ContraPest
- Biotechnology
- Pest Control
![ContraPest Tank](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/CP_res-57.jpg/220px-CP_res-57.jpg)
ContraPest is a contraceptive pest control tool designed to reduce fertility in brown and black rats. It was developed by the U.S. biotechnology company SenesTech.[1]
Originally designed to supplement existing rodent control strategies, is a sweet liquid that appeals to rats.[2] However, it does not sterilize them, so a continuous supply is required.[3] The company claims that in field tests, ContraPest use caused a reduction in rat populations of roughly 40% over a period of 12 weeks or longer.[1] The product was approved for commercial use by the U.S. Environmental Protection Agency in August 2016.[4]
Mechanism
The formula was originally used by Dr. Loretta Mayer and Dr. Cheryl Dyer as part of a research program to study heart disease in post-menopausal women through menopausal mice.[5] The active ingredient of ContraPest is the chemical 4-vinylcyclohexene diepoxide (VCD), which is a known to work when injected into peritoneal cavities of a target animal.[3][6][7] ContraPest also contains triptolide, which has been reported to reduce male rat fertility.[1] Both chemicals inhibit spermatogenesis in males and ovulation in females.[8]
ContraPest uses oral ingestion as a major uptake method.[9] It is appealing to rats due to its fat and salt content, which they find preferable to scavenging through trash.[10]
Studies conducted by SenesTech demonstrated 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 reproduce.[2]
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 in wild-caught black rats for at least 15 consecutive days before mating and throughout a 43-day breeding cycle. The inhibitory effect persisted through a second breeding cycle, with partial suppression evident in a third cycle. However, fertility rebounded by the fourth cycle. It's uncertain whether the contraceptive effect affects males or females, given the treatment's impact on both sexes. Control group reproduction was not 100%, potentially due to factors like the adjustment to captivity or incomplete fertility in the source population. ContraPest did not induce permanent infertility, suggesting it's a contraceptive rather than a sterilant. Further studies are needed to assess long-term exposure effects.[8]
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.[2]
Deployment
The city of Washington D.C. 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.[11] Local news reported that the district was unsure of the company's early claims of success in rat control.[12]
ContraPest was tested in Seattle's Queen Anne neighborhood in spring 2022 and demonstrated a 90% decrease in the rodent population within months.[13]
Successful trials in the New York City Subway system have suggested ContraPest's efficacy in reducing brown rat populations.[8]
In 2024, a City Council bill in New York proposed deploying contraceptive pellets, including ContraPest, to sterilize both male and female rats in designated areas, aiming to reduce the rat population. Sponsored by Councilman Shaun Abreu, the initiative seeks to address the long-standing rat problem in the city while minimizing harm to wildlife, such as the beloved Eurasian eagle-owl, Flaco, whose death was partially attributed to rat poison.[10]
References
- ^ a b c "Man v rat: could the long war soon be over?". The Guardian. 2016-09-20. ISSN 0261-3077. Retrieved 2016-09-21.
- ^ a b c Marini, Miriam. "Rat birth control is latest way to reduce rodent population: How it works". Detroit Free Press. Retrieved 2024-05-09.
- ^ a b "FAQ | Senestech". Retrieved 2019-03-07.
- ^ "ContraPest Rodent Control Product Wins EPA Approval". Pest Control Technology, GIA Media, Inc. 12 August 2016. Retrieved 11 November 2016.
- ^ "Loretta Mayer: Features - Executive Profile". Pest Control Technology. 2018-12-11. Retrieved 2019-03-07.
- ^ 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.
- ^ 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 b c 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.
- ^ "Case Studies Senestech website" (PDF).
- ^ a b 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.
- ^ "SenesTech Announces Progress and Expansion of Washington DC ContraPest® Deployment". www.prnewswire.com (Press release). SenesTech. PR Newswire. Retrieved 2021-01-05.
- ^ "Is Rat Birth Control Working in DC?". NBC4 Washington. Retrieved 2023-09-05.
- ^ "Rats Are a Global Problem. Is Birth Control the Solution?". Time. 2023-03-27. Retrieved 2023-11-09.