Zika Virus in Mexico: Symptoms, Causes & Treatment | aihealz
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Zika Virus.Care & specialists in Mexico
In Mexico, zika Virus is managed by tropical medicines. Zika virus is a flavivirus transmitted by Aedes aegypti and Aedes albopictus mosquitoes that caused a massive outbreak across the Americas in 2015-2016. WHO declared a Public Health Emergency of International Concern when the virus was linked to a sharp rise in microcephaly and other congenital brain malformations in infants born to women infected during pregnancy.
aliases · Zika virus disease· Zika fever· Doença do Zika· Enfermedad por el virus Zika· reviewed May 14, 2026
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Reviewed by AIHealz Medical Editorial Board · Tropical MedicineLast reviewed May 13, 2026
Zika virus disease (ICD-10: A92.5) is an arboviral infection caused by the Zika virus, a single-stranded RNA flavivirus closely related to dengue, West Nile, and Japanese encephalitis viruses. The virus is primarily transmitted by the bite of an infected Aedes mosquito, with secondary transmission through sexual contact, blood transfusion, organ transplantation, and from mother to fetus during pregnancy or around the time of delivery. Most adult infections are asymptomatic (around 80%) or produce a mild self-limited febrile illness with rash. The clinical significance derives from two severe manifestations: congenital Zika syndrome — a pattern of microcephaly, brain calcifications, ocular abnormalities, and limb contractures in infants exposed in utero, especially during the first and early second trimesters — and Guillain-Barre syndrome, an immune-mediated polyneuropathy occurring days to weeks after infection.
key facts
Prevalence
More than 86 countries have reported mosquito-transmitted Zika; an estimated 1.5 million people infected in Brazil alone in 2015-2016
Demographics
Adults and children affected equally; pregnant women face the highest consequences because of vertical transmission risk
Avg. age
Symptomatic cases reported across all ages; serosurveys suggest most infections in endemic regions occur in childhood and adolescence
Global cases
Approximately 3,700 cases of congenital Zika syndrome documented during the 2015-2017 outbreak in the Americas; transmission continues at lower levels in tropical and subtropical regions
Specialist
Tropical Medicine
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How you might notice it
The key symptoms of Zika Virus are: Low-grade fever (37.5-38.5°C) developing 3-14 days after a mosquito bite in an endemic area., Pruritic maculopapular rash starting on the face or trunk and spreading distally over 2-3 days., Non-purulent bilateral conjunctivitis with red eyes and mild discomfort but no discharge., Arthralgia or polyarthritis, typically of the small joints of the hands and feet, that lasts up to 1 week., Retro-orbital pain that worsens with eye movement, often a clinical clue toward an arboviral illness., Headache, often moderate, frontal or retro-orbital, lasting 3-5 days., Generalized myalgia, fatigue, and malaise lasting up to 1 week..
01Low-grade fever (37.5-38.5°C) developing 3-14 days after a mosquito bite in an endemic area.
02Pruritic maculopapular rash starting on the face or trunk and spreading distally over 2-3 days.
03Non-purulent bilateral conjunctivitis with red eyes and mild discomfort but no discharge.
04Arthralgia or polyarthritis, typically of the small joints of the hands and feet, that lasts up to 1 week.
05Retro-orbital pain that worsens with eye movement, often a clinical clue toward an arboviral illness.
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How it’s diagnosed
diagnosis
Suspect Zika in any person with compatible symptoms (fever, maculopapular rash, conjunctivitis, arthralgia) and possible exposure (travel to or residence in an active transmission area, sexual contact with an exposed partner, or living in a region with local Aedes vectors). Pregnant women with even a suspicious exposure history warrant testing regardless of symptoms. Diagnosis uses molecular and serologic tests with timing-dependent sensitivity. Reverse-transcription PCR (RT-PCR) on serum within 7-10 days of symptom onset and on urine within 14 days is the most specific test; RT-PCR on amniotic fluid and on cord blood/neonatal serum at birth contributes to congenital diagnosis. Serology (IgM ELISA) becomes positive 4-7 days after symptom onset but cross-reacts extensively with dengue, yellow fever, West Nile, and Japanese encephalitis antibodies; positive IgM is followed by plaque-reduction neutralization testing (PRNT) for species specificity. Concurrent dengue and chikungunya testing is mandatory because the three viruses co-circulate, present similarly, and have very different management implications. In pregnancy, serial fetal ultrasound at 3-4 week intervals from the time of suspected exposure tracks head circumference, ventricular size, and brain echogenicity. Neonates exposed in utero undergo head ultrasound or MRI, ophthalmologic examination, and auditory screening at birth and again at 1, 6, and 12 months. Adult patients presenting with neurological symptoms after a compatible illness need lumbar puncture, nerve conduction studies, and infectious disease consultation for Guillain-Barre evaluation.
