Carnival is under way in Brazil, but in Recife there is nothing to celebrate for hundreds of families caring for children with microcephaly, and for more pregnant women whom tests show are about to give birth to a baby with the same congenital defect.
It was in December, while on holidays in Brazil, that I first heard of the possible link between a "new" mosquito-borne virus called Zika and a birth defect called microcephaly.
By January, the number of reported cases had skyrocketed, especially in the hot and humid northeastern state of Pernambuco.
So, we went to see for ourselves what was happening.
At a rehabilitation centre, we found 70 mothers holding their newborn babies, all of them diagnosed with microcephaly.
It was heart-breaking to see how so many of the mothers had dressed their baby girls with large, colourful headbands and bows, that only partially disguised their visibly smaller than normal heads.
Children born with microcephaly have smaller brains, which usually limits intellectual and motor skill development.
On this day, the mothers were waiting for their children to be checked by ophthalmologists for possible scarring of the retina, which doctors are finding in more than 40 percent of cases of babies born with microcephaly.
"We do not know for sure if this is another consequence of the Zika virus, but we suspect it is," Dr Natalia Ventura told me.
"The vast majority of these children will have permanent disabilities, so it is extremely important to start rehabilitation right away."
When I picked up three-month-old Daniel, a beautiful baby boy, I immediately noticed that his arms and legs were unusually stiff.
"Yes, this is common for babies with microcephaly. His legs and arms hurt, so I have to massage him," Cassia Carneiro, Daniel's mother, told me.
"I had no idea that my baby could be in danger when I was pregnant and caught Zika.
"Now, my biggest concern is to find someone who can take care of the baby so I can return to work. But no one wants to look after him when they discover he has microcephaly, which also causes seizures.
"They say it is too much responsibility."
Rumours and speculation
One month later, I've returned to Recife to find that even more babies are being born with microcephaly, as well as hearing and sight defects.
The virus has now spread to 22 other countries in the Americas, as fast as the rumours and speculation associated with Zika.
Is it true that the virus can be spread by sexual contact? Does the virus remain dormant in the body even after the symptoms have passed?
When is it safe to have children after being infected?
Are young children infected with Zika after birth also at risk of suffering brain lesions?
And why is it taking so long to scientifically prove or disprove that the virus is in fact responsible for the alarming rate of birth defects?
I went to Sao Paulo to talk to the scientists who have been leading the investigation into the virus, which was discovered in Africa and Polynesia decades ago, but is new to the Americas.
Very little is really known about it. A Zika Network, or taskforce, has been set up with 300 researchers from Brazil's top universities, especially the University of Sao Paulo, where I meet Professor Jean Pierre Schatzmann Peron.
He is an epidemiologist at the Institute of Biomedical Science and has been experimenting with mice with young since December, to try to establish the link between Zika and newborn babies.
He says he and his team have barely slept since the experiments began.
"We have no time to waste," he said.
"Mice are not the same as humans, but they provide an important guideline, or indication, of what the virus is capable of doing. From a scientific point of view, we are just beginning. It is not something you can establish overnight."
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I ask if it is possible for a woman to pass the virus onto her unborn child if she becomes pregnant weeks, or months or years after she has become infected.
"Yes, it is possible," he replied.
"We simply do not know where the virus goes after it leaves the bloodstream, which occurs very quickly. It could go to the liver, or to another organ, as happens with chicken pox, for example. There is so much we do not yet know. Nothing can be confirmed or discounted at this point."
Peron also told me he believes the number of reported cases of microcephaly in Brazil - more than 4,000 - has been overestimated, because very small newborns are sometimes misdiagnosed.
"But this does not minimise the very real spike in the number of brain defects we are seeing, nor the need to urgently determine what is causing it.
That is exactly what Professor Margareth Caputto also tells us when we visit her in her laboratory.
She is a biochemist who has been experimenting for years with genetically modified male mosquitos.
She says she and her team have created a new one that can basically sterilise the female mosquito, so that it cannot produce larvae. It should be ready for wide use within the year, she hopes.
"Genetically modified mosquitos are not the silver bullet that will eliminate dengue, chikungunya and now Zika, which are all carried by the same type of mosquito, the Aedes aegypti," she said.
"But it is a powerful weapon against an urban mosquito that the world can live without. It's a kind of war. If you have this war, you don't send just the soldiers, you need to send the entire army that you have. The army, navy, everything. The tanks, the bombs - everything."
She says an integrated control strategy is needed, that includes genetically modified mosquitos, programmes to eliminate mosquito breeding grounds, insecticides and vaccines.
"There is no single solution," Caputto said.
I then went to speak to Jorge Kalil, the director of the Butantan Institute, a world-renowned biomedical research centre with an impressive record for discovering vaccines, most recently, for dengue fever.
Dr Kalil tells me they are "working against the clock" to create a Zika vaccine.
"There is no time to lose because this virus could potentially have devastating consequences for an entire generation, if it is proven to provoke birth defects. It can spread far beyond the Americas, so it is an issue for the entire world," he says.
But Dr Kalil is optimistic. "We have been working for decades unsuccessfully to find a vaccine against HIV, but I believe we will soon be successful in the case of Zika, because it is related to the dengue virus, and here we have already created a vaccine."
This hopefully should make it easier to "decode" the Zika virus in order to do the same, but just how quickly he cannot say.
I mention that we have just heard reports that a person in Texas is believed to have been infected with Zika through sexual contact with a person who caught the virus in Latin America.
Is it possible, I ask?
"That is surprising, but not impossible.
"However, it would be very rare, because the Zika virus remains a short time in the bloodstream and in a low concentration, which would make it difficult for it to be passed on through semen, for example. In any case, the link has not been established."
Can a child who is infected by a mosquito suffer brain lesions, as social networks are suggesting?
"We don't know that for sure either," he concedes, adding that funding for more research is urgently needed.
So, as I fly back to Recife to meet more mothers at the Rehabilitation Centre, to see how they learning to care for their babies with microcephaly, I can't help but lament that for them and the world, there are still so few answers to so many pressing questions about this mysterious disease.
Source: Al Jazeera