FDA's latest warnings about eye drop contamination put consumers on edge − a team of infectious disease experts explain the risks

What has led to the spate of eye drop contaminations this year?

The recent alerts of eye drop contamination may be a result of several key factors.

First, the outbreak from February 2023 came to light when a previously unknown strain of antibiotic-resistant bacteria began cropping up across the U.S. Federal investigators were prompted to intervene, and they employed a sophisticated genomic fingerprinting approach to connect cases associated with contaminated eye drop use.

Second, more than 50% of drugs consumed in the U.S. are produced overseas, but at the height of the COVID-19 pandemic, the FDA sharply curtailed its ongoing inspections of international manufacturing facilities. Although the reduction in oversight was temporary, it may have allowed product contamination to go unchecked.

Finally, until this year, infections from contaminated eye drops were rare. Given the glaring sterility issues it found in the manufacturing process during its initial inspections, the FDA was prompted to do further investigation, and found yet more issues – which may have led to the increase in alerts.

Why is this type of bacterial contamination potentially dangerous?

Our bodies possess natural defense systems. Our skin, for example, acts as a barrier that stops bacteria from causing infections.

But eye drops containing pathogens can bypass these safeguards and introduce resistant bacteria directly into the susceptible environment of the eye. There, they can cause severe infections that are difficult to treat with conventional antibiotics.

This past February’s outbreak and the four tragic deaths resulting from it highlight the peril of bacterial contamination in consumer products. The specific strain involved – Pseudomonas aeruginosa – displayed an alarming resistance to multiple antibiotics, even those typically used as last-resort treatments.

This resistance makes it harder to treat these infections effectively. In response, some health care institutions are using experimental treatments like bacteriophage therapy as a way to combat these extremely drug-resistant pathogens. Essentially, phage therapy uses bacteria-killing viruses to treat antibiotic-resistant infections.

The contaminated eye drops were also free of preservatives, which further increased contamination risk. Preservatives help prevent the growth of harmful bacteria within eye drop containers.

Why might some of these products remain on shelves?

Recalling a product is typically a long and laborious process. When the FDA issues a recall notice, it must work with the manufacturing facility to track all affected batches. This requires the cooperation of multiple entities, including distributors and retail outlets, which must physically remove products from the shelves and online.

What’s more, a speedy removal of the eye drop products may be further hampered by the FDA’s lack of investigators, a decline that began in 2016. As the FDA continues to carry out inspections, more recalls could occur.

How can detection of these contamination issues be improved?

Unfortunately, contaminated medications and medical products are not uncommon. Just in 2023, a tuberculosis outbreak linked to contaminated bone graft material, as well as a large fungal outbreak related to epidural anesthesia, have occurred.

Detecting these cases is difficult. However, our research team performs genomic fingerprinting on nearly all bacterial infections at our hospital. Genomic fingerprinting lets researchers see if multiple patients have the same infection, which would indicate they are part of an outbreak. It is key to detecting outbreaks at an earlier stage.

In October, 2022, about four months prior to the announcement of the eye drop outbreak, our team found two cases of the drug-resistant bacterium Pseudomonas aeruginosa through genomic fingerprinting. Once the CDC shared details of its investigation, we were able to connect these patients to the larger outbreak.

If more hospitals and public health institutions adopted the use of genomic fingerprinting, outbreaks caused by contaminated medicine or procedures would be much easier to identify. While this approach requires initial investment of a few hundred thousand dollars for a large hospital, we and other researchers have shown that it’s cost-saving in the long run.

What do consumers need to do to protect themselves?

You can keep checking the continually updated list of potentially contaminated eye products, as provided by the FDA.

You can also subscribe to the FDA’s recall alerts on medications. If a medication that you’ve used or are now using is recalled, contact your health care provider. Consumers should also consult the FDA’s online warning and avoid purchasing eye drop brands that have been recalled or have been flagged as having contamination risk. The list of brands to avoid is being continually updated.

And before purchasing eye drops, or any over-the-counter medication, it’s a good practice to carefully read the product label. Check the expiration date and any warnings or usage instructions. If you have any questions or concerns about eye drops you are using, consult your doctor.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.