Preliminary data suggest that Zika virus induced fetal abnormalities can occur in every trimester of pregnancy but the worst manifestations are associated with infections that occur in the first and second trimesters.
It was reported in Cell that a group at Washington University School of Medicine, Saint Louis that had previously developed an adult mouse model of Zika virus infection has now created a mouse model of in utero transmission of Zika. They used their previous adult model, mice that don’t produce or respond to Type I interferon (IFN) - a large group of proteins that are critical for immune system regulation. While adult wild-type (WT) mice did not develop illness after they were infected with a Zika, the mice that lacked the IFN response did develop severe neurological disease, associated with high viral loads in the spinal cord and brain, and also experienced high rates of death.
Their findings could establish reliable models for studying the mechanisms of in utero transmission of Zika, as well as testing of candidate therapies to prevent congenital malformations. The scientists also highlight the concern that Zika infection could happen in the fetus of an otherwise healthy looking parent, with unknown neurodevelopmental consequences. Animal models of Zika virus infection during pregnancy may also provide fundamental understanding of how the placental barrier can protect the developing fetus from viral infection, and why that protection fails in the context of some pathogens.
Source: Cell