(NEXSTAR) — The Centers for Disease Control and Prevention is asking people to stop using a brand of artificial tears that could be behind dozens of infections across the U.S.

The CDC says lab and epidemiological evidence have tied the use of EzriCare Artificial Tears to a multi-state cluster of Pseudomonas aeruginosa patients, but the investigation is ongoing and there is not yet a definite link.

Pseudomonas aeruginosa bacteria live in the environment, are highly resistant to antibiotics and can cause infections in the blood, lungs (pneumonia) and other body parts. Often these cases occur after surgery.

The CDC is investigating at least 50 cases in 11 states that have led to hospitalization, permanent vision loss and even one death. The cases are located in California, Colorado, Connecticut, Florida, New Jersey, New Mexico, New York, Nevada, Texas, Utah and Washington.

While working to determine the cause of the illnesses, CDC investigators found that the majority of people used artificial tears, with EzriCare being the most popular brand. Investigators identified the drug-resistant bacteria in open bottles of the drops, the CDC said. Testing of sealed bottles is ongoing.

“CDC recommends that clinicians and patients immediately discontinue the use of EzriCare Artificial Tears until the epidemiological investigation and laboratory analyses are complete,” according to a Jan. 20 news release.

EzriCare said in a statement Wednesday that they were not aware of any testing that definitely linked the eye drops to Pseudomonas aeruginosa, but said they stopped selling the product.

“To the greatest extent possible, we have been contacting customers to advise them against continued use of the product, the company said in a statement on its website. “We also immediately reached out to both CDC and FDA and indicated our willingness to cooperate with any requests they may have of us.”

A 2019 report found that 2,700 people in the U.S. died from Pseudomonas aeruginosa infections and another 32,600 were hospitalized.