(WFLA) — U.S. officials are reporting two more deaths and additional cases of vision loss linked to eyedrops tainted with a drug-resistant bacteria.

The outbreak has infected 68 people in 16 states, according to the latest update from the Centers for Disease Control and Prevention. The bacteria has now caused a total of three deaths and eight cases of people losing their vision, the Centers for Disease Control and Prevention reported on Tuesday. That’s up from one death and five cases of permanent vision loss reported last month.

The CDC said four people have undergone surgery to remove an eyeball due to the infections.

The CDC said it is investigating the outbreak of an extensively drug-resistant strain of Pseudomonas aeruginosa. Health officials said the stain, called VIM-GES-CRPA, had never been reported in the United States prior to the outbreak.

“Most patients reported using artificial tears,” the CDC said. “Patients reported over 10 different brands of artificial tears and some patients used multiple brands. EzriCare Artificial Tears, a preservative-free, over-the-counter product packaged in multidose bottles, was the brand most commonly reported.”

Eyedrops from EzriCare and Delsam Phama were recalled in February and health authorities are continuing to track infections as they investigate the outbreak.

The CDC said it is still testing unopened bottles to see if they were contaminated during manufacturing.

The CDC and the Food and Drug Administration recommend clinicians and patients stop using EzriCare or Delsam Pharma’s artificial tears products.

According to health officials, those who have used EzriCare or Delsam Pharma’s artificial tears and have signs or symptoms of an eye infection should seek medical care immediately.

According to the CDC, eye infection symptoms may 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

“At this time, there is no recommendation for testing of patients who have used this product and who are not experiencing any signs or symptoms of infection,” the CDC said.

The recalled drops were manufactured by Global Pharma Healthcare in India, where the bacteria — Pseudomonas aeruginosa — is commonly linked to outbreaks in hospitals. It can spread through contaminated hands or medical equipment.

The FDA recently posted recall notices for two other types of eye drops from Pharmedica and Apotex for non-sterility concerns. The drops have not been linked to the VIM-GES-CRPA outbreak.

The Associated Press contributed to this report.