The U.S. Centers for Disease Control and Prevention said on Friday 100 people who may have had contact with an unidentified virus, which shares similarities with the Zika virus, have been identified. The 100 people infected with the new virus are in various stages of illness and no deaths have been reported, the CDC said. The CDC said it is still investigating many more cases, and there is no current information linking the new virus to Zika virus. Previously, a separate strain of the virus was diagnosed in Chicago and Texas.

“We are in the process of gathering additional information about the origins of this virus,” the CDC said in a statement. “Based on what we know, the odds of catching this virus if you have no symptoms are very low. The risk is very low. This virus does not cause illness and has caused no known long-term health problems for most people who have been infected.”

While Zika virus is transmitted by a mosquito that spreads the disease, the new virus is thought to have entered the human population via human carrier, meaning it could be transmitted via person-to-person transfer. The CDC said the new virus differs from other similar cases, such as the “ring of illness” that was tied to cases of Zika in Texas. The CDC urged doctors to be on the lookout for cases.