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 Consultations among doctors in Brazil and the United States have
increased in the last two weeks, and some of the leading authorities
on the condition are finding patterns of unusual devastation in
scans of the newborns' malformed brains.
While it's not known how representative the scans are, the early
observations of these doctors point to a tough road ahead for the
babies, their families and their communities and heighten the
concern surrounding Zika, which is suspected of causing microcephaly.
"We are in the process of very rapid information gathering on what
has been seen," said Dr. William Dobyns, a geneticist at Seattle
Children's Hospital. "The condition that I've been able to review,
very preliminarily, is more severe than simple microcephaly."
The Zika virus is transmitted by mosquito, causing mild symptoms in
about 20 percent of cases, and most people experience no illness at
all. But a spike in reported microcephaly cases among babies in
areas of Brazil with Zika outbreaks has triggered an international
effort to determine whether the virus causes the condition. The
suspected association moved the World Health Organization (WHO) on
Monday to declare an international health emergency.
Dobyns has spent 30 years researching and treating microcephaly, a
condition defined by abnormally small heads in newborns that can
lead to developmental disabilities, from mild to severe. The U.S.
Centers for Disease Control and Prevention (CDC) has sought out his
expertise in understanding the unfolding epidemic.
With a small group of geneticists and other microcephaly
specialists, he recently reviewed scans of a handful of babies sent
by a colleague in Brazil. All the experts were struck by the scale
of malformations, he said.
"These children have a very severe form of microcephaly," Dobyns
said. "The brain is not just small, it's small with malformations of
the cerebral cortex and calcifications. It has the appearance of a
very severe, destructive injury to the brain."
Particularly alarming, Dobyns said, is the presence in the Brazilian
cases of excess spinal fluid between the brain and skull of the
babies.
"If the brain is growing and then suddenly shrinks, then you'll see
fluid between the brain and skull," he said. "It has a pattern that
suggests that the brain has actually decreased in size."
Dr. Leonardo Vedolin, a neuroradiologist and researcher at the
Moinhos de Vento hospital in Porto Alegre, Brazil, shared with
Dobyns scans of two more microcephalic babies this week. The doctors
belong to a brain defects study group that convenes via
videoconference each month. The group is now focused on Zika.
Neither Vedolin nor Brazil's Health Ministry were able to provide a
breakdown on the severity of confirmed microcephaly cases. In
general, Vedolin said, 5 percent of microcephaly cases are severe.
But the proportion appears greater among the cases in Brazil, he
said.
THE CASELOAD
Public health officials in Brazil are investigating more than 4,000
cases of suspected microcephaly, and have confirmed more than 400.
Prior to the Zika outbreak, Brazil saw on average 163 cases annually
of microcephaly over the past five years, according to WHO. In 17 of
the new cases, the presence of Zika was identified in the mother or
the baby.
A study of 35 Brazilian babies born with microcephaly during the
Zika outbreak reported by the CDC Jan. 29 added strength to the
suspected connection.
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The mothers of all 35 infants had lived in or visited Zika
virus-affected areas during pregnancy, the report said. Twenty-five
infants had severe microcephaly, and 17 had at least one neurologic
abnormality.
Dr. Frank Esper, an infectious disease expert from Rainbow Babies &
Children's Hospital in Cleveland, said he expects a steady wave of
studies on Zika and microcephaly that will provide a much clearer
picture over the first half of 2016.
By the broadest definition, about 2.3 percent of all babies are
microcephalic, Dobyns said. Some cases are so mild they involve no
complications at all.
About one tenth of one percent of the cases are so severe that
lifelong care is required, he said. There are many known causes,
including a wide range of genetic disorders such as Down syndrome,
as well as oxygen deprivation to the fetus, cytomegalovirus and
severe fetal alcohol syndrome.
Lifespan in severe cases can be months or as long as 10 years,
depending on proximity to good medical care, Dobyns said.
Dr. Dawn Nolt, a member of the American Association of Pediatrics' (AAP)
Committee on Infectious Diseases, and other doctors, said more
severely affected children often require treatment for epileptic
seizures, as well as physical, respiratory and speech therapy. They
may need help with everyday activities, such as eating or walking.
"It's crucial to go to a care center with good neurology and
genetics teams that can evaluate the child comprehensively," said
Dr. Ghayda Mirzaa, a pediatric neurologist and colleague of Dobyns
at Seattle Children's.
Doctors in Recife, Brazil are sending mothers with afflicted babies
for therapy to help stimulate eyesight, hearing and motor skills to
minimize retardation in mental and physical development.
There are a handful of centers of microcephaly research and
treatment in the U.S., including Dobyns' hospital in Seattle. The
consultations of physicians like Dobyns in the Brazil cases is
informal at this point but could form the basis for an organized
exchange of expertise that will inform the ongoing care of the
children of the epidemic.
"We need to get the message out that this is real, and coming,
without getting everybody to panic," Dobyns said. "There will be a
steep curve of new information coming in."
(Reporting by Bill Berkrot and Anthony Boadle; Editing by Michele
Gershberg and Lisa Girion)
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