Key tests
01
Zika virus RT-PCR (serum, urine)Detects viral RNA during acute viremia; most specific test within 7-14 days of symptom onset
02
Zika IgM ELISA serology with PRNT confirmationDetects antibody response 4 days to 12 weeks after infection; PRNT distinguishes Zika from other flaviviruses
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Treatment & cost
medical treatments
✓Paracetamol (acetaminophen) 500-1000 mg every 4-6 hours as needed (max 4 g/day)
✓Oral rehydration and supportive care
✓Intravenous immunoglobulin (IVIG) 0.4 g/kg/day for 5 days (Guillain-Barre)
✓Plasma exchange (5 sessions over 1-2 weeks)
surgical options
Shunting for hydrocephalus in congenital Zika syndromeEffective ventricular decompression in over 90%; shunt revision required in 30-40% within 5 years
Orthopedic correction of contractures (arthrogryposis)Functional improvement variable; goals are typically positional rather than ambulatory
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Causes & risk factors
known causes
Aedes aegypti and Aedes albopictus mosquito bites
Day-biting Aedes mosquitoes acquire Zika virus by feeding on viremic humans and transmit it to others 7-10 days later. Aedes aegypti is the principal vector in tropical areas; Aedes albopictus extends transmission into temperate zones. Mosquitoes breed in small containers of standing water (flowerpots, tires, water storage drums).
Sexual transmission
Zika RNA persists in semen for up to 3 months after infection (and rarely longer) and in vaginal secretions for shorter periods. Vaginal, anal, and oral sex can transmit the virus, including from asymptomatic partners. Sexual transmission is well-documented in non-endemic countries where local mosquito spread has not occurred.
Vertical (mother-to-fetus) transmission
Zika crosses the placenta and directly infects fetal neural progenitor cells, interfering with neurogenesis and producing congenital Zika syndrome. Risk is highest with first-trimester maternal infection (5-15% of infants with severe defects in some cohorts) and persists through pregnancy at lower frequency.
Blood transfusion and organ transplantation
Asymptomatic viremic donors have transmitted Zika through transfusion and transplantation. Blood services in endemic regions screen donors with PCR or by deferral of recent travelers; risk in non-endemic regions remains low but not zero.
Laboratory and occupational exposure
Rare cases reported among laboratory workers handling live Zika virus and healthcare workers exposed to body fluids of viremic patients. Standard biosafety precautions effectively prevent these exposures.
risk factors
Residence or travel in a Zika-endemic regionenvironmental
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Living with it
01Use insect repellent containing DEET (20-30%), picaridin, IR3535, or oil of lemon eucalyptus on exposed skin and reapply per label instructions during the day in endemic regions.
02Wear long sleeves, long trousers, and treated clothing (permethrin-impregnated) during peak Aedes activity (dawn and dusk).
03Stay in accommodation with air conditioning and intact window screens; sleep under a permethrin-treated bed net if the room is not screened.
04Eliminate breeding sites around the home: empty flowerpots, change water in bird baths twice weekly, cover or discard tires and containers, clear blocked gutters.
05Use condoms or abstain from sex for at least 3 months (male partner) and 2 months (female partner) after travel to an active transmission area, even if asymptomatic.
06Pregnant women and women planning pregnancy should avoid travel to areas with active Zika transmission per CDC and WHO guidance; if travel is unavoidable, apply intensified mosquito precautions.
recommended foods
•Adequate oral fluids (2-3 liters of water, oral rehydration solution, broths) during the acute illness
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When to seek help
why see a tropical medicine
Infectious disease and maternal-fetal medicine referral is essential for any pregnant woman with confirmed or suspected Zika exposure, and for any adult with neurological symptoms after a compatible illness. Pediatric neurology, ophthalmology, audiology, and developmental pediatrics manage newborns with congenital Zika syndrome.
