The epidemiologic parameters for a disease to be considered a public health problem are magnitude, vulnerability and transcendence. If you consider only magnitude and vulnerability based on incidence of rickettsial diseases in Latin America and in the absence of an effective vaccine against these kind of diseases, you can say that rickettsial diseases are not priority and are not a public health problem. If you investigate other epidemiologic parameters we can have another vision about the rickettsial diseases. The objective of this paper is to analyze the epidemiologic risk factors in rickettsial diseases by an historic retrospective in Latin America, to confirm our hypothesis of the public health relevance of rickettsial diseases.