According to the Centers for Disease Control and Prevention (CDC), up to 12000 Americans per year are being exposed to a type of deadly bacteria carried by cats and kittens.
Bartonella henselae is a rare type of bacteria that is carried in the mouths and claws of cats, which means that a simple scratch or bite could actually result in a deadly disease known as ‘cat scratch disease’.
If a cat scratches or bites hard enough to break the skin, infection is easily transferred to humans.
Where does it come from?
The bacteria’s origin has been difficult to trace, but it has been confirmed that it can be passed on from cat to cat.
Approximately 40% of all cats carry the bacteria at some point in their lives but because there are no symptoms in animals there’s no way of knowing which one have it and which ones don’t.
Cats can transfer the disease to each other through licking, scratching, biting, and through open wounds that are exposed to fleas and flea droppings. By scratching and biting at flea bites, infected flea droppings can enter open wounds or be swallowed, which can cause the spread of the disease between cats. 
Kittens have the most concentrated amount of Bartonella henselae in their blood and are the most playful, which is why they are the most likely culprits for spreading the infection to humans. Unfortunately, they are also the most adorable to play with.
While animals are not affected by it, the bacteria can cause chronic infections in humans and could even be fatal.
What are the symptoms?
Bartonella infection can cause headaches, fever, the swelling of the brain and lymph nodes, bone pain, and heart infection. It can also cause painful and itchy skin or a rash around the affected area.
Dr. Christina Nelson of the CDC says: “The scope and impact of the disease is a little bit larger than we thought.”
Dr. Aaron Glatt, the chairman of medicine at South Nassau Community Hospital in New York, said that people who have weakened immune systems, like HIV patients, are reporting even more serious complications from cat scratch disease.
“Most of the people who get seriously sick from cat-scratch are immunocompromised, the classic example being patients with HIV,” she said.
These extreme cases can be fatal.
What can be done about it? 
Infection data was tracked between 2005 and 2013, which showed that an average of 12000 Americans are affected by cat scratch disease every single year and that 5% of infected people end up being hospitalized.
The CDC said that children were the most susceptible to infection, but that the numbers were steadily decreasing.
Officials are now urging cat owners to wash their hands as often as possible and to avoid cuddling their pets in order to try to curb the number of outbreaks.
Do not allow cats to lick your open wounds, do not play roughly with them, and ensure that flea control measures are in place if they have them. It’s also advisable to keep their nails trim and to wash any bites or scratches with soap and water immediately if it does occur.
Sources:
https://wwwnc.cdc.gov/eid/article/22/10/16-0115_article?ncid=txtlnkusaolp00000618
https://www.medicinenet.com/cat_scratch_disease/article.htm
https://www.cdc.gov/bartonella/symptoms/
https://www.healthline.com/health/cat-scratch-disease
https://medlineplus.gov/ency/article/001614.htm
