The fever pattern in brucellosis is typically relapsing because the infection causes intermittent bacteraemia as Brucella organisms multiply intracellularly and then are released periodically into the bloodstream. This leads to recurring febrile episodes separated by afebrile intervals. Unlike continuous or remittent fevers, the relapsing nature is a hallmark feature that helps differentiate brucellosis from other febrile illnesses. Recognizing this pattern is key to clinical diagnosis and management.

Reference: Harrison's Principles of Internal Medicine, Jameson et al., 20th Edition.