Research

CURRENT RESEARCH PROJECTS:

 

Towards Real-Time Fecal Indicator Bacteria Monitoring in Nearshore Waters

It is important for the public to be alerted swiftly when coastal waters experience elevated concentrations of fecal bacteria. However, current procedures to measure fecal bacteria concentrations involve processing that often takes over 24 hours – resulting in a lag period between a change in water quality and when the public is informed. To bridge this time gap, there is an interest in using multi-parameter water quality sondes to estimate fecal bacteria concentrations at high frequencies.
In the summer of 2021, with support from NC State’s Research and Innovation Seed Funding (RISF), the Harris group worked with Dr. Natalie Nelson of the Dept. of Biological & Agricultural Engineering, to deploy a sonde equipped with 7 sensors that collected measurements every 15 minutes. During the sonde’s deployment, the Harris Lab collected water samples daily, and bi-hourly during high-frequency sampling events. The water samples collected by the sonde’s installation site in Beaufort, NC were analyzed for the fecal indicator bacteria (FIB), Enterococci and E. Coli using the IDEXX system.  The FIB and optical properties data will help validate the sonde’s measurements and be used to create machine learning models that predict and estimate fecal contamination in coastal waters based on real-time data collected by a deployed sonde.
Collaborators: Natalie Nelson (BAE Dept.) and Chris Osburn (MEAS Dept.)
Funding Source: NCSU RISF Grant

Detecting Antibiotic Resistant Bacteria in the Environment

Antibiotic resistant bacteria has been recognized by numerous intergovernmental organizations as one of the principal public health threats of the 21st century. The impact of antibiotic resistant bacteria will only be magnified in low- and middle-income countries which account for roughly 80% of the global burden of disease. Our lab’s work on antibiotic resistance is multi-faceted, with studies being conducted in both eastern NC waterways and in peri-urban households in Bekasi, Indonesia. At the core of this work is developing new methods for detecting antibiotic resistant bacteria under field conditions, outside of a traditional laboratory setting to bolster global surveillance efforts for monitoring antibiotic resistant organisms.
Collaborators: University of Technology Sydney, University of Indonesia
Funding Source: Australia Water for Women Fund

Field lab in Bekasi, Indonesia. Photo credits: Jeremy Lowe

 

A Randomized Controlled Trial of a Poultry Management Intervention in Rural Western Uganda

Diarrheal disease continues to have devastating global impacts on children under the age of 5. Enteric infections, which commonly cause diarrhea, have been attributed to fecal contamination in the home environment by numerous studies, but fecal-oral transmission pathways can be complex and difficult to disrupt. Through a partnership with The Water Trust, we are evaluating the impact of a poultry management intervention on child health and environmental fecal contamination along with other factors such as the use of multiple water sources, participation in self-help groups, and economic and nutritional benefits of poultry ownership. A baseline survey was administered to all participating households with the start of the poultry management intervention in 2019, and water, soil, and fecal sampling will occur with the administration of the endline survey at a future date. This project is in collaboration with Dr. Ayse Ercumen in the Dept. of Forestry and Environmental Resources at NC State.
Collaborators: The Water Trust
Funding Source: USAID

The Water Trust site in Masindi, Uganda. Photo Credits: Jeremy Lowe

 

 Leverage Citizen-Science as a Tool in Disaster-Recovery and Community Resilience

Residents of Robeson County, NC experienced a resurgence of environmental awareness following Hurricane Matthew in 2016 that inspired concern over the potential distribution of bacterial contamination into human landscapes and systems, specifically the risk associated with municipal wastewater and livestock operations. To encourage individuals to consider relevant environmental risks after flood waters have receded and after the initial disaster response phase has passed, we have engaged Lumberton, NC residents who experienced flooding from Hurricane Florence in 2018 in a citizen science project focused on building community resilience to flooding. Semi-structured interviews were conducted with 18 Lumberton residents, in conjunction with citizen science soil sampling and a household survey, to explore coping strategies and feelings of self-efficacy. Survey results indicate households felt confident they could nurture close relationships in the wake of Hurricane Florence but felt less equipped to cope with emotions evoked by the storm and beginning to return to a normal routine. Soil testing results revealed fecal contamination in 64% of household samples, however federal or state regulations regarding fecal contamination are lacking and make this data more difficult to interpret. This project is in conjunction with Dr. Bethany Cutts in the Department of Parks, Recreation at NC State.
Funding Source: NC Sea Grant, Foundation for the Carolinas

Showing soil sampling methods to community partners. Photo credits: Olivia V.

