In general, the chances of a cat transmitting contagious diseases to humans are quite low, especially cats that are raised indoors and have no contact with the outside environment. However, there are some contagious diseases that cats can transmit to humans, these are called zoonoses. That is, any disease that can be transmitted from animals to humans is called a zoonosis.
First of all, if you don't want to adopt a cat, don't look for the excuse "I can get sick from the cat". You are much more likely to contract a disease from your fellow humans than from a cat or dog. As a short parenthesis, if you adopt a cat from the street, it is highly advisable to first take it to a veterinary office for deworming and analysis.
Going back to zoonoses, cats can transmit some pretty serious diseases to humans if the cat is sick and you come into direct contact with it.
The main contagious diseases that cats can transmit to humans (zoonoses)
Parasitic, fungal and parasitic diseases are the main zoonoses that humans can get from cats.
Toxoplasmosis is the most common of the contagious parasitic diseases that cats can transmit to humans, cats being the only living mammals that can carry this parasite. However, in order for a cat to contact the parasite Toxoplasma gondii, it must consume raw meat in which this parasite is found. So, it is unlikely that a house-raised cat will be able to contact this parasite. In addition, humans cannot get this parasite from the cat unless they come into direct contact with the cat's feces.
Read about toxoplasmosis in cats: Cats and pregnant women. Should the cat be removed?
Cat Scratch Disease is one of the contagious diseases that cats can transmit to humans. Infection occurs from cat scratches if the cat is carrying the bacteria or if it is stroked after the cat has washed its fur and left saliva on it.
Read about: Cat Scratch Disease. What it is and how it manifests itself.
Ascariasis (intestinal worms, known as roundworms), can be classified among the most common contagious diseases that cats can transmit to humans.
Ascariasis is caused by Toxocara cati. The eggs of the parasite are passed from the cat's intestine in the faeces and develop into second-stage larvae (the infective form for humans). Transmission to humans is achieved by not washing hands after handling cat feces. While adults can be asymptomatic, severe forms can occur in children, especially at the eye level, which can lead to blindness.
Mycosis and eczema are common and are contracted through direct contact with the secretions, fur and skin of the sick animal. In the category of fungal diseases, dermatomycoses are included. Microsporia, a contagious disease that affects the superficial layer of the skin and hair, is more common in children who play with cats, but it can also affect adults. The condition is easily passed down within the same family. In children, the fungus affects the scalp in the form of large, round plates covered with scales, and the hairs break from the root. In adults, the fungus appears as a herpes surrounded by inflammation.
Another contagious disease is favus, a dermatomycosis of the scalp and hairless skin characterized by skin ulcers that bleed when removed and, left untreated, can lead to extensive hair loss. Cryptococcosis is another mycosis transmitted from cats, localized in the skin, lungs or brain. In humans, this disease can take the form of meningoencephalitis or a skin condition.
It should be noted that cats can make people sick if the human immune system is weakened. Also, to avoid the infestation of the cat and, implicitly, ours, it is recommended to carry out periodic internal and external deworming.
Bacterial infections are contagious diseases that can accompany or follow viral or mycobacterial infections. The most common such contagious diseases caused by cats are caused by bacteria such as streptococci, campylobacter and staphylococci. Treatment for the cat and for the person consists of the administration of antibiotics, under the supervision of a specialist doctor.
Helicobacter pylori is a bacterium that can cause zoonoses and that, once in the human body, can lead to diseases of the stomach and duodenal mucosa, including gastric ulcers, which are difficult to treat due to the resistance of the bacterium to antibiotics.
Feline conjunctivitis, Salmonella infections (from cats fed raw poultry) or Pasteurella multocida can easily be transmitted to humans. Symptoms range from fever and inflammation to tonsillitis, pharyngitis, etc.
Another very serious disease that ticks can transmit to humans is rabies (or rabies). This is a condition caused by a virus that affects the central nervous system, including the brain and spinal cord, in both animals and humans. Humans can contract the disease through bites, and cats can acquire it either through bites or by eating infected animals such as mice, rats, or other wild animals. The disease can only be treated immediately after the bite; once clinically triggered, treatment becomes ineffective. In such situations, it is essential to wash the affected area with soap and water and consult a specialist doctor in the anti-rabies centers of infectious diseases hospitals. To prevent rabies in cats, anti-rabies vaccination is recommended, starting from the age of 3 months, and repeated annually.
Even though there are some contagious diseases that cats can transmit to humans, the chances of this happening are quite limited, especially if it is a cat that is kept indoors, vaccinated and neutered. It is also very important to observe hygiene rules.
