Emerging viruses are an underestimated cause of undiagnosed febrile illness in uganda

Background Viruses that cause acute febrile illness (AFI) in sub-Saharan Africa cause a spectrum of disease from mild to life-threatening. Viral infection is often undiagnosed, as routine diagnostics are insufficient to capture the diversity of circulating pathogens. Methods 1281 patients with fever of 2-7 days were prospectively recruited from three sites in Uganda as part of the CDC-UVRI AFI Study and screened with enhanced diagnostics. Plasma from 233 undiagnosed patients was analysed using metagenomic next-generation sequencing (mNGS). Confirmatory testing was carried out by PCR and serology. Findings Thirty-eight viral pathogens were identified by mNGS in 35/233 (15%) undiagnosed patients including Measles, Hepatitis A/B/E viruses, Human immunodeficiency virus-1, Rhinovirus, Rotavirus-like virus, Human herpesvirus 6B, Human parainfluenza virus 3 and Enteroviruses. Four high-consequence arboviruses were found in six patients; Crimean-Congo haemorrhagic fever virus, Rift Valley fever virus, dengue virus and yellow fever virus. Le Dantec virus, last reported in 1969, was detected and confirmed by serology in one patient (and a contact of that patient). The majority of patients (23/30; 76%) diagnosed with an acute viral infection were treated with antibiotics and/or (12/30; 40%) antimalarials. Interpretation AFI in Uganda is commonly associated with undiagnosed viral infection, including high-consequence and rarely reported viruses. This highlights an ongoing risk to public health and the need for improved vigilance. MNGS alongside diagnostic serology is a powerful method for clinical surveillance to investigate circulating viral pathogens. Cost-effective diagnostic assays should be adapted according to regional needs for testing. Funding Medical Research Council and Wellcome Trust ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by the Medical Research Council and the Wellcome Trust ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Uganda Virus Research Institute (UVRI) Research Ethics Committee (REC) and the Uganda National Council for Science and Technology (UNCST) gave approval for this study. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Anonymised data produced in the present study are available upon reasonable request to the authors. Clinically identifiable data will not be provided under restrictions for the use of the data provided by the UVRI REC.