University of Iowa researchers are partnering with GoDx, Inc. based in Madison, Wisconsin, to develop a low-cost test for rapidly identifying gut bugs that cause diarrheal disease and whether they are resistant to certain antibiotics. Knowing quickly which bug is causing a patient’s disease can help with prompt and appropriate treatment.

Exposure to a variety of infectious organisms, or pathogens, in food and water can cause diarrhea. Diarrheal disease is a common problem in the United States and a major issue in developing countries. Globally, there are nearly 1.7 billion cases of childhood diarrheal disease every year, according to the World Health Organization, and diarrheal diseases account for 1 in 9 child deaths worldwide.

The interdisciplinary research team includes co-principal investigators Kelly Baker, associate professor of occupational and environmental health, University of Iowa (UI) College of Public Health; Michael Pentella, director of the State Hygienic Laboratory (SHL) at the University of Iowa and clinical professor of epidemiology, UI College of Public Health; and Chang Hee Kim, CEO of GoDx, Inc. Additional co-investigators include Wade Aldous, CLIA director of the State Hygienic Laboratory, and Kelly Wood, clinical professor of pediatrics and pediatric hospitalist with UI Stead Family Children’s Hospital.

The researchers have received funding from the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, and the federal Small Business Innovation Research Contract program to develop and evaluate the pathogen detecting device.  

The first phase of the research centered on creating a simple diagnostic test that can quickly identify Salmonella and Campylobacter – two pathogens that cause diarrheal illness – as well as antimicrobial resistance markers. The test, which doesn’t require a laboratory or special supplies, uses paper strips to check stool samples for the pathogens and antibiotic resistant genes. The test results are available in under an hour and can help health providers prescribe the best course of treatment and appropriate antibiotics.

“Antimicrobial resistant infections are increasing globally for both Salmonella and Campylobacter, making it more difficult for health care providers to effectively treat sick patients,” Baker explains. “Antibiotics are widely prescribed to treat patients with diarrhea and other symptoms. However, antibiotics should not be prescribed for most diarrhea cases and can actually do more harm than good by causing bacteria to develop resistance to antibiotics. Low-cost, rapid diagnostics can help providers better understand which patients should be treated by antibiotics and prevent antibiotic overuse.”

The second phase of research, launching in September 2023, will involve validating a prototype test device in a patient care setting through a trial at University of Iowa Hospitals & Clinics. About 400 patients experiencing diarrhea will be recruited for the study at several pediatric and family clinics within the UI Hospitals & Clinics system. The results from the test device will be compared against traditional laboratory sequencing and culture techniques, considered the gold standard.

Information gathered during the second phase will also help the researchers understand how to optimize the test’s design and user guidelines to increase adoption of its use for clinical treatment decisions by health care providers.

“This testing will allow providers to make treatment decisions in real time,” Wood says. “With traditional testing, results take time and often aren’t available until after the patient has left the health care setting. Having a rapid diagnostic test for diarrheal illnesses will improve care for patients across the globe.”

Additional potential uses of the test could include identifying diseases in farm animals or detecting pathogens in wastewater. Ultimately, the researchers’ goal is to make the rapid, low-cost test available in global settings where diarrheal disease is a major health threat.

“Mortality and morbidity from diarrheal diseases is very high in developing countries,” Kim says. “We’re interested in empowering countries to be able to manufacture diagnostic tests locally to lower the costs.”

“Public health-related research is a core function of the public health laboratory,” Pentella adds. “SHL is excited to be participating in this project, which has the potential to make rapid test results available to many people.”

This research was funded by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, and the federal Small Business Innovation Research Contract program (Contract No. 75N93022C00018).