Deborah Lehman, MD reviewing Schuler-Faccini L et al. MMWR Morb Mortal Wkly Rep 2016 Jan 29.

Significant increase in congenital microcephaly may be linked to this mosquito-borne virus.

Zika virus, an RNA virus transmitted by Aedes aegypti, the same mosquito that transmits dengue and chikungunya viruses, has been recognized in increasing numbers in Brazil and surrounding countries. The virus, first identified in Uganda in 1947, has been linked both epidemiologically and virologically to fetal neurologic disease. In early 2015, there was an outbreak of Zika virus in Brazil. In September, there was a sharp increase in the prevalence of microcephaly in the outbreak areas, with more than 3000 cases reported in Brazil since October. Brazil's Ministry of Health established a task force and registry to investigate the possible association.

Thirty-five infants born with microcephaly between August and October 2015 were investigated. Of these, 71% had severe microcephaly and 49% had an associated neurologic abnormality. Of 29 infants who underwent neuroimaging, 77% had abnormalities (calcifications, ventricular enlargement, and neuronal migration disorders typical of congenital viral infection). Viral analysis of cerebrospinal fluid is pending, but amniotic fluid testing from two affected infants revealed Zika RNA. Of the mothers, 74% recalled a rash during the first or second trimester of their pregnancy (rash is a symptom of Zika infection).

Citation(s):

Schuler-Faccini L et al. Possible association between Zika virus infection and microcephaly — Brazil, 2015. MMWR Morb Mortal Wkly Rep 2016 Jan 29; 65:59.

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