 

Understanding the health risks associated with multiple water source use behaviors

The Joint Monitoring Programme 2017 Update and SDG Baselines report classified 71% of the global population as having access to ‘safely managed’ drinking water. Current global monitoring efforts to track access to safely managed drinking water rely on collecting information on the ‘primary’ source of drinking water. However, there is evidence that households often rely on multiple sources to meet their water needs in many low- and middle-income countries (LMIC). We are involved in systematic literature reviews and exposure modeling studies to better understand the health impacts of multiple water source use behaviors. Multiple water source use, particularly supplementing improved primary sources with unimproved water sources, represents an unmonitored pathway for household exposure to fecal contamination. We recommend these behaviors should be captured in efforts to assess safe drinking water access, such as in household survey campaigns, risk assessments of primary and secondary/alternative water sources, and particularly for global monitoring of the Sustainable Development Goals.

Water collected from a shallow well in rural Tanzania. Photo credit: Angela Harris

 

Understanding surface water contamination after extreme flooding events

Description: North Carolina has experienced increased occurrences of extreme precipitation events, and research suggests these events are more likely to happen in the future due to anthropogenic climate change. Our group is involved in several studies to assess the water quality impacts of extreme flooding in North Carolina in areas that represent diverse landuses (e.g., developed, industrial agriculture, forested). We are using advanced microbial source tracking methods to identify the animal hosts of contamination and also partner with other researchers to characterize water quality along multiple dimensions, including emerging pathogens and chemical contaminants. We have conducted studies after Hurricane Florence and Hurricane Dorian, and are involved in extensive monitoring of surface water quality. We prioritize working closely with community partners, such as Indigenous Tribes and RiverKeepers, to make sure our results can empower informed decision making. Collaborators include other faculty at NC State: Ryan Emanuel, Natalie Nelson, Chris Osburn, Jay Levine, Sophia Kathariou, Francis de los Reyes, and Mamoud Sharara.
Collaborators: UNC Chapel Hill
Funding Source: North Carolina Policy Collaboratory, NSF

Collecting surface water in Eastern North Carolina. Photo Credit: Tanvir Pasha

Collecting poultry litter for MST assay validation. Photo Credit: Breon Hanley

 

Informing irrigation water quality guidelines to protect human health Health Risks Associated with Animal Fecal Contamination in Irrigation Water

Irrigation water is often contaminated with both human and animal fecal matter from various municipal and agricultural sources. This contamination leads to food-borne illness within the United States with the Centers for Disease Control and Prevention estimating one in every 6 Americans get sick, 128,000 are hospitalized, and 3,000 die of foodborne illness. The Food Safety Modernization Act (FSMA) created guidelines for irrigation water quality based on the presence of E. coli; however, these regulations are based on the EPA criteria for recreational water. Various limitations exist from using recreational water as a basis for irrigation water quality. Farmers, policy makers, and researchers need to understand the health risks associated with fecal contamination of irrigation water to be able to set accurate thresholds for E. coli contamination to protect human health. We are involved in QMRA studies to assess the human health risks associated with varying levels of fecally contaminated irrigation water stemming from different animal hosts.

Box of leafy greens. Photo Credit: Kendall Zorn

 

Investigating the health impacts of WASH in educational facilities on pupils and other household members

Diarrheal disease is a major contributor to the disease burden in low-income countries. It especially impacts children under 5 years old. In recent years, educational facilities have been identified as key players in the promotion of sanitation and hygiene practices. While there are studies investigating the impact of these programs on the health of pupils, few investigate secondary transmission back to households. The health of the children remaining in domestic environments might be impacted by the sanitation practices or disease exposure of older siblings who attend educational facilities. These younger siblings are especially susceptible to disease and could experience long-term cognitive impacts due to repeated illnesses. Using advanced modeling techniques of large secondary datasets, this study seeks to identify if an older siblings’ attendance at an educational facility poses a significant health risk to the younger siblings who remain at home.