AFP, Geneva :The World Health Organization’s emergency committee will on Monday debate whether a Zika virus outbreak suspected of causing a surge in serious birth defects in South America should be considered a global health emergency.The UN health agency warned last week that the mosquito-borne virus was “spreading explosively” in the Americas, with the region expected to see up to four million cases this year.The WHO is under pressure to act quickly in the fight against Zika, after admitting it was slow to respond to the recent Ebola outbreak that ravaged parts of west Africa.Although the mosquito-borne virus’s symptoms are relatively mild, it is believed to be linked to a surge in cases of microcephaly, a devastating condition in which a baby is born with an abnormally small head and brain.While it has yet to be definitely proven that the microcephaly cases are caused in some way by the Zika virus, WHO chief Margaret Chan warned last week the causal relationship was “strongly suspected”.Zika is also suspected of links to a neurological disorder called Guillain-Barre syndrome.Brazil, the hardest hit country, sounded the alarm in October, when a rash of microcephaly cases emerged in the northeast.Since then, there have been 270 confirmed cases of microcephaly and 3,448 suspected cases, up from 147 in 2014.Amid alarm over the surge in microcephaly cases, Colombia, Ecuador, El Salvador, Jamaica and Puerto Rico have even warned women to delay conceiving until the Zika outbreak is brought under control.Jitters over Zika have spread far beyond the affected areas to Europe and North America, where dozens of cases have been identified among people returning from vacation or business abroad.