Problem: Although high maternal mortality was reported in the most recent pandemic of swine-origin influenza A H1N1/09 (H1N1/09), its direct effects on the feto-placental unit are unknown. In the present study, we examined the susceptibility of immortalized human trophoblasts to clinical isolates of pandemic 2009 H1N1 influenza A (H1N1/09) virus.
Method of study: The H1N1/09 virus was isolated from a patient with influenza, sequenced and identified as the A/Narita/2009 (H1N1) strain. The trophoblast cell lines Swan71 and HTR8 were challenged with the virus and examined for the expression of H1N1/09 viral RNA and proteins.
Results: Viral RNA and proteins were observed 24 hr after inoculation. However, viral release was not detected.
Conclusion: First trimester human trophoblast cell lines were susceptible to the H1N1/09 influenza A virus. However, viral release and cytopathic effects were minimal. Our data suggest that placental damage by the H1N1/09 virus may be limited.
© 2012 John Wiley & Sons A/S.