Written by Staff Writer

Based on the outbreak of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) in Saudi Arabia, people think it's a bird flu virus.

But, it's not. It's a new kind of virus. The WHO explains how it works.

The WHO said it has received reports of 90 probable human cases and 40 confirmed deaths from the virus in Saudi Arabia and are warning that "mortality rates are increasing and new cases are increasingly being reported outside of the Middle East."

The research team isn't limiting its study to the Middle East: people have also been infected with the virus in France, South Korea, Hong Kong, England, France, Italy, Greece, Spain, Germany, Switzerland, Malaysia, Austria, South Africa, and Turkey, they said.

Saudi Arabia has one of the highest rates of these infections, and on February 5, officials announced that a second case was diagnosed, Reuters reported.

CNN Staff Writer Dr. Sanjay Gupta said Thursday that the new MERS strain, "like previous flu viruses like the H1N1, is distinct from the [human-to-human] "swine flu" that swamped the U.S. in 2009 and that no vaccines or treatments have been developed.

Coronaviruses are a family of viruses, similar to the influenza that causes colds, said Charles-Edouard Monseau, a professor of virology at the Institut Pasteur in Paris.

The coronavirus is common and spread easily between birds, Monseau said. But, "it looks like in humans we have things going for us."

For example, the virus is zoonotic -- meaning it is spreading through a different species -- rather than being transported from person to person, he said.

Monseau added that the virus seems to be more infectious, or less "geopathic," than influenza viruses, because the body doesn't become "drowsy" from the virus infection.

The virus that has caused the current MERS outbreak is known as SA330 or the MERS-CoV, Monseau said. The virus was first reported in 2011 in the eastern region of Saudi Arabia.

When the virus was discovered, an initial analysis by the WHO showed it had a high mortality rate. (A 10% rate in humans is considered to be high.)

The WHO said the rise in cases was likely due to the introduction of another coronavirus into the population in previous years, which may have caused the virus to mutate. This new pathogen could have evolved to be more infectious than SA330.

The increase in MERS infections in recent months could also be due to a "mixing" of another strain of SA330 with the virus circulating in the region around that time, the WHO said.

About two weeks ago, a Chinese woman died of a different respiratory virus. There have been no reported cases of MERS in China.

The WHO and other international health bodies have long warned about the potential of a "new influenza pandemic" in the coming years.

The odds of a serious illness related to an influenza virus, such as pneumonia, remain very low, Monseau said.

The WHO has responded to this latest outbreak by putting together a group of international experts, including practitioners, virologists, and public health specialists, to discuss potential approaches to preventing MERS and to its spread and to mitigate its impact.