The majority (50 to 80%) of Zika virus (ZIKV) infections are asymptomatic. Symptomatic ZIKV infection has an incubation period of 3 to 14 days and is a mild illness, with a duration of up to 1 week, that manifests as a rash, low-grade fever, arthralgia and myalgia, and conjunctivitis. Complications are infrequent, but when they occur, they are severe and may be fatal.
The ZIKV causes a spectrum of fetal and birth defects that extends beyond microcephaly and is distinct from other congenital infections in that its pathologic manifestations are restricted primarily to the central nervous system.
Features of Congenital Zika Syndrome
| Lesion Type | Manifestations |
| Structural lesions | |
| Fetal brain disruption sequence* | Severe microcephaly, premature closure of fontanels, collapsed skull, overlapping sutures, redundant scalp skin |
| Brain abnormalities | Cortical atrophy with decreased myelination, cerebellar hypoplasia Neuronal migration disorder – lissencephaly, agyria, pachygyria, polymicrogyria, heterotopia, dysgenesis of corpus callosum Calcifications, mainly subcortical* Ventriculomegaly, increased posterior fossa and pericerebral spaces |
| Ocular abnormalities | Pigmented retinal mottling*, chorioretinal atrophy*, macular scarring, glaucoma, optic nerve atrophy and abnormalities, intraocular calcifications Microphthalmia, anophthalmia Iris coloboma, lens subluxation, cataract |
| Congenital contractures | Arthrogryposis, talipes equinovarus, hip dislocation |
| Intrauterine growth restriction | |
| Functional lesions | |
| Seizures | |
| Pyramidal or extrapyramidal abnormalities* | Body tone abnormalities (mainly hypertonia), swallowing disorder, movement abnormalities (dyskinesia, dystonia), hyperexcitability, impatient crying, sleep disorders |
| Neurodevelopmental abnormalities |
Visual impairment (strabismus, nystagmus, vision loss) Hearing loss or deafness Developmental delay |
* Lesions are rarely observed in other congenital infections.
References:
- Musso D, Ko AI, Baud D. Zika Virus Infection – After the Pandemic. N Engl J Med. 2019 Oct 10;381(15):1444-1457. [Medline]
- Lebov JF, Brown LM, MacDonald PDM, Robertson K, Bowman NM, Hooper SR, Becker-Dreps S. Review: Evidence of Neurological Sequelae in Children With Acquired Zika Virus Infection. Pediatr Neurol. 2018 Aug;85:16-20. [Medline]
Created Oct 11, 2019.
