When the Zika virus first began wreaking havoc last year in Brazil, there was a crippling neurological defect on thousands of babies – which had never been seen in a mosquito-borne virus.

It also raised a puzzling question: how had a virus that for many decades was just an annex in the medical logs of contagious diseases have suddenly taken such a crippling turn in the Americas? This sharply contrasts with the situation in Africa and Asia, Zika had circulated under the radar for many years with no reports of serious outbreaks or severe complications.

Some scientists initially theorised that the long tenure of the virus in the southern hemisphere may have given those populations in the “dengue belt” a widespread immunity to both viruses. The other hypothesis was that older strains may be less virulent than the one linked in Brazil to more than 2,100 cases of microcephaly.

Now, researchers have found that some babies infected with Zika at birth, but who appeared normal, still showed significant brain defects later in their life and eventually developed microcephaly.

Small study of Brazilian newborns

Researchers followed a total of 13 Brazilian babies, whose mothers had tested positive for the mosquito-borne virus while pregnant. This was reported in the US Centers for Disease Control and Prevention (CDC).

The CDC stated that, “Among these infants, 11 later developed microcephaly.” They added, “Slowed head growth and microcephaly were accompanied by significant neurologic complications.”

Of the 13 babies followed, seven suffered from epilepsy, and it in the report, the CDC concluded that, “all had significant motor disabilities consistent with mixed cerebral palsy.”

However, as they were all too young, evaluation on how Zika may have affected the babies intellectually would have been premature.

Researchers worldwide have long established a general understanding that Zika might result in newborns bring birthed with microcephaly. This condition is defined and diagnosed when the baby has a head circumference (HC) that is two standard deviations below the mean for age and gender.

However, the findings now show that, the Zika virus infection in the womb can lead to the onset of this condition after birth.

“This report documents that microcephaly at birth is not an essential hallmark of congenital Zika syndrome,” it said. “Microcephaly might not be evident at birth but can develop after birth in infants with underlying brain abnormalities.”

Despite this, expectant mothers who are infected with Zika during pregnancy should not be overly concerned, as not all infants born after exposure to Zika suffer from developmental problems, and the researchers corroborated that at present, this study cannot confirm just how common the issue of delayed onset microcephaly actually is.

Regular tests and checks recommended

Due to a lack of medical literature on the links of Zika and microcephaly, it is advised that paediatric doctors conduct regular prenatal brain scans on Zika-exposed foetuses. They also underscored the need for comprehensive medical and developmental follow-up for the babies.

Although Zika has been removed from the World Health Organisation’s global emergency list, the many detrimental effects of Zika remains yet unknown. What we do know, it that apart from causing microcephaly in newborns, it may cause males to be infertile.

As of 23 November, there were 453 individuals in Singapore that have tested positive for the Zika virus, data from the National Environment Agency (NEA) shows. The first case was reported by three doctors from the Sims Drive Medical Clinic back in 22 August. MIMS

Read more:
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WHO takes Zika off global emergency list, but stresses long term problem
Infographic: Zika in Singapore & Malaysia
Male infertility may be associated with the Zika virus