How Mild Zika Affects Offspring

University of Saskatchewan researchers have shown that mild Zika virus infection in pig fetuses can cause abnormal brain development in apparently healthy young animals. The study, published yesterday in PLOS Pathogens, provides new insights into the potential outcomes of Zika virus infection and could point to new prevention and treatment strategies to alleviate the long-term effects of Zika virus infection.

Spread by the bite of an infected mosquito, Zika infection of pregnant mothers can lead to death and decreased brain size in fetuses. However, there is growing concern that even sub-clinical infections (those showing no symptoms) in pregnant mothers can result in brain disorders and delayed neurodevelopmental abnormalities in offspring after birth. The new study has provided direct evidence to support this concern.

“We have demonstrated in a relevant animal model that mild infection in fetuses results in abnormal brain development and impaired immunity in young pigs,” says VIDO-InterVac Director and coauthor Volker Gerdts.

Some of the affected offspring also showed altered behavior during stress. “For the first time, we have shown that mild fetal infection can lead to sex-specific brain disease in offspring: male piglets showed more molecular brain abnormalities than female piglets,” says senior author Uladzimir Karniychuk. “We are now able to better understand the disease in fetuses and how it affects health in offspring.”

In 2016, the World Health Organization declared Zika virus a public health emergency. While this emergency declaration has been lifted, Zika infection remains a public health concern. There is currently no approved vaccine or therapy available to combat the infection.

According to Karniychuk, a next step would be to develop an animal model for the study of how to treat and cure infections like Zika in utero. There are currently no in utero therapies for congenital viral infections.