Rickettsial infections in America: A persistent public health challenge at the Human–Animal–Environment interface

Rickettsioses represent a growing and persistent public health challenge in the Americas, where incidence and case-fatality rates in Mexico and Brazil exceed those reported in the United States—a disparity associated with genomic variation among bacterial strains as well as environmental, socioeconomic, and health care factors. For this systematic review, a search was conducted in the Google Scholar, ACS Publications, and PubMed databases following the guidelines of the PRISMA 2020 statement. Articles published between January 2016 and July 2026 were included, using keywords such as "Rickettsiosis," "Vector-Borne Diseases," "Ticks," "One Health," "Climate change," and "Diagnosis," among others, combined with the Boolean operators AND and OR. Of the 33,133 documents initially identified, 110 were selected for full analysis. The analysis reveals that climate change and unplanned urbanization have favored the geographic expansion and prolonged seasonal activity of vectors such as Rhipicephalus sanguineus, while domestic and wild animals act as reservoirs. Diagnosis remains challenging because of the nonspecific nature of the initial clinical presentation and limited access to serological and molecular testing, which delays doxycycline treatment. Elevated mortality in Central and South America is associated not only with environmental factors but also with inequities in health care systems. The One Health approach is essential for addressing rickettsioses because their transmission cannot be explained, or interrupted, by acting on a single component. Rickettsia circulates through a cycle that links the environment, the arthropod vector, and vertebrate hosts. It is concluded that only through sustained multidisciplinary and social commitment will it be possible to reduce the impact of these diseases.