Zika Virus, Pyriproxyfen, and Monsanto: What's Causing Brazil's Microcephaly Outbreak?

Dan Wilson

Senior Member
Zika virus has quickly gained the attention of the world in the past few weeks due to its association with a large outbreak of microcephaly cases in Brazil. However, not everyone thinks the microcephaly outbreak is simply due to Zika virus. Everything from vaccines to GM mosquitoes to man-made pathogens has been accused as the real cause of Brazil's microcephaly.
A new story, however, is gaining a lot of traction on social media and various news sources. A group of doctors from Argentina are proposing that a larvicide, pyriproxifen, is responsible for the outbreak.
Furthermore, they claim that the focus on Zika virus is an intentional cover-up and that a Japanese branch of Monsanto, Sumitomo Chemical, manufactures it (EDIT: Sumitomo is not owned by Monsanto). The report that started this whole story was written by Dr. Medardo Vasquez.
http://www.reduas.com.ar/wp-content/uploads/downloads/2016/02/Informe-Zika-de-Reduas_TRAD.pdf
So what's going on? Is there a cover-up? What's actually causing the microcephaly outbreak? To start off, let's talk about what pyriproxifen is.

What is pyriproxifen and is it toxic to humans?
Pyriproxifen is a larvicide (kills insect larvae) that most people have probably used before. In the U.S., it is marketed as Nylar, an anti-flea product used generally by pet owners. It has been marketed since 1996 and has been subjected to a variety of toxicology tests.

Pyriproxyfen is listed as a Group E carcinogen, as in there was no evidence of carcinogenicity found associated with the compound. In this case, however, we are talking about substances that can cause birth defects (teratogens), which are not necessarily in the same category of carcinogens.
Dr. Vasquez claims that because the larvicide interferes with the normal development of mosquitoes, we should not assume it does not affect human development, as many developmental pathways are conserved between humans and distantly related organisms.

He is right that we should not assume that something that affects insects doesn't affect humans. The problem is that he gives no evidence that pyriproxifen is a teratogen. In fact, all of the available toxicological data would suggest that it is not.
https://pubchem.ncbi.nlm.nih.gov/compound/Pyriproxyfen#section=Spillage-Disposal
Although you certainly should not regularly consume pesticides, this one has been determined to not be of significant worry so far. But then again, neither has Zika. Zika virus, as Dr. Vasquez points out, has been around for a long time and has never before been linked to any serious health effects even in the event of large outbreaks. So what is the evidence that Zika or pyriproxifen is responsible for the outbreak?

What's causing the microcephaly outbreak?
The evidence implicating pyriproxifen in the microcephaly outbreak that Dr. Vasquex reports is purely coincidental and also vague. So far the only evidence seems to be that pyriproxyfen (brand name Sumilarv) has started being used within the past 18 months in Brazil in an attempt to control mosquito populations.
No specific regions that received this spraying were mentioned and I have not yet been able to locate any corroborating information on this. That's really all Dr. Vasquez has to offer in his report, there is not much to the link between pyriproxyfen and microcephaly. He seems to be more against the general spraying of chemicals in Brazil altogether, but that is another topic.
The evidence that Zika is causing the outbreak could be described as preliminary. It certainly is a mystery why Zika would suddenly be causing microcephaly when it has a long history of being benign infections. There could very well be another factor involved here, but keep in mind that travel, climate change, and viral mutations could be factors in explaining Zika's sudden spread and emergence of symptoms.
http://www.sciencemag.org/news/2016/01/zika-virus-your-questions-answered
The take home message here is that there is a lot we still don't know about the microcephaly outbreak and Zika virus itself. Implicating pyriproxyfen as the culprit is an extremely premature assumption that has the attraction of blaming Monsanto for more things.
There is currently no evidence that supports the idea that pyriproxyfen is responsible for Brazil's recent reported birth defects. When new outbreaks and public health problems appear, it is important to not let fear-mongering influence decision-making and not be swayed by an explanation that is better described as a guess. More information on this topic will help to clear up the situation, but until then it's better to not simply default to blaming corporations and chemicals.
 
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deirdre

Moderator
Staff member
also to bear in mind, Dr Vasquex in his report you linked says

But what i've found so far is:
Yap, the country with 75% infected and no known birth defects, is only a population of 12,000 and the outbreak studied occured in 2007. As you have stated earlier viruses can and do mutate.

And, if this reporting is accurate, it seems Columbia wouldn't know yet. (bold mine)

 

Dan Wilson

Senior Member
Yap, the country with 75% infected and no known birth defects, is only a population of 12,000 and the outbreak studied occured in 2007.
The population size infected could certainly matter. In some past examples of outbreaks of devastating diseases, only a small fraction of the total infected population developed symptoms or died. Polio is probably the most well-known. Though it was devastating, most people that got infected did not become paralyzed. This could very well be the case with Zika, but so much just remains to be seen.
 

KellyCdB

New Member
Furthermore, they claim that the focus on Zika virus is an intentional cover-up because a Japanese branch of Monsanto, Sumimoto Chemical, manufactures it.

In your write up, you state that Sumimoto is a branch of Monsanto - do you have a source for that information?
 
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Auldy

Senior Member
In your write up, you state that Sumimoto is a branch of Monsanto - do you have a source for that information?
Dan doesn't actually state that, it says those who are making the claim re: Zika caused by pyriproxyfen say that Sumimoto is a branch is Monsanto. That comes from the link in the OP, dot point 3 on page one:

Edit: of course they haven't provided a source for making that connection, and I would doubt that it's true. All I can find is that the two companies have worked together in the past, but are not subsidiary's of each other.
 

KellyCdB

New Member
Dan doesn't actually state that, it says those who are making the claim re: Zika caused by pyriproxyfen say that Sumimoto is a branch is Monsanto. That comes from the link in the OP, dot point 3 on page one:
Excellent - thanks for clearing that up.
 

deirdre

Moderator
Staff member
In your write up, you state that Sumimoto is a branch of Monsanto - do you have a source for that information?
i found this PDF from Sumimoto. Doesnt sound like a subsidiary, but says there is a collaboration. This is for weeds, Dec 2014.
 

Auldy

Senior Member
Monsanto addressing this theory directly on their blog

Emphasis is my own

http://monsantoblog.com/2016/02/13/the-truth-about-monsanto-and-the-zika-virus/
 

Dan Wilson

Senior Member
Monsanto addressing this theory directly on their blog
Thank you, I had searched briefly for any confirmation on whether or not Sumitomo Chemical is actually owned by Monsanto but couldn't be sure at the time so I didn't follow up on it. It seems like Dr. Vasquez simply made up the idea of Monsanto being involved.. Goes to show how fast some people will believe stories like this I suppose.
 
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deirdre

Moderator
Staff member
bold mine


and from CNN
 

Dan Wilson

Senior Member
In an important update on the Zika virus, a little more evidence has come to light strengthening the link between microcephaly and the virus.
http://www.cdc.gov/mmwr/volumes/65/wr/mm6508e1er.htm?s_cid=mm6508e1er.htm_w
We still don't have a confirmed causative link but the available evidence supports the idea for now. This evidence in these case reports also further reject the idea that pyriproxyfen is responsible for anything.
 
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