CREOG Quiz #370

A 25-year-old woman, G2P0010,  at 8w 2 d gestation presented for a new obstetrical visit and expressed concern about a rash on her arms and legs, as well as diffuse joint pains. She stated that she had traveled to the Dominican Republic for a wedding 5 days ago and had sustained "lots of mosquito bites". Her temperature was 37.1 degrees C, pulse 84 bpm, respirations 16/minute, and BP 110/70 mm Hg. Her eye examination was remarkable for the finding shown in the photograph.

  1. Which laboratory test is most appropriate in evaluation of this patient?

    •  Zika virus RT-PCR of maternal serum
    •  Zika virus RT-PCR of maternal serum and urine
    •  Zika virus IgM antibody titer
    •  Plaque reduction neutralization test


  2. Approximately what percent of patients with Zika virus infection will manifest symptoms?

    •  10%
    •  20%
    •  40%
    •  80%





Summary

Given the patient’s recent travel history as well as her clinical symptoms, she most likely has an acute Zika virus (ZIKV) infection. ZIKV is a flavivirus, sharing homology with such infections as West Nile virus, Chikungunya virus, and Dengue virus. The Aedes spp of mosquito (Aedes aegypti and Aedes albopictus) are the primary insect vectors for transmission of this infection to humans. Though rare, transmission of infection by sexual contact is also possible. While 80% of those individuals infected with ZIKV will not show any clinical signs of infection, 20% may have findings such as low-grade fever, arthralgias, maculopapular rash, and conjunctivitis. Rare complications such as Guillain-Barre syndrome have also been reported in infected patients. The incubation period for the virus is 3-14 days. According to CDC guidelines, for pregnant women within 2 weeks of exposure to Zika virus who are currently symptomatic, both serum and urine should be tested by RT-PCR. An IgM immune response typically is not mounted until 2 weeks after infection. Once infection is confirmed, the patient should be followed with serial ultrasound examinations to assess for fetal microcephaly and other CNS abnormalities.

Reference 

Oduyebo T, Igbinosa I, Petersen EE et al. Update: Interim Guidance for Health Care Providers Caring for Pregnant Women with Possible Zika Virus Exposure – United States, July 2016. MMWR Morb Mortal Wkly Rep 2016;65: 739-744. DOI: http://dx.doi.org/10.15585/mmwr.mm6529e1.

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