Cat Scratch Disease

An acute infectious disease that occurs through contact with infected cats - through bites, scratches, salivation. Characterized by fever, regional lymphadenitis, enlarged liver and spleen, sometimes a primary effect and exanthema.

Etiology, pathogenesis
The causative agent belongs to chlamydia. Infected cats remain healthy. Human infection occurs through contact, through damage to the skin or conjunctiva of the eyes.

Symptoms, course
The incubation period lasts from 3 to 60 days (usually 2-3 weeks). In typical cases, the disease may begin with the appearance of a small ulcer or pustule at the site of a scratch (bite), but the patient remains in good health.

15-30 days after infection, regional lymphadenitis appears - the most characteristic sign of the disease. More often the axillary, elbow, cervical, and less often other lymph nodes are enlarged. They reach 3-5 cm in diameter, are painful on palpation, and are not fused with the surrounding tissues.

In 50% of cases, they suppurate with the formation of thick yellowish-green pus (bacteria cannot be cultured). At the same time, symptoms of general intoxication, fever, enlargement of the liver and spleen appear. Lymphadenitis can persist for up to several months.

In 1-3% of patients, changes in the central nervous system are observed. They appear 1-6 weeks after the development of lymphadenopathy and are accompanied by high fever. Possible manifestations are encephalopathy, meningitis, radiculitis, polyneuritis, myelitis with paraplegia.

Eye damage (observed in 4-7% of patients) apparently develops when saliva from an infected cat gets on the conjunctiva. As a rule, one eye is affected: the conjunctiva is hyperemic, swollen, against this background one or more nodules appear that can ulcerate. The parotid and sometimes submandibular lymph nodes become enlarged, fever and signs of intoxication appear.

Inflammatory changes in the conjunctiva persist for 1-2 weeks. The diagnosis can be confirmed by a microbiological study of blood with inoculation on blood agar, a histological study of a biopsy of a papule or lymph node, as well as a molecular genetic study of the DNA of the pathogen from a patient’s biopsy.

Treatment
The disease ends in spontaneous recovery. In case of suppuration of the lymph node - puncture with suction of pus. The use of a new antibiotic, ketolide, from the group of macrolides, is promising.