Two more Americans have died after being infected with Pseudomonas aeruginosa, a drug-resistant bacteria linked to recalled eye drops, according to the Centers for Disease Control and Prevention (CDC).
The bacteria has now been detected in 16 states, the CDC reports in its latest update on the outbreak, with the only previous fatality out of 68 cases claiming a man in Washington State.
However, a further eight patients from that total have reportedly permanently lost their vision and four have had to have eyeballs removed.
According to CNN, the eye care product thought to link the cases is Artificial Tears Lubricant Eye Drops, which is manufactured by Indian company Global Pharma Healthcare and distributed in the US by EzriCare and Delsam Pharma.
It was first recalled from over-the-counter sale in early February as a precaution while public health investigators raced to track the bacteria.
Delsam’s Artificial Eye Ointment was also recalled shortly after at the recommendation of the US Food and Drug Administration, while two more eye drops ranges from Pharmedica USA and Apotex have also been temporarily withdrawn, although neither has been linked to the present outbreak.
The CDC advises in its release that patients who have used any of the recalled products and subsequently experience signs or symptoms of an eye infection should seek medical attention immediately.
It lists the symptoms to watch out for as yellow, green or clear discharge from the eye, any pain, discomfort or redness around the eye and increased sensitivity to light or blurry vision.
The particular Pseudomonas aeruginosa strain involved in the outbreak is regarded as extremely rare and has never before been detected in the US, the CDC says.
It has proven to be immune to the effects of at least 12 different antibiotics in laboratory testing, making it difficult to tackle, although the public health body states that researchers at the University of California at San Diego have identified a bacteriophage that could work against it.
“The approach we take is that we respond to inquiries from physicians about patients they feel might benefit from phage therapy and, if it appears that phages might be beneficial in a particular patient, we work with the physician,” Dr Robert Schooley, co-director of the university’s Center for Innovative Phage Applications and Therapeutics, told CBS News.
He added that no patients have yet received the phages treatment as his team were still navigating the “intricacies of obtaining and using them”.