Dengue fever
Dengue or dengue fever has not substantially changed since the days before the collapse of civilization. The warmer climate has provided a global range for mosquitoes, which has only made dengue more widespread.
Dengue causes fever, headache, vomiting, muscle and joint pain, and a distinctive skin rash. In extreme cases, patients might begin bleeding. Healers should not cut or bleed anyone affected by dengue, though, as the bleeding may become difficult to stop.
Like most mosquito-borne illnesses, dengue becomes a problem when mosquitoes abound near a community (see Mosquito for how communities in the Fifth World handle them as a more general threat). People afflicted with dengue need lots of water, especially with some sodium and potassium. While people in the Fifth World have no means of testing for sodium and potassium levels directly, “healing springs” known for their magical, curative qualities often provide this.
Crushed papaya leaves also provide a common remedy for dengue.