A man lost part of his vision due to cat scratch disease, a rare infection that can be spread by kittens
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- A man who partly lost his vision while driving turned out to have cat scratch disease.
- Doctors diagnosed him after learning he had recently adopted a cat, according to a case report.
- Cat scratch disease infects about 12,000 people a year in the US, but it's usually mild.
Cat lovers know to expect the occasional scratch from their furry friends. It's an occupational hazard when you invite a skilled predator (albeit a cute one) into your home.
But sometimes, a cat's scratch can make a human sick with potentially serious complications. One new cat dad learned this the hard way when he experienced partial vision loss while driving, according to a description of his case recently published in the American Journal of Case Reports.
The 47-year-old man, who was unnamed in the report, had adopted his cat about two months before he started feeling ill. He visited his doctor because he had recurring fevers and a constant headache for a week, but the doctor said his symptoms could be related to a previous COVID-19 infection.
As he was driving home from the doctor's office, however, the man abruptly lost his vision on his left side. He re-routed to the local emergency department, where he was eventually diagnosed with cat scratch disease with associated swelling around his optic nerve.
Cat scratch disease actually comes from fleas, and rarely sickens cats
Cat scratch disease is caused by a type of bacteria called Bartonella henselae, which may be spread to cats via flea bite.
Although 40% of cats carry the bacteria at some point in their lives, according to the Centers for Disease Control and Prevention, most of them do not show symptoms and rarely spread the infection to humans.
Cats that go outside or have been recently adopted are more likely to have the bacteria from contact with fleas, according to the Cleveland Clinic. Kittens younger than 1 year are also more likely to spread it through rough play, or if they lick an open wound.
In humans the disease can cause fever, exhaustion, and swelling
About 12,000 people are diagnosed with cat scratch disease each year in the US, according to Cleveland Clinic. The disease is also called cat scratch fever, lymphoreticulosis, and felinosis.
Most cases consist of fevers, exhaustion, mild swelling at the scratch site, and swollen lymph nodes; more rarely, the infection can spread to the brain, eyes, or heart. The CDC says symptoms may start between 3 and 14 days after the initial scratch.
Because the man described in the case report didn't have swollen lymph nodes and mainly reported headaches and light sensitivity, the doctors' main concern was meningitis. But when he was negative for the brain infection, and mentioned that his new cat had been scratching him often, the medical team made the connection.
The patient eventually tested positive for Bartonella henselae and was also diagnosed with neuroretinitis, or a swelling of the nerve in the retina that connects the eye to the brain.
Cat scratch disease can be treated with antibiotics, which cured the man's fever and headache. However, his visual field loss was only partly resolved. According to the case study authors, his case underscores the need to treat cat scratch disease promptly for the best possible recovery.