia and Jordan, raised the possibility of "limited human-to-human transmission", or exposure to a common source, the WHO said.
"Ongoing investigation may or may not be able to distinguish between these possibilities," it said, noting some viruses are transmitted within families but are not transmissible enough to cause large community outbreaks.
The WHO urged health authorities in its 194 member states to continue surveillance for the new virus and investigate any unusual patterns.
"Testing for the new coronavirus of patients with unexplained pneumonias should be considered, especially in persons residing in or returning from the Arabian peninsula and neighboring countries," it said.