By lifting its nine-month-old declaration, the UN's health agency is acknowledging that Zika is here to stay.

The infection has been linked to severe birth defects in almost 30 countries.

These include microcephaly, where babies are born with abnormally small heads and restricted brain development.

The WHO says more than 2,100 cases of nervous-system malformations have been reported in Brazil alone.

Although the virus is mostly spread by mosquitoes, it can also be sexually transmitted.

Few people die from Zika and only one in five people infected is thought to develop symptoms. These can include fever, a rash and joint pain.

Dr David Heymann, the head of a WHO emergency committee on the virus, said it still posed a "significant and enduring" threat.

The WHO will now shift to a longer-term approach against the infection, which has spread across Latin America, the Caribbean and beyond.