Water Resources Research Act Program

Details for Project ID HI_2024_Kirs

Animal reservoirs of pathogenic Leptospira in American Samoa

Institute: Hawaii
Year Established: 2024 Start Date: 2024-09-01 End Date: 2025-08-31
Total Federal Funds: $42,000 Total Non-Federal Funds: Not available

Principal Investigators: Marek Kirs

Project Summary: Leptospirosis is a neglected, growing, and underestimated global public health concern. Globally, there are approximately 1.03 million cases and 58.9 thousand deaths associated with leptospirosis annually. Leptospirosis is endemic to American Samoa, where 15.5-17 % of the population has antibodies indicative of past Leptospira infections, and conditions for the spread of the disease are especially favorable. Leptospirosis, the most common zoonotic disease, is caused by pathogenic bacteria belonging to the genus Leptospira. Leptospira is shed mainly in the urine and, to a lesser extent, in the feces of infected domestic and wild animals. An infected animal can shed infectious organisms for its entire lifetime. Human infections are typically due to direct or indirect exposure (mainly through cuts and skin abrasions, mucous membranes) to an infected animal’s body fluids. The overarching goal of this project is to evaluate potential sources and risk factors associated with the spread of leptospirosis in American Samoa. Using quantitative PCR assays for lip32 and other genes associated with Leptospira pathogenicity, the project determines the prevalence of pathogenic Leptospira in selected animal (urine) and stream (water) samples collected in American Samoa. The project also seeks to identify links between contamination sources as identified by microbial source tracking markers (human, dog, and pig-associated) and pathogenic Leptospira concentrations in the selected watersheds. The effect of population density and land use on the concentrations of pathogenic Leptospira in the stream water will also be evaluated. Identification of dominant animal sources of Leptospira in American Samoa will improve disease prevention as meaningful management strategies such as targeted animal control, vaccination efforts, and others to minimize the risk can be applied. Improved disease prevention should result in lower leptospirosis rates, benefiting American Samoa residents. The results are likely applicable and transferable to other islands in the region, benefiting the wider community of Pacific islanders. The project will support one graduate student and will include a free five-day training workshop to introduce American Samoa Community College students to water sampling and analysis methods. The students will learn to test water samples for fecal indicator bacteria using Colilert and Enterolert kits, and for microbial source tracking markers and pathogenic Leptospira using quantitative PCR.