Diversity and pathogen surveillance in chigger mites across Brazil's five biogeographic regions

The expansion of land use in Brazil has caused biodiversity loss and increased human interaction with parasites and pathogens previously restricted to natural ecosystems. Chigger mites are ectoparasites during the larval stage and can cause skin reactions or transmit pathogens to their hosts, including humans. This study aimed to evaluate the diversity of chiggers collected from all five Brazilian biogeographical regions, along with pathogen surveillance. Specimens were subjected to both morphological taxonomy and endogenous control, followed by PCR assays targeting pathogens of the genera Borrelia, Orientia, and Rickettsia. The analyses revealed a high species richness, including two novel records in Brazil: the genus Boshkerria and the species Quadraseta antillarum. Additionally, the genus Quadraseta tested positive for Rickettsia sp., while tests for the other agents were negative. This is the first report of a Rickettsia sp. agent detected in a Quadraseta nymph.