Comments on: A Possible Link Between Pyriproxyfen and Microcephaly

By: yaneer@necsi.edu

yaneer@necsi.edu — Sun, 25 Feb 2018 16:38:51 +0000

The following article supports our conclusions that there should be more tests of the toxicity of pyriproxyfen and specifically its potential causal role in microcephaly: Karine Audouzea, Olivier Taboureaua, Philippe Grandjean. A systems biology approach to predictive developmental neurotoxicity of a larvicide used in the prevention of Zika virus transmission Toxicology and Applied Pharmacology https://www.sciencedirect.com/science/article/pii/S0041008X18300607

By: rparen01

rparen01 — Thu, 21 Dec 2017 20:45:26 +0000

The cited paper in the Lancet titled “Association between microcephaly, Zika virus infection, and other risk factors in Brazil: final report of a case-control study” identified a sample of 91 cases of microcephaly diagnosed births and 173 controls. Of the 91 microcephaly cases, the number of positive tests for Zika infections is 32 while the controls had none. While this surely indicates a positive correlation of Zika infection with microcephaly (consistent with what has been reported by other studies), the microcephaly cases without positive Zika tests suggests that other causes may also be present.

This study, like others before it, does not confirm that Zika is the primary cause of microcephaly cases in Brazil. Many other countries and other regions of Brazil have large numbers of Zika cases but do not have a correspondingly large number of microcephaly cases. Thus, the geographic distribution of microcephaly does not support a conclusion that Zika is the primary cause.

By: email123

email123 — Wed, 20 Dec 2017 05:48:39 +0000

As a response to this speculative article, please see Lancet Infect. Dis: http://dx.doi.org/10.1016/S1473-3099(17)30727-2.

That article confirms the association between congenital Zika virus infection and microcephaly and suggests no association between microcephaly and exposure to pyriproxyfen.