Urological profile of children with microcephaly and congenital zika syndrome

Introduction An outbreak of Zika virus disease, a self-limiting arbovirus infection involving skin rash and fever, occurred in Brazil in 2015 and was followed by an increase in newborns with microcephaly and brain malformations. Although two recent studies reported neurogenic bladder in children with microcephaly and congenital Zika syndrome (CZS), urologic evaluation is not yet routine. Objective To investigate the urological profile of children with microcephaly and CZS. Study design A descriptive, cross-sectional study conducted with children with microcephaly undergoing clinical, laboratory, urodynamic and ultrasonographic evaluation at a center for childhood urinary disorders in Salvador, Bahia, Brazil. Results Thirty-three children were evaluated. Mean age was 40.3 +/- 3.2 months (range 35-47 months). Twentyone (63.6%) were female. None urinated voluntarily. Urine stream was continuous in 22 (66.7%) and intermittent in 3 (9.1%), with no information in 8 cases (24.2%). Abdominal straining during voiding was absent in 27 (81.8%) and present in 3 (9.1%), with no information in 3 cases (9.1%). Upper urinary tract dilatation was not detected in any of the 27 ultrasounds performed. Twenty-two urine cultures were performed, with no cases of bacterial growth.Renal function was normal in all cases (mean creatinine 0.41 +/- 0.1 mg/dl, range 0.29-0.79 mg/dl and urea 20 +/- 7 mg/dl, 6-36 mg/dl). Mean maximum bladder capacity was lower than expected for age: 46.4 +/- 25.6 mL range 15-110 mL versus 135.2 +/- 6.6 mL, 125.5-153 mL, respectively (p < 0.0001). Sixteen patients (59.2%) had immature and reflex bladder, 3 (11.1%) had neurogenic bladder with small bladder compliance, 5 (18.5%) had neurogenic bladder and detrusor overactivity and 1 (3.7%) had normal bladder capacity and compliance, but urinated with abdominal straining and a significant residue. Urodynamic evaluation was normal in only two children (7.4%). Discussion Most children evaluated had immature and reflex bladder, with no repercussions on the upper urinary tract. Literature on urological complications in children with microcephaly is sparse; however, the present results differ from cases of neurogenic bladder in children with neural tube closure defects. Microcephaly in CZS involves a neurological and urodynamic pattern very similar to that found in children with cerebral palsy. Study limitations include the absence of a control group and neurological data with which to correlate these findings. Conclusion Neurogenic bladder in children with CZS-associated microcephaly was much less common than recently reported. Most patients had no kidney abnormalities, but small bladder capacity and reflex bladder, with non-significant post-void residual urine.