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

A systematic search was conducted using relevant keywords in different databases. All studies that studied the etiology of AFI in febrile patients were included. The analysis was conducted in accordance with the PRISMA reporting guidelines. Percentages of the causative agents were analyzed using pooled prevalence and 95% CIs via a Random-effects model. The Q and I2 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.