Abstract
BACKGROUND: Diarrhea causes significant morbidity among people living with human immunodeficiency virus. Compared to conventional diagnostic tests, multiplex polymerase chain reaction gastrointestinal panels provide faster and more accurate pathogen detection. OBJECTIVES: This study aimed to characterize diarrheal pathogens in people living with human immunodeficiency virus using multiplex gastrointestinal polymerase chain reaction, evaluate their impact on antibiotic use, and synthesize global evidence through a systematic review. DESIGN: We conducted a retrospective, cross-sectional study at a hospital in the Caribbean region of Colombia from 2020 to 2024. Concurrently, a systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. METHODS: Adult people living with human immunodeficiency virus hospitalized with diarrhea who underwent testing using a multiplex gastrointestinal polymerase chain reaction panel were included in the cross-sectional study. A systematic review was conducted by searching major electronic databases without geographic or language restrictions. Clinical, microbiological, and treatment-related data were extracted and analyzed. RESULTS: The retrospective study included 49 people living with human immunodeficiency virus hospitalized with diarrhea, while the systematic review analyzed 679 cases across 8 studies. Compared to conventional methods, multiplex polymerase chain reaction panels showed higher overall pathogen detection rates. At least one pathogen was detected in 79.5% of cases in the retrospective study. Bacterial pathogens were the most frequent in both the retrospective (70.1%) and the systematic review studies (58%-80%), with diarrheagenic Escherichia coli strains predominating. Parasites were detected in 18.6% of patients from the retrospective study and 2.4%-25% across the systematic review, while viruses accounted for 11.3% and 13%-57%, respectively. Etiological patterns varied by age, immunosuppression level, and geographic region. Empirical antibiotic therapy was modified based on multiplex polymerase chain reaction results in 34.6% of people living with human immunodeficiency virus in the retrospective study and 20%-50% of cases in the systematic review studies. CONCLUSION: Multiplex gastrointestinal polymerase chain reaction panels improve pathogen detection and help guide antimicrobial decision-making in people living with human immunodeficiency virus with diarrhea. These findings support the use of molecular diagnostics to enhance clinical management and epidemiological surveillance in this population. REGISTRATION: PROSPERO (CRD42025644820).