The outbreak of Zika in Brazil has been linked to microcephaly in children whose mothers contracted the disease while pregnant. However, new evidence has given scientists reason to question the Zika-microcephaly link. A recent study of almost 12,000 pregnant women in Colombia, who also have Zika, found no cases of microcephaly. If the two diseases were linked, then there should have been some cases based on the rate of concurrence of the two diseases in Brazil.
But those cases are there. Four women with Zika who did not show symptoms have had children with microcephaly, though because they didn’t show symptoms they weren’t part of the study. They illustrate that there are likely many more cases of pregnant women with Zika not showing signs of the illness, but those four cases don’t show a correlation between the two diseases. They are likely just a coincidence, because if Zika were a cause of microcephaly, there would be more cases.
As such, the New England Complex Systems Institute (NECSI), which conducted the study, has suggested that we rethink the cause of microcephaly in Brazil. One possible culprit, which NECSI thinks we should be looking at, is the pesticide pyriproxyfen, which is used to treat water in Brazil in order to kill the larvae of mosquitoes which spread Zika. That pesticide is analogous to juvenile mosquito hormones, which can react to things in very similar ways to retinoic acid, a known cause of microcephaly.
So it might be, pending investigation, that the pesticide used to try and prevent the spread of Zika might be the actual culprit in the spread of the disease. Of course, more research is needed before any final conclusions can be made, but the latest news provides a break-through in alternative treatment options.