@entity9556 is a common and underdiagnosed cause of @entity221 in Southeast Asia, caused by @entity281 with @entity9557 . Inoculation of the organism at a cutaneous mite bite site commonly results in formation of a localized pathological skin reaction termed an eschar. The site of development of the obligate intracellular bacteria within the eschar and the mechanisms of dissemination to cause @entity281 are unclear. Previous postmortem and in vitro reports demonstrated @entity281 of endothelial cells, but recent pathophysiological investigations of @entity23244 @entity1 using surrogate markers of endothelial cell and leucocyte activation indicated a more prevalent host leucocyte than endothelial cell response in vivo. We therefore examined eschar skin biopsies from @entity1 with @entity9556 to determine and characterize the phenotypes of host cells in vivo with intracellular @entity281 by @entity9557 , using histology, immunohistochemistry, double immunofluorescence confocal laser scanning microscopy and electron microscopy. Immunophenotyping of host leucocytes infected with @entity9557 showed a tropism for host monocytes and dendritic cells, which were spatially related to different histological zones of the eschar. Infected leucocyte subsets were characterized by expression of HLADR+, with an "inflammatory" monocyte phenotype of CD14/LSP-1/CD68 positive or dendritic cell phenotype of CD1a/DCSIGN/S100/FXIIIa and CD163 positive staining, or occasional CD3 positive T-cells. Endothelial cell @entity281 was rare, and histology did not indicate a widespread inflammatory @entity1333 as the cause of the eschar. Infection of dendritic cells and activated inflammatory monocytes offers a potential route for dissemination of @entity9557 from the initial eschar site. This newly described cellular tropism for @entity9557 may influence its interaction with local host immune responses.

@entity9557 in @entity1 XXXX shows tropism for dendritic cells and monocytes rather than endothelium.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity9556 :: ('MESH:D012612', 'Disease') :: ['scrub typhus', 'Scrub typhus'] @entity1333 :: ('MESH:D014657', 'Disease') :: ['vasculitis'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection', 'systemic infection'] @entity9557 :: ('784', 'Species') :: ['O. tsutsugamushi', 'Orientia tsutsugamushi'] @entity221 :: ('MESH:D005334', 'Disease') :: ['febrile illness'] @entity23244 :: ('MESH:D014438', 'Disease') :: ['typhus']
@entity9556 :: (MESH:D012612,Disease) :: ['scrub typhus eschars']
