NIH Examines Outcomes of Postnatal Zika Infection in Guatemalan Infants & Children

The National Institutes of Health recently announced that the National Institute of Allergy and Infectious Diseases (NIAID) has teamed up with a nonprofit foundation called FUNSALUD to conduct a large natural history study that will take a closer look at “neurologic, neurodevelopmental, and clinical outcomes” pertaining to Zika virus in infants and young children residing in Guatemala. The NIH will provide funding for the study.

Researchers have already discovered that if a woman becomes infected with the Zika virus while she is pregnant it can have serious implications for the unborn fetus, such as the development of congenital Zika syndrome which could lead to birth defects such as microcephaly. The NIAID study will focus on infants and children in Guatemala who are infected postnatally, however, rather than congenitally. This is because although past research has suggested that Zika virus possesses the potential to impact early brain development, “the full spectrum of possible consequences” remains unknown.

“The natural history study of Zika among Guatemalan children promises to yield valuable insights into acute and longer-term outcomes of infection,” NIAID Director Anthony S. Fauci, MD, explained in the press release. “It is imperative that we understand the potential neurologic and neurodevelopmental outcomes of Zika virus infection in children infected in infancy and early childhood.”

According to the Pan American Health Organization, in different parts of Guatemala, Zika virus transmission remains active, despite reports that the virus is no longer active in other regions, such as Puerto Rico. A surveillance study “characterizing the incidence and pattern of Dengue virus in children in” southwestern Guatemala, conducted by the University of Colorado, also confirmed active transmission of the virus as well as high infection rates among “children with fever.”

This new study can have a positive impact on families living in rural Guatemala, a place that is fraught with poverty, in that it can provide access to an early Zika diagnosis. The researchers are looking for answers regarding whether the virus is capable of interfering “with the normal development of young children.” According to Antonio Bolaños, MD, medical director at the FUNSALUD clinic where the study will occur, “any Zika effect on neurodevelopment [of impoverished children in the country] will add burden to their futures.”

The researchers aim to enroll around 1200 infants and children (all under 5 years) in the study. In addition, they plan to include a cohort consisting of 300 children who were infected with Zika and/or Dengue virus postnatally. These children were also included in the University of Colorado’s surveillance study. They will also enroll a cohort of around 500 newborn babies who have not been infected with Zika virus, as well as these babies’ mothers and siblings. The cohort consisting of siblings will comprise about 400 children who are under 5 years of age.

Over the course of 1 year, the researchers will monitor the “infants, children, and mothers” through home visits, phone calls, and appointments at the FUNSALUD clinic. Study participants will, on a regular basis, provide “body fluid samples” and undergo screening for new potential infection with either Zika, Dengue, or Chikungunya viruses. In addition, the participants will undergo several examinations, including: physical, neurologic, neurodevelopmental, hearing, and eye tests. Families who choose to enroll their children in the study will be provided with preventive counseling. Some of the topics that they will discuss include:

• The best ways to prevent mosquito-borne illnesses
• How to remove standing water in and around the home
• The correct use of mosquito nets, insect repellants, and protective clothing

The chief aims of the study are to “classify these outcomes among children with or without symptoms of Zika virus infection and compare them to the outcomes of other viral infections, such as dengue or chikungunya.” Furthermore, the researchers will also be taking a closer look at “levels of Zika virus nucleic acid” as well as “neutralizing antibodies” to understand if “certain thresholds correlate with specific clinical, neurologic, or neurodevelopmental outcomes.”

The researchers also aim to “characterize the effect of prior maternal Dengue virus infection in Zika virus-infected infants.” They also seek to assess if maternal infection, or a child’s own previous Dengue infection, could result in increased severity of Zika virus in the child “via antibody-dependent enhancement.”

According to the press release, other avenues that researchers wish to find answers to are:

• How long Zika virus RNA can persist in body fluids in infants/young children
• How long Zika virus RNA can persist in maternal breast milk
• If lingering virus impacts clinical and neurologic outcomes
• To determine any potential for virus transmission

The researchers expect the study to take 3 years for completion; however, they predict that preliminary results may be available in 1 year.

They hope that the findings yielded from this study will not only “help inform global public health practices and assist Guatemalan health officials as they seek to understand the risks associated with early childhood Zika infection,” but also help create “healthcare programs that will provide Zika-related healthcare of benefit to Guatemalan children and families.”