CHAPTER XIX
RAT-BITE DISEASE
Definition and description.—A disease, according to Hata, long known to Japanese physicians, but until lately little known in Europe, America, or Africa. It is characterized by a local disturbance at the site of inoculation, and by general fever which is often accompanied by a papular rash. The mortality is low, about 10 per cent. (Hata). The symptoms develop only in a proportion of those bitten by rats. The incubation period varies from five weeks to two months, during which time the wound heals.
Symptoms.—The site of the bite shows inflammatory changes, a process which may spread to surrounding tissues with formation of blebs and even necrotic areas; the lymphatic glands draining the area are also implicated. Rigors, headache, and fever (103-4 F.) are present. The fever lasts generally some three or four days and ends in crisis, after which the local inflammatory symptoms subside. A second attack of fever, associated with the same symptoms and in addition with a papular exanthem, generally occurs within a week. Further recurrences are common.
In most cases the reflexes are increased. In severe cases, pains in the muscles and joints, hyperaesthesia, and oedema of various portions of the body are a marked feature. The end is ushered in by delirium often lapsing into coma.
Certain observers have found a Gram-negative streptothrix in the blood, similar to one common in the tracheal mucus and broncho-pneumonia of rats.
Treatment.—Hata reports that in eight cases intravenous injections of salvarsan were followed by marked improvement; others claim equally good
results from neo-salvarsan.
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