Parvovirus (PARVO) B19 is a small DNA virus that causes erythema infectiosum (fifth disease) or "slapped cheek syndrome" in children. The onset of this disease appears as a red splotch or "slapped cheek" and later spreads to the arms and legs.
PARVO replicates in bone marrow cells and inhibits red blood cell (RBC) production (erythropoiesis) causing hemolytic complications. PARVO B19 has also been implicated in hydrops fetalis which causes spontaneous abortion in humans. B19 is also a cause of chronic anemia in individuals with human immunodeficiency virus (HIV) and can infect sickle cell patients with erythrocyte (red blood cell) abnormalities. B19 should not be confused with the parvovirus that infects dogs and cats. A vaccine for B19 does not exist for humans. Mouse IgG1 monoclonal antibody clone R92F6 is specific for viral antigens VP1 (84 kD) and VP2 (58 kD). PARVO B19 is easily demonstrated with standard heat-induced epitope retrieval (HIER) protocols using citrate buffer and routine IHC methodologies. The placenta or bone marrow are commonly infected tissues and can serve as positive controls.
