Newark, California (April 19, 2017) -Scientists at the U.S. Centers for Disease Control and Prevention (CDC) recently reported replication and persistence of Zika virus RNA in placentas of women who had pregnancy losses and in brain tissues of infants with microcephaly.
According to the findings published in the March 2017 issue of the Emerging Infectious Diseases journal, 52 patients with clinically suspected Zika virus infection were studied, including 8 infants with microcephaly who died. The researchers tested the placental tissue of 22 women who either had a miscarriage, still birth, pregnancy termination, or a baby born with microcephaly. They also tested the placental tissue of another 22 women who had babies that appeared healthy.
The study visualized Zika virus RNA transcripts directly in the autopsied brains of infants or placental tissues through in situ hybridization (ISH) using the RNAscope™ technology from Advance Cell Diagnostics, a Bio-Techne company. Because this technology allows detection of RNA transcripts while retaining the cellular morphology of the tissues, the researchers were able to localize Zika virus negative sense replicative RNA directly in placental Hofbauer cells and neural cells/neurons of brains. Based on RT-PCR, ISH and histopathology findings described in the study, CDC researchers concluded that Zika virus replicates in fetal brain and placental tissues and Hofbauer cells may play an important role in the dissemination or transfer of Zika virus to the fetal brain.
The work also showed that Zika virus RNA persisted in fetal brains and in placentas for more than seven months after the mothers contracted Zika. CDC scientists have suggested that the persistence of Zika virus could have implications for babies born with microcephaly and for apparently healthy infants whose mothers had Zika infections during their pregnancies. Molecular analysis of tissues extends the timeframe of Zika virus detection in congenital and pregnancy-associated infections and provides valuable insights into mechanisms of Zika virus intrauterine transmission and replication. More studies are needed to fully understand how the virus can affect babies.
"We are honored that RNAscope ISH aided CDC researchers in advancing the understanding of Zika pathogenesis,” said Yuling Luo, PhD, President and founder of ACD. “During this past year, scientists around the world have intensified their research to reduce the impact of the Zika epidemic. RNAscope has been an essential tool in nine Zika publications during the past nine months, so we are proud to provide solutions that can elucidate this complex and devastating virus."
