If you have cats, you probably enjoy cuddling them. But a new study may make you think twice about those close encounters. New research shows that your cat may be hiding germs that can make you sick.

Cat-scratch disease (also called cat-scratch fever) is a bacterial infection spread by cats. The disease is caused by the bacteria Bartonella henselae spread by fleas. Cats get infected with the bacteria from flea bites and flea dirt (droppings) that gets on their fur and into their wounds, according to the Centers for Disease Control and Prevention. When cats bite and scratch at the fleas, the bacteria is picked up in their mouth and nails. The disease can then be spread to humans via a scratch or bite from an infected cat, or when an infected cat licks an open sore or wound on a person.

About 40 percent of cats carry the bacteria at some point in their lives, thought they likely will not show sign of illness, according to the CDC. Kittens under a year old are more likely to carry the bacteria and spread it to people because they often scratch and bite while playing.

Recently a team of epidemiologists with the CDC conducted a review of the disease. They analyzed health insurance claims from 2005 to 2013 and found that while the total number of people to contract cat-scratch disease has gone down, complications from the illness have risen dramatically.

Around 12,000 people develop cat-scratch disease every year. Symptoms of the condition include fever, fatigue and swollen lymph nodes. But in about 500 cases annually, complications arise that require hospitalization, such as swelling in the brain or heart. These more serious complications typically develop in people who are already immunocompromised, such as those with AIDS or those undergoing chemotherapy to treat cancer.

According to the review, the majority of those who contract cat-scratch disease are women or children — those who more likely to play with cats — and many are from the South, where fleas are most common.

To help lower your chances of catching cat-scratch fever, the CDC recommends washing cat bites and scratches right away with soap and water and always washing your hands immediately after playing with your pet. It's also key to keep cats on monthly flea prevention and have their claws trimmed regularly.