Latin America could be faced with thousands of neurological birth defects in the wake of current Zika outbreaks, World Health Organization (WHO) officials said Tuesday in Geneva.
Governments should therefore start expanding their health services to care for these children in the long term, rather than focusing only on individual cases, WHO Director General Margaret Chan said.
"A shift in our thinking is needed," she said.
WHO experts told reporters that 6,480 cases of babies born with unusually small heads have been reported alone in northeast Brazil, which is at the centre of the outbreak.
Of these, 2,212 have been investigated and 863 confirmed.
"If that rate continues, just over 2,500 cases will emerge" as confirmed cases in that region of the country, said Anthony Costello, the chief paediatric expert of the UN health agency.
"Infections certainly run in many, many millions" in Latin America, and thousands of cases of serious neurological effects from Zika could therefore be expected, said Christopher Dye, WHO's strategy chief.
There is not only growing evidence that Zika causes immune reactions leading to abnormally small heads in newborns - a condition known as microcephaly - but also to inflammation of the spinal chord and brain tissue, as well as impaired hearing and sight.
In addition, the virus has been linked to rising numbers of cases of Guillain-Barre syndrome in adults. This neurological disorder can lead to paralysis.
WHO has received only 3 million dollars of the 65 million it has requested in the fight against Zika, even though there is a risk that the virus could be transmitted in other regions by Aedes aegypti mosquitoes, Chan noted.
"More than half of the world population lives in areas where the Aedes aegypti mosquito is present," she said.