Evaluating Antibiotics Misuse and Cost Analysis among Hospitalized Dengue Virus Infected Adults: Insights from a Retrospective Cohort Study

Background Dengue is a prevalent cause of acute febrile illness, predominantly in Asia, where it necessitates supportive care without the need for antibiotics. This study aims to evaluate antibiotics usage and analyze the hospitalization costs among adults infected with the dengue virus. Methods This retrospective cohort study was conducted at the Hospital for Tropical Diseases, Thailand, in 2022. Two independent reviewers assessed all adult cases with confirmed dengue from 2016 to 2021. Determinants of inappropriateness were analyzed using Poisson regression. Results The study included 249 participants with over half presenting with severe dengue or dengue with warning signs upon admission. The cumulative incidence of antibiotics use was 9.3% (95% confidence interval [CI]: 8.23–10.47), predominantly involving empirical treatment strategies. Ceftriaxone and doxycycline were the most frequently prescribed antibiotics. Notably, patients who received empirical antibiotics showed no definite or presumed bacterial infections. Among those who received definite strategies, inappropriate durations, including both short treatments and the overuse of broad-spectrum antibiotics, were observed. A private ward admission was identified as a significant predictor of inappropriate use, with an incidence rate ratio of 4.15 (95% CI: 1.16–14.82) compared to ICU admission. Direct medical costs did not differ significantly between appropriate and inappropriate uses. Conclusions The incidence of antibiotic use among dengue cases was moderate; however, inappropriate use by indications were mainly observed. Antimicrobial Stewardship (AMS) strategies should be encouraged, particularly in dengue with warning signs, admitted to general or private ward. Direct medical costs between appropriate and inappropriate uses were comparable.