# Trends and Challenges of Surgical Site Infections Burden in Croatia: A Nationwide Comparative Analysis of Two Point Prevalence Surveys (2017–2023)

## TL;DR

This study analyzed surgical site infections in Croatia before and after the pandemic, finding increased infection rates and shifts in bacterial causes.

## Contribution

The study provides a nationwide comparative analysis of surgical site infection trends in Croatia using two point prevalence surveys.

## Key findings

- The prevalence of healthcare-associated infections in acute care hospitals increased from 5.3% in 2017 to 7.2% in 2023.
- Deep-seated surgical site infections increased significantly, while superficial infections decreased.
- There was a shift in bacterial causative agents from Gram-positive cocci to Enterobacterales species.

## Abstract

Background: Surgical site infections (SSIs) are among the most frequent healthcare-associated infections (HCAIs) worldwide. Changes in the functioning of healthcare systems may affect the implementation of SSIs prevention practices, with consequent alterations in the occurrence of HCAIs. The main aims of our study were to analyze specific SSIs prevalence and proportions together with overall HCAIs prevalence in acute care hospitals (ACHs) before and after the COVID-19 pandemic. Additional aims were to identify bacterial causative agents, the use of perioperative antibiotic prophylaxis (PAP), related structural and process quality indicators, and to determine trends between two periods. Methods: The National Reference Centre for HCAIs (University Hospital Centre Zagreb) conducted point prevalence surveys in May 2017 and May 2023 in ACHs throughout Croatia, using the technical protocol developed by the European Centre for Disease Prevention and Control (ECDC). Results: The prevalence of HCAIs in ACHs in Croatia rose from 5.3% (95% CI 4.8–5.7) in 2017 to 7.2% (95% CI 6.6–7.8) in 2023 (p = 9.93 × 10−14). This trend was paralleled with the rising of the HCAIs prevalence in surgical departments from 5.1% to 6.7% (p = 0.0099). The prevalence of overall SSIs across ACHs increased from 0.9% (95% CI 0.7–1.1) in 2017 to 1.2% (95% CI 1.0–1.5) in 2023 (OR 1.36 (1.03–1.80), p = 0.032. While the prevalence of superficial incisional SSIs significantly decreased (OR 0.53 (0.30–0.95), p = 0.028), the share of deep-seated SSIs (deep incisional and organ/space SSIs) among classified SSIs shifted from 48/92 to 77/96; odds ratio (OR) 2.09 (95% CI 1.45–3.01). In 2017, Gram-positive cocci were the most frequently isolated bacterial causative agents (44.6%). By 2023, this shifted, with Enterobacterales species comprising most isolates (42.2%). In 2023, significantly a higher proportion of patients received PAP (χ2 = 25.419, df = 1, p  < 0.5). An increase in the positive trend of alcohol-based hand rub antiseptics use in surgical departments (+15.7 L/patient-days, p < 0.001) contrasted with a decrease in infection prevention and control (IPC) nurses and medical doctors per hospital (−0.5, p = 0.041/−0.5, p = 0.003). Conclusions: Findings of the two point prevalence surveys over time indicate the changes in trends in surgical site infections burden, and highlight the need for the implementation and strengthening of preventive measures with the focus on targeted prevention of deep-seated infections.