Zika Virus Affecting Infant Hearts

Higher frequency of major heart defects noted in Zika virus exposed infants

infant with dads hands

The Zika virus has now been found to impact the hearts of infants.

A team of researchers performed a cardiologic assessment of 120 infants born with confirmed vertical exposure to Zika virus (ZIKV).

This study found a 10.8 percent incidence of structural heart defects in infants with a history of intrauterine exposure to ZIKV.

Which is a rate considerably higher than the general population.

The presence of major heart defects was increased in infants in three ways:

  • 14% more frequent in preterm infants than in term babies,
  • 11% higher in infants with altered CNS imaging tests,
  • 10% higher in infants whose mothers had a history of rash in the 2nd trimester as compared to other time points or no rash.

Severe heart defects requiring immediate intervention were not identified during this study.

The group based its findings on clinical exams from November 2015 to January 2017 in Rio de Janeiro whose Zika exposure was confirmed by maternal blood or amniotic fluid tests or lab tests of samples from the infant after birth.

Congenital Zika syndrome, resulting from vertical transmission of the virus, includes microcephaly, specific findings from imaging of the central nervous system, visual and auditory deficits, and arthrogryposis.

All 120 infants in this study had negative serology result for other congenital infectious including toxoplasmosis, rubella, cytomegalovirus, hepatitis B, C, and HIV, in addition to no diagnosis of genetic syndromes potentially accompanied by congenital heart defects.

None of the children had previous fetal ECHOs.

The diagnosis of ZIKV exposure was confirmed by RT-PCR in a blood sample from the mother and/or in the amniotic fluid during pregnancy and/or in infant specimens including PCR of the cerebrospinal fluid and/or urine following birth.

The authors said their study is the first to report echocardiogram findings. The cardiologic assessment includes echocardiography performed by pediatric cardiologists.

The researchers said that routine echocardiography for all Zika-exposed babies doesn't appear to be warranted.

With the increase in the number of studies ordered in mother-infant pairs with suspected or confirmed ZIKV infection in pregnancy, it becomes important to verify which tests are really necessary to promote better use of health resources in Brazil and elsewhere, while still enabling optimal care for these patients.

In the USA, the CDC recommends Zika virus testing for:

  • Anyone with possible Zika virus exposure who has or recently experienced symptoms of Zika
  • Symptomatic pregnant women with possible Zika virus exposure
  • Asymptomatic pregnant women with ongoing possible Zika virus exposure
  • Pregnant women with possible Zika virus exposure who have a fetus with prenatal ultrasound findings consistent with congenital Zika virus infection

The rise in the spread of Zika virus has been accompanied by a rise in cases of microcephaly and Guillain-Barré syndrome. First identified in Uganda in 1947 in monkeys, Zika was later identified in humans in 1952.

The first large outbreak of disease caused by Zika infection was reported from the Island of Yap in 2007. There are currently several countries experiencing Zika virus outbreaks, reports the WHO.

As of March 20, 2018, 52 additional pregnant women with laboratory evidence of possible Zika virus infection in the US States and the District of Columbia have been included since the last reporting date, February 20, 2018.

Study funding: Sonia Regina Lambert Passos was supported by MCTI | Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Grants 440846/2016-1 and 310765/2016-1; supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Grant 88881130793/2016-01 and by Universidade Estácio de Sá-Bolsa Produtividade. Helena Alencar Rosa Teixeira Mendes was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Grant 88887130789/2016-00. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.