Parvovirus B19 Infection

Abstract

Primary parvovirus B19 infection is not uncommon during pregnancy, and is often asymptomatic in the mother (de Jong et al, J Clin Virol. 2006;36:1–7). Vertical transmission to the fetus occurs in roughly 30% of patients with primary infection (Koch et al, Pediatr Infect Dis J. 1998;17:489–494). The risk of an adverse fetal outcome following parvovirus B19 infection is low; however, severe infections can lead to fetal hydrops and intrauterine fetal demise (de Jong et al, J Clin Virol. 2006;36:1–7; Koch et al, Pediatr Infect Dis J. 1998;17:489–494; Young et al, N Engl J Med. 2004;350:586–597). Diagnosis of parvovirus B19 infection can be made by identification of the characteristic findings within the placenta, including a grossly hydropic placental disc and the presence of intranuclear inclusions within fetal red blood cells (Koduri et al, Am J Hematol. 1998;58:95–99; Quemelo et al, Inst Med Trop Sao Paulo. 2007;49:103–107). Similar inclusions can be seen in various tissues of fetuses who experience an intrauterine demise and present for autopsy (Rodriguez et al, Pediatr Dev Pathol. 2002;5:365–374; O'Malley et al, Pediatr Dev Pathol. 2003;6:414–420). The current case report illustrates an example of parvovirus B19 infection in a pregnant woman whose fetus subsequently developed hydrops fetalis and died in utero. The accompanying placental and fetal pathology depict classic findings of parvovirus B19 infection. The differential diagnosis of parvovirus B19 infection in a placental specimen is also discussed.