Guideline 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). 1 2 2 2 3 4 5 6 Definition The Zika virus is a mosquito-borne flavivirus that is associated with fetal anomalies in humans, including microcephaly and brain abnormalities. 2 Epidemiology 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. 4 5 Pathophysiology In regions of the United States 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. 3 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 https://web.pathway.md/diseases/recowEdMFjkB9sjFO 1/3 6/29/23, 3:11 AM Zika virus infection Pathway syndrome). In neonates, Zika virus can lead to birth defects (microcephaly) and death. 2 2 Prognosis and risk of recurrence The case fatality rate in neonates is estimated at 8.3% (95% CI, 7.2-9.6). 6 Guidelines 1. Screening and diagnosis Indications for testing (symptomatic patients): Test for Zika virus infection in pregnant women with recent possible exposure and symptoms of Zika virus disease. E Test for Zika virus infection in pregnant women with recent possible exposure and prenatal ultrasound findings consistent with congenital Zika virus syndrome. E Indications for testing (asymptomatic patients): Obtain Zika virus NAAT testing 3 times during pregnancy in asymptomatic pregnant women with ongoing possible Zika virus exposure. E Avoid routinely testing asymptomatic pregnant women who have recent possible Zika virus exposure (through travel or sexual exposure) but without ongoing possible exposure. D Indications for testing (preconception): avoid testing for Zika virus infection as part of preconception counseling in nonpregnant women with ongoing possible Zika virus exposure. D 2. Diagnostic investigations Clinical history: ask all pregnant women in the United States and U.S. territories about possible Zika virus exposure before and during the current pregnancy, at every prenatal care visit. E Serologic tests: Obtain the following tests concurrently in patients with suspected acute Zika virus infection: serum Zika virus NAAT test urine Zika virus NAAT test zika virus IgM antibody test. E Clinical findings Symptoms Past obstetric history Arthralgia Miscarriage Fever Neurological exam Headache Malaise Peripheral neuropathy Myalgia https://web.pathway.md/diseases/recowEdMFjkB9sjFO 2/3 6/29/23, 3:11 AM Zika virus infection Pathway Red eyes Musculoskeletal exam Retro-orbital pain Arthropathy Social history Polyarticular synovitis Tenosynovitis Exposure to aedes mosquitoes Lab findings Ocular exam serum CRP Conjunctival injection Serological findings Integument exam serum zika virus IgM antibodies Maculopapular rash Rash serum zika virus PCR Hematological findings WBC count Imaging findings Intracranial calcifications Microcephaly References 1. Oduyebo T, Polen KD, Walke HT et al. Update: Interim Guidance for Health Care Providers Caring for Pregnant Women with Possible Zika Virus Exposure United States Including U.S. Territories), July 2017. MMWR Morb Mortal Wkly Rep. 2017 Jul 28;66 29 781 793. Open 2. Plourde AR, Bloch EM. A Literature Review of Zika Virus. Emerg Infect Dis. 2016 Jul;22 7 1185 92. Open 3. Delaney A, Mai C, Smoots A et al. Population-Based Surveillance of Birth Defects Potentially Related to Zika Virus Infection 15 States and U.S. Territories, 2016. MMWR Morb Mortal Wkly Rep. 2018 Jan 26;67 3 91 96. Open 4. Petersen LR, Jamieson DJ, Powers AM et al. Zika Virus. N Engl J Med. 2016 Apr 21;374 16 1552 63. Open 5. Chan JF, Choi GK, Yip CC et al. Zika fever and congenital Zika syndrome: An unexpected emerging arboviral disease. J Infect. 2016 May;72 5 507 24. Open 6. Cunha AJ, de Magalh es-Barbosa MC, Lima-Setta F et al. Microcephaly Case Fatality Rate Associated with Zika Virus Infection in Brazil: Current Estimates. Pediatr Infect Dis J. 2017 May;36 5 528 530. Open 7. No authors listed. Guidelines for the Clinical Diagnosis and Treatment of Dengue, Chikungunya, and Zika. PAHO. 2022. Open https://web.pathway.md/diseases/recowEdMFjkB9sjFO 3/3