An erythema infectiosum-like illness caused by human parvovirus infection

In the spring of 1980, an epidemic of an illness that resembled erythema infectiosum occurred in Manitoba, Canada. We initiated prospective epidemiologic, clinical, and microbiologic studies of this illness among elementary-school children and their families. Initial microbiologic studies failed to identify the cause of the exanthem. After a similar illness associated with serologic evidence of human parvovirus infection occurred in London, stored specimens of 12 patients with exanthem were investigated for parvovirus infection. Eleven patients had parvovirus-specific IgM antibody, as did two family contacts and a teacher with nonexanthematous illnesses, and two asymptomatic family members. None of 28 children with measles or rubella had serologic evidence of recent parvovirus infection. Human parvovirus was detected by DNA hybridization and immune electron microscopy in the serum of one patient who later had a rash and in one unaffected family contact. Parvovirus DNA was also detected in the pharyngeal specimen of the teacher who was ill but did not have a rash. We conclude that human parvovirus infection can be asymptomatic or cause a variety of clinical manifestations, including nonexanthematous illness and an illness resembling erythema infectiosum.