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By Megan Cooley

Megan CooleyThe potential for birth abnormalities in babies has put the outbreak of the Zika virus in the headlines. The World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) have issued advisories on traveling to and sexual contact with people who have traveled to Brazil, Venezuela, Columbia, and several states in Mexico. A direct correlation between Zika and microcephaly has been suggested but not proven at this point. There is some evidence that Zika can be transmitted sexually, although this mechanism has garnered less attention.

As Brazil is preparing to host the summer Olympics this year, the country has come under harsh criticism over its struggle to complete facilities for the games, but perhaps the bigger issue is its struggle to clean up water systems that will be used for the games. With Brazil’s reports of raw sewage in the water systems, the health of tourists and athletes is of great concern. In 2014 the Physicians In Crop-Sprayed Towns (PCST) claimed that the Brazilian Health Ministry approved the addition of pyriproxyfen to the drinking water to combat mosquito larvae growing. Coincidentally the number of microcephaly cases started to rise shortly after and in areas where water systems had been treated with the pesticide.

MosquitoPyriproxyfen has been used in the agricultural industry since the mid-90s with the WHO since approving its use worldwide. Pyriproxyfen is a larvicide that stops the maturation of mosquitos. Companies linked to the pesticide have been quick to distance themselves from the Zika-larvicide connection by stating through media outlets that the pesticide has been deemed safe and that all testing in mammals suggests no birth defects as a result of the pesticides use. A number of experts have come forward saying that the accusations of a connection are unwarranted and the research that was conducted is sound. Researchers in particular are firing back at environmentalists for raising a question about the link between the use of this pesticide and microcephaly, suggesting that they are simply exploiting the situation to push their own agenda to stop pesticide usage.

While it is advisable to exercise caution when traveling to affected areas, as the CDC and WHO have recommended, it is also important to not become hysterical about the situation either. Although the correlation between pyriproxyfen and microcephaly does not appear to be plausible based on extensive toxicology studies, the correlation between Zika and microcephaly has also not been solidified. As previously reported, Zika was first identified in 1947 in Africa. Although it is likely that records of abnormal births were not recorded or reported consistently when first identified, the roughly 70 years that has lapsed between now and then has never drawn a correlation. Rubella, another viral infection affecting fetal development, was identified in significantly shorter period of time with significantly more births effected. Correlation does not mean cause.

Megan Cooley is not authorized to speak on behalf of MRIGlobal, and the opinions expressed are my personal opinions and not those of MRIGlobal.

Megan Cooley, Ph.D., is a postdoctoral fellow at the University of Kansas Medical Center. Her research is focused on understanding the effects of the tumor microenvironment on acquired chemoresistance and metastasis.