Pyriproxyfen#Rumor of link to microcephaly outbreak in Brazil

Pyriproxyfen has low acute toxicity.{{Cite web | url = http://inchem.org/documents/jmpr/jmpmono/v99pr12.htm | title = Toxicological evaluations | website = inchem.org | access-date = 2016-04-13 | quote = ...it was not necessary to establish an acute reference dose because of the low acute toxicity of pyriproxyfen.}} According to WHO and FAO, at elevated doses exceeding 5000 mg/kg of body weight, pyriproxyfen affects the liver in mice, rats and dogs.{{Cite web

| url = http://inchem.org/documents/jmpr/jmpmono/v99pr12.htm

| title = Toxicological evaluations

| website = inchem.org

| access-date = 2016-02-28

}} It also changes cholesterol levels, and may cause modest anemia at high doses.{{Cite web

| url =https://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfen2ndadd.pdf

| title = Pyriproxyfen in Drinking-water, Background document for development of WHO Guidelines for Drinking-water Quality

}}

{{broader|2015–16 Zika virus epidemic}}

Starting in 2014, pyriproxifen was put into Brazilian water supplies to fight the proliferation of mosquito larvae.[http://u.saude.gov.br/images/pdf/2014/maio/30/Instrucoes-para-uso-de-pyriproxifen-maio-2014.pdf "Technical instructions for the utilization of the larvicide pyriproxyfen (0.5 G) for the control of Aedes aegypti", Brazilian Ministry of Health] This is in line with the World Health Organization (WHO)'s Pesticide Evaluation Scheme (WHOPES) for larvicides.[https://web.archive.org/web/20160222235133/http://www.who.int/whopes/Mosquito_Larvicides_25_Oct_2013.pdf?ua=1 WHOPES-recommended compounds and formulations for control of mosquito larvae (25 October 2013)] In January 2016, the Brazilian Association for Collective Health (Abrasco; {{langx|pt|Associação Brasileira de Saúde Coletiva}}) criticized the introduction of pyriproxyfen in Brazil. Abrasco demanded the "immediate suspension of [use of] pyriproxyfen and all growth inhibitors ... in drinking water." The organization is opposed to the use of growth inhibitors in the context of an ongoing outbreak of fetal malformation.{{cite web |url=https://www.abrasco.org.br/site/2016/02/nota-tecnica-sobre-microcefalia-e-doencas-vetoriais-relacionadas-ao-aedes-aegypti-os-perigos-das-abordagens-com-larvicidas-e-nebulizacoes-quimicas-fumace/ |trans-title=Technical note on microcephaly and vector diseases related to the Aedes aegypti: the dangers of approaches using larvicides and chemical nebulization |title=Nota técnica sobre microcefalia e doenças vetoriais relacionadas ao Aedes aegypti: os perigos das abordagens com larvicidas e nebulizações químicas – fumacê |publisher=Brazilian Association for Collective Health (Associação Brasileira de Saúde Coletiva, Abrasco) |quote=reivindicamos das autoridades competentes a adoção das medidas a seguir: ... (3) Nas medidas adotadas pelo MS [Ministério da Saúde] para controle de Aedes aegypti em suas formas larva e adulto, imediata suspensão do Pyriproxyfen (0,5 G) e de todos os inibidores de crescimento como o Diflubenzuron e o Novaluron, ou qualquer outro produto químico ou biológico em água potável. |language=pt}}

