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ContraPest
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<h2 id="mechanism">Mechanism</h2> <p>The formula was originally developed by Drs. Loretta Mayer and Cheryl Dyer as part of a research program studying <a href="/facts/Heart_disease/HD420nMv">heart disease</a> in <a href="/facts/Post-menopausal_women/b3Fz6NHb">post-menopausal women</a> using menopausal mice.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> The first <a href="/facts/Active_ingredient/oeDx5S19">active ingredient</a> of ContraPest is <a href="/facts/4-vinylcyclohexene_diepoxide/N6yIMu1N">4-vinylcyclohexene diepoxide</a> (VCD), which causes destruction of the <a href="/facts/Antral_follicle/ujf6uhWI">antral follicle</a> during <a href="/facts/Folliculogenesis/Wccv9PuQ">folliculogenesis</a> in the female ovary.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a><a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> ContraPest also contains <a href="/facts/Triptolide/5kN4NhNJ">triptolide</a>, which has been reported to reduce male rat fertility by reducing <a href="/facts/Sperm_motility/PKHcbdjk">sperm motility</a> and <a href="/facts/Sperm_viability/DgsKJmyp">viability</a>.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a><a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a><a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> </p><p>Studies conducted by SenesTech claim to demonstrate that prolonged consumption of ContraPest led to a significant decrease in rat fertility. Rats exposed to ContraPest for 50 days experienced infertility lasting up to 100 days, with reduced litter sizes in those that could still reproduce.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> </p><p>A 2020 short-term laboratory trial with wild-caught adult black rats from Hawai'i indicated that exposure to ContraPest bait resulted in complete reproductive inhibition for at least 15 consecutive days before mating and throughout a 43-day breeding cycle. The effect persisted through a second breeding cycle, with partial suppression evident in a third cycle. However, fertility rebounded by the fourth cycle. It is uncertain whether the contraceptive effect affects males or females, given that the treatment impacts both sexes. <a href="/facts/Control_group/zeT4uJ2S">Control group</a> reproduction was not 100%, potentially due to factors like adjustment to captivity or incomplete fertility in the source population. ContraPest did not induce permanent infertility, suggesting it is a contraceptive rather than a sterilant.<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> </p><p>Toxicity studies on ContraPest in other animals have revealed few adverse effects. The active ingredients metabolize quickly, typically within 15 minutes. Thus, if a dog or cat consumed a rat that had recently ingested ContraPest, it might experience temporary infertility as a minor side effect.<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> </p> <h2 id="use">Use</h2> <p>The city of <a href="/facts/Washington,_D.C./enXPK156">Washington D.C.</a> was utilizing a 5,000 unit, four-year supply of ContraPest to be used in all eight wards of the city in an attempt to combat the increasing rat population in 2020.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> Local news reported that the district was unsure of the company's early claims of success in rat control.<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> Trials in the <a href="/facts/New_York_City_Subway/1NKtIgLr">New York City Subway</a> system have suggested ContraPest's efficacy in reducing brown rat populations.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> </p><p>In 2024, a <a href="/facts/Municipal_council/nrnR6T5p">City Council</a> bill in <a href="/facts/New_York_City/YlyvFmVC">New York</a> proposed deploying contraceptive pellets, including ContraPest, to sterilize both male and female rats in designated areas, aiming to reduce the rat population.