Improving diagnosis of non-malarial fevers in Senegal:Borreliaand the contribution of tick-borne bacteria

Abstract

AbstractThe worldwide decline in malaria incidence is revealing the extensive burden of non-malarial febrile illness (NMFI), which remains poorly understood and difficult to diagnose. To characterize NMFI in Senegal, we collected venous blood and clinical metadata from febrile patients and healthy controls in a low malaria burden area. Using 16S and unbiased sequencing, we detected viral, bacterial, or eukaryotic pathogens in 29% of NMFI cases. Bacteria were the most common, with relapsing feverBorreliaand spotted feverRickettsiafound in 15% and 3.7% of cases, respectively. Four viral pathogens were found in a total of 7 febrile cases (3.5%). Sequencing also detected undiagnosedPlasmodium, including one putativeP. ovaleinfection. We developed a logistic regression model to distinguishBorreliafrom NMFIs with similar presentation based on symptoms and vital signs. These results highlight the challenge and importance of improved diagnostics, especially forBorrelia, to support diagnosis and surveillance.