Nav: Home

Two Brazilian studies show new discoveries related to Zika virus

October 11, 2016

A Brazilian study shows that infection of a pregnant woman by Zika virus may represent a risk to the baby's neurological development even when it occurs only a few days before the mother gives birth.

"Until now, the paradigm has been that infection by Zika was a problem only if it occurred in the first trimester, but we observed brain damage in four infants whose mothers were infected between two weeks and one week before they gave birth," said Maurício Lacerda Nogueira, a professor at the São José do Rio Preto Medical School (FAMERP) in São Paulo State, Brazil, and a member of the state's Zika Virus Research Network (Rede Zika).

In the five-year prospective cohort study, a group of 55 women infected by Zika during pregnancy are being monitored at Hospital de Base, São José do Rio Preto's reference hospital. Zika infection in these women was diagnosed by real-time polymerase chain reaction (RT-PCR) testing. Their babies are also being submitted to detailed tests and examinations as they are born.

In four of the newborns exposed to the pathogen during the last trimester of gestation, diagnostic imaging showed central nervous system lesions that are characteristic of congenital viral infections. Moreover, Zika virus was detected in the babies' urine and blood at delivery, confirming vertical transmission (from mother to fetus). Two of these cases are reported in the published article.

"These infants were born with normal length and weight and without microcephaly or any other symptoms of the disease," Nogueira said. "The lesions would have gone unnoticed by health workers if the mothers hadn't been part of a study group."

According to Nogueira, the lesions observed - including lenticulostriate vasculopathy (ultrasound-visible brain lesions appearing as streaks or spots in certain arteries) - have not been associated with severe complications in previous studies, but the implications for the neurocognitive development of these Zika-infected infants are unknown.

"We mean to keep monitoring the development of these babies for several years in order to detect any problems," he said. "This discovery reveals another spectrum of the disease, making it even more complex. In addition to the dramatic cases of microcephaly, there are less severe manifestations that need to be properly understood."

Zika in transplant recipients

Another article by researchers at FAMERP describes for the first time manifestations of Zika virus in patients previously receiving organ transplants. The study was also led by Nogueira under the aegis of Rede Zika.

As Nogueira explained, these patients take immunosuppressants continuously to prevent rejection of the transplanted tissue, so any infection can become severe with a heightened risk of complications.

"Because Sã José do Rio Preto is one of the leading transplant hubs in the interior of São Paulo State, as well as a major focus of dengue, for some years we've been painstakingly monitoring transplant recipients with symptoms of dengue fever," he said. "When the Zika epidemic emerged, we began investigating whether some of the suspected dengue cases were actually Zika infections."

Two recipients of kidney transplants and two recipients of liver transplants were diagnosed with Zika using RT-PCR assays performed at Hospital de Base. All four had to be hospitalized and presented with complications, notably bacterial infections. The good news is that all four survived.

"These transplant recipients didn't have the typical symptoms of Zika, such as exanthema (skin rash), itching and conjunctivitis," Nogueira said. "Actually, it was hard to distinguish their clinical manifestations from those observed in dengue patients. They had a low platelet count, for example."

None of them had severe manifestations such as Guillain-Barré syndrome, "but as the number of cases rises, it should be easier to detect these phenomena," he said.
-end-


Fundação de Amparo à Pesquisa do Estado de São Paulo

Related Infants Articles:

Deaf infants' gaze behavior more advanced than that of hearing infants
Deaf infants who have been exposed to American Sign Language are better at following an adult's gaze than their hearing peers, supporting the idea that social-cognitive development is sensitive to different kinds of life experiences.
Initiating breastfeeding in vulnerable infants
The benefits of breastfeeding for both mother and child are well-recognized, including for late preterm infants (LPI).
Young infants with fever may be more likely to develop infections
Infants with a high fever may be at increased risk for infections, according to research from Penn State College of Medicine.
Early term infants less likely to breastfeed
A new, prospective study provides evidence that 'early term' infants (those born at 37-38 weeks) are less likely than full-term infants to be breastfeed within the first hour and at one month after birth.
Infants are more likely to learn when with a peer
Researchers at the University of Connecticut and University of Washington looked at the mechanisms involved in language learning among nine-month-olds, the youngest population known to be studied in relation to on-screen learning.
Allergic reactions to foods are milder in infants
Majority of infants with food-induced anaphylaxis present with hives and vomiting, suggesting there is less concern for life-threatening response to early food introduction.
Non-dairy drinks can be dangerous for infants
A brief report published in Acta Paediatrica points to the dangers of replacing breast milk or infant formula with a non-dairy drink before one year of age.
Infants can't talk, but they know how to reason
A new study reveals that preverbal infants are able to make rational deductions, showing surprise when an outcome does not occur as expected.
Infants are able to learn abstract rules visually
Three-month-old babies cannot sit up or roll over, yet they are already capable of learning patterns from simply looking at the world around them, according to a recent Northwestern University study published in PLOS One.
Baby brains help infants figure it out before they try it out
Researchers at Penn State are using new statistical analysis methods to compare how we observe infants develop new skills with the unseen changes in electrical activity in the brain, or electroencephalography (EEG) power.
More Infants News and Infants Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.