On February 3, the rumor that pyriproxyfen, not the Zika virus, is the cause of the 2015-2016 microcephaly outbreak in Brazil was raised in a report of the Argentinean organization Physicians in the Crop-Sprayed Villages (PCST).[http://www.reduas.com.ar/report-from-physicians-in-the-crop-sprayed-town-regarding-dengue-zika-microcephaly-and-massive-spraying-with-chemical-poisons/ "Report from Physicians in the Crop-Sprayed Villages regarding Dengue-Zika, microcephaly, and mass-spraying with chemical poisons", Coordinator: Dr. Medardo Avila Vazquez]: “Malformations detected in thousands of children from pregnant women living in areas where the Brazilian state added pyriproxyfen to drinking water is not a coincidence, even though the Ministry of Health places a direct blame on Zika virus for this damage, while trying to ignore its responsibility and ruling out the hypothesis of direct and cumulative chemical damage caused by years of endocrine and immunological disruption of the affected population.,” PCST said. It attracted wide media coverage.{{cite web | url = http://www.theecologist.org/News/news_analysis/2987137/argentine_and_brazilian_doctors_suspect_mosquito_insecticide_as_cause_of_microcephaly.html | title = Argentine and Brazilian doctors suspect mosquito insecticide as cause of microcephaly | publisher = Ecologist}}{{cite news |last=Almendrala |first=Anna |date=February 16, 2016 |title=A Viral Story Links The Zika Crisis To Monsanto. Don't Believe It. |url=http://www.huffingtonpost.com/entry/zika-monsanto-pyriproxyfen-microcephaly_us_56c2712de4b0b40245c79f7c |newspaper=Huffington Post |access-date=February 16, 2016}}

The statement from Abrasco was cited in the PCST report; subsequently, Abrasco clarified that position as a misinterpretation of their statement, saying "at no time did we state that pesticides, insecticides, or other chemicals are responsible for the increasing number of microcephaly cases in Brazil". They also condemned the behavior of the websites that spread the misinformation, adding that such "untruths...violates the anguish and suffering of the people in vulnerable positions".[http://www.bbc.com/portuguese/noticias/2016/02/160215_zika_larvicida_cc.shtml Entidade diz ter sido mal-interpretada e não ver ligação entre microcefalia e larvicida] In addition, the coordinator for the PCST statement, Medardo Ávila Vazquez, acknowledged in an interview that "the group hasn't done any lab studies or epidemiological research to support its assertions, but it argues that using larvicides may cause human deformities."{{cite news |last1=Johnson |first1=Reed |last2=Jelmayer |first2=Rogerio |date=February 15, 2016 |title=Brazil State Bans Pesticide After Zika Claim |url=https://www.wsj.com/articles/brazil-state-bans-pesticide-after-zika-claim-1455584596 |newspaper=Wall Street Journal |access-date=February 16, 2016}}

On February 13, the Brazilian state of Rio Grande do Sul suspended pyriproxyfen's use, citing both Abrasco and PCST positions.[https://www.telegraph.co.uk/news/worldnews/zika/12157747/Zika-virus-Brazil-dismisses-link-between-larvicide-and-microcephaly.html Zika virus: Brazil dismisses link between larvicide and microcephaly][http://agenciabrasil.ebc.com.br/geral/noticia/2016-02/rs-suspende-larvicida-pyriproxyfen-usado-em-caixas-dagua-para-combater-aedes Rio Grande do Sul discontinues the use of larvicide Pyriproxyfen against Aedes aegypti mosquitoes ({{lang|pt|RS suspende uso de larvicida Pyriproxyfen no combate ao mosquito Aedes}})] The Health Minister of Brazil, Marcelo Castro, criticized this step, noting that the claim is "a rumor lacking logic and sense. It has no basis." They also noted that the insecticide is approved by the National Sanitary Monitoring Agency and "all regulatory agencies in the whole world". The manufacturer of the insecticide, Sumitomo Chemical, stated "there is no scientific basis for such a claim" and also referred to the approval of pyriproxyfen by the World Health Organization since 2004 and the United States Environmental Protection Agency since 2001.{{cite news | url = http://latino.foxnews.com/latino/news/2016/02/14/brazilian-state-suspends-larvicide-used-to-combat-zika-virus/ | title = Brazilian state suspends larvicide used to combat Zika virus | publisher = Fox News Latino | date = February 14, 2016}}{{cite news |url=http://www.sciencealert.com/argentinian-report-says-monsanto-linked-pesticide-is-to-blame-for-microcephaly-outbreak-not-zika |title=Report says Monsanto-linked pesticide is to blame for microcephaly outbreak - not Zika |work=Science Alert |date=16 February 2016 |access-date=2016-02-16 }}

