Which of the following diseases is caused by a spirochete?

tularemia

relapsing fever

rheumatic fever

Rocky Mountain spotted fever

Relapsing fever.

Explanation:

Relapsing fever is a type of recurring febrile disease that are mainly transmitted by ticks or lice. The main symptoms are myalgia, vomiting and headache.

The main causative agent of relapsing fever is spirochete Borrelia. Spirochetes are the flexible and twisting gram negative bacteria. These bacteria have endocellular flagella and known to cause a large number of diseases in humans.

Thus, the correct answer is option (2).