A recent study by the California National Primate Research Center at the University of California, Davis, found that Zika virus in pregnant rhesus macaques hampers fetal growth and alters early mother-infant interactions during the first month of life.
Zika infection during pregnancy affect developmental trajectories of infants
The study published in Science Translational Medicine on October 25 discusses the impact of fetal infections on developmental trajectories, with implications for Zika virus exposure and other viruses that can cross the placenta, such as SARS-CoV2. Professor Eliza Bliss-Moreau of UC Davis, the senior author, highlights the broader significance of the findings beyond Zika virus.
Zika virus typically results in mild or asymptomatic infections in most individuals, leading to lasting immunity. However, it poses a risk to fetal nervous systems when contracted during pregnancy, potentially causing microcephaly.
UC Davis researchers found that Zika virus can penetrate the fetal brain in pregnant macaques. A recent study, led by Bliss-Moreau and her team, investigated the impact of Zika infection during the second trimester of pregnancy on infants up to one month after birth.
While the pregnant animals didn’t exhibit obvious symptoms, ultrasounds revealed that fetal growth slowed after infection. Consequently, Zika-exposed infants had smaller head sizes at birth compared to other rhesus macaques.
Higher levels of Zika virus correlated with slower growth in infant monkeys, with significant differences in behavior compared to typical infants. The Zika-affected infants clung to their mothers for an extended period, raising questions about the initiator of this contact.
Male children more affected
Male infants experienced greater growth delays and mother-infant interaction effects due to viral infections, despite both genders showing delays compared to uninfected controls. The correlation between pregnancy viral load and outcomes suggests potential interventions, even if the virus isn’t completely eliminated, which could apply to infections like COVID affecting fetuses.
Reducing viral load benefits infant development, according to Bliss-Moreau. A 2019 study from CNPRC scientists, in collaboration with the National Institute of Allergy and Infectious Diseases, observed decreased circulating virus levels in pregnant macaques with an experimental Zika vaccine.
