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Fiocruz identifies higher mortality in children with Congenital Zika Syndrome


Mariana Sebastião (Cidacs/Fiocruz Bahia)


When he was about to turn 4 years old, Julinho started to attend a day care center near his home. The adaptation was difficult for the adults in the family, who were used to taking care of him all the time. “What if he had a seizure?”, “What if he cried a lot?”, “What if they forgot the medication schedule?”. The questions were frequent. But the boy surprised everyone with his good integration: he didn't seem to miss his mother and grandmother, he was kind to his classmates and encouraged all the time to try new things. Even chicken with cassava, which he previously disliked, became his favorite food. Living with other children helped him to develop his walking, playing and eating in a surprising way.

Children with Congenital Zika Syndrome may have structural abnormalities such as microcephaly

Julinho is a four-year-old child born with the Congenital Zika Syndrome, an epidemic that reached its peak in Brazil in 2015. His story is told by the sociologist Ana Claudia Camargo in the book Micro-histórias para pensar macropolíticas (Micro Stories to Think Macropolitics). In the report, Dona Lúcia, the boy's grandmother, was constantly moved by having to leave him “alone” in these moments because, according to her, “these children are very fragile (...) any wind takes his life away...”

Dona Lúcia’s fear is real. An unprecedented study recently published in The New England Journal of Medicine, the journal with the greatest impact on the scientific community overall, found that children with Congenital Zika Syndrome are up to 11 times more likely to die when compared to children without the Syndrome by their third year of life. The study is part of the Long-Term Surveillance Platform for Zika and its Consequences research, coordinated by the Center of Integration of Data and Knowledge for Health (Cidacs/Fiocruz Bahia).

According to research associate at Cidacs and assistant professor at the London School of Hygiene & Tropical Medicine (LSHTM), Enny Paixão, author of the study, the main goal of the research was to compare the mortality between children with and without the syndrome, considering factors such as weight and gestational age at birth. Furthermore, the idea was also to analyze the main causes of death of children with Congenital Zika Syndrome, always comparing with children who do not have it.

Congenital Zika Syndrome may be presented in several ways. Children may have structural abnormalities such as microcephaly, functional abnormalities such as difficulty to swallow, or have clinical sequelae such as epilepsy. These consequences are caused by the effect of Zika virus on the babies' central nervous system when mothers are infected during pregnancy.

Mortality increased up to 3 years of age

To get to the results, data from more than 11 million live births registered in the Information System on Live Births (Sinasc) were analyzed in the period between 2015 and 2018 and crossed with data from the Public Health Events Registry (Resp). In this process, twins and children who were not yet confirmed or who were ruled out as having Congenital Zika Syndrome were excluded. The final sample of children with Congenital Zika Syndrome was 3,308 and, in this group, 398 deaths were recorded.

The work followed up these newborns for 36 months. It is the first study that analyzed the mortality of children diagnosed with the Syndrome with follow-up until the third year of life.

The research results show that, both in the neonatal period and after the first year of life, children with Congenital Zika Syndrome are more likely to die. Up to 28 days of life these chances are seven times greater than for children without Syndrome. This number increases even more between 1 and 3 years of age: the possibility of a child with Congenital Zika Syndrome dying is 22 times greater.

Age and gestational age influence the mortality rate

Although the study has identified that there is no difference in the mortality rate of children born at less than 32 weeks, whether they have the syndrome or not, this changes from that period onwards. Babies who have Congenital Zika Syndrome and are born between 32 and 36 weeks of gestation are nine times more likely to die. The chances increase to 14 times when the birth happens after 37 weeks.

The pattern is the same for birth weight. Although there is no difference for those born weighing less than 1.5 kg, whether or not they have Congenital Zika Syndrome, the picture changes if they are born with a weight considered adequate: the possibility of death of children with the Syndrome is 13 times greater.

For Enny Paixão, in the face of such alarming numbers, it is necessary to implement measures after birth that help improve the survival of these children: “We need well-established postnatal protocols, including early intervention, to help reduce sequels and improve their survival”, she explains.

The professor at the Federal University of Bahia and researcher associated with Cidacs/Fiocruz Bahia, Glória Teixeira, also author of the study, highlights that these children and their families need to be supported by policies from the point of view of health care and socioeconomic issues: “The increase in neonatal ICU beds is a fundamental policy to prevent deaths from congenital neurological syndromes. We observed that children died more frequently in locations with few neonatal ICU beds. These children need rehabilitation centers: they are born with fewer neurons and with damaged neurons, but they have neurons that can be stimulated, which can improve their cognition and motor process”, she explains.

Main causes of registered deaths

In addition to analyzing the main causes of deaths registered among children with Congenital Zika Syndrome in the period studied, the work also compared these causes in the deaths of children without the Syndrome.

The analysis showed that among children who had Congenital Zika Syndrome, mortality from congenital anomalies is much higher. Infectious and parasitic diseases are also among the main causes of death in this group when compared to children without any syndrome. After one year of life, deaths from causes related to the central nervous system start to increase significantly when compared to children without Congenital Zika Syndrome.

Enny Paixão believes that the study draws attention to the need to prevent infection by the zika virus: “Primary prevention is essential to avoid congenital infection”. Glória Teixeira draws attention to the union of the municipal, state and federal spheres to better distribute care to these children and mothers: “It is essential to provide services and trained professionals for care at the local level. Health Surveillance managers and technicians from the three management levels must exchange information and think of strategies to capillarize actions”, she says.

The coordinator of Cidacs/Fiocruz Bahia, Mauricio Barreto, co-author of the study, believes that the study has the potential to be used immediately by managers of health systems. “We are very proud of this study as a complement to the effort to demonstrate the power of Brazilian routine health data, carefully processed by Cidacs, to produce solid scientific knowledge around critical health issues, with a high level of generalization and applicability, and for immediate use by decision-makers”, he says.

It is these public policies supported by solid scientific evidence that will help other mothers like Julinho's to see their children survive the syndrome and face other challenges of childhood.

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