The mosquito-borne Zika virus, which has been linked to brain damage in thousands of babies in Brazil, is likely to spread to all countries in the Americas except for Canada and Chile, the World Health Organisation said yesterday.
Zika transmission has not yet been reported in the continental United States, although a woman who fell ill with the virus in Brazil later gave birth to a brain-damaged baby in Hawaii.
Brazil’s Health Ministry said in November that Zika was linked to a foetal deformation known as microcephaly, in which infants are born with smaller-than-usual brains.
Brazil has reported 3,893 suspected cases of microcephaly, the WHO said, over 30 times more than in any year since 2010.
The Zika outbreak comes hard on the heels of the Ebola epidemic in West Africa, demonstrating once again how little-understood diseases can rapidly emerge as global threats.
“We’ve got no drugs and we’ve got no vaccines. It’s a case of deja vu because that’s exactly what we were saying with Ebola,” said Trudie Lang, a professor of global health at the University of Oxford. “It’s really important to develop a vaccine as quickly as possible.”
The Sao Paulo-based Butantan Institute is leading the research charge on Zika and said last week it planned to develop a vaccine “in record time”, although its director warned this was still likely to take three to five years.
If the epidemic was still going on in August, when Brazil is due to host the Olympic Games in Rio de Janeiro, then pregnant women should either stay away or be obsessive about covering up against mosquito bites, said Laura Rodrigues of the London School of Hygiene and Tropical Medicine.
The WHO advised pregnant women planning to travel to areas where Zika is circulating to consult a healthcare provider before travelling and on return.
The symptoms of Zika are usually mild and often similar to dengue, leading to fears that Zika will spread into all parts of the world where dengue is commonplace. More than one-third of the world’s population lives in areas at risk of dengue infection, in a band stretching through Africa, India, south-east Asia and Latin America.