01Congenital Zika syndrome in infants of exposed mothers — microcephaly, brain calcifications, contractures, ocular and hearing impairment; lifelong disability requiring multidisciplinary care.
02Guillain-Barre syndrome in adults — ascending paralysis with potential need for ventilatory support; mortality 3-7% in untreated cases, lower with prompt IVIG or plasma exchange.
03Meningoencephalitis or myelitis in rare adult cases — present with altered consciousness, seizures, or focal neurological deficits.
04Pregnancy loss (miscarriage, stillbirth) in a subset of confirmed maternal infections.
05Sexual onward transmission to partners, sometimes weeks to months after the index case has recovered.
06Co-infection with dengue or chikungunya carrying additional risks of hemorrhagic disease or chronic arthralgia.
Asymptomatic Zika infectionMost common form — accounts for approximately 80% of infections in adults. No clinical illness; only detected by serosurveillance or screening during pregnancy. Still capable of vertical transmission to the fetus and sexual transmission to partners.
Symptomatic acute Zika virus diseaseMild febrile illness with low-grade fever (under 38.5°C), maculopapular rash starting on the face and spreading distally, non-purulent conjunctivitis, and joint pain (typically small joints of the hands and feet). Lasts 2-7 days and resolves without complications in most adults.
Congenital Zika syndromeA pattern of fetal abnormalities arising from maternal infection during pregnancy: severe microcephaly with overlapping cranial sutures, subcortical calcifications, ventriculomegaly, ocular abnormalities (chorioretinal atrophy, optic nerve hypoplasia), congenital contractures (arthrogryposis), and hypertonia. First-trimester infection carries the highest risk.
Zika-associated Guillain-Barre syndromeAscending symmetric paralysis developing days to weeks after acute Zika infection. Pathophysiology involves immune-mediated demyelination. Most cases recover with intravenous immunoglobulin or plasmapheresis but recovery may be prolonged.
Zika in immunocompromised hosts and adults with neurological complicationsRare reports of meningoencephalitis, myelitis, and acute disseminated encephalomyelitis in adults, especially with comorbidities. Outcomes generally favorable with supportive care.
Living with Zika Virus
Timeline
Acute symptoms in adults resolve over 2-7 days with full recovery in 1-2 weeks. Joint pain may linger for weeks in some patients. Guillain-Barre recovery is over months; most patients walk independently again by 6-12 months. Congenital Zika syndrome is lifelong; developmental gains continue with sustained therapy but full functional recovery does not occur.
Lifestyle
01Postpone non-essential travel to areas with active Zika transmission, especially during pregnancy.
02Use mosquito repellent diligently during the first week of illness to prevent onward transmission to others.
03Counsel partners on the timeline for safer-sex precautions after possible exposure.
04Stay current with travel advisories from CDC, WHO, or your country's public health agency before each trip.
05Document any febrile illness with rash that occurred during or shortly after travel — this may matter for future pregnancy counseling.
06Donate blood only after the deferral period (28 days or longer per local rules) following travel to an endemic area.
Daily management
01Take paracetamol (acetaminophen) for fever and aches; avoid aspirin and NSAIDs until dengue is excluded.
02
Complementary approaches
Structured early-intervention developmental programsCoordinated home-based and clinic-based services for infants with congenital Zika syndrome. Evidence from developmental disability cohorts supports earlier and more intensive programs for better motor, language, and cognitive outcomes.
Family education and psychosocial supportCoordinated counseling, peer support groups, and respite services reduce caregiver burnout in families of affected infants and improve adherence to long-term care plans.
Choosing a doctor
Look for an infectious disease specialist familiar with arboviral disease in your region; many academic centers run dedicated travel or tropical medicine clinics. Maternal-fetal medicine units with experience in congenital infection follow exposed pregnancies. Newborns with congenital Zika syndrome benefit from coordinated care at a tertiary children's hospital with a developmental pediatrics service.
Patient support resources
CDC Zika Virus →Current US public health guidance on diagnosis, prevention, traveler advisories, and pregnancy outcomes.
