And kissing kittens increases the risk of being infected.
“The scope and impact of the disease is a little bit larger than we thought,” says Dr. Christina Nelson, a medical epidemiologist with the Centers for Disease Control and Prevention and lead author on the study. It’s the first large-scale evaluation of the illness in the United States in over 15 years.
While the total number of people infected with the disease has gone down, the number of people becoming seriously ill has increased. Symptoms typically involve fatigue, fever and swollen lymph nodes. But in a small number of cases, cat-scratch disease can cause the brain to swell or infect the heart. Infections like those can be fatal if they aren’t properly treated.
“Most of the people who get seriously sick from cat-scratch are immunocompromised. The classic example is patients with HIV,” says Dr. Aaron Glatt, chairman of medicine and hospital epidemiology of South Nassau Community Hospital in New York. Glatt was not involved in the study
The fact that there are more people with suppressed immune systems today may be why a larger number of patients are getting dangerously ill, Glatt says. But Nelson thinks that severe cases of cat-scratch disease may have been misdiagnosed in the past. Either way, she says, this study, which was published Wednesday in Emerging Infectious Diseases, is a good first step.
“Cat-scratch is preventable,” Nelson says. “If we can identify the populations at risk and the patterns of disease, we can focus the prevention efforts.”
It’s preventable because you need direct contact with a cat to get it. The disease is caused by bacteria, usually Bartonella henselae, and passed between cats by fleas. The bacteria are also present in flea dirt — the official name for flea feces — which build up in the cats’ fur. It gets …