Cat scratch fever CSF also known as cat scratch disease CSD occurs when you are bitten or scratched by a cat. It is the bacteria by name Bartonella nenselae that causes CSF. The person would develop mild infection at the spot where the cat has scratched. Once the bacteria enter into your bloodstream, it causes swelling of lymph nodes of head, neck and limbs. Lymphadenopathy is the term given for swollen lymph nodes. This fever is commonly seen in children and adolescents. Cat scratch fever is also known as cat scratch oculoglandular syndrome, Debre’s syndrome, cat scratch Adenitis, Parinaud’s syndrome and Petzetakis syndrome.
Effects of CSF :
A person affected with cat scratch fever will develop swelling of lymph nodes. It occurs within one to three weeks after the injury. Lymphadenopathy occurs either in single node or group of lymph nodes affecting the nodes of the anterior or posterior triangles present in the neck. More than 60% of the affected people would develop swelling in their neck region. Normally the swelling may last for 8-12 months. In case it if persist for more than a year, it has to be drained by needle aspiration.
About 2-3% of the cases may develop encephalopathy causing swelling of lymph nodes in the brain. The person may develop loss of concentration, impaired judgment and in rare cases may develop coma. Cat scratch fever can also affect your eyes causing neuroretinitis. It causes reduced visual acuity and reduction of color vision and in extreme cases loss of vision. People who have weakened immunity developing CSF can develop bacillary angiomatasis causing skin lesions.
The bacterium B. nenselae causes cat scratch fever. It is a gram negative microbe causing infection in cats. It is believed to get transmitted through flea which bites the cat passing on the bacteria. The affected cat would then bite or scratch the person and pass on the infection through saliva or claws.
Some of the common signs of cat scratch fever include extreme tiredness, fever, headache, nausea, vomiting, sore throat and anorexia. Almost 90% of the patients develop skin rashes forming reddish brown lesions on the bitten area. Swelling of lymph nodes on the neck occurs within 2-3 weeks of infection. In rare cases, CSD can cause seizures, change in mental state, disorientation and retinitis.
The doctor will examine the body for skin lesions on the spot of injury. He would look for the above symptoms to confirm the diagnoses. ELISA test is done to detect the serum antibody and IFA test is also done. If necessary he may order for immunoglobulin G test and skin biopsy will be done by node aspiration for collecting the fluid of lymph nodes.
Risk Factors :
Having pet animals specially kittens in your home makes you prone for developing CSF. Not all the cat bites/scratches carry infection. Often cats that carry infectious B. nenselae will not show any symptoms. Individuals who have weakened immunity and those with HIV/AIDS and those who are receiving chemotherapy for cancer are at high risk of developing this infection from cats.
How the disease is contracted?
It is believed that about 30-40% of the cats would carry the bacteria in its saliva but not all of them would infect the microbes to you. The infected cats will not show any visible signs of illness and the person who is bitten by the cat would receive the bacteria through saliva or even by skin contact. It is not known exactly how cats acquire these bacteria. It can contract it from fleas.
Very often, cat scratch fever does not require any special treatment unless the symptoms are severe. Antibiotics are prescribed for reducing the swelling of lymph nodes. Antibiotic creams are given for treating skin lesions. As such the disease is self limited and gets resolved on its own within few days.
In some cases, if there is excess of swelling in lymph nodes, needle aspiration is to be done for draining the fluid. In rare cases surgical excision is done for enlarged node when aspiration methods fail to give relief. Effective antibiotics like azithromycin, ciprofloxacin and Rifampin are prescribed for controlling symptoms. Individuals who have weakened immunity may be asked to continue the antibiotics for longer duration.
No methods are available to prevent the cats from getting infected with B. nenselae. And cats will not show any visible signs of being infected. Some cats treated with doxycycline have reduced chance of getting transmission. Children playing with pets specially kitten should be taught how to handle them. They should be instructed to notify the parents if cats have bitten them or they received scratches by cats.
Avoid “rough play” with your cats which may lead to sudden scratches. You can prevent getting CSF/CSD by washing your hands or other areas (with soap and water) thoroughly after playing with kittens. Stay away from cats/kittens if you have any open wounds or injury.