Arthropod-Borne Bacteria Cause Nonmalarial Fever in Rural Ethiopia: A Cross-Sectional Study in 394 Patients

Bacterial arthropod-borne pathogens are a common cause of fever in Africa, but their precise impact is unknown and usually underdiagnosed in the basic rural laboratories of low-resourced African countries. Our aim was to determine the prevalence of arthropod-borne bacterial diseases causing fever among malaria smear-negative patients in a rural hospital located in Ethiopia. The study population included patients aged 2 years or older; referred to Gambo Rural General Hospital (West Arsi, Ethiopia), between July and November 2013, for fever or report of fever in the previous 48 h; attending the outpatient department; and testing negative for malaria by Giemsa-stained thin blood smears. We extracted DNA from 394 whole blood samples, using reverse line blot assays of amplicons to look for bacteria from the genera: Anaplasma , Bartonella , Borrelia , Coxiella , Ehrlichia , Francisella , and Rickettsia . Thirteen patients showed presence of DNA for these pathogens: three each by Borrelia spp., the Francisella group ( F. tularensis tularensis , F. tularensis holartica , and F. novicia) , Rickettsia bellii , and Rickettsia Felis , and one by Bartonella rochalimae . Thus, in this rural area of Africa, febrile symptoms could be due to bacteria transmitted by arthropods. Further studies are needed to evaluate the pathogenic role of R. bellii .