Francesco M. Labricciosa, MD, Specialist in Hygiene and Preventive Medicine

Intra-abdominal infections (IAIs) are common and serious surgical emergencies. Over the past few years, an increase in antimicrobial resistance (AMR) associated with IAIs has been observed worldwide, responsible for a significant increase in morbidity and mortality rates, and overall healthcare costs. In order to improve the quality of treatment, it is essential to recognize the underlying local epidemiology, clinical implications, and appropriate management of AMR.

In a paper recently published in the World Journal of Emergency Surgery, a prospective, observational, nationwide, multicentre study was conducted to investigate the epidemiology and initial management of complicated IAIs (cIAIs) in Italy.

The IRIS study (Italian Register of Complicated Intra-abdominal InfectionS) included 4,530 consecutively hospitalized patients – older than 16 years of age – from 23 different Italian hospitals, between May 1, 2021 and April 31, 2023, with diagnosis of cIAIs undergoing surgery, interventional drainage or conservative treatment.

Overall, 70.9% of the cases were community acquired infections, the predominant type of infection for all the diagnosis. The majority of healthcare-associated infections were represented by colonic perforation and diverticulitis (28.3%), small bowel occlusion (19%) and intestinal ischemia (18%). At presentation, 27.8% of patients had a septic shock. The overall mortality rate was 5.13%, and 16.5% of patients required admission to Intensive Care Unit.

Microbiological samples were collected from 3,208 (70.8%) patients; 48.8% of intrabdominal samples resulted positive. Not surprisingly, the major pathogen involved in IAIs was E. coli (45.6%). Remarkably, in 29% of the cases microbiological samples were not collected.

During hospital stay, an empiric antimicrobial therapy was administered in 78.4% of patients. Amoxicillin/clavulanate was the most common antibiotic used (e.g., in 30.1% appendicitis, 30.5% of cholecystitis, and 55% small bowel perforation), followed by piperacillin/tazobactam (e.g., in 13.3% colonic perforation and diverticulitis, 22.6% cholecystitis, 28.6% pancreatitis). Empiric antifungal therapy was administered in 2.6% of patients with no sign of sepsis, 3.1% of patients with clinical sign of sepsis and 4.1% of patients with septic shock. Azoles were the most used antifungals in patients that received empiric antifungal therapy.

The authors concluded that antibiotic stewardship programs and correct antimicrobial and antifungal prescription campaigns are needed to further improve the appropriateness of drug usage and reduce the burden of AMR. This will contribute to better care and treatment for the next generations.

Reference

1. Coccolini F, Brogi E, Ceresoli M, et al. Epidemiological analysis of intra-abdominal infections in Italy from the Italian register of complicated intra-abdominal infections—the IRIS study: a prospective observational nationwide study. World J Emerg Surg. 2025;20:22.