DIAGNOSIS OF SPOTTED FEVER

Abstract

This chapter addresses the diagnosis of Spotted Fever (SF), a group of rickettsioses caused by bacteria of the genus Rickettsia, with emphasis on Rickettsia rickettsii, the agent of the most lethal form in the Americas. The authors highlight that the initial clinical picture is nonspecific (high fever, headache, myalgia, and nausea), making differential diagnosis with other acute febrile illnesses difficult. Laboratory diagnosis faces significant limitations: serological methods (such as IFA) depend on seroconversion, which occurs late, while molecular techniques (real-time PCR, LAMP, and multiplex HDPCR) allow early detection, but require infrastructure and training that are not always available in endemic regions. The narrative literature review (2019-2025) shows that the therapeutic decision with doxycycline should be based on clinical and epidemiological suspicion, without waiting for laboratory confirmation. It is concluded that the ideal diagnosis is multimodal, integrating high clinical suspicion, rapid molecular methods and genomic surveillance, in addition to policies of diagnostic decentralization and professional training to reduce the lethality of the disease.