cat scratch disease

Cat scratch disease is an infection caused by the bacterium Bartonella henselae. It really is transmitted by cat scratches (kittens seem to be worse about it - maybe they just scratch more). It is not contagious from human to human.

One theory is that the cats might get it from their fleas, which carry the germ. The germ is found in the mouths of kittens, and presumably is transmitted to the claws during normal preening. It disappears from the mouth as the kitten grows older. The germ is also suspected to be transmitted through flea feces under the claws of cats. Now that new flea treatments make it possible to more or less rid cats of fleas, some infectious disease experts recommend flea treatment - especially if the cat lives with an immunocompromised patient (chemotherapy, HIV infection).

Classic cat scratch disease starts with the scratch, which heals without incident. Then a tiny sore is noticed at the site of the scratch. This happens from 7-12 days after the scratch. Then from 5 to 50 days after the sore appears, a local lymph node will be noticed to be swollen and perhaps a little tender, and less commonly, red.

Over the course of the next few weeks to a couple of months, the node goes through a cycle of growth, then stabilizing in size and softening to a very squishy consistency. Eventually the node shrinks back to normal size without any treatment. Surgeons are reluctant to drain these nodes because the incision can leave a chronic draining hole; for that reason these nodes are either left alone, aspirated (sucked out) with a needle, or removed entirely.

In the last couple of years, some doctors have again tried antibiotics for this infection, especially if the lymph node is very large and painful. Trimethoprim-sulfa (Bactrim®, Septra®), azithrocin (Zithromax®), and rifampin have been used. Again - cat scratch disease is not contagious from person to person, and you do NOT have to get rid of the cat! Only 5% of family members scratched by the same cat get cat scratch disease.

Preventive measures include

de-clawing and regular nail clipping for young cats
keeping the cats indoors
flea control
proper litter box handling, hand washing after handling or close contact with a cat (especially kittens)
washing any bites or scratches with soap and water

So now you know why your child's doctor may someday look knowingly at a little sore on the forearm, feel under the armpit, and ask your child, "What is your kitty's name?"

A recent report in the adult literature has apparently confirmed that at least in a series of adults, the cat scratch organism can produce an inflammation of the optic nerve which could cause some vision loss. Antibiotics were used to treat these patients, who largely recovered their visual acuity after some months. To repeat, this is from the adult literature, so I cannot vouch for its validity in children. However, if your child were to seem to have more systemic symptoms, such as fever, malaise, or any hint of decreased vision, I think I would advise ophthalmologic and perhaps infectious disease consultations.
Similarly, cat scratch disease should be considered for cases of new-onset seizures in children in the 5-12 year age group. One study stated that up to half of all new-onset seizures in this age range were associated with cat scratch disease.
Other interesting news: It turns out that the causative bacteria can be found in ticks as well; this may account for some infections in which there is no history of cat or dog exposure.

Site Information/Disclaimer