The World Health Organization on Friday declared that Zika no longer constitutes an international emergency, but it stressed a need for a long-term effort to address the virus, which has been linked to birth defects and neurological complications.

WHO in February declared Zika a public health emergency of international concern - a designation under international law that compels countries to report outbreaks. The moved was part of an effort to determine if Zika was linked to reports in Brazil of the severe birth defect microcephaly and the neurological disorder Guillain-Barre Syndrome. Traditionally, Zika had only been thought to cause mild symptoms.

That goal has been met, said Dr David Heymann, chair of the Zika Emergency Committee and a professor of infectious disease at the London School of Hygiene and Tropical Medicine, in a conference call with reporters following the committee meeting in Geneva.