There are now three confirmed cases of the MERS virus in the US. The US Centers for Disease Control (CDC) announced today that an unidentified Illinois man tested positive for the deadly respiratory virus yesterday, two weeks after the first confirmed case of MERS in the US.

According to the CDC, the man was in close contact with the Indiana patient who was the first in the US to officially contract the virus. Before the first patient knew that he had MERS, he held a 30- to 40-minute, face-to-face business meeting with the man from Illinois, according to NBC News. This marks the first known transmission of the virus on US soil — the other two patients are thought to have contracted the virus abroad.

The CDC and state officials have been working to contain the virus by tracking down anyone who was in contact with the confirmed cases. The third patient was confirmed through this process — a test on May 5th came up negative, and a follow-up exam yesterday was positive. While he's confirmed to have the virus, the CDC says that he "did not seek or require medical care" and "is reported to be feeling well."

MERS was first discovered in Saudi Arabia in 2012, and it has since claimed 173 lives. About a third of those who have contracted the virus have been killed by it, but it is not as contagious as some other viruses. Known cases mostly involve the elderly or young, and it seems to pass only through close, sustained contact.