ISLAMABAD: The mosquito-borne Zika virus will no longer be treated as an international medical emergency, the World Health Organisation (WHO) has declared.

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.