In the diverse sub-Saharan ecosystems of Ethiopia, interaction between humans and animals is part of daily life.
This reality is likely a key player in the spread of infectious bacteria like salmonella, which is capable of interspecies transmission. And when frequent human-animal interaction is combined with mal/under-nutrition, subpar sanitation, an HIV/AIDS epidemic and the misuse of antibiotic drugs, the progression of salmonellosis (salmonella infection) in Ethiopia becomes an issue of global significance.
Dr. Wondwossen Gebreyes, professor and director of Global Health Programs at The Ohio State University College of Veterinary Medicine, has led a research initiative addressing infectious disease in Ethiopia since 2011. One of the initiative’s goals is to discover the various strains, sources and avenues of salmonella in the region.
Of primary concern is multi-drug resistant (MDR) salmonella, which has found refuge in Ethiopia and other developing regions due to the overuse and misuse of antibiotics. When antimicrobial drugs are misused, more paths are cleared for bacteria to develop new, multi-drug resistant strains. When an infection is immune to available treatments, morbidity and mortality rates rise.
A study conducted in 2013-14 tested stool samples from 765 humans with gastrointestinal complaints at 10 primary health care centers in Addis Ababa, Ethiopia. 59 samples tested positive for salmonella; 27 of these were resistant to three or more antimicrobials; 17
were resistant to five or more antimicrobials; and two were resistant to more than 10 drugs.
This summer, Ohio State veterinary student Balbine Jourdan is working with the Gebreyes team in Ethiopia to study the role of wildlife in circulating MDR salmonella across space and species, which is currently unknown.
Previous work has focused on the prevalence of MDR salmonella in livestock, since the bacteria is known to spread via consumption of animal-derived food products or contaminated water. The next step is for researchers like Jourdan to examine other nearby channels, so that risk factors can be determined.
“The study Balbine is doing this summer will be invaluable in identifying reservoirs of MDR salmonella,” Dr. Gebreyes said. “The data could potentially identify highly MDR strains of wildlife origin, as well as unique genes and resistance factors.”
While in Ethiopia, Jourdan will collect samples from carnivorous wildlife carcasses (including hyenas, jackals, foxes and servals) to test for the presence of salmonella. She will also test domestic dog and livestock feces found near sampled carcasses to help indicate direct or indirect transmission from domestic sources.
After seven weeks, Jourdan will return to the U.S. to conduct antimicrobial susceptibility tests, in which salmonella isolates are tested against 12 antimicrobial drugs to detect resistance. This will yield a better understanding of the scope of MDR salmonella in Ethiopian wildlife.
“The findings can be used to evaluate the magnitude of antimicrobial resistance and advise proper antibiotic use not only in Ethiopia, but in other developing countries,” she said. “Such information will be vital for the interruption of transmission cycles and the development of management strategies.”
The results will be compared to prior research on MDR salmonella found in livestock and domestic dogs, in order to map any geographic or pathogenic patterns of resistance.
When asked about the challenges she’ll face during the course of this research, Jourdan noted communication struggles between researchers and Ethiopian locals.
“It has been a challenge already to educate the locals on the importance of research and disease surveillance not only in terms of finding treatments, but in terms of disease prevention.”
That being said, she has thoroughly enjoyed becoming acquainted with a different way of life.
“This project encompasses two of my biggest passions: research and travel,” she said. “I cannot put into words how important I think it is to experience different cultures and traditions. We have so much to give, but we cannot forget that others have so much to give back.”
Jourdan is working toward a dual DVM/MPH-VPH (Master of Public Health in Veterinary Public Health) degree, which she will complete in 2020.
“I have always had a passion for Global Health work, particularly in zoonotic diseases and conservation,” she said. “I want to use my degree to help improve the lives of both humans and animals.”
She plans to collect further data in Ethiopia next year.
Jourdan’s research team includes Dr. Gebreyes, Dr. Jeanette O’Quin, assistant professor-clinical in the Department of Veterinary Preventive Medicine and Laura Binkley, a doctorate student at the college working on disease surveillance in Ethiopian wildlife with a focus on rabies and pathogen discovery.
This study is part of the Ohio State-Ethiopia One Health Initiative, a partnership between the university and various U.S. and Ethiopian institutions that aims to prevent the spread of infectious and chronic diseases, build capacity for the healthcare workforce in Ethiopia, address environmental concerns and more.