The fast-spreading Zika virus, which is believed to cause birth defects, has already reached 21 countries in Central and South America, the World Health Organisation warned yesterday.
The virus is likely to affect the entire western hemisphere, apart from frost-prone regions that are too cold to support the mosquitoes that transmit the disease.
Margaret Chan, WHO director-general, described the “explosive spread” of Zika as “extremely worrying”. Virologists say the virus infects the brain in the growing foetus, causing microcephaly — babies born with a very small head and associated neurological problems — although the causal link has not yet been proved.
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