HANA, Maui — Biologists with an Arizona company that sells a liquid rat contraceptive made a brief trip to Hana last month at the invitation of the state to see if its products could be effective in reducing rodent hosts of rat lungworm disease.

Brandy Pyzyna and Nick Trulove, employees of SenesTech, a small startup biotechnology company in Flagstaff, Arizona, spent four days moving three remote-controlled infrared game cameras around Hana High and Elementary School to document rat behavior and attempt a population count on the 15-acre campus that’s surrounded by 25 acres of jungle.

They brought no SenesTech products with them.

“It’s just us, the cameras and our notebooks,” said Pyzyna. She and Trulove introduced themselves during an on-site interview. Initially reluctant to discuss their four-day mission, they warmed to talking about the science of their company’s invention.

Tad Bartimus/Civil Beat

Their visit was not announced by the Department of Health or political representatives aware of their trip. In the weeks following their visit, controversy surfaced among local residents on social media about the lack of information provided in advance. Concern centered on whether chemicals were brought onto the campus, whether there was any danger to humans, and why the school was chosen rather than local farms or commercial locations.

Rat lungworm is a disease that affects the brain and spinal cord. It is caused by a roundworm parasite found in rodents, who can pass larvae of the worm in their feces. Snails, slugs, and certain other animals can become infected by ingesting this larvae; humans can become infected with if they eat raw or undercooked food containing an infected host.

At least five people confirmed to have the disease this year had Hana connections.

SenesTech Vice President Ali Applin, interviewed by phone, said surveying the school site for rats was suggested by state Sen. J. Kalani English during the first of two meetings he convened at his Honolulu office to discuss rat lungworm issues in his East Maui district.

“We came because we were asked, ‘could you guys help?’” Applin said. “No money changed hands, no commitments were made. SenesTech has borne all expenses. We are still evaluating the results of our brief preliminary site visit and expect a report soon.”

“Rats are opportunistic breeders.” — Ali Applin, SenesTech, adding that a mating pair can produce up to 15,000 offspring a year.

She said DOH director Virginia Pressler, aware that SenesTech officials already were on Oahu for another project, suggested to English they might be available to discuss the rat contraceptive. English invited two company officials to a May 5 meeting along with Pressler, Department of Agriculture Director Scott Enright and Department of Land and Natural Resources Director Suzanne Case.

“We left the meeting knowing we’d have to decide, one, can we help; two, is it feasible (to use our product); and three, figure out how we can set up a project.” Applin said. “The first step was evaluating the site to see what’s out there.”

Hana School Principal Rick Paul, participating by phone during a second meeting called by English on May 24, was asked about Hana School as a possible reconnaissance location for SenesTech’s field technicians.

Paul reportedly told the group there’d been a jump in the rat population on campus, and he knew about the problem first-hand because he lives in the principal’s cottage. Applin said English then suggested the school could be a good study site.

The senator’s office confirmed others’ accounts of the meetings.

Pyzyna and Trulove arrived at Hana School on June 12. Maintenance, custodial and office staff were on campus but students and faculty were away on summer break. Former principal Melanie Coates substituted for the vacationing Paul.

SenesTech received EPA approval a year ago and is registering its product in each state. The rat contraceptive formula has had limited field tests in New York subway stations, on a North Carolina pig farm, in agriculture areas of Laos, and on black rats at the USDA station in Hilo.

Both biologists expressed surprise and awe at the dense foliage covering most of East Maui, and especially the tangle of tropical trees and vines on private and public land surrounding Hana School’s manicured lawns.

“We saw the campus on Google maps but that’s nothing compared to being here, walking it and studying the terrain and environment,” Pyzna said. “It’s a challenge.”

Interviewed on the third of their four days in town, Pyzyna and Trulove were trying to imagine how effective SenesTech’s bait stations would be in a cleared area surrounded by a rainforest of rats.

“Their usual lifespan is six to eight months,” Trulove said. “Females become fertile in eight weeks, pregnancy takes 21 days, the usual litter is six to eight pups, and she kicks them out of the nest in three weeks. Within 48 hours after giving birth the female is fertile again.”

Applin said a mating pair can produce up to 15,000 offspring a year.

“Rats are opportunistic breeders,” she said. “Climate changes have added to the seasonal fluctuations – more rainfall means more more available food means more rats.”

SenesTech claims to “address major urban and agricultural problems by safely managing rodent populations through novel fertility control technology” that does not harm the environment or land, is “environmentally neutral” and humane to the rodents.

Pyznya said the liquid contraceptive bait is “not poisonous and does not harm the rats who ingest it. It’s delivered in small feeder trays that look like a dog or cat self-watering bowl and costs about $100 for a once-a-month refill.”

The liquid contraceptive bait makes both male and female rodents unable to reproduce as long as they consume it.

The company says the feeders are child-, pet-, weather- and tamper-proof, and that its formula is not harmful to skin and cannot be inhaled.

The company’s literature claims that although one of its “plant-derived active ingredients may have a temporary effect on fertility in humans, a 165-pound person would have to ingest 2 gallons of the product every day for 15 days to be possibly affected.”

Echoing her biologists’ assessment that Hana’s environment represents a first for SenesTech’s product, Applin said success against rodents here could signal another weapon against rat lungworm disease.

“The state is looking at all angles to tackle the issue and this is just one effort,” she said. “If that’s where the need is, that’s where we go.”