George Dimech, the director of Disease Control and Diseases of the Health Department of Pernambuco in Brazil, gave an interview to the BBC where he pointed out that the city of Recife has the current highest reported number of cases of microcephaly, yet pyriproxyfen is not used in the region, but another insecticide altogether. He added that "this lack of spatial correlation weakens the idea that the larvicide is the cause of the problem." In addition, the BBC interviewed researchers in Pernambuco, where no evidence has been found of the cases being linked to any environmental cause like an insecticide. Neurologist Vanessa van der Linden stated in an interview, "Clinically, the changes we see in the scans of babies suggest that the injuries were caused by congenital infection and not by larvicide, drug or vaccine."

Noted skeptic David Gorski called the claim a conspiracy theory and pointed out that antivaccine proponents had also claimed that the Tdap vaccine was the cause of the microcephaly outbreak, due to its introduction in 2014, along with adding, "One can't help but wonder what else the Brazilian Ministry of Health did in 2014 that cranks can blame microcephaly on." Gorski also pointed out the extensive physiochemical understanding of pyriproxyfen coded in the WHO Guidelines for Drinking-water Quality, which concluded in a past evaluation that the insecticide is not genotoxic, and that the doctor organization making the claim has been advocating against all pesticides since 2010, complicating their reliability.{{cite web |url=http://scienceblogs.com/insolence/2016/02/15/say-it-aint-so-george-george-takei-falls-for-a-zika-virus-conspiracy-theory/ |title=Oh, myyyy! George Takei falls for a Zika virus conspiracy theory |last1=Gorski |first1=David |author-link=David Gorski |date=February 15, 2016 |website=Respectful Insolence |publisher=ScienceBlogs |access-date=February 15, 2016}}{{cite web|title=Chemical hazards in drinking-water: Pyriproxyfen|url=https://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfen/en/|archive-url=https://web.archive.org/web/20071014054118/http://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfen/en/|url-status=dead|archive-date=October 14, 2007|website=who.int|publisher=World Health Organization|access-date=15 February 2016}}EFSA (European Food Safety Authority), 2014. Conclusion on the peer review of the pesticide risk assessment of confirmatory data submitted for the active substance pyriproxyfen. EFSA Journal 2014;12(8):3813, 19 pp. doi:10.2903/j.efsa.2014.3813 [http://www.efsa.europa.eu/sites/default/files/scientific_output/files/main_documents/336r.pdf PDF] Aces. Jan. 13

A professor from the University of Adelaide in Australia, stated that "The effect of pyriproxyfen on reproduction and fetal abnormalities is well studied in animals. In a variety of animal species even enormous quantities of pyriproxyfen do not cause the defects seen during the recent Zika outbreak."{{cite news |url=https://www.scimex.org/newsfeed/expert-reaction-is-a-pesticide,-not-zika-virus,-causing-microcephaly |title=EXPERT REACTION: Is a pesticide, not Zika virus, causing microcephaly? |work=SCIMEX |date=15 February 2016 |access-date=2016-02-16 }} A colleague also from the University of Adelaide stated that "While the evidence that Zika virus is responsible for the rise in microcephaly in Brazil is not conclusive, the role of pyriproxyfen is simply not plausible." Another professor in Australia concluded that "insect development is quite different to human development and involves different hormones, developmental pathways and sets of genes, so it cannot be assumed that chemicals affecting insect development also influence mammalian development."

• Insect growth regulator

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• {{PPDB|574|Name=Pyriproxyfen}}

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Category:Insecticides

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