Could the Zika virus be heading for Europe?
Until last year outbreaks of the Zika virus were relatively short-lived and slow moving.
It was first discovered in Uganda in 1947, but because the virus is only transmitted by the Aedes mosquito, it took decades to cross the Pacific.
Then everything changed. Since reaching South America in 2014 Zika has spread rapidly northwards all the way up to Mexico - an unprecedented epidemic.
For most of its victims, Zika is little more than an inconvenience with symptoms including a low grade fever, a mild rash and possible conjunctivitis. It was thought to be a relatively benign.
Then came the awful realisation, only dawning over the past year, that if a mother-to-be contracts the virus the effects on her unborn child can be catastrophic.
That is the reality right now for pregnant women in Brazil, where most states have the mosquito-borne virus.
The country has witnessed a devastating explosion in the number of children being born with smaller heads or brains than usual - the medical name for that condition is Microcephaly - and with 30 more cases than any year since 2010 the evidence suggests it is being caused by the Zika virus destroying structures in the unborn child's brain.
There is no cure for Zika and no vaccine either - although the race is on to find one.
In Ebola-hit Africa, clinical trials that would normally take 18 months were completed in six weeks and a similar international effort is needed now in South America.
Trials for vaccines and drugs have to take place while the epidemic is still underway.
But at the moment, the authorities in Brazil, El Salvador and even Jamaica can only advise women to avoid getting pregnant.
What might sharpen minds and loosen governmental purse-strings further afield is how fast Zika could spread. The World Health Organisation warned today it could affect all of the Americas, bar Chile and Canada where it is too cold for mosquitoes that carry it to survive.
So could Zika spread beyond the tropics to Europe? And can in be controlled?
Although there have been reports of the virus being detected in sperm there is no evidence it can be caught from human to human contact - so you won't get it from somone with the disease travelling home to the UK.
But its pattern of spreading is thought to closely mirror Dengue Fever. A disease carried by the same Aedes mosquito which, despite control programmes, has proved very difficult to eradicate.
Professor Laura Rodrigues, Professor of Infectious Disease Epidemiology at the London School of Hygiene and Tropical medicine thinks Zika could now affect any area where dengue fever is widespread.
Before 1970 only nine countries had experienced severe dengue outbreaks.
In the past few decades international trade and our changing climate means the number of countries affected has become more than a hundred - from Africa, and Asia to the Eastern Mediterranean and the Western Pacific. In the past five years there have been cases in Florida, Madeira, Portugal and France with the WHO stating "The threat of a possible outbreak of dengue fever in Europe now exists".
And that pattern of mosquito movement means that although Zika may feel like a Latin American problem, it has the potential to affect us in future much closer to our shores. The best hope against that is a new vaccine - or the population in Latin America quickly developing local immunity.
Right now though, a generation of mothers and children on the other side of the globe are being dealt the toughest of hands.
As Professor Trudie Lang, Professor of Global Health Research at the University of Oxford, puts it, "Here we are again. As with Ebola, we have no drugs and no vaccines. We need international collaboration, partnerships and funding for research - and we need to get moving as quickly as we can".