(Reuters) - A third patient in Britain has contracted a new SARS-like virus, becoming the second confirmed UK case in a week and showing the deadly infection is being spread from person to person, health officials said on Wednesday.
The latest case, who is a member of the family of another patient, brings the worldwide number of confirmed infections with the new virus - known as the novel coronavirus or NCoV - to 11.
Of that total, five have died. Most of those infected had recently travelled in the Middle East and three have been diagnosed in Britain.
NCoV was identified when the World Health Organisation (WHO) issued an international alert in September 2012 saying a virus previously unknown in humans had infected a Qatari man who had recently been in Saudi Arabia.
The virus belongs to the same family as SARS, or Severe Acute Respiratory Syndrome - a coronavirus that emerged in China in 2002 and killed about a tenth of the 8,000 people it infected worldwide. Symptoms common to both viruses include severe respiratory illness, fever, coughing and breathing difficulties.
The UK Health Protection Agency (HPA) said on Wednesday the latest patient, who is a UK resident and does not have any recent travel history, is receiving intensive care treatment at a hospital in Birmingham, central England.
"Confirmed novel coronavirus infection in a person without travel history to the Middle East suggests that person-to-person transmission has occurred, and that it occurred in the UK," said John Watson, the HPA's head of respiratory diseases.
He said the new case was a family member who was in close personal contact with another UK case confirmed on Monday and who may have been at greater risk of infection because of underlying health conditions.
Coronaviruses are typically spread like other respiratory infections such as flu, travelling in airborne droplets when an infected person coughs or sneezes.
Yet since the new virus was first identified in September, health experts say evidence of person-to-person transmission of NCoV has been limited.
Watson said the fact it had probably taken place in the latest two cases in Britain gave no reason for increased alarm.
"Although this case provides strong evidence for person-to-person transmission, the risk of infection in most circumstances is still considered to be very low," he said.
"If novel coronavirus were more infectious, we would have expected to have seen a larger number of cases than we have seen since the first case was reported three months ago.
The WHO said on Monday that the confirmation of a new British case did not alter its risk assessment but "does indicate that the virus is persistent".
The British patient confirmed on Monday had recently travelled to Saudi Arabia and Pakistan, and is also receiving intensive care treatment in hospital, the HPA said.
Among the 11 laboratory confirmed cases to date, five are in Saudi Arabia, with three deaths; two are in Jordan, where both patients died; three are in Britain, where all three are receiving treatment; and one was in Germany in a patient from Qatar who had since been discharged from medical care.
The WHO reiterated on Monday that at this stage there was no need for any travel or trade restrictions, or for any special screening at border points.
(Reporting by Kate Kelland; Editing by John Stonestreet)