<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> On September 26, the city council approved pilot programs to use the contraceptive in an effort to reduce its rodent population. The initiative marked a potential shift in the city's long-standing strategy against its rat infestation and was inspired by the death of <a href="/facts/Flaco_(owl)/dD3nSco8">Flaco the Owl</a>, which raised concerns about rat poison effects.<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a> </p> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Marini, Miriam. "Rat birth control is latest way to reduce rodent population: How it works". Detroit Free Press. Retrieved 2024-05-09. <a href="https://www.freep.com/story/news/local/michigan/2022/01/31/contrapest-rat-birth-control-contra-pest/9283887002/" target="_blank">https://www.freep.com/story/news/local/michigan/2022/01/31/contrapest-rat-birth-control-contra-pest/9283887002/</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"Man v rat: could the long war soon be over?". The Guardian. 2016-09-20. ISSN 0261-3077. Retrieved 2016-09-21. <a href="https://www.theguardian.com/science/2016/sep/20/man-v-rat-war-could-the-long-war-soon-be-over" target="_blank">https://www.theguardian.com/science/2016/sep/20/man-v-rat-war-could-the-long-war-soon-be-over</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>"FAQ | Senestech". Retrieved 2019-03-07. <a href="https://senestech.com/contrapest/faq/" target="_blank">https://senestech.com/contrapest/faq/</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>"Man v rat: could the long war soon be over?". The Guardian. 2016-09-20. ISSN 0261-3077. Retrieved 2016-09-21. <a href="https://www.theguardian.com/science/2016/sep/20/man-v-rat-war-could-the-long-war-soon-be-over" target="_blank">https://www.theguardian.com/science/2016/sep/20/man-v-rat-war-could-the-long-war-soon-be-over</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>"ContraPest Rodent Control Product Wins EPA Approval". Pest Control Technology, GIA Media, Inc. 12 August 2016. Retrieved 11 November 2016. <a href="http://www.pctonline.com/article/senestech-contrapest-rodent-product-epa-approval/" target="_blank">http://www.pctonline.com/article/senestech-contrapest-rodent-product-epa-approval/</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>"Loretta Mayer: Features - Executive Profile". Pest Control Technology. 2018-12-11. Retrieved 2019-03-07. <a href="https://www.pctonline.com/article/loretta-mayer/" target="_blank">https://www.pctonline.com/article/loretta-mayer/</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Kappeler, Connie J.; Hoyer, Patricia B. (2012-02-01). "4-vinylcyclohexene diepoxide: a model chemical for ovotoxicity". Systems Biology in Reproductive Medicine. 58 (1): 57–62. doi:10.3109/19396368.2011.648820. ISSN 1939-6376. PMC 3307534. PMID 22239082. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3307534" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3307534</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Takai, Yasushi; Canning, Jacqueline; Perez, Gloria I.; Pru, James K.; Schlezinger, Jennifer J.; Sherr, David H.; Kolesnick, Richard N.; Yuan, Junying; Flavell, Richard A. (2003-01-01). "Bax, caspase-2, and caspase-3 are required for ovarian follicle loss caused by 4-vinylcyclohexene diepoxide exposure of female mice in vivo". Endocrinology. 144 (1): 69–74. doi:10.1210/en.2002-220814. ISSN 0013-7227. PMID 12488331. <a href="https://doi.org/10.1210%2Fen.2002-220814" target="_blank">https://doi.org/10.1210%2Fen.2002-220814</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>"Man v rat: could the long war soon be over?". The Guardian. 2016-09-20. ISSN 0261-3077. Retrieved 2016-09-21. <a href="https://www.theguardian.com/science/2016/sep/20/man-v-rat-war-could-the-long-war-soon-be-over" target="_blank">https://www.theguardian.com/science/2016/sep/20/man-v-rat-war-could-the-long-war-soon-be-over</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>Lue, Y.; Sinha Hikim, A. P.; Wang, C.; Leung, A.; Baravarian, S.; Reutrakul, V.; Sangsawan, R.; Chaichana, S.; Swerdloff, R. S. (1998). "Triptolide: a potential male contraceptive". Journal of Andrology. 