By: Madeline Steck, MPH
The Laroche laboratory team has initiated an international One Health project in partnership with Dr. Jose Pietri,
a medical entomologist and microbiologist at the University of South Dakota, and Dr. Tamrat Abebe,
a clinical microbiologist at the University of Addis Ababa. The project will investigate the etiologic origins of acute febrile illnesses within refugee communities of the Gambella region in western Ethiopia. Current disease surveillance in these
internally displaced populations is mostly limited to malaria, HIV, syphilis, tuberculosis, and other expected respiratory or diarrheal diseases. Unfortunately, there are few tools to appropriately diagnose or treat for any other pathogenic species
that are simply not searched for, especially vector-borne bacteria.
Laroche noted that many NGOs already conduct humanitarian work in the Gambella region alongside established medical teams. These workers will significantly assist the study with identification of eligible febrile patients and sample collection. Blood
and nasal swab samples will be collected from consenting febrile participants which notably excludes patients with diarrhea to avoid logistical complications of fecal sample collections. After enrollment, healthcare workers and veterinarians will
go to the case patient’s house to collect arthropod vectors from the bedding, as well as blood from animals (e.g., goats, rodents) living in the vicinity. “We just try to make this triangle with the person, the bug, and the animals…and
see if we can kind of paint a picture of the zoonotic cycle,” Laroche described.
Collaborating Ethiopian facilities at the University of Addis Ababa will perform an initial screening for common diseases such as malaria. Secondary screening will be conducted in the United States to complete the panel of tests unavailable in
Ethiopia and target specific pathogens of interest, especially bacteria within the Rickettsia, Bartonella, Coxiella, Orientia, Anaplasma, Ehrlichia and Borrelia genera. The Laroche lab will directly isolate bacteria cultured from humans, animals,
and arthropods, while the Pietri lab will use metagenomics to uncover genetic traces of all pathogens in the same samples, bacterial or otherwise. Each lab will also perform complementary transmission studies with animal models (ex. mice, rats,
guinea pigs) by infecting lice, bed bugs, fleas and ticks to validate the transmission capacity of each vector with the isolated bacteria. Furthermore, antibiotic resistance testing of isolates will provide a significant translational aspect to
the project. “The end goal is to improve disease management and provide better guidance in terms of antibiotic treatment,” explained Laroche, “we want to improve the guidelines when it comes to antibiotics and tailor it to what
they [medical teams] have access to”. These sets of experiments will clarify the burden of vector-borne bacterial disease, likely transmission routes, and the susceptibility of the infectious pathogenic bacteria to accessible antibiotics.
The knowledge resulting from this One Health collaboration can directly help medical teams increase the positive treatment outcomes of the displaced and susceptible individuals living in these refugee communities.