A mouse study has suggested that Zika virus may reproduce in the vagina of pregnant women several days after infection, from where it spreads and infects the fetal brain and impairing fetal development.
This is contained in a new study published on Friday in Washington in the U.S. journal Cell by researchers from the Yale University.
The researchers observed that Zika is commonly transmitted through a bite from an infected mosquito, and recent reports have confirmed it is also capable of leaping from person to person through sexual transmission.
The researchers, however, said that they have not determined whether the Zika virus replicated in the vagina after women were exposed through sexual intercourse.
Akiko Iwasaki, Senior Author and Immunobiologist at Yale University, said that the study observed replication of the Zika virus in the vaginal tissue of wild-type mice and mice genetically modified to be susceptible to Zika.
“Normally, mice cannot be infected by the virus,” she said.
She said they found that the Zika virus replicated in the vagina and persisted post-infection, even in normal mice.
“We saw significant virus replication in the genital tissue, up to four to five days.
“What surprised us most was that the virus replicated in the vagina of wild-type mice,” she said.
Iwasaki said that the prolonged presence of the virus had not been observed in other sites of infection in wild-type mice.
She noted that the team also detected Zika virus in the fetal brains of mice, and that infection was associated with fetal weight loss.
“Early during pregnancy, if the mother is infected, there is significant impact on the fetus, even in wild type mice.
The immunobiologist observed that while the immune response to Zika virus is different in people, the study results raised critical questions about the impact of sexual transmission.
Iwasaki advised that the finding is very important for women, rather than pregnant women alone.
“The vagina is a site where the virus can replicate and possibly transmit to partners.
“In pregnant women, vaginal transmission of Zika virus may have a significant impact on the developing fetus,’’ she said.
SOURCES: Daily Post/Xinhua/NAN