title: Newly discovered KI, WU, and Merkel cell polyomaviruses: no evidence of mother-to-fetus transmission.
abstract: BACKGROUND
  Three* human polyomaviruses have been discovered recently, KIPyV, WUPyV and MCPyV. These viruses appear to circulate ubiquitously; however, their clinical significance beyond Merkel cell carcinoma is almost completely unknown. In particular, nothing is known about their preponderance in vertical transmission. The aim of this study was to investigate the frequency of fetal infections by these viruses. We sought the three by PCR, and MCPyV also by real-time quantitative PCR (qPCR), from 535 fetal autopsy samples (heart, liver, placenta) from intrauterine fetal deaths (IUFDs) (N = 169), miscarriages (120) or induced abortions (246). We also measured the MCPyV IgG antibodies in the corresponding maternal sera (N = 462) mostly from the first trimester.
  
  
  RESULTS
  No sample showed KIPyV or WUPyV DNA. Interestingly, one placenta was reproducibly PCR positive for MCPyV. Among the 462 corresponding pregnant women, 212 (45.9%) were MCPyV IgG seropositive.
  
  
  CONCLUSIONS
  Our data suggest that none of the three emerging polyomaviruses often cause miscarriages or IUFDs, nor are they transmitted to fetuses. Yet, more than half the expectant mothers were susceptible to infection by the MCPyV.
authors.affiliation: Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Sadeghi
authors.forename: Anita
authors.initials: A
authors.lastname: Riipinen
authors.forename: Elina
authors.initials: E
authors.lastname: Väisänen
authors.forename: Tingting
authors.initials: T
authors.lastname: Chen
authors.forename: Kalle
authors.initials: K
authors.lastname: Kantola
authors.forename: Heljä-Marja
authors.initials: HM
authors.lastname: Surcel
authors.forename: Riitta
authors.initials: R
authors.lastname: Karikoski
authors.forename: Helena
authors.initials: H
authors.lastname: Taskinen
authors.forename: Maria
authors.initials: M
authors.lastname: Söderlund-Venermo
authors.forename: Klaus
authors.initials: K
authors.lastname: Hedman
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D005333:Fetus / Q000821:virology; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011120:Polyomavirus / Q000302:isolation & purification*; D027601:Polyomavirus Infections / Q000635:transmission*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000821:virology*; D014412:Tumor Virus Infections / Q000635:transmission*; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral