Immunolocalization and Distribution of Rubella Antigen in Fatal Congenital Rubella Syndrome

•Autopsy tissues from three fatal CRS cases were analyzed immunohistochemically.•Rigorous negative controls were used to verify the specificity of immunostaining.•Rubella antigen was detected in cardiac fibroblasts, alveolar macrophages, neuronal progenitor cells and endothelial cells.•Rubella antigen localization was consistent with CRS pathology.Wild type rubella virus (RV) transferred from mothers with rubella to their unborn children results in 100,000infants/year worldwide born with birth defects collectively known as congenital rubella syndrome (CRS). Indeed, RV is the most teratogenic infectious agent known. Identifying cell types involved in RV infection of infants with CRS was possible using tissues from three Romanian infants, who unfortunately died, and using a very specific antiserum to RV. The cell types involved in RV infection which were identified were consistent with the pathology of CRS. Additional studies further enumerating the cell types involved in CRS are needed.