One of six identified types of the human coronavirus. The technical classification of the 2012 strain that erupted in Saudi Arabia is HCoV-EMC. At least 33 people have been infected and 18 of those cases were fatal. CDC

The World Health Organization now suspects that the novel coronavirus (NCoV) is being passed person-to-person, a condition that would significantly raise concerns that the potentially fatal virus could be more easily spread than the unrelated H7N9 or other avian bird flu virus strains that are currently known to be contracted only by contact with infected fowl.

The suspicions have been raised after health authorities in France confirmed a second case of the virus and Saudi authorities announced two more deaths caused by NCoV infection.

Since 2012, the number of infections has been small -- only 33 in Europe and the Middle East, led by 24 cases in Saudi Arabia -- but the fatality rate is high with 18 deaths, also mostly in Saudi Arabia. The WHO is calling for countries to step up monitoring for the virus in order to identify clusters as early as possible.

So far cases outside of the Arabian Peninsula have been found in France, Germany, the UK and Jordan. The first case emerged in Abu Dhabi in June 2012.

“The different clusters seen in multiple countries increasingly support the hypothesis that when there is close contact, this novel coronavirus can transmit from person to person,” the WHO said in a statement released Sunday. “There are many other things that we don’t understand. For example, how are people getting infected? Is it from animals? Is it from contaminated surfaces? Is it from other people? Finally, we don’t know how widespread is this virus, both in this region and in other countries.”

The second confirmed case in France was identified as that of a 50-year-old man who shared a room with a 65-year-old man who is believed to have contracted the virus on a trip to Dubai.

The Saudi Ministry of Health said Sunday that two more people have died from the infection in a cluster discovered in Al-Ahsa, in the country’s Eastern Province, where nine of the 15 fatalities in the country have been reported.

Most cases have been found in older males. The virus causes extreme pneumonia and in some cases kidney failure.