Zika Virus

Zika virus is a mosquito-borne virus. In most people, Zika causes a mild illness — or no symptoms at all. The major concern is Zika infection during pregnancy, which can cause serious birth defects — most notably microcephaly (small head) and other brain abnormalities in the baby. Zika is spread primarily by Aedes mosquitoes, the same mosquitoes that transmit dengue and chikungunya; small outbreaks have occurred in parts of India.

How it spreads

• Primarily — bite of an infected Aedes mosquito (daytime biter; breeds in clean standing water in and around homes)
• From mother to baby — during pregnancy (can cause severe birth defects)
• Sexual transmission — Zika can persist in semen longer than in blood; sexual transmission from an infected male to partner is documented
• Blood transfusion — screening is done where Zika circulates
• Not spread — through casual contact, breastfeeding (benefits outweigh any risk), sneezing, or sharing food

Symptoms

Most people have no symptoms. When symptoms occur (usually 3-14 days after exposure), they are mild:

• Mild fever
• Rash
• Joint pain (hands, feet, knees)
• Red eyes (conjunctivitis)
• Muscle pain, headache
• Tiredness

Symptoms usually resolve in about a week. Rarely, Zika is associated with Guillain-Barré syndrome in adults (weakness, paralysis).

Zika in pregnancy

This is the main reason Zika is taken so seriously. Zika infection during pregnancy can cross to the baby and cause:

• Microcephaly — abnormally small head, often with brain abnormalities
• Other congenital Zika syndrome features — eye problems, seizures, developmental delays, joint problems
• Pregnancy loss, stillbirth
• Some babies with Zika-related effects appear normal at birth and show problems later

Diagnosis and treatment

• Blood or urine tests (PCR in the first week, antibody tests later)
• No specific antiviral treatment — supportive care with rest, fluids, paracetamol
• Avoid aspirin and NSAIDs until dengue is ruled out
• In pregnancy — foetal ultrasounds and specialist review if Zika is confirmed or strongly suspected

Prevention

Same as dengue and chikungunya — stop mosquito breeding around your home:

• Empty or cover any water-holding container weekly
• Mosquito nets, screens, repellents
• Long sleeves and trousers
• Clean drains and surroundings
• Pregnant women should be particularly careful about mosquito bites in areas with known Zika circulation
• Sexual transmission prevention — use condoms for several weeks to months after possible Zika exposure, particularly if the partner is pregnant; your doctor can advise current guidance
• Delaying pregnancy for a time after suspected Zika infection is sometimes advised; discuss with your obstetrician

Pregnant women, and couples planning pregnancy, should check whether Zika is circulating in areas they live in or travel to.