RELAPSING fever is an uncommonly diagnosed disease in this country (12 cases reported in 1977).1 The few cases reported each year mainly occur in the western United States, and only recently has a case been documented that originated east of the Mississippi.2
Two forms of relapsing fever are recognized, louse-borne (epidemic) and tick-borne (endemic). Both are caused by spirochetes of the genus Borrelia and have similar symptoms. The louse-borne variety requires a human reservoir and is common in many other parts of the world. The only case of louse-borne relapsing fever reported in this century in the United States was in a recent Ethiopian immigrant,3 but tick-borne relapsing fever has many endemic foci in North America, largely because of the prevalence of animal reservoirs.
The following two cases appeared in a two-month period at the same hospital. Both fortuitously were diagnosed by the laboratory technicians, who noticed