Zika virus infection
Zika virus is an Aedes-transmitted flavivirus causing a usually mild febrile illness with rash and conjunctivitis, but infection during pregnancy can cross the placenta and cause congenital Zika syndrome with microcephaly, and postinfectious Guillain-Barre syndrome is a recognized complication. Diagnosis uses RT-PCR in the first 2 weeks of illness and IgM serology thereafter, treatment is supportive, and prevention centers on avoiding travel to endemic areas during pregnancy and preventing sexual transmission.
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What this article covers
- Overview
An Aedes-transmitted flavivirus that is usually mild in the infected adult but dangerous to the fetus: most people recover uneventfully from a self-limited febrile illness, but the same virus crosses…
- Epidemiology
Outbreak activity in the Americas and the Caribbean: thousands of Zika virus infections were reported in the United States between 2015 and 2016, several presumed to be from local mosquito-borne transmission.
- Risk factors
Travel to or residence in an area with active Zika transmission, particularly the Caribbean and Central America.
- Pathophysiology
Aedes mosquito inoculation or sexual/vertical exposure introduces the flavivirus into the bloodstream, producing a systemic viremia responsible for the fever, rash, and conjunctivitis of acute infection.
- Clinical features
Most infections are mild or asymptomatic, with the majority of patients recovering uneventfully.
- Differential diagnosis
Dengue virus infection: shares the Aedes vector and febrile presentation, but is distinguished by prominent retro-orbital pain, severe lumbosacral pain, a scarlatiniform rash evolving to petechiae…
- Diagnosis
The diagnosis is confirmed by detection of Zika virus, Zika virus RNA, or Zika antigen in serum, urine, or another body fluid or tissue specimen, with the specific test chosen according to the time since symptom onset.
- Management
First, confirm the diagnosis and assess pregnancy status, since management priorities diverge sharply between the nonpregnant patient with self-limited illness and the pregnant patient at risk of fetal transmission.
- Complications
Congenital Zika syndrome, the most feared complication, comprising microcephaly, ventriculomegaly and subcortical calcifications on imaging, ocular anomalies, and motor abnormalities including…
- Prognosis
Excellent for the typical nonpregnant, immunocompetent adult, who recovers uneventfully after a mild, self-limited illness.
- Prevention
Pregnant women should avoid travel to areas with active Zika outbreaks entirely, and those who are pregnant or planning to conceive should consult current CDC guidance before any travel to an endemic area.
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