Zika Virus
Zika virus (ZIKV), an arbovirus and member of the Flaviviridae family, is named after a forest in Uganda. Similar to dengue and chikungunya viruses, mosquitos (often Aedes aegypti) transmit ZIKV to humans. Coinfection with any of those 3 distinct viral diseases may occur in endemic areas. Sexual transmission has been reported. A large proportion of patients infected with ZIKV will have no symptoms or minimal symptoms (fever, headache, rash, arthralgia, myalgia, conjunctivitis) that typically resolve within a week.
Acute infection in adults has been reported to cause individual cases of conjunctivitis, anterior uveitis, posterior uveitis with numerous chorioretinal lesions, and unilateral acute maculopathy. There is no defined treatment, but topical, systemic, or local steroids may be considered.
Brazil experienced an epidemic of ZIKV that began in April 2015. A 20-fold spike in newborns with microcephaly was noted in the ensuing months, suggesting ZIKV congenital infection. The United States Centers for Disease Control and Prevention (CDC) has defined congenital Zika syndrome with the following 5 features:
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microcephaly
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structural brain abnormalities
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ocular findings
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congenital contractures such as clubfoot
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hypertonia restricting body movement soon after birth
There have been no reports of uveitis associated with congenital infection. Observed ocular abnormalities include microphthalmia, cataract, glaucoma, iris coloboma, retinal pigment mottling, chorioretinal atrophy, and optic nerve hypoplasia or atrophy (Fig 11-20). No vaccine exists to prevent Zika at this time. Mosquito-borne transmission of ZIKV has been reported in the United States, and current prevention efforts focus on education and mosquito control.
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de Paula Freitas B, de Oliveira Dias JR, Prazeres J, et al. Ocular findings in infants with microcephaly associated with presumed Zika virus congenital infection in Salvador, Brazil. JAMA Ophthalmol. 2016;134(5):529–535.
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de Paula Freitas B, Ventura CV, Maia M, Belfort R Jr. Zika virus and the eye. Curr Opin Ophthalmol. 2017;28(6):595–599.
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Furtado JM, Espósito DL, Klein TM, Teixeira-Pinto T, da Fonseca BA. Uveitis associated with Zika virus infection. N Engl J Med. 2016;375:394–396.
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Kodati S, Palmore TN, Spellman FA, Cunningham D, Weistrop B, Sen HN. Bilateral posterior uveitis associated with Zika virus infection. Lancet. 2017;389(10064):125–126.
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Parke DW 3rd, Almeida DR, Albini TA, Ventura CV, Berrocal AM, Mittra RA. Serologically confirmed Zika-related unilateral acute maculopathy in an adult. Ophthalmology. 2016;123(11):2432–433.
Excerpted from BCSC 2020-2021 series: Section 9 - Uveitis and Ocular Inflammation. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.