Babies born to mothers infected with the Zika during pregnancy may have the virus in their systems for more than 2 months after birth.
Babies born to mothers infected with Zika virus during pregnancy may have the virus in their systems for more than 2 months after birth, according to a case report published in the New England Journal of Medicine.
Physicians at the Universidade de São Paulo and the Irmandade da Santa Casa de Misericórdia de São Paulo in São Paulo, Brazil monitored the health of a male child born with microcephaly at 40 weeks of gestation to a mother who had reported having Zika-like symptoms during the 26th week of pregnancy. The mother had presented with fever, pruritic maculopapular rash, headache, conjunctival hyperemia, and swelling and pain in the joints of the hands and feet during her third trimester, and all the symptoms had resolved spontaneously. She had not left São Paulo during her pregnancy; the physicians treating her suspect that she could have been infected via sexual transmission from the baby’s father, who had traveled to the northeast region of Brazil, where there have been multiple outbreaks of the virus. Samples obtained from the mother and father at days 59 and 67 after birth were positive for Zika-specific IgG and negative for IgM.
The child, who was born on January 2, 2016, was 6.8 pounds at birth; he was 18.9 inches long and had a head circumference of 12.8 inches. Microcephaly was not detected during an initial physical examination. At birth, the physicians analyzed the baby’s cerebrospinal fluid and performed ophthalmologic and optoacoustic exams; findings on all were normal. However, an MRI revealed “reduced brain parenchyma, notably in the frontal and parietal lobes, foci of calcification in the subcortical area, and compensatory dilatation of the infratentorial supraventricular system,” they wrote.
The baby’s serum, saliva, and urine were tested for Zika virus using qRT-PCR assay at day 54, and all 3 were positive for Zika RNA, with 1.4×105 copies per milliliter in the serum, 4.1×104 in the saliva, and 5.4×103 in the urine, respectively. RNA sequencing of a urine sample obtained from the infant showed a high degree of similarity with samples isolated in the Americas with 98.5% bootstrap support. According to the authors, virus-specific IgM and IgG were positive as well. On day 67, the baby still had detectable levels of Zika RNA in his blood (2.8×104 copies per milliliter) and, on day 216, although virus RNA was no longer detectable, virus-specific IgG titer remained high (>320).
“When the infant was examined on day 54, he had no obvious illness or evidence of any immunocompromising condition,” the authors wrote in their report. “However, by 6 months of age, he showed neuropsychomotor developmental delay, with global hypertonia and spastic hemiplegia, with the right dominant side more severely affected.”
Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.