Zika and Pregnancy in the Caribbean: Real Risks and Essential Precautions

The Zika Virus: A Silent Threat

The Zika virus (ZIKV) belongs to the Flaviviridae family, like dengue and yellow fever. Discovered in 1947 in Uganda's Zika forest, it remained largely unknown before triggering a major global epidemic between 2015 and 2016, particularly affecting Latin America and the Caribbean.

Zika's distinctive feature is its ability to cause severe congenital malformations when the mother is infected during pregnancy. This characteristic makes it a primary health concern for pregnant travelers or women of childbearing age.

Transmission: How Is Zika Contracted?

Zika is primarily transmitted through the bite of the Aedes aegypti mosquito and, to a lesser extent, Aedes albopictus — the two most widespread species in the Caribbean. But unlike dengue, Zika has additional transmission routes:

Key point: Sexual transmission of Zika is documented and can occur even without symptoms in the infected partner. This transmission route is particularly important for couples to understand.

Symptoms: An Often Asymptomatic Disease

One of Zika's most deceptive characteristics is that 80% of infected people show no symptoms. When symptoms do appear, they are generally mild and last 2 to 7 days:

• Mild fever (37.8–38.5°C / 100–101.3°F), less intense than dengue
• Maculopapular rash (small red spots on the skin)
• Conjunctivitis (red, irritated eyes)
• Joint pain (arthralgia), particularly in the hands and feet
• Moderate headaches
• General fatigue

These symptoms are often confused with mild dengue or flu. Without laboratory testing, clinical diagnosis alone is insufficient.

Pregnancy Risks: Congenital Zika Syndrome

This is the most serious risk associated with Zika. When a pregnant woman is infected, the virus can cross the placenta and infect the fetus, causing Congenital Zika Syndrome (CZS), which encompasses several malformations:

Microcephaly

Microcephaly — an abnormal reduction in skull and brain size — is the most publicized manifestation of CZS. It can lead to developmental delays, neurological disorders, seizures, and intellectual disabilities of varying severity.

Other Neurological Malformations

• Intracranial calcifications
• Corpus callosum abnormalities
• Ventriculomegaly (dilation of brain ventricles)
• Cerebral atrophy

Other Complications

• Ocular abnormalities (optic nerve atrophy, chorioretinitis)
• Arthrogryposis (congenital joint stiffness)
• Intrauterine growth restriction

Important: The risk of malformations exists throughout pregnancy, but is particularly high in the first trimester, when fetal brain development is most active.

Risk by Caribbean Island

Zika virus circulation in the Caribbean varies by island and period. Here is a reference table based on recent epidemiological data:

Sources: WHO, CDC, ECDC — 2025 data

Official Recommendations for Pregnant Women

Global health authorities (WHO, CDC, ECDC) are unanimous on recommendations regarding Zika and pregnancy:

If You Are Pregnant

• Avoid traveling to Zika risk areas if possible
• If travel is unavoidable, consult your doctor or gynecologist at least 4 to 6 weeks before departure
• Apply maximum mosquito protection: skin repellent (icaridin or IR3535 preferred over DEET), covering clothing, impregnated mosquito net
• Avoid unprotected sexual intercourse with a potentially exposed partner

If You Are Planning a Pregnancy

• Wait at least 2 months after returning from a risk area before conceiving (if you traveled without symptoms)
• If you experienced Zika-like symptoms, wait 6 months before conceiving
• Your male partner must use a condom for 6 months after returning from a risk area, even without symptoms

Medical Follow-up After Return

• Consult your doctor upon return if you traveled to a risk area during pregnancy
• A Zika serological test may be prescribed
• Enhanced ultrasound monitoring of fetal brain development will be recommended

Repellents Authorized During Pregnancy

Repellent choice is crucial for pregnant women. Here are the recommendations:

Essential oils (citronella, lemon eucalyptus) are contraindicated during the 1st trimester and their insufficient efficacy in endemic areas makes them unsuitable as primary protection.

Diagnosis and Treatment

Diagnosis

Zika diagnosis relies on specific biological tests:

• RT-PCR: detects the virus in blood, urine, or saliva during the acute phase (1 to 5 days after symptoms)
• Serology: detects IgM and IgG antibodies, useful after the acute phase but with cross-reaction risks with dengue

Treatment

There is no specific antiviral treatment for Zika, nor a vaccine available to the general public. Management is symptomatic:

• Rest
• Adequate hydration
• Paracetamol/acetaminophen for fever and pain (aspirin and anti-inflammatories are contraindicated)

Conclusion

The Zika virus perfectly illustrates why mosquito prevention goes beyond avoiding an uncomfortable bite — it can protect an unborn child's health. For pregnant women or those planning a pregnancy, a Caribbean trip requires rigorous medical preparation, maximum mosquito protection, and careful medical follow-up upon return. Always consult a travel medicine specialist before departure.