WHO Zika Virus Disease →Global epidemiology, prevention guidance, and emergency response framework for Zika outbreaks.
Zika is a flavivirus transmitted by Aedes aegypti and Aedes albopictus mosquitoes that causes a mild illness with fever, rash, conjunctivitis, and joint pain in adults. Its major risks are birth defects in babies born to women infected during pregnancy and Guillain-Barre syndrome in adults. No vaccine or specific antiviral is available.
How is Zika virus transmitted?▾▴
Primarily through the bite of infected Aedes mosquitoes that bite during the day. Zika also spreads through unprotected sex with an infected partner (virus persists in semen for up to 3 months), from mother to fetus during pregnancy, and rarely through blood transfusion or organ transplantation.
What are the symptoms of Zika?▾▴
About 80% of infections cause no symptoms. Symptomatic illness produces low-grade fever, itchy maculopapular rash, non-purulent conjunctivitis (red eyes), and joint pain in the hands and feet, lasting 2-7 days. Headache, retro-orbital pain, muscle aches, and fatigue are common. Severe complications are rare in adults.
Is Zika dangerous during pregnancy?▾▴
Yes. Zika crosses the placenta and can cause congenital Zika syndrome — microcephaly, brain calcifications, ventriculomegaly, ocular abnormalities, and contractures. First-trimester infection carries the highest risk; an estimated 5-15% of infants exposed in the first trimester develop severe abnormalities.
How is Zika diagnosed?▾▴
RT-PCR on serum within 7-10 days or urine within 14 days of symptom onset detects viral RNA. After that window, IgM serology is used, followed by plaque-reduction neutralization testing to distinguish Zika from dengue and other flaviviruses. Pregnant women with possible exposure should be tested regardless of symptoms.
Is there a vaccine for Zika?▾▴
No licensed Zika vaccine is currently available. Several candidates have completed early-phase trials and continue in development. Prevention relies on mosquito bite avoidance, safer sex practices after potential exposure, and travel advisories for pregnant women.
How long does Zika stay in semen?▾▴
Zika RNA has been detected in semen for up to 3 months after infection, with rare cases extending further. CDC and WHO recommend condom use or abstinence for at least 3 months after travel to an active transmission area for male partners, and 2 months for female partners, even if asymptomatic.
Can men transmit Zika sexually if they have no symptoms?▾▴
Yes. Asymptomatic men have transmitted Zika to female partners through unprotected sex. Because up to 80% of infections are asymptomatic, sexual prevention guidance applies after any travel to an active transmission area regardless of whether symptoms occurred.
How is Zika treated?▾▴
There is no specific antiviral therapy. Treatment is supportive — paracetamol for fever and pain, oral fluids, rest, and mosquito protection during the first week of illness to prevent onward transmission. Avoid aspirin and NSAIDs until dengue has been excluded.
Where is Zika virus found?▾▴
Tropical and subtropical regions of the Americas, Caribbean, Southeast Asia, parts of Africa, and Pacific islands have ongoing or periodic Zika transmission. CDC and WHO maintain travel advisories with country-by-country guidance updated regularly.
Can Zika be transmitted through breastfeeding?▾▴
Zika RNA has been detected in breast milk, but transmission through breastfeeding has not been clearly documented. WHO continues to recommend breastfeeding even in mothers with confirmed Zika because the proven benefits outweigh the theoretical risk.
What is congenital Zika syndrome?▾▴
Congenital Zika syndrome is a recognizable pattern of severe brain and limb abnormalities in babies born to women infected during pregnancy. Features include microcephaly with overlapping skull sutures, subcortical brain calcifications, ventriculomegaly, ocular abnormalities, joint contractures, and hypertonia.
Does prior dengue protect against Zika?▾▴
No. Prior dengue infection does not prevent Zika, although it may modify the immune response and complicate serological diagnosis through antibody cross-reactivity. Clinical impact on Zika severity remains debated and careful interpretation of serology is needed.
What is the link between Zika and Guillain-Barre?▾▴
Adult Zika infection can trigger Guillain-Barre syndrome, an immune-mediated ascending paralysis, days to weeks after the acute illness. Recognized during the 2015-2016 outbreak in French Polynesia and the Americas, it is treated with intravenous immunoglobulin or plasma exchange and supportive care.
