The Zika virus, primarily spread by Aedes mosquitoes, has emerged as a significant global health concern. It is particularly notable for its association with serious birth defects when a pregnant individual becomes infected. While most Zika infections are mild or asymptomatic, the potential for severe consequences in unborn babies has led to public health advisories and research efforts.
Understanding Congenital Zika Syndrome
Congenital Zika Syndrome (CZS) encompasses a range of birth defects and developmental problems in infants whose mothers were infected with the Zika virus during pregnancy. The most recognized defect is microcephaly, a condition where a baby’s head is significantly smaller than expected, often indicating improper brain development.
CZS can also involve other severe brain abnormalities, such as intracranial calcifications (calcium deposits in brain tissue) and ventriculomegaly (enlarged fluid-filled spaces in the brain). Eye defects are common, including macular scarring, optic nerve hypoplasia, and cataracts. Some affected infants may exhibit joint problems like clubfoot or arthrogryposis, a condition marked by joint contractures that limit movement. Hearing loss, feeding difficulties, and seizures are additional complications.
The severity and combination of these defects vary considerably. The risk of birth defects is highest when infection occurs early in pregnancy.
How Zika Reaches the Unborn Baby
The Zika virus primarily spreads through the bite of an infected Aedes aegypti mosquito. Sexual transmission from an infected partner is another documented route. Less commonly, the virus can spread through blood transfusions.
Zika virus can be transmitted from a pregnant individual directly to their developing fetus, a process known as vertical transmission. The virus crosses the placental barrier, the organ that supplies oxygen and nutrients to the growing fetus. It can replicate within placental and fetal cells, eventually reaching the fetal brain, posing a risk to the fetus at any point during pregnancy.
Preventing Zika Infection During Pregnancy
Preventing Zika infection is important for pregnant individuals or those considering pregnancy, as there is currently no vaccine or specific antiviral treatment. Avoiding mosquito bites is a primary prevention strategy. This involves using EPA-registered insect repellents containing ingredients such as DEET, picaridin, or oil of lemon eucalyptus, and reapplying them as directed.
Wearing long-sleeved shirts and long pants can cover exposed skin. Staying in screened or air-conditioned rooms helps prevent exposure to mosquitoes. Eliminating standing water around homes removes potential breeding sites for mosquitoes.
For sexual transmission, consistent use of condoms or abstaining from sex with partners who have traveled to or live in Zika-affected areas is recommended. Pregnant individuals should consider postponing travel to areas with active Zika transmission. Checking travel advisories from health organizations like the CDC before any travel is important to understand current risks.
Diagnosis and Support for Affected Infants
Diagnosis of Zika infection during pregnancy can involve maternal blood and urine tests, and ultrasound monitoring for fetal abnormalities. After birth, diagnosis in newborns includes testing the baby’s blood, urine, or cerebrospinal fluid for Zika virus RNA and IgM antibodies. Head circumference measurements and brain imaging, such as head ultrasounds, are also performed to assess for microcephaly and other brain anomalies.
There is no specific cure for the Zika virus or the birth defects it causes. However, ongoing care and multidisciplinary support are available for children diagnosed with Congenital Zika Syndrome. This supportive therapy focuses on managing symptoms and improving developmental outcomes.
Infants with CZS often benefit from early intervention services, which can include physical therapy, occupational therapy, and speech therapy to help with developmental delays. A team of healthcare providers, including developmental pediatricians and specialists for vision or hearing, coordinates the child’s care to address their specific needs as they grow.