The number of people with highly drug-resistant bacterial infections linked to contaminated eyedrops has reached 81, the Centers for Disease Control and Prevention reported Friday.
The 81 cases, up from 68 identified in March, include 14 people who have been blinded and four others who had to have their eyeballs surgically removed.
Though most infections have been limited to the eyes, the bacteria can be fatal when it enters the bloodstream. As of Monday, the CDC said, four people have died.
"These were catastrophic and life-altering infections," Maroya Spalding Walters, who leads the CDC's antimicrobial resistance team, said in an interview.
Though many patients said they’d used multiple brands of eyedrops, EzriCare Artificial Tears was found to be a common brand among those infected. Opened bottles of the EzriCare eyedrops were also found to harbor the same bacteria found in samples taken from patients.
The EzriCare products were manufactured by Global Pharma Healthcare in India and sold mostly online. The CDC and FDA said people should stop using them, as well as two other eye products made by the same manufacturer: Delsam Pharma’s Artificial Tears and Delsam Pharma’s Artificial Eye Ointment.
The CDC expects the case count to rise, although the rate has slowed since Global Pharma recalled all three of those products in February.
The infections come from a specific strain of Pseudomonas aeruginosa bacteria that has proven difficult, if not impossible in many cases, to control with standard antibiotics.
Before last year, this particular form of the bacteria had never been reported in the United States.
Now, cases have been discovered in 18 states: California, Colorado, Connecticut, Delaware, Florida, Illinois, North Carolina, New Jersey, New Mexico, Nevada, New York, Ohio, Pennsylvania, South Dakota, Texas, Utah, Washington and Wisconsin.
The initial infections started popping up last year.
Cases were first investigated in Connecticut early last summer. Doctors in Miami started seeing such infections late last summer. An Ohio woman became infected in November.
Some cases occurred among clusters of people living in long-term care facilities, the CDC said, even among patients who never used artificial tears.
Sometimes, the bacteria can enter a person's body through the eyes via the eyedrops but never affect the eyes.
Those bacteria can then set up shop in the body, colonizing in the respiratory or digestive systems for months without making the person sick.
That bacteria, however, can be transmitted to others through shared medical equipment, for example.
The Food and Drug Administration has also been leading an investigation into the contaminated drops. But the agency's last update on the matter was Feb. 22.
The FDA did not respond to requests from NBC News for a more recent update.
Both the CDC and FDA have urged consumers to stop using any of the recalled products.
"Make sure that these recalled products are not still present, aren't hiding on a shelf," Spalding Walters said. "Anytime a product is recalled, there's always a chance that it's going to be still in homes and be used months or years down the road."
Symptoms of an eye infection include:
- Yellow, green or clear discharge from the eye.
- Eye pain or discomfort.
- Redness of the eye or eyelid.
- Feeling of something in your eye (foreign body sensation).
- Increased sensitivity to light.
- Blurry vision.
Follow NBC HEALTH on Twitter & Facebook.