Should I cancel travel because of Zika?▾▴
Pregnant women and women planning pregnancy should avoid travel to areas with active Zika transmission per CDC and WHO. Other travelers should weigh personal risk, follow strict mosquito-bite prevention, and observe safer-sex precautions for 2-3 months after return. Check current travel advisories before booking.
What is the best mosquito repellent for Zika prevention?▾▴
Insect repellents containing DEET (20-30%), picaridin, IR3535, or oil of lemon eucalyptus offer effective protection against Aedes mosquitoes. Apply per label instructions, reapply during the day, and use on top of sunscreen. Combine with permethrin-treated clothing for the highest protection.
Can children get Zika?▾▴
Yes. Children can be infected and most cases are mild, with fever, rash, and joint symptoms similar to adults. Severe pediatric complications are rare. Congenital Zika syndrome refers specifically to in-utero infection rather than infection acquired by a child after birth.
Is Zika still spreading in 2024 and 2025?▾▴
Yes, at lower levels than during the 2015-2016 outbreak. Sporadic and seasonal transmission continues in many endemic regions; small outbreaks have been reported in Brazil, India, and parts of Southeast Asia. Recurrent outbreaks are likely when vector density rises and population immunity wanes.
Can Zika cause death?▾▴
Death from Zika is uncommon in adults; most fatalities are linked to severe Guillain-Barre syndrome or other rare neurological complications, especially in patients with underlying conditions. Infant mortality in severe congenital Zika syndrome reaches 5-10% in the first year of life.
What is the difference between Zika and dengue?▾▴
Both are transmitted by the same Aedes mosquito and cause fever and rash, but dengue typically produces higher fever, severe bone pain, low platelets, and potential hemorrhage. Zika causes lower fever, prominent conjunctivitis, and the unique risks of congenital infection and Guillain-Barre. Both must be tested in any compatible patient.
When should I see a doctor for possible Zika?▾▴
See a doctor if you develop fever, rash, joint pain, or red eyes within two weeks of travel to an endemic area or sex with an exposed partner. Pregnant women with any possible exposure should seek care promptly. Urgent evaluation is needed for limb weakness, breathing difficulty, or fetal ultrasound concerns.
09Edema of the hands or feet in a minority of patients, distinguishing Zika rash from other arbovirus rashes.
10Lymphadenopathy, especially in the posterior cervical chain.
early warning signs
•Maculopapular rash with low-grade fever 3-14 days after travel to or residence in an Aedes mosquito-endemic region
•Non-purulent red eyes and joint pain coinciding with a febrile illness during a known Zika outbreak
•Unexplained polyarthralgia of the small joints of the hands and feet in a sexually active partner of someone who recently returned from an endemic area
•Concerning fetal ultrasound findings (microcephaly, intracranial calcifications, ventriculomegaly) in a pregnancy with potential Zika exposure
•Ascending limb weakness or paresthesia within 1-3 weeks of a Zika-compatible illness — possible Guillain-Barre
● emergency signs
•Progressive ascending weakness with areflexia, gait instability, or breathing difficulty — emergency evaluation for Guillain-Barre syndrome
•Severe abdominal pain, persistent vomiting, mucosal bleeding, or hypotension — concurrent dengue must be excluded urgently
•Pregnant patient with confirmed or suspected Zika and rapidly changing fetal ultrasound — urgent referral to maternal-fetal medicine
•Newborn with microcephaly, contractures, or visible brain malformations — admit for full evaluation and supportive care
Concurrent dengue and chikungunya testingExcludes the two main differential diagnoses, which co-circulate with Zika and have overlapping clinical features
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Fetal ultrasound (maternal-fetal medicine)Detects microcephaly, intracranial calcifications, ventriculomegaly, and other congenital Zika syndrome features during pregnancy
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Neonatal head imaging (ultrasound or MRI) and ophthalmologic examinationConfirms congenital Zika syndrome in newborns of women with confirmed or possible Zika infection during pregnancy
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Lumbar puncture and nerve conduction studies (suspected Guillain-Barre)Documents elevated CSF protein with normal cell count (albumin-cytological dissociation) and demyelinating polyneuropathy
Outlook
Outcomes vary dramatically by clinical form. Symptomatic acute Zika in non-pregnant adults has an excellent prognosis: more than 95% recover fully within 1-2 weeks without sequelae. Post-Zika Guillain-Barre syndrome has a more variable course; most patients improve over 6-12 months with treatment but a minority have residual weakness or chronic pain. Congenital Zika syndrome carries a guarded long-term prognosis: surviving infants have lifelong neurodevelopmental disability with severe motor impairment, epilepsy, sensory deficits, and feeding difficulties. Mortality in the first year of life is around 5-10% in case series, and ongoing care needs are substantial. The 2015-2016 outbreak has been followed by lower-level endemic transmission in many countries; recurrent outbreaks are anticipated whenever vector density rises and population immunity wanes. Vaccine development is active and a licensed product would change this prognosis dramatically.
