Zika Virus May Affect Babies With Normal-Sized Heads

A recent study suggests that newborns with normal-sized heads may also be affected by the mosquito-borne Zika virus.

According to Daily Times, a paper published in The Lancet reveals that a fifth of the “definite or probable” Zika virus infection cases in Brazilian infants involved in the new study had head circumferences within the normal range.

The paper’s lead author, Cesar Victora, of the Federal University of Pelotas, in Brazil, said,”Most suspected cases ended up being normal newborn babies with small heads. However, one in five definite or probable Zika cases had head circumference values in the normal range. Therefore, the current focus on microcephaly screening alone is too narrow.”

Until recently, attention has been largely focused on infants born with too-small heads, or microcephaly (abnormal smallness of the brain). However, the new findings from Victora’s team of researchers suggest that the focus should not only be on the size of a baby’s head but on signs and symptoms of brain abnormalities, reports Daily Times.

Victora further said, “Although we believe that the under reporting of microcephaly cases is rare during the epidemic, newborns infected with the virus late in pregnancy may go unreported due to their head size being within normal range.”

He added that rash in late pregnancy, which is another sign of maternal Zika infection, was also absent in one-third of the examined cases. In some cases, he said, women experienced the Zika-linked rash in late pregnancy and delivered babies with brain damage, even though their babies were born with normal-sized heads.

Victora asserted, “Our findings suggest that among pregnancies affected by Zika virus, some fetuses will have brain abnormalities and microcephaly, others will have abnormalities with normal head sizes, and others will not be affected.”

He further noted that the development of a baby’s skull is complete by week 30 of gestation, which suggests that Zika infection in newborns might be causing brain damage without the telltale sign of microcephaly.

“A surveillance system aimed at detecting all affected newborns should not just focus on microcephaly and rash during pregnancy and should be revised, and examination of all newborns during epidemic waves should be considered,” the professor said.

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