With one-third of the households in the United States having cats as pets totally approximately 60 million, human exposure to cats can occasionally result in a variety of infections.

Photo/Robert Herriman
Photo/Robert Herriman

Infections from cats can be from bites and scratches, from their contaminated feces, from vectors living on their body and from microorganisms found on their coat.

Bites and scratches are a frequent occurrence from playing around with your cat. Cat scratch disease is one which is usually associated with young, newly acquired cats and strays. Bacteria from the genus Bartonella are the frequent offenders.

People typically get infected from a bite, scratch or a lick. It is usually a benign, self-limiting disease in immunocompetent people. Frequently only flu-like symptoms and a red papule lesion at the site of the scratch are present.

Rare complications may occur such as encephalopathy.

Diagnosis is made on symptoms and history of contact with an immature cat. Laboratory diagnosis is infrequently pursued.

Another relatively common infection as the result of a cat bite is Pasteurella multocida infection. This organism is found in the mouth of basically all cats. In addition, when cats lick their paws, the organism gets onto their claws.

While many cat bites or severe scratches never get infected, when they do it is something that requires medical attention. While dog bites are also implicated inPasteurella infections, cat bites become infected more frequently.

Their teeth are small but very sharp and a bite to the hand can easily penetrate joints, bones and tendons. Infections start as a cellulitis and can spread to the bloodstream, cause infections in the joints and bones and sometime central nervous system infection.

Pasteurella can easily be diagnosed by culture and a history of cat or dog bite.

Both Bartonella and Pasteurella are treatable with antibiotics.

Other diseases that can be transmitted through a cat bite are rabies, Erysipelothrix and mixed bacterial infections.

Cats may have an assortment of fungi on their coats and skin. These are transmitted to people through direct contact. Most common are the fungi that cause ringworm.

Also humans can get infested with cat scabies and the mite Cheyletiella.

There are numerous intestinal parasites and bacteria that cats may harbor which people can inadvertently get infected.

Bacterial pathogens such as Campylobacter and Salmonella can be found in cat feces.

Related: Infections you can get from dogs

With Campylobacter, young, newly acquired cats tend to be carriers.

Around 20% of normal, healthy appearing cats may be infected or carriers of Salmonella when their diet is other than commercial foods.

To help avoid getting these infections, wash your hands after handling the animal or their waste. Do not feed them raw meats or other infected foodstuffs. However, outdoor cats may still get infected when eating live prey like birds.

Parasites that can be transmitted to humans include Cryptosporidium, Toxoplasmosis, Toxocara cati, hookworms and other intestinal parasites.

People rarely get a respiratory illness from cats called Bordetella bronchiseptica. This organism is related to the one that causes pertussis. In dogs its causes Kennel cough.

In cats it is less prominent. Fever, nasal discharge and sneezing may be symptoms the cat will show.

The ticks found on cats can sometimes carry disease that can infect humans. Ehrlichia, Q fever and other Rickettsial infections are possible.

There are vaccinations and medications for your cat against some of these infections I’ve mentioned.

Of special note is the care that someone with a compromised immune system should take when dealing with cats. What may be simple, self-limiting disease in the immunocompetent, can be very severe in the immunocompromised.

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