Tropical and subtropical regions of the Americas, Caribbean, Southeast Asia, parts of Africa, and Pacific islands have ongoing or periodic Zika transmission. CDC maintains a country-by-country travel advisory updated regularly.
Pregnancynon-modifiable
Pregnant women face the most serious outcomes because of fetal risk. First-trimester infection carries 5-15% risk of severe congenital abnormalities; risk persists through pregnancy. WHO and CDC advise pregnant women to avoid travel to areas of active transmission.
Unprotected sex with a partner who has visited or lives in an endemic regionmodifiable
Asymptomatic male partners can transmit virus in semen for up to 3 months. CDC advises condom use or abstinence for 3 months after male and 2 months after female travel to endemic areas.
Outdoor activity in mosquito-active hoursmodifiable
Aedes mosquitoes bite primarily during daylight hours, with peak activity around dawn and dusk. Outdoor work, sports, and travel during these hours increase exposure.
Inadequate vector control around the homemodifiable
Standing water in flowerpots, used tires, blocked gutters, water storage containers, and discarded bottles all support Aedes breeding. Eliminating these sources cuts local mosquito density dramatically.
Prior dengue virus infectionnon-modifiable
Prior exposure to dengue may alter immune responses to Zika and complicates serological diagnosis through antibody cross-reactivity. Clinical impact on Zika severity remains debated but careful interpretation of serology is required.
•Easily digested foods (rice, broth, fruits, plain yogurt) during the febrile phase
•Folate-rich foods (leafy greens, legumes, fortified grains) in women planning pregnancy
•Iron-rich foods if anemia accompanies prolonged convalescence
foods to avoid
•Alcohol during the acute illness — interacts with hepatic clearance and dehydration
•Aspirin and NSAIDs until dengue is excluded — they can worsen hemorrhagic complications in dengue
•Unsafe street food or untreated water that may add an enteric infection on top of viral illness
•Unproven herbal 'remedies' marketed for Zika — none have evidence of antiviral activity
choosing the right hospital
01On-site access to Zika RT-PCR or contracted reference laboratory
02Maternal-fetal medicine clinic with high-resolution fetal ultrasound and neurosonography
03Pediatric neurology, ophthalmology, and audiology services for newborn evaluation
04Intensive care with respiratory support for severe Guillain-Barre syndrome
05Public health reporting and vector control coordination
Essential facilities
Tropical medicine and travel medicine clinicsMaternal-fetal medicine and high-risk obstetric unitsPediatric neurology and developmental medicine servicesReference virology laboratoriesPublic health vector control programs
Drink at least 2-3 liters of fluid each day during the acute illness.
03Use mosquito repellent and stay in screened or air-conditioned accommodation through the first week of symptoms.
04Use condoms or abstain from sex for the recommended duration after travel or symptoms.
05Attend prenatal follow-up with serial ultrasound if pregnant and exposed.
06Report any new neurological symptoms (limb weakness, paresthesia, breathing difficulty) urgently.
Exercise
Rest during the acute febrile illness. Most adults resume normal activity within 1-2 weeks. Patients with post-Zika Guillain-Barre syndrome follow structured neurological rehabilitation with progressive mobilization, strengthening, and gait training under physiotherapy. Pregnant women with Zika exposure continue routine pregnancy exercise unless complicated by other obstetric issues.