A65-A69: Other spirochaetal diseases

A68: Relapsing fevers

Relapsing Fevers refer to a group of fever illnesses primarily caused by bacteria from the Borrelia species. These conditions are usually transmitted to humans by ticks or lice. The defining characteristic of these fevers is multiple episodes or "relapses" of fever, occurring after the initial fever has resolved. Other symptoms can include headache, muscle and joint aches, chills, nausea, and fatigue. Each relapsing fever can vary in duration—ranging from hours to days—and the period of good health between episodes can also vary. In some cases, disease progression may involve other systems in the body, potentially affecting the liver, spleen, heart, or central nervous system. These fevers may also lead to complications such as jaundice or eye inflammation. However, the precise symptoms and disease progress depend on the specific Borrelia species involved.