Return to heat

Treponema pallidum is a pathogen that causes fever. Relapsing fever is an acute infectious disease caused by a variety of recurrent fevers. Its clinical features are paroxysmal fever with systemic pain, liver and splenomegaly, and jaundice and bleeding may occur in severe cases. Fever period and intermittent period appear alternately, cold and heat return, so it is called return to fever. The disease is divided into two major categories according to the different vectors, namely tick-borne recurrent fever (epidemic recurrent fever) and tick-borne recurrent fever (endemic regression fever).