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Rat Population Management Scientific Field Study

In support of a National Institute of Health Phase II Small Business Innovative Research (SBIR) award, MTA New York City Transit will host a 3 to 4 month scientific field study of ContraPest® , a non-lethal, environmentally friendly rat fertility management bait. 

ContraPest® is a product of SenesTech Inc, a biotechnology company based in Flagstaff, Arizona who is the recipient of the Phase II NIH award. ContraPest® accelerates the natural egg loss in female rats which eventually leads to permanent, irreversible sterility.  The bait is not lethal, does not affect other species or humans, and is environmentally friendly as well as cost effective.  SenesTech has employed ContraPest® with significant success in numerous Asian agricultural environments where rat populations pose a serious problem for rice farmers.

NYC Transit is providing access to its subway trash rooms to support the NIH funded SenesTech field study work examining the potential impact of this product on subway trash room rodent populations.  SenesTech scientists will be performing the research work, including population studies, baiting, and follow-up assessments of the ingestion and effectiveness of ContraPest® on the population of rats in the subway trash rooms.  The potential impact of a product like ContraPest® within the subway system is unknown and we caution that this is only a first step in field studies of this product.  An initial, successful field study would need to be followed by additional field work to determine its efficacy in a much wider metropolitan environment.

Frequently Asked Questions

Q. Does  ContraPest® affect the food chain?
A. No, if a predatory animal ate an animal that was treated with ContraPest®, it would not become sterilized because ContraPest®  is broken down into an inactive compound, then excreted after a short period of time in urine with no ability to harm other animals, humans or the environment.

Q. Does ContraPest® affect the land or environment?
A. No, SenesTech products are environmentally neutral. Animals that have been baited excrete an inactive ingredient in their urine and feces.  ContraPest® product that comes in direct contact with soil or water is rapidly broken down into inactive by-products

Q. Does ContraPest® hurt the animals that eat it?
A. No, SenesTech products are not poisons and do not hurt the animals that come in contact with them. There are no adverse side effects of the product.

Q. If a different animal, like a feral dog or cat, ate the bait in the fields would they become sterilized also?
A. No, each bait formulation is species specific and only has enough of the active ingredient to sterilize the target animal. Like most bait stations, the ones that will be the receptacles for ContraPest® will restrict access to small mammals only.

Q. What happens if the rat that eats ContraPest® is pregnant?
A. Healthy normal pups are born and the females are typically sterile.

Q. Is there risk to human handlers that are putting the bait out?
A. No, the way in which the product is formulated a human handler would not receive a significant exposure even if they decided to eat it, which we find highly unlikely. In addition, the active ingredient cannot be inhaled by this route of exposure. Most importantly, higher mammals, like monkeys, apes, and humans do not respond to the fertility control agents in the product. There are no documented cases of cancer or illness from the products active ingredient in humans.

Q: Is it true that it is necessary to completely remove every egg cell from an ovary in order for a female rat to become sterile?
A: It is not necessary to deplete 100% of all follicles in the ovary to cause permanent sterility. It is a textbook fact, therefore repeatedly documented in peer reviewed scientific literature, that even though a female mammal has eggs in her ovaries it does not mean she can reproduce. Probably the best example is with humans. Women approaching menopause have eggs in their ovaries and yet cannot conceive naturally. What follicle depletion percentage is required for sterility will be specific to the mammalian species being treated.

Q: How much does a rat need to consume in order to become sterile?
A: This varies by individual, but, roughly a rat eating 8-10% of their body weight for 5-10 days will have reduced litter sizes within 4 weeks and the numbers will decline to zero.

Q: How long does it take for a rat to become sterile?
A: The slow elimination of eggs from the rat ovary will occur at various times depending on the amount of bait the rat eats. In laboratory rats sterility will occur within 8-12 weeks.

Q: How long will the Field Study Research be carried out by SenesTech in the targeted Subway Trash Room?
A:  Once initiated, the Field Study will take an estimated 3- 4 months to complete.

Q: Who will be performing the Field Study Research and what does this entail?
A:  SenesTech scientists will be performing the Field Study Research work.  They will conduct rodent population studies and pursue baiting with ContraPest® followed by testing for bait uptake and efficacy of ContraPest®  in the rat population study areas.




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