Noah McCrory
Two dogs treated at a New Jersey veterinary hospital last year tested positive for a rare, drug-resistant strain of bacteria linked to a fatal outbreak attributed to now remembered eye drops that has been used in humans, a CDC investigator said Friday.
The animals were infected by a bacteria known as carbapenemase-resistant Pseudomonas aeruginosa, found in lung and ear swabs from two dogs owned by different owners at the hospital.
Tests of the dog bacteria found it was “highly genetically related” to the germs behind an outbreak last year who finally fell ill 81 human patients in 18 states. At the end of this outbreak, 14 patients lost their vision and four died.
Germs that produce carbapenemases are of particular concern to health officials, in part because they can break down carbapenem antibiotics, a class of drugs normally reserved for infections resistant to other treatments, and can easily spread their resistance genes to other pathogens.
“So now that this bacteria has been introduced into the U.S. from artificial tears, this resistance could spread,” the CDC’s Emma Price said Friday, presenting her team’s report. discoveries at a conference of the agency’s Epidemic Intelligence Service.
The CDC charges its Annual conference as a gathering of the agency’s up-and-coming “disease detectives,” providing updates on their work on a range of investigations and studies.
Price said one of the dogs was examined while being treated at the hospital to try to diagnose a chronic cough. For the other dog, veterinarians were trying to figure out the culprit of a persistent ear infection.
The swabs were sent to an academic veterinary laboratory in Pennsylvania, which detected unusual signs of resistance in the germs and uploaded the strain’s genetic sequence to a national database — prompting the CDC and state health officials to launch an investigation.
“Because they had a grant and a veterinary microbiologist works there, he did his due diligence and uploaded the results. That’s how we got the notification, because the strain matched the outbreak strain,” Price said.
However, the human eye drop outbreak also prompted an industry-wide crackdown by the Food and Drug Administration, causing millions more bottles of over-the-counter brands to be pulled from shelves and banned from import.
The initial outbreak was traced to contaminated eye drops produced at a factory in India where the Food and Drug Administration inspectors finally found dirty equipment and a long list of shortcuts in hygiene procedures. Other factories have also revealed troubling issues, ranging from barefoot workers to falsified records.
The FDA issued this year a warning to veterinary hospitals and pet owners, asking them to check their supplies for recalled eye drops following a report of infection.
“The adverse event occurred in a cat that developed an eye infection after being treated with the eye drops. However, tests were unable to conclusively prove that the eye drops caused the infection,” an FDA spokesperson told CBS News in March after the warning. .
Price said interviews with the two pet owners revealed no obvious explanations for how the drug-resistant germs got into their dogs. None of them have traveled internationally or visited human hospitals.
“None of the dog owners remember using tears [eye drops]although we recognize the difficulty of remembering the past year,” Price said.
Both pets eventually recovered and are now doing well, Price said. But his findings worried investigators, who found gaps in the veterinary hospital’s infection prevention routines. This could have provided a pathway for the germs to spread to employees or other pets.
Hospital staff had “limited” options for hand hygiene, falling short of recommendations to offer hand sanitizer in all treatment areas.
“There was also limited availability and just a general lack of use of personal protective equipment, especially gloves,” Price said.
Other possible bacterial fermentation sites included equipment shared among employees that also had “visible dirt and dust accumulation” and supposedly clean supplies stored in the splash zone of the sinks.
“These findings are not specific to this hospital. This is part of a broader lack of emphasis on infection prevention and control in the veterinary setting,” Price said.
One of the dogs also lives at home with three other pets, she said, raising concerns that the drug-resistant bacteria may have “colonized” the dog long-term and could eventually spread to other people.
Human patients are sometimes colonized for months or years by Pseudomonas aeruginosa infections, according to for the CDC.
“Fortunately, the owners were not immunocompromised, but we alerted them to the fact that there could be potential transmission to them and to alert their doctors as well for future health appointments,” Price said, “and ideally keep the dogs away from other dogs in the future, which we understand is a difficult thing to do.”
