Researchers are using new genetic technology to try to contain the spread of the Zika virus by mosquitoes.

Brazilian health officials have reported a sharp increase in cases of microcephaly, a rare condition in which an infant's head is abnormally small.

Experts say they strongly suspect that the Zika virus is to blame and say there have been more than 4,000 suspected cases since the start of 2015.

Wyre Davies reports.