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Zika virus infection



The Zika virus is a mosquito-borne flavivirus that is associated with fetal anomalies in humans, including microcephaly and brain abnormalities.
Zika virus infection is transmitted primarily via the bite of infected mosquitoes (Aedes aegypti and Aedes albopictus species), although vertical and sexual transmission has been reported. When the mosquito's saliva containing the Zika virus is inoculated into human skin, the virus can infect epidermal keratinocytes, skin fibroblasts in the subcutaneous layer, and the Langerhans cells. After replication in these local tissue cells and the regional lymph nodes, the Zika virus can disseminate via the lymphatics and bloodstream to reach other organs and tissues, including the CNS, skeletal muscles, myocardium.
In regions of the US with confirmed local transmission of Zika virus, the prevalence of birth defects potentially related to Zika virus infection is estimated at 3.0 per 1,000 live births.
Disease course
In adults, acute infection typically results in a self-limiting febrile illness, but may also lead to the development to neurological complications (meningitis, meningoencephalitis, Guillain-Barre syndrome). In neonates, Zika virus can lead to birth defects (microcephaly) and death.
Prognosis and risk of recurrence
The case fatality rate in neonates is estimated at 8.3% (95% CI, 7.2-9.6).


Key sources

The following summarized guidelines for the evaluation of Zika virus are prepared by our editorial team based on guidelines from the Center for Disease Control (CDC 2017). ...
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Screening and diagnosis

Indications for testing, symptomatic patients
As per CDC 2017 guidelines:
Test for Zika virus infection in pregnant women with recent possible exposure and symptoms of Zika virus disease.
Test for Zika virus infection in pregnant women with recent possible exposure and prenatal ultrasound findings consistent with congenital Zika virus syndrome.
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  • Indications for testing (asymptomatic patients)

  • Indications for testing (preconception)

Diagnostic investigations

Clinical history: as per CDC 2017 guidelines, ask all pregnant women in the US and U.S. territories about possible Zika virus exposure before and during the current pregnancy, at every prenatal care visit.

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  • Serologic tests