U.S. health officials are investigating whether a specific brand of over-the-counter eyedrops are behind one death and dozens of bacterial infections in several states.
The infections have not been traced to preservative-free EzriCare Artificial Tears, but a majority of people who became ill reported using the drops, the U.S. Centers for Disease Control and Prevention said in a statement.
The agency found the bacteria in bottles of the eyedrops, and it's now testing to see if the strain found in the eyedrop bottles matches that found in patients.
CDC officials recommended that "patients immediately discontinue the use of EzriCare Artificial Tears until the epidemiological investigation and laboratory analyses are complete."
At least 50 people in 11 states have been infected with the bacterium Pseudomonas aeruginosa, which is resistant to most antibiotics. One of those infected died after the bacterium entered the patient's bloodstream.
"That's what's so concerning," Dr. Jill Weatherhead, an assistant professor of tropical medicine and infectious diseases at the Baylor College of Medicine in Houston, told NBC News. "Our standard treatments are no longer available" to treat this infection.
In 11 cases, people developed eye infections. Three were blinded in one eye. Some of those infected had respiratory or urinary tract infections.
P. aeruginosa infections typically happen in hospital settings in people with weakened immune systems, though the bacteria can be found in water and soil. People can also carry it on their hands.
The eyedrops may have been contaminated during manufacturing or as a person with bacteria on their hands opened them. The drops being investigated do not contain preservatives to inhibit the growth of germs, NBC News reported.
Health officials have not said whether those infected had an underlying eye condition that would have made them more vulnerable to infections.
Cases were reported in California, Colorado, Connecticut, Florida, New Jersey, New Mexico, New York, Nevada, Texas, Utah and Washington.
EzriCare Artificial Tears have not been recalled at this time. They were sold on Amazon and at stores such as Walmart, NBC News reported.
Eye infection symptoms include pain and swelling. A person may experience redness, discharge, blurry vision, light sensitivity and the feeling of having a foreign object in the eye.
The U.S. National Library of Medicine has more on eye infections.
SOURCE: NBC News