Introduction: Jamaica experienced its maiden Zika virus (ZIKV) epidemic in 2016, while dengue (serotypes 3 and 4) and chikungunya were also circulating.
Aim: We describe initial trends in microcephaly and arthrogryposis observed by the clinicians from three urban birthing facilities during late 2016 to early 2017.
Methods: Reporting of infant microcephaly was required from all birthing facilities in Jamaica. Staff were to be trained in measuring the occipito-frontal head circumference (OFC) using World Health Organization’s (WHO) standards. Affected newborns were to be referred for comprehensive paediatric evaluation.
Results: Hospital A reported 15 full-term newborns with microcephaly, 10 were delivered between November 10, 2016 and January 6, 2017. All were full-term newborns with OFC ranging from 28.5 to 31.5 cm, severe microcephaly with OFC’s <-3 Z scores was seen in ten. Most (12, 80%) had the characteristic craniofacial phenotype of congenital syndrome associated with Zika (CSAZ). Ten had neonatal ultrasounds which revealed intracerebral calcifications (4), dilated and/or asymmetric lateral ventricles (4), grossly overlapping sutures and/or closed or small fontanelles (3), cerebral atrophy (one) and absent frontal lobe sulcation with increased periventricular white matter (one). Computerized tomography (CT) scans revealed calcifications and dilated ventricles with thinning of cortical mantle (two others). Four mothers reported rash. The rate of microcephaly was estimated as 0.8% (10/1212) live births. In hospital B, among 414/629 (65%) of primarily term vaginal live births reviewed during eight weeks of December to January 2017, 17 had OFCs < 32 cm; eight patients had OFC < -2 Z score, six patients had OFC < -3 Z score and three patients had OFC at -2 Z score; 14 patients (3%) were therefore microcephalic. Seventeen had relative microcephaly. Among the 14 microcephaly cases, five term babies had low birthweight, three had seizures within 24 hours, 6/14 were adolescents aged 15–19 years and among 11/14 with uterine ultrasonography, one was abnormal with head-body discrepancy. Two had a cranial ultrasonogram showing intracerebral calcifications, dilated lateral ventricle and cerebral atrophy. One mother reported rash in pregnancy. Microcephaly rate was 1.63% (14/857 live births). Hospital C identified 2% (1/43) microcephaly rate (OFC < 31.4 cm < - 2 Z scores) amongst symptomatic mothers during May 1, 2016 through March 31, 2017. Four others had low OFCs (< 33 cm), but not in the range for microcephaly. Therefore, 84% (36/43) of babies born to symptomatic mothers had normal OFC. Microcephaly rate for all live births for the period was 2.2% (26/1180). The monthly rate varied from 0% to 5% (6/118) peaking in March. Of two babies referred with severe arthrogryposis and microcephaly, one had characteristic evidence on nuclear magnetic resonance imaging of corpus callosum dysgenesis, occipital lobe cyst, cerebellar hypoplasia and intracranial calcifications. In the other, CT scan of the brain revealed microcephaly with cortical atrophy, severe ventriculomegaly of the lateral and third ventricles, fine calcifications in the thalami and basal ganglia bilaterally and in the right frontal lobe, with a huge posterior fossa cyst communicating with the 4 th ventricle. He died and autopsy confirmed these findings. Cross-reactivity of serological tests for dengue and Zika virus challenged laboratory diagnosis in mothers and newborns.
Conclusion: Newborns with “characteristic CSAZ features” are being born in urban settings primarily to asymptomatic mothers in Jamaica. Diagnosis is challenged by serological cross-reactivity between the circulating flaviviruses. Team management is multidisciplinary and will be a costly intervention for developing countries to implement to maximize the neuro-developmental potential of this new and vulnerable population of children.