US and Brazilian health workers fanned out across one of Brazil’s poorest states in search of mothers and their infants for a study aimed at determining whether the Zika virus is causing birth defects in babies.
Brazil’s health minister, Marcelo Castro, said yesterday he is “absolutely sure” mosquito-borne Zika is responsible for a spike in cases of the rare birth defect microcephaly, which sees babies born with small heads and brains and can cause severe developmental problems. But with scant scientific literature published on the matter, some doctors in Brazil and elsewhere say there is not yet enough scientific data to prove the connection.
Jointly run by the Brazil’s Health Ministry and the US Centers for Disease Control and Prevention, the study is intended to fill that vacuum by comparing babies with microcephaly and their mothers to babies without the condition.
The popular “understanding is that Zika virus (behind the microcephaly spike). How much of that is Zika virus is really one of the important goals of this study,” said Erin Staples, a Colorado-based epidemiologist who heads the CDC contingent in Paraiba state. “I do believe there is something occurring that is unique and knowable, but we really need to understand better, mostly so we can prevent this from happening to other generations.”
Eight teams made up of one CDC staffer and three Brazilian health workers will knock on the doors of several hundred randomly selected families with infants throughout Paraiba, a northeastern coastal state that is one of Brazil’s least developed. The teams hope to recruit at least 130 babies with microcephaly and their mothers and two to three times that number of mothers and babies without the condition, all born in the same areas and at around the same time.
The researchers will take blood samples from mothers and babies that will be sent to labs in Brazil and the United States to test for Zika and dengue, a similar virus also transmitted by the Aedes aegypti mosquito.
The idea is to determine whether mothers whose babies have microcephaly were infected with Zika and, if so, when during their pregnancies.Teams will also be on the lookout for other factors that, possibly in conjunction with Zika, could be behind Brazil’s increase in microcephaly, such as a prior infection with dengue, toxoplasmosis or the ingestion of toxins.
“If we can provide some basic information or show a potential association, that will allow us another avenue of how do we prevent this and what do we need to do next,” Staples said.