In recent weeks, many news reports suggest there may be a strong connection between new cases of microcephaly in Brazil and the Zika virus outbreak there. Predictably, pregnant women infected with Zika are being encouraged to abort their babies. However, several health organizations have noticed issues that may point to other factors in the environment being the actual cause of the increase of Brazilian microcephaly.
The first cases of Zika virus in Brazil were confirmed in May 2015 and most likely came from French Polynesia. The Zika virus affected French Polynesia in 2013 through the first part of 2014 and then receded as quickly as it came. During that outbreak, there were at least 17 central nervous system malformations (microcephaly is a type of central nervous system malformation) seen in newborns which may have been related to the virus. Or they may have been due to something entirely different.
Importantly, microcephaly was never identified as one of the 17 malformations in French Polynesia. Researchers are also finding that many other areas that have had Zika virus outbreaks have not seen increases in microcephaly.
The Brazilian Ministry of Health noticed that the increase of microcephaly was occurring around 9 months after the Zika virus outbreak began and hurriedly concluded the two were likely related. However, researcher Dr. Sandra Mattos disagrees. When the outbreak occurred, she had already been collecting data on newborns in the Northeast Brazilian state of Paraiba. Looking back at her data, she discovered the increase of microcephaly had been occurring long before the initial outbreak of the Zika virus. Dr. Mattos believes that pesticides, malnutrition, drugs and infection by multiple viruses at once are the likely causes of the deformity.
Two other Latin American medical organizations believe that the larvicide (pyriproxyfen) – added to drinking water in 2014 – is the likely cause of the increase in microcephaly and other birth defects. Their findings, combined with the research by Dr. Mattos, strongly implicate factors other than the Zika virus as the true causes of increasing cases of microcephaly.
The Ministry of Health of Brazil – and the US Centers for Disease Control – should take note of this research rather than causing unwarranted panic and increasing abortions by suggesting that the rapidly-spreading Zika virus is likely to cause an explosion in birth defects across Latin America and the southern United States.