Zika and dengue viruses are mosquito-borne infections that can cross the placenta and threaten maternal and fetal health. A recent review examines how these viruses infect the placenta and compares their epidemiology, pregnancy complications, and mechanisms of vertical transmission (Figure 1).
Figure 1: Graphical abstract
Although both viruses belong to the same flavivirus family, they affect pregnancy in different ways. Zika virus is strongly associated with severe fetal outcomes, including congenital abnormalities, while dengue infection during pregnancy can increase risks such as maternal complications, preterm birth, and fetal distress.
Recent molecular studies suggest that both viruses manipulate placental signalling pathways, including JAK/STAT and mTOR, which regulate immune responses and cell growth. They can also evade immune defences in the placenta, including Hofbauer cells, specialized macrophages that normally help protect the fetus from infection.
Understanding how these viruses bypass placental immune barriers is critical for improving maternal–fetal health. Insights into these mechanisms may guide the development of better diagnostics, vaccines, and treatments aimed at preventing viral transmission from mother to fetus.
Journal article: Mukherjee, I., et al. 2026. Comparative analysis of placental transmission mechanisms for Dengue and Zika viruses: outcomes and future directions. Frontiers Immunology.
Summary by Stefan Botha
