There have been 11 confirmed cases of the infection around the world. It causes pneumonia and sometimes kidney failure - five patients have died.
This is the third case identified in the UK. The first was a patient flown in from Qatar for treatment. The second was linked to travel to the Middle East and Pakistan.
The virus is then thought to have spread from the second patient to a close relative. There have been suggestions of person to person transmission in earlier cases in the Middle East, but this was not confirmed.