Regional burden of undifferentiated fever and leading infectious etiologies of acute febrile illness in low- and middle-income countries: a meta-analysis

OBJECTIVES: To analyze the pooled prevalence of the undifferentiated fever cases and the top 10 most investigated etiologies of AFI in LMICs. METHODS: statistics were used to assess Heterogeneity. RESULTS: The pooled prevalence of malaria among AFI cases was 20.2%. The pooled prevalence of DENV, CHIKV, influenza, and hepatitis was 15.0%, 1.5%, 5.4%, and 3.3%, respectively. The pooled prevalence of bacterial etiologies among AFI cases as an AFI etiology in LMICs was 7.9% for rickettsiosis, 5.7% for leptospirosis, 8.0% for enteric fever, 3.5% for scrub typhus, and 6.8% for streptococci, respectively. The pooled prevalence of fever of unknown origin among AFI cases was 36.9%. CONCLUSIONS: These findings reveal significant regional and etiological variations among the leading AFI etiologies, with over one-third of cases remaining undiagnosed, underscoring the need for improved diagnostic strategies and surveillance to better identify and manage AFI in LMICs.