Short Course and Conventional Antimicrobial Duration in Mild and Moderate Intra-abdominal Infection Among Admitted Patients

Abstract

Prolonged antibiotic therapy for community-acquired intra-abdominal infections (CA-IAIs) has traditionally been prescribed for seven to ten days, despite growing evidence that shorter regimens may be equally effective after adequate source control. Optimizing antibiotic duration is critical to improving antimicrobial stewardship, minimizing drug resistance, and reducing hospital resource utilization. Objective: To compare clinical efficacy, safety, and resource utilisation of a protocol-driven four-day short-course versus conventional seven-to-ten-day antimicrobial therapy in adults hospitalised with mild or moderate community-acquired intra-abdominal infection. Methods: This single-centre, prospective, parallel-group study was conducted between 1 July 2024 and 31 March 2025. Adults ≥ 18 years admitted with a radiologically confirmed mild or moderate community-acquired intra-abdominal infection (IAI)—including perforated appendicitis, localized diverticulitis, cholecystitis, or contained hollow-viscus perforation—were screened within 24 h of source-control intervention (laparoscopic/open surgery or image-guided percutaneous drainage). Results: Baseline inflammatory markers were comparable: mean white‐cell count was 12.8 ± 2.8 × 10^9/L in the conventional arm and 11.8 ± 3.3 × 10^9/L in the short‐course arm (p = 0.367), while mean C-reactive protein levels were 48.9 ± 19.6 mg/L versus 47.2 ± 20.3 mg/L (p = 0.741). Length of stay averaged 12.7 ± 2.8 days for conventional therapy and 9.42 ± 3.95 days for short‐course therapy, though this difference did not reach statistical significance (p = 0.638). Clinical success rates were 100% (58/58) in the conventional group and 95% (40/42) in the short‐course group (p = 0.16). Recurrence occurred in 2% (1/58) of conventional patients and none of the short‐course patients (p = 0.323), while 30-day mortality was 5% in both arms (3/58 vs. 2/42; p = 0.57). Adverse events were reported in 9% (5/58) of the conventional group and 19% (8/42) of the short‐course group (p = 0.372). Conclusion:  A fixed four-day regimen after adequate source control produced the same clinical success, mortality, and recurrence as conventional eight-day therapy.