The second case was a 24-year-old pregnant woman from Colombia. During the 17th week of gestation, she became acutely ill, with fatigue that was followed by severe generalized itching and maculopapular rash for seven days, associated with anorexia, nausea, vomiting, and headache. The illness continued for the following five days, when the generalized rash disappeared. Her close familial group (her partner, mother, and sister) were concomitantly reporting similar symptoms. Since there was a ZIKV outbreak in Colombia, infection with the virus or another arthropod-transmitted virus was suspected, but no virological or serological diagnostic testing was performed. Multiple fetal ultrasonographies were performed at 20, 24, 30, 31, and 34 weeks of gestation (4, 8, 14, 15, and 18 weeks after the resolution of symptoms) (Figure 3A-C). Until 30 weeks of gestation, the fetal ultrasonography evaluations showed normal anatomy and fetal growth with no birth defects. No evidence of microcephaly or intracranial calcifications was observed until 30.3 weeks of gestation. However, there was an increase in the fetal atrial diameter to 19.6 mm at 30 gestational weeks (Figure 3A-C). This finding was considered indicative of severely isolated ventriculomegaly because the fetus had no other evident abnormalities. After this finding, a virologic test was performed in the amniotic fluid, which tested positive for ZIKV.
The fetal ultrasonography at 30 gestational weeks showed abnormal intracranial ventricular dilatation. Medium line elements were conserved, and the cavum septum pellucidum was not visualized. Moderate communicable ventriculomegaly was observed. The head circumference measured in the 85th percentile for gestational age. Fetal ultrasonographies were also performed at 31 and 34 weeks of gestation and showed dilatation and enlarged posterior horns of the lateral ventricles; the third ventricle had a transverse diameter at the level of the atria that measured 16.2 mm (average measurement at gestational age, 6.73 mm [range, 5.7-7.7]) (Figure 3A-C). The fourth ventricle and the choroid plexus were healthy, with no evidence of hemorrhage. No focal destructive lesions were identified within the cerebral cortex or white matter.
At 31 weeks of gestation, the presence of flavivirus in the amniotic liquid was detected in the RT-PCR assay. This finding was confirmed with a specific ZIKV quantitative RT-PCR assay. The National Health Institute in Colombia (NHI) reported serological and virologic evidence of infection at 36 weeks of gestation, with RT-PCR positivity in the amniotic liquid for ZIKV. At 37 weeks of gestation, the baby was born through vaginal delivery without complications and was evaluated by an expert neonatologist. The baby was male with a weight of 2,629 g (p10), a height of 48 cm (p50-10), and a head circumference of 32 cm (p10) (average measurement at gestational age). A brain tomography showed hydrocephalus (Figure 3D).
The presence of other possible perinatal infections was evaluated including Toxoplasma gondii, rubella virus, cytomegalovirus, herpes simplex virus, HIV, hepatitis B and C, and parvovirus B19 (STORCH); however, negative results were reported for these infections (Table 1).