Schools to test, develop electric anti-slug strips
Goal is to help prevent growth of rat lungworm cases
Four Maui County schools may spend the next school year tinkering with electrical barriers to growing numbers of snails and slugs blamed for a large outbreak of rat lungworm disease statewide last year.
Maui District Health Officer Dr. Lorrin Pang said Friday that he solicited the help of Kamehameha Schools Maui and Hana High and Elementary, Maui High and Kalama Intermediate schools, which are “very interested” in developing the systems that would shock snails and slugs that carry the parasitic disease.
He said the systems developed by students could be used by residents and farmers trying to stop the slugs from passing the disease to their food crops.
“This is not a dangerous project or complex gizmo,” Pang said. “The science in this is not robotics, it’s called probability science. They’re going to come up with stuff that’s better than us.
“I don’t know what will work, but all I know is we have something very promising here and it’s doable.”
Pang’s office has spent more than a year conducting experiments and studying the behavior of Maui’s snails and slugs, which include the invasive semi-slug that is host to twice as many parasites as other mollusk species. The species of slug is thought to be the culprit of 2017’s unprecedented number of rat lungworm cases.
There were six cases reported in the first three months of that year on Maui, compared to only two in the previous decade.
This year, only one case has been reported. The individual became ill in mid-February and was briefly hospitalized, the Health Department said. The department believes the infection likely occurred on Maui but could not say conclusively because the person traveled to Oahu and the Big Island during the time the individual was infected.
Pang brought on two college students to continue testing. The team’s “most promising intervention” was using live wires plugged into a battery. He said the team got the idea from Chinese escargot farmers, who use electrical fence tape to keep its snails inside the property.
Pang said the electrical tape is about an inch and a half wide with four metal bands running through a fabricated plastic material. He also noted that it has three circuits that plug into a 6-volt battery.
Previously tested electrical systems used only one electrical circuit, but the team was able to refine the three-circuit system and has “enough numbers to see it’s not a fluke.”
“There’s definitely a big difference,” he said. “Zero crossed the electrified barrier. When you shock the slug, the slugs panic, and they can run forward across the wires or run back. With this, some slugs may panic and charge through, but they’ll never get past. They’ll all die.
“We know something is going to work, we just have to expand on it.”
Aside from its effectiveness in lab tests, the material costs just 50 cents a yard, or 1/50th the cost of slug pellets, Pang said. He said his office will be giving the electrical systems out to the four schools so they can put up a barrier around 800 square feet.
Pang plans to meet with school officials starting next week to provide standard procedures, such as documenting what voltage they are using, how many times the barrier is challenged by snails and repeating experiments.
He said Maui High likely will test the lower-risk Cuban slug, Hana will take on the semi-slug, and Kamehameha and Kalama will experiment with the deroceras slug.
Pang said the deroceras slug recently has been found Upcountry and has a disease carrier rate of about 60 percent. He said the discovery is particularly concerning because the deroceras slug appears to be gradually spreading.
“There’s been lots of reports from Upcountry from people saying, ‘Hey we got semi-slug up here,’ ” Pang said. “We tell them, ‘No that’s not semi-slug, but that’s picking up and it’s not a good one.’ ”
The schools will spend one year testing different systems in their labs and another year in the field with their best product. Pang plans to give teachers and students some guidance, but wants them to think critically on their own.
“I want things done right and well, but yet I’m not going to spoon feed the kids,” he said. “I want them to have a little bit of creativity.”
Pang made clear that the students must focus and not “fuss around” because their systems could help farmers and residents statewide. He said data on how long the barrier can last and under what conditions still need to be documented.
“The rat lungworm cases really do have permanent changes in people’s lives,” he said. “It really changes your lifestyle. You can’t drive, you can’t work . . . some people can’t even walk anymore.”
The disease causes a rare type of meningitis, according to the Health Department. Symptoms include severe headaches and stiffness of the neck, tingling or painful feelings in the skin or extremities, low-grade fever, nausea and vomiting. They usually occur one to three weeks after exposure and last two to eight weeks, though symptoms vary by person.
There is no cure for the disease.
Tips to prevent rat lungworm disease:
• Inspect, wash and store produce in sealed containers, regardless of whether it came from a local retailer, farmers market or backyard garden.
• Wash all fruits and vegetables under clean, running water to remove any tiny slugs or snails. Pay close attention to leafy greens.
• Control snail, slug and rat populations around homes, gardens and farms. Get rid of them safely by using traps and baits and always wear gloves.
For more information about rat lungworm disease and how to prevent its spread, visit the following websites:
• Health Department, health.hawaii.gov/docd/disease_listing/rat-lungworm-angiostrongyliasis/.
• Agriculture Department, hdoa.hawaii.gov/blog/main/rat-lungworm-information/.
• University of Hawaii College of Tropical Agriculture and Human Resources, manoa.hawaii.edu/ctahr/farmfoodsafety/rat-lungworm/.
• Centers for Disease Control and Prevention, www.cdc.gov/parasites/angiostrongylus/index.html.
* Chris Sugidono can be reached at csugidono@mauinews.com.