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

Abstract

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.