ContraPest is a contraceptive-based pest control tool that causes infertility in brown and black rats. It was originally created to supplement existing rodent control strategies and is formulated as a sweet liquid that appeals to rats.[1] It is developed by the U.S. biotechnology company SenesTech.[2]
 ContraPest bait station | |
| Type | Pest control |
|---|---|
| Manufacturer | SenesTech |
| Available | 2004 |
| Website | senestech |
ContraPest does not sterilize rats permanently; therefore, a continuous supply of the product is required to be effective.[3] In field tests, SenesTech claims that using ContraPest led to a reduction in rat populations by approximately 40% over a period of 12 weeks or longer.[2] In August 2016, the U.S. Environmental Protection Agency approved ContraPest for commercial use.[4]
Mechanism
editThe formula was originally developed by Drs. Loretta Mayer and Cheryl Dyer as part of a research program studying heart disease in post-menopausal women using menopausal mice.[5] The first active ingredient of ContraPest is 4-vinylcyclohexene diepoxide (VCD), which causes destruction of the antral follicle during folliculogenesis in the female ovary.[6][7] ContraPest also contains triptolide, which has been reported to reduce male rat fertility by reducing sperm motility and viability.[2][8][9]
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.[1]
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. Control group 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.[10]
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.[1]
Use
editThe 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.[10]
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.[14] 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 Flaco the Owl, which raised concerns about rat poison effects.[15]
References
edit- ^ 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 c "Man v rat: could the long war soon be over?". The Guardian. 2016-09-20. ISSN 0261-3077. Retrieved 2016-09-21.
- ^ "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.
- ^ 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.
- ^ 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 b 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.
- ^ "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.
- ^ 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.
- ^ "New York greenlights rat birth control to curb city's infestation". The Guardian. 2024-09-27. ISSN 0261-3077. Retrieved 2024-09-30.