Of the 49 known infections with the MERS-CoV virus, 27 have resulted in death, the organization said.

The latest deaths were reported in Saudi Arabia.

The Saudi health ministry said Wednesday that three people died from their infections in the country’s eastern region…

It acts like a cold virus and attacks the respiratory system, the Centers for Disease Control and Prevention has said. But symptoms, which include fever and a cough, are severe and can lead to pneumonia and kidney failure.

Health officials do not yet know much about how the virus spreads, which makes it hard for scientists to prevent infections, Chan said.