Despite the heat, I'm in long sleeves and long pants, with an extra layer of pesticide for good measure. I'm not making it easy for any local mosquitoes to bite me and implant the virus they carry. But everywhere I look, women and children are in shorts and tank tops, and the men bare chested. Even in the dead of winter, Brazil's heat is oppressive.
Beside me walks Dr. Jamary Oliveira Filho, a Harvard-trained neurologist who is showing me around his hometown, where his family still lives. He's taken me to this favela to show me firsthand the sort of environment that is the perfect breeding ground for Zika.
"This is a typical community in Salvador," he tells me. The houses are often half-finished and there are no screens on the windows, no climate control. Roofs are flat, where water can gather. Main streets might be asphalt, he says, but the side streets will be dirt, where water can also pool and attract mosquitoes.
"The people move in without good infrastructure because they need to live close to work," Filho explains. "And it's the perfect setup for an epidemic to occur, where there's already inadequate economic and social conditions."
Right now in Brazil, there are more than 1,700 confirmed cases of Zika-related microcephaly, a rare birth defect that results in an underdeveloped brain. More than 1,400 of those cases are in the northeast region of the country, in and around Salvador. Compare that to 121 cases in the Southeast, 61 in the center and 11 in the South, and you begin to wonder: Just what is it about this part of the country that is making women and their babies so susceptible to Zika's birth defects? Could it be nutrition? Some unknown environmental factor?
It's a question Filho and his colleagues desperately want to answer.
The epidemic up close
Three mothers and their babies are gathered in a clean, sparsely decorated room at the Hospital Geral Roberto Santos. They've brought their babies at our request for an extra day of therapy at the hospital's microcephaly clinic. It's located in a simple neighborhood not far from Engomadeira, one of the poorest and most dangerous favelas in the city.
All of these mothers were bitten during their pregnancy by Zika-carrying mosquitoes, long before anyone knew of the danger. Today they are living with the consequences, babies with brains that did not develop, leaving them prone to blindness, deafness, epileptic seizures and even the inability to suckle and grow.
No one knows what the long-term impact of microcephaly will be for these families. In the U.S., the March of Dimes recently estimated the cost of care for one American child with microcephaly to be $10 million dollars.
These mothers jumped at the chance to get additional therapy for their babies. It's mostly sensory stimulation designed to get the children to use their senses and galvanize new brain growth. Therapists slather shaving cream on giant red balls, and encourage the children to stroke. Tiny feet are placed in buckets with pea-sized balls, and enticed to kick.
Zika has robbed them of much of their sight, so glasses are put on each of the children several times a day, to encourage them to open their eyes and take in the world. Black and white toys, the sort you give a newborn for stimulation, are dangled to excite, even though these infants range from six to eight months old.
I am quickly drawn to 7-month-old baby Julia, a chubby darling with wide brown eyes. She seems to be sitting up straighter, and managing to hold her head up higher than the other babies in the room. It's a skill they should have all mastered by three months of age.
I cuddle her in my arms and quickly feel the rigidity in her muscles, a classic sign of microcephaly. Despite that, she grasps my finger firmly.
"That's a good grip!" I tell her with a smile. "Can I give your hand a kissie?" I kiss it again and again, with exaggerated smacking sounds. And guess what? Julia laughs! And then she stares deeply into my eyes.
"We've got a connection here," I tell her mom. "We have certainly got a connection."
And then we all laugh, Julia included.
A ray of hope?
The clinic is the brainchild of hospital director Dr. Antonio Raimundo Pinto de Almeida and Yale University Professor Dr. Albert Ko
. Along with Filho, they are part of a multi-disciplinary team that had been studying health issues in urban slums for more than 20 years when Zika appeared on the scene. They quickly turned their attention to the virus and began to investigate the unknowns. To do so, they found and enrolled more than 1,200 women in the area to follow the progress of their babies, many born with microcephaly.
They were one of the first teams in Brazil to discover birth defects beside microcephaly in children born of Zika, and began cataloging their findings months ago. Even in children born with normal heads, they've documented eye lesions, hearing loss and developmental delays, and fear they have only seen a small part of what Zika may have in store.
Filho and I huddle in front of images of Julia's brain, captured by a CAT scan and projected upon the wall. He points to the telltale signs of microcephaly, calcifications and a loss of brain volume, and shows me how he can tell that Julia was one of the unlucky ones. Her mother was bitten in her first trimester of pregnancy. Studies show the brains of those children are the most severely damaged.
"You see the brain is severely distorted," says Filho, pointing with his finger. "This is pretty severe for a congenital disease."
Is there anything he's learned from these brains that has surprised him?
"Certainly the difference between how severe the brains look and how well the children are developing. I think with the stimulation the children are getting from the therapy, we see better outcomes than we'd expect from looking at the scans."
Is that some good news? I'm hoping the answer is "yes."
"That's some good news, yes," he tells me. "At least for the time being, they are growing well, despite all of the challenges they are facing."