By Kate Kelland, Health and Science Correspondent
LONDON (Reuters) - Another three people in the United Arab Emirates are sick with the Middle East Respiratory Syndrome (MERS) virus and two people infected with it in Qatar have died, the World Health Organisation (WHO) said on Monday.
The new cases in UAE were in a family in Abu Dhabi - a mother, father and an 8-year-old boy - the United Nations health agency said in a disease outbreak update. The parents are both in a critical condition in hospital, the boy has mild respiratory symptoms.
The WHO said the mother gave birth while in hospital, adding the baby, other close family contacts and healthcare staff were being monitored and tested for signs of the virus.
MERS, which emerged last year and can cause coughing, fever and pneumonia, has killed almost 40 percent of the people it has so far infected around the world, with cases in countries across the Middle East as well as in Europe and north Africa.
The Geneva-based WHO says it has been informed of a total of 163 laboratory-confirmed cases of infection as well as at least a dozen probable cases, and 70 people have died.
Patients diagnosed and reported to date have had respiratory disease as their primary illness, the WHO said.
Diarrhoea is also commonly reported among MERS patients and severe complications include renal failure and acute respiratory distress syndrome (ARDS) with shock.
Scientists have been trying to work out the animal source of MERS virus infections since the first human cases were found in late 2012.
Qatari health officials said last week scientists had found cases of MERS in camels there, fuelling speculation that camels might be the "animal reservoir" of the virus that is passing into humans.
Saudi officials last month also said a camel there had tested positive for MERS a few days after its owner was confirmed to have the virus.
The WHO, which last week said there was not yet enough evidence to say what the source of the human MERS infections is, cautioned on Monday that people with underlying health conditions putting them at high risk of severe disease should "avoid close contact with animals when visiting farms or barn areas where the virus is known to be potentially circulating".
Human cases of MERS have so far been reported in Saudi Arabia, Qatar, Kuwait, Jordan, United Arab Emirates, Oman, Tunisia, France, Germany, Spain, Italy and Britain.
The WHO is due to hold its fourth emergency meeting on MERS on December 4 in Geneva.
(Editing by Janet Lawrence)