An outbreak of SARS, or Severe Acute Respiratory Syndrome, emerged in 2002 and eventually killed 800 people.
The Qatari patient was admitted to a Doha hospital on Sept. 7 and later rushed by air ambulance to a specialized British clinic suffering from acute respiratory infection and kidney failure.
While no link has been detected between the Qatar and Saudi cases, the coronaviruses responsible were found to be nearly identical and of a type never before seen in humans.
Coronaviruses are responsible for the common cold and can also lead to more severe illnesses such as SARS.
There is so far no evidence of sustained human-to-human transmission that could bring on a pandemic.
Experts say that the low number of cases and distribution of the new virus could mean that this is some rare event that in past times, before genetic analysis was available, might have gone undiagnosed.