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Zika-Linked Brain Damage In Infants May Be 'Tip Of The Iceberg'

Gleyse Kelly da Silva holds her daughter, Maria Giovanna, who was born with microcephaly.
Felipe Dana
The Florida Channel
Leon County Judge John Cooper on June 30, 2022, in a screen grab from The Florida Channel.

Dr. João Ricardo de Almeida is part of a team in Brazil that's investigating the cases of microcephaly — brain damage in infants born to mothers who contracted Zika virus during their pregnancy. He's examined dozens of brain scans, and he says that the scans are "very scary to look at."

"You see very profound abnormalities," says the neuro-radiologist. "Usually it's striking."

And they're notably different than scans of other babies born with the birth defect.

That's one of the disturbing findings in a large-scale study of the babies born with microcephaly. A team of doctors — from a neuro-pediatrician to an ophthalmologist — have taken a good look at dozens of affected infants. They're conducting the study at Roberto Santos General Hospital in the city of Salvador in Bahia.

One goal is to establish whether the Zika virus is in fact the cause of the thousands of cases of microcephaly in babies born since the fall.

Dr. Adriana Mattos examines three-month-old Barbara Antonia, who has microcephaly. Her mother, Ana Claudia Teixera, caught the Zika virus when she was four months pregnant.
/ Lourdes Garcia-Navarro/NPR
The Florida Channel
Dr. Adriana Mattos examines three-month-old Barbara Antonia, who has microcephaly. Her mother, Ana Claudia Teixera, caught the Zika virus when she was four months pregnant.

"Of course the evidence is mounting but we need to prove," says Dr. Antonio Raimundo de Almeida, director of the hospital, which is in the city of Salvador in the state of Bahia. (He is a cousin of the other Dr. de Almeida.)

This week, 16 mothers and their microcephalic babies came to the hospital for a battery of tests.

"We do a full history, we do a blood test, everything," hospital director de Almeida says.

In the waiting room, the mothers cradle their infants, who all have the small cranium that is typical of microcephaly. Microcephaly itself is not a disease. It's a condition caused by the failure of a fetus's brain to develop in the mother's womb. There can be a number of causes, including toxoplasmosis, cytomegalovirus, syphilis, rubella and genetic abnormalities. So first, the researchers need to rule out these causes out.

In their research, the doctors have made some startling discoveries: There are some unique markers in the infants who have suspected cases of Zika-related microcephaly.

In one of the rooms, Dr. Adriana Mattos examines 3-month-old Barbara Antonia. Her mother, Ana Claudia Teixera, caught Zika when she was four months pregnant.

Dr. Mattos flips the child so she's lying on her chest. The doctor points out that in these Zika-related cases, the muscles in the upper body and neck are unusually stiff. And that's very different from cases of microcephaly caused by other infections.

Dr. João Ricardo de Almeida says the infants born to mothers who were infected in the first trimester seem to suffer the most brain damage. And that kind of damage also appears to be different than what you would see with microcephaly caused by other types of infections.

"Regarding Zika there seems to be some particular abnormalities that we do not see in [microcephaly cases caused by] toxoplasmosis or cytomegalovirus or rubella."

A normal brain has ridges like coral. The brains of these babies look "like a smooth rock," he says.

He says the degree of brain damage he is seeing will probably mean that rehabilitation will be very difficult.

"They are not going to be functional," he says of the babies he has examined. "They'll need care for the rest of their lives."

Dr. Albert Ko from Yale University has been collaborating with the study in Bahia. He says that while the cases of microcephaly are getting all the attention, the Zika virus could be having a wider range of effects on the development of a fetus.

"We are seeing cases in the hospital of children who have normal size heads but are having neurological lesions and eye lesions," he says. "And we are extremely concerned ... this might suggest that [the microcephaly cases] are just the tip of the iceberg."

In other words, even children who appear normal may suffer from a range of developmental delays. So the deeper the investigation goes into this outbreak, the more worrying it becomes.

Valdemar Geo contributed to this report.

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Lulu Garcia-Navarro is the host of Weekend Edition Sunday and one of the hosts of NPR's morning news podcast Up First. She is infamous in the IT department of NPR for losing laptops to bullets, hurricanes, and bomb blasts.