UH Hilo researchers working on rat lungworm study
Hawaiʻi, specifically the Puna district on the Island of Hawaiʻi, is the epicenter for rat lungworm disease in the U.S., says researcher Susan Jarvi.
By Susan Enright/UH Hilo Stories.
Researchers at the University of Hawaiʻi at Hilo are working on a study about the prevalence of human rat lungworm infection in East Hawaiʻi. The Daniel K. Inouye College of Pharmacy is conducting a trial with partners Puna Community Medical Center and Clinical Labs of Hawaiʻi located at Pāhoa Marketplace.
“Hawaiʻi, specifically the Puna district on the Island of Hawaiʻi, is the epicenter for rat lungworm disease in the U.S.,” says Susan Jarvi, professor of pharmaceutical sciences and principal investigator of the trial. Jarvi, who specializes in rat lungworm disease (RLWD), researches parasites and their transmission of infectious disease.
RLWD is caused by the parasite Angiostrongylus cantonensis. The cycle of infection in humans involves both rats and slugs or snails. Rats eat infected slugs or snails, ingesting larvae at the first stage of growth, which eventually grow to sexual maturity and reproduce in the heart of the host. Eggs hatch in the rat’s lung (hence the name), and the larvae migrate up the bronchial tree, are swallowed, and six to eight weeks after infection are excreted with feces. Slugs or snails then eat rat feces and acquire the larvae, now at an advanced larval stage.
Humans can become infected by ingesting slugs or snails containing larvae at this advanced stage. This can occur by eating unwashed homegrown produce, although other means of transmission are believed possible.
Angiostrongyliasis in humans can cause meningitis (inflammation in the brain and spinal cord) or a more serious disease involving the brain, spinal cord, and nerve roots. Humans are a “dead-end” host, meaning the parasites do not reproduce in humans but remain in the central nervous system or can move to the eye chamber causing ocular problems.
Research and education
Jarvi and her research team have already completed two trials in local rats with USDA Animal and Plant Health Inspection Service (APHIS). One was to see if detection of parasite DNA was possible in rat blood in hopes of developing an early diagnostic test for humans. The other was to determine the efficacy of a vaccine against RLW in local rats (they concluded that a vaccine developed in Spain was not effective in stopping the development of RLW in rats under the conditions of the trial).
They also are evaluating the possibility of RLW larvae transmission in catchment water.
- Learn more about Jarvi’s research: Susan Jarvi, pharmaceutical sciences: Researches parasite influences on infectious disease.
For two years, Jarvi and other researchers in the state have made considerable progress towards reducing RLWD through educational and research approaches. They have provided public forums, talks, handouts, brochures and are in the process of integrating RLWD education into the Hawaiʻi DOE curriculum. They produced and piloted an activity book, The Mystery of Rat Lungworm Disease, in four East Hawaiʻi schools for second graders.
“This was very well-received, and we are in the process of distribution across the islands and state,” Jarvi says. The researchers also are developing a “junior investigator scientific journal” that will encompass many STEM disciplines while learning about RLWD for tenth grade students.
The current trial
Jarvi and her research team are currently working on their newest study, entitled, “Determining the prevalence of human rat lungworm infection in East Hawaiʻi Island.”
The three-month study began on June 15 and ends Sept. 15 or until the researchers have at least 400 participants.
Story by Susan Enright, a public information specialist for the Office of the Chancellor and editor of UH Hilo Stories. She received her bachelor of arts in English and certificate in women’s studies from UH Hilo.
