Systematic review of distribution models for Amblyomma ticks and Rickettsial group pathogens

The rising prevalence of tick-borne diseases in humans in recent decades has called attention to the need for more information on geographic risk for public health planning. Species distribution models (SDMs) are an increasingly utilized method of constructing potential geographic ranges.There are many knowledge gaps in our understanding of risk of exposure to tick-borne pathogens, particularly for those in the rickettsial group. Here, we conducted a systematic review of the SDM literature for rickettsial pathogens and tick vectors in the genus Amblyomma . Of the 174 reviewed papers, only 24 studies used SDMs to estimate the potential extent of vector and/or pathogen ranges. The majority of studies (79%) estimated only tick distributions using vector presence as a proxy for pathogen exposure. Studies were conducted at different scales and across multiple continents. Few studies undertook original data collection, and SDMs were mostly built with presence-only datasets from public database or surveillance sources. While we identify agap in knowledge, this may simply reflect a lag in new data acquisition and a thorough understanding of the tick-pathogen ecology involved.