Recent studies using animals, in the USA and Brazil, have shed light on the effect of Zika virus infection during pregnancy, which could lead to better diagnoses and treatments for babies.

Zika virus is primarily spread by infected mosquitoes, with symptoms generally tending to be mild or harmless, however, it can be serious if caught during pregnancy and can cause developmental defects in babies.

Research at the California National Primate Research Center at the University of California, Davis (UC Davis), USA, studied pregnant macaque monkeys infected with Zika to understand how it affects foetal development.

Researchers found that the virus can enter the brain of the foetus and slow its overall growth, which also resulted in the monkeys having a smaller head than normal (a condition similar in humans is called microcephaly). The study showed that after birth the way babies interacted with their mothers was also affected.

The macaques will continue to be studied for the next two years to understand how Zika may affect their development and other aspects in the long term, in order to identify opportunities to intervene with drugs and other treatments.

Meanwhile, a Brazilian study led by the Federal University of São Paulo (UNIFESP) and Federal University of Rio de Janeiro found, using pregnant mice infected with Zika, that an enzyme called Ndel1 is involved in the development of microcephaly in infant mice.

Mirian Hayashi, at UNIFESP, said: “The discovery of this link between Ndel1 activity and brain size is only the beginning of the journey but offers great hope.”