19 (4): 479–486. doi:10.1002/j.1939-4640.1998.tb02042.x. ISSN 0196-3635. PMID 9733151. <a href="https://pubmed.ncbi.nlm.nih.gov/9733151/#:~:text=Thus,%20triptolide,%20at%20a%20dose,a%20post-testicular%20male%20contraceptive." target="_blank">https://pubmed.ncbi.nlm.nih.gov/9733151/#:~:text=Thus,%20triptolide,%20at%20a%20dose,a%20post-testicular%20male%20contraceptive.</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Singla, Neena; Challana, Swati (2014). "Reproductive Toxicity of Triptolide in Male House Rat, Rattus rattus". The Scientific World Journal. 2014: 1–6. doi:10.1155/2014/879405. ISSN 2356-6140. PMC 4211135. PMID 25374942. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4211135" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4211135</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Marini, Miriam. "Rat birth control is latest way to reduce rodent population: How it works". Detroit Free Press. Retrieved 2024-05-09. <a href="https://www.freep.com/story/news/local/michigan/2022/01/31/contrapest-rat-birth-control-contra-pest/9283887002/" target="_blank">https://www.freep.com/story/news/local/michigan/2022/01/31/contrapest-rat-birth-control-contra-pest/9283887002/</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>Siers, Shane R.; Sugihara, Robert T.; Leinbach, Israel L.; Pyzyna, Brandy R.; Witmer, Gary W. (2020). "Laboratory Evaluation of the Effectiveness of the Fertility Control Bait ContraPest® on Wild-Captured Black Rats (Rattus rattus)". Proceedings of the Vertebrate Pest Conference. 29 (29). ISSN 0507-6773. <a href="https://escholarship.org/uc/item/81d987p5" target="_blank">https://escholarship.org/uc/item/81d987p5</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>Marini, Miriam. "Rat birth control is latest way to reduce rodent population: How it works". Detroit Free Press. Retrieved 2024-05-09. <a href="https://www.freep.com/story/news/local/michigan/2022/01/31/contrapest-rat-birth-control-contra-pest/9283887002/" target="_blank">https://www.freep.com/story/news/local/michigan/2022/01/31/contrapest-rat-birth-control-contra-pest/9283887002/</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>"SenesTech Announces Progress and Expansion of Washington DC ContraPest® Deployment". www.prnewswire.com (Press release). SenesTech. PR Newswire. Retrieved 2021-01-05. <a href="https://www.prnewswire.com/news-releases/senestech-announces-progress-and-expansion-of-washington-dc-contrapest-deployment-300801828.html" target="_blank">https://www.prnewswire.com/news-releases/senestech-announces-progress-and-expansion-of-washington-dc-contrapest-deployment-300801828.html</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>"Is Rat Birth Control Working in DC?". NBC4 Washington. Retrieved 2023-09-05. <a href="https://www.nbcwashington.com/news/local/is-rat-birth-control-working-in-dc/2193307/" target="_blank">https://www.nbcwashington.com/news/local/is-rat-birth-control-working-in-dc/2193307/</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>Siers, Shane R.; Sugihara, Robert T.; Leinbach, Israel L.; Pyzyna, Brandy R.; Witmer, Gary W. (2020). "Laboratory Evaluation of the Effectiveness of the Fertility Control Bait ContraPest® on Wild-Captured Black Rats (Rattus rattus)". Proceedings of the Vertebrate Pest Conference. 29 (29). ISSN 0507-6773. <a href="https://escholarship.org/uc/item/81d987p5" target="_blank">https://escholarship.org/uc/item/81d987p5</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>Fitzsimmons, Emma G. (2024-04-10). "The Next Frontier in New York's War on Rats: Birth Control". The New York Times. ISSN 0362-4331. Retrieved 2024-05-07. <a href="https://www.nytimes.com/2024/04/10/nyregion/nyc-rat-contraception-birth-control.html" target="_blank">https://www.nytimes.com/2024/04/10/nyregion/nyc-rat-contraception-birth-control.html</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> <li id="fn:19"><p>"New York greenlights rat birth control to curb city's infestation". The Guardian. 2024-09-27. ISSN 0261-3077. Retrieved 2024-09-30. <a href="https://www.theguardian.com/us-news/2024/sep/27/rat-birth-control-nyc" target="_blank">https://www.theguardian.com/us-news/2024/sep/27/rat-birth-control-nyc</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></p></li> </ol>