RELAPSING FEVER (Febris recurrens), the name given to a specific infectious disease occasionally appearing as an epidemic in communities suffering from scarcity or famine. It is characterized mainly by its sudden invasion, with violent febrile symptoms, which continue for about a week and end in a crisis, but are followed after another week, during which the patient is fairly well, by a return of the fever. In exceptional cases, second, third and even fourth relapses may occur.
This disease has received many other names, the best known of which are famine fever, seven-day bilious relapsing fever, and spirillum fever. Like typhoid, relapsing fever was long believed to be simply a form of typhus. The distinction between them appears to have been first clearly established in 1826, in con nection with an epidemic in Ireland.
In 1873 Obermeier discovered in the blood of persons suffering from relapsing fever minute spiral filaments of the genus Spiro chaete, having rotatory or twisting movements. This organism
received the name of Spirillum obermeieri. Fritz Schaudinn brought forward evidence that it is an animal parasite. Relapsing fever is most commonly met with in the young. One attack does not appear to protect from others, but rather, according to some authorities, engenders liability. The incubation of the disease is about one week.
The mortality in relapsing fever is comparatively small, about 5% being the average death-rate in epidemics (Murchison). The fatal cases occur mostly from the complications common to con tinued fevers. The treatment is essentially the same as that for typhus fever. Lowenthal and Gabritochewsky by using the serum of an immune succeeded in averting the relapse in 4o% of cases.