Cat scratch disease (CSD)
Cat scratch disease (CSD), also known as cat scratch fever, is a bacterial infection primarily caused by a scratch or bite from an infected cat or kitten, though it can also be transmitted through contact with infected saliva. The responsible bacteria, Bartonella henselae, are typically carried by fleas and passed to cats, which then can transmit the infection to humans. CSD commonly affects children, particularly because they often play with cats and are more prone to being scratched or bitten. Symptoms may include swollen lymph nodes, low-grade fever, and flu-like symptoms such as weakness and nausea, with more severe cases potentially leading to complications like encephalitis or pneumonia.
Diagnosis typically involves a physical examination and discussion of symptoms, with blood tests sometimes ordered for clarification. Treatment usually focuses on managing symptoms with rest and pain relievers, though antibiotics may be necessary in more severe cases or for immunocompromised individuals. Preventive measures include minimizing the risk of scratches or bites and maintaining flea control for pets. While CSD often resolves on its own, awareness and appropriate care are essential for those experiencing severe symptoms or complications.
Cat scratch disease (CSD)
- ANATOMY OR SYSTEM AFFECTED: All
- ALSO KNOWN AS: Cat scratch fever, subacute regional lymphadenitis
Definition
Cat scratch disease (CSD) is a bacterial infection caused by a scratch or bite from a cat or kitten (and sometimes from a dog). The infection usually heals without treatment, but it can become a potentially serious condition requiring a doctor's care.
Causes
The bacteria that cause CSD, Bartonella henselae, are found in fleas. They are passed to cats through flea bites and then to humans through a cat scratch or bite. Transmission can also occur if infected saliva comes into contact with an open wound. Children are most often affected because they are often bitten or scratched by a cat during play. Kittens are more likely than older cats to carry the bacteria.
Risk Factors
Factors that increase the chance of getting CSD include a recent bite or scratch from a cat or kitten and a weakened immune system, which also increases the chance of serious complications from the disease. People with weakened immune systems include babies, the elderly, organ transplant recipients, and individuals with human immunodeficiency virus (HIV), acquired immunodeficiency syndrome (AIDS), or cancer. Additional risk factors include being younger, living in the southern United States, not properly disinfecting a wound from a cat, and working in an occupation that requires contact with cats, such as a veterinarian or veterinary technician.
Symptoms
Symptoms of CSD include a crusting sore or blister that develops over the scratch or bite site; swollen, painful lymph nodes; low-grade fever; and flulike symptoms, such as weakness, nausea, chills, loss of appetite, joint pain, and headache. A sore throat, weight loss, and rash are less common symptoms. If the patient does not begin to get well within a few days, they may develop complications, such as a high fever or pneumonia. Severe cases have caused infections of the brain (encephalitis), hepatitis, and even death. Other potentially severe complications include neuroretinitis, parinaud oculoglandular syndrome, spleen issues, endocarditis, and osteomyelitis.
Screening and Diagnosis
A doctor will ask about symptoms and medical history and perform a physical exam. The doctor will probably be able to diagnose the disease based on painful, swollen lymph nodes and the patient’s knowledge of being bitten or scratched. However, the doctor may order a blood test, especially if the diagnosis is unclear from the exam and medical history.
Treatment and Therapy
Treatment options include rest and nonprescription pain relievers, such as acetaminophen. If a lymph node is swollen or painful, the doctor may drain it to relieve pain and help it heal. To do this, the doctor will put a hypodermic needle into the swollen node. The fluid inside the node will then drain out through the needle.
CSD usually clears up without treatment, but if the lymph nodes stay painful and swollen for more than two or three weeks or if the patient gets very ill, the doctor may prescribe antibiotics. Antibiotics may also be prescribed for those with HIV infection or other immunocompromising health conditions. For instances of CSD that develop more serious symptoms and complications, longer treatment may be necessary.
Prevention and Outcomes
The best prevention against CSD is to avoid being scratched or bitten by a cat or dog. If bitten or scratched, one should wash the bite or scratch immediately with antiseptic soap and hot water. Also, one should keep pets free of fleas.
Bibliography
"Cat Scratch Disease." Johns Hopkins Medicine, www.hopkinsmedicine.org/health/conditions-and-diseases/cat-scratch-disease. Accessed 30 Sept. 2024.
Conrad, Dennis A. "Treatment of Cat-Scratch Disease." Current Opinion in Pediatrics, vol. 13, no. 1, 2001, pp. 56–59.
Dehio, Christoph. "Cat Scratch Disease, Bacillary Angiomatosis, and Other Bartonelloses." Schaechter's Mechanisms of Microbial Disease. Edited by N. Cary Engleberg, Victor DiRita, and Terence S. Dermody. 5th ed., Baltimore: Lippincott, 2013. 287–91.
Lamps, Laura W., and Margie A. Scott. "Cat-Scratch Disease: Historic, Clinical, and Pathologic Perspectives." Supp. to American Journal of Clinical Pathology, vol. 121, 2004, pp. S71–80
Murrell, Daniel. "Cat Scratch Fever: Causes, Symptoms, and Diagnosis." Healthline, 5 Jan. 2024, www.healthline.com/health/cat-scratch-disease. Accessed 30 Sept. 2024.
Reynolds, Mary G., et al. "Epidemiology of Cat-Scratch Disease Hospitalizations among Children in the United States." Pediatric Infectious Disease Journal, vol. 24, no. 8, 2005, pp. 700–704.
Windsor, Jeffrey J. "Cat-Scratch Disease: Epidemiology, Aetiology and Treatment." British Journal of Biomedical Science, vol. 58, no. 2, 2001, pp. 101–10.