Prolonged Parvovirus B19 Viremia in Spite of Neutralizing Antibodies after Erythema Infectiosum in Pregnancy

Abstract

Objective: To check the clearance of parvovirus B19 in the course of the development of neutralizing antibodies after Erythema infectiosum in pregnancy. Methods: Parvovirus B19 serology (Parvovirus B19 IFA IgG, IgM Antibody Test Kit, Biotrin, Ireland and Immunoblot RIDA Blot Parvovirus B19, R-Biopharm, Germany) and polymerase chain reaction (PCR Parvovirus B19, Roche Diagnostics, Switzerland) were performed in eight predelivery sera, one cord blood sample and one serum 2 months after delivery. Results: Acute parvovirus B19 infection in pregnancy was diagnosed by seroconversion in the IgM and IgG antibody class and detection of viral DNA by PCR. Despite the presence of neutralizing antibodies, PCR gave positive results in all subsequent sera including the cord blood sample and the postdelivery sample 7 months after primary infection. Neonatal examination on the 4th day after delivery was normal and no clinical sign of intrauterine infection was noted. Conclusions: Prolonged parvovirus B19 viremia infection can be seen in spite of neutralizing IgG antibodies and in IgM negative patients. Therefore, the presence of IgG antibodies in the absence of IgM antibodies should not always be interpreted as a past infection. The infectivity of patients with persistent parvovirus B19 infection requires further studies.