THIS REPORT was developed to assist physicians, public health officials, and other health-care professionals respond to public concerns about recently recognized, serious complications of human parvovirus B19 (B19) infection, including transient aplastic crisis (TAC), chronic anemia, and fetal death. It includes background information about the virus, clinical manifestations, pathogenesis, epidemiology, and diagnostic testing. In addition, interim guidelines are presented for preventing B19 infection, managing persons exposed to persons with B19 infection, and managing patients infected with B19. These guidelines reflect both the current limited information about the extent to which B19 infection leads to severe complications and the limited availability of diagnostic testing. Priorities for future research are identified.
B19 was discovered in England in 1975 in serum specimens from healthy blood donors.1 Since its discovery, B19 has been shown to be the causative agent of erythema infectiosum (EI) (also known as fifth disease) and is the