Parvovirus B19 (Slapped Cheek Syndrome, Fifth Disease or Erythema Infectiosum)

Parvovirus B19 was discovered by chance in 1975 at the Central Public Health Laboratory during routine screening for hepatitis B of asymptomatic blood donors from the South London Blood Transfusion Centre. B19 happened to be the serial number of the parvovirus positive specimen. Parvovirus B19 is a single-stranded DNA virus belonging to the Parvoviridae family of viruses, which includes a number of animal parvoviruses such as the canine parvovirus and feline panleukopenia virus.

Parvoviruses are species specific and B19 is the only known pathogenic human parvovirus. The virus is known to replicate in rapidly dividing erythroid progenitor cells. Other target cells are less well defined and may include myocardial tissue.