Probable vertical transmission of Alpha variant of concern (B.1.1.7) with evidence of SARS-CoV-2 infection in the syncytiotrophoblast, a case report

• Published in: Frontiers in medicine 2022, Vol.9, p.1099408-1099408
• Main Authors: Bullock, Hannah A, Fuchs, Erika, Martines, Roosecelis B, Lush, Mamie, Bollweg, Brigid, Rutan, Alyssa, Nelson, Amy, Brisso, Mark, Owusu-Ansah, Albert, Sitzman, Craig, Ketterl, Laurie, Timmons, Tim, Lopez, Patricia, Mitchell, Elizabeth, McCutchen, Emily, Figliomeni, Jonathan, Iwen, Peter, Uyeki, Timothy M, Reagan-Steiner, Sarah, Donahue, Matthew
• Format: Report
• Language: English
• ISSN: 2296-858X; 2296-858X
• DOI: 10.3389/fmed.2022.1099408

IntroductionDefinitive vertical transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has been rarely reported. We present a case of a third trimester pregnancy with fetal distress necessitating cesarean section that demonstrated maternal, placental, and infant infection with the SARS-CoV-2 Alpha variant/B.1.1.7. MethodsCDC's Influenza SARS-CoV-2 Multiplex RT-PCR Assay was used to test for SARS-CoV-2 in a maternal NP swab, maternal plasma, infant NP swab, and formalin-fixed paraffin-embedded (FFPE) placental tissue specimens. Whole genome sequencing (WGS) was performed on maternal plasma, infant, and placental specimens to determine the SARS-CoV-2 genotype. Histopathological evaluation, SARS-CoV-2 immunohistochemistry testing (IHC), and electron microscopy (EM) analysis were performed on placenta, umbilical cord, and membrane FFPE blocks. ResultsAll specimens tested positive for SARS-CoV-2 by RT-PCR. WGS further revealed identical SARS-CoV-2 sequences from clade 20I/501Y.V1 (lineage Alpha/B.1.1.7) in maternal plasma, infant, and placental specimens. Histopathologic evaluation of the placenta showed histiocytic and neutrophilic intervillositis with fibrin deposition and trophoblast necrosis with positive SARS-CoV-2 immunostaining in the syncytiotrophoblast and electron microscopy evidence of coronavirus. DiscussionThese findings suggest vertical transmission of SARS-CoV-2, supported by clinical course timing, identical SARS-CoV-2 genotypes from maternal, placental, and infant samples, and IHC and EM evidence of placental infection. However, determination of the timing or distinction between prepartum and peripartum SARS-CoV-2 transmission remains unclear.