533 - Increasing Frequency of Streptococcus anginosus (SA) in pediatric appendicitis patients with intra-abdominal collections

Publication Number: 4521.533

Jenna Cusick, University of Nebraska College of Medicine, Omaha, NE, United States; Robert A. Cusick, Children's Nebraska, Omaha, NE, United States; Melissa K. Suh, University of Nebraska College of Medicine, Omaha, NE, United States

Background: A higher-than-expected postoperative infection rate was identified following appendectomy at Children’s Nebraska. One hypothesized contributor to this trend was an increased prevalence of Streptococcus anginosus (SA), a pathogen associated with abscess formation in cases of ruptured appendicitis. To explore this possibility, a retrospective review of all appendectomy cases performed at Children’s Nebraska between 2014 and 2024 was conducted to evaluate the frequency of S. anginosus and identify additional factors contributing to postoperative infections.

Objective: The aim of this study was to determine the frequency of Strep anginosus in ruptured appendicitis and to identify factors contributing to high postoperative infection rate.

Design/Methods: A ten-year retrospective chart review was performed on patients who underwent appendectomy between January 2014 and December 2024. Data collected included initial length of hospital stay, intra-operative findings, microbiological culture results, readmission rates, and postoperative complications.

Results: A total of 3049 appendectomy cases from 2014 to 2024 were reviewed. Of these, 866 (28%) patients had ruptured appendicitis. Intra-operative cultures were obtained in 400 of these cases (46%), with 255 (64%) positive for Strep anginosus. Strep anginosus was the most common isolated organism, followed by mixed anaerobic flora and Escherichia coli. The incidence of Strep anginosus in complicated appendicitis increased from 55 percent in 2014 to 65 percent in 2024. Strep anginosus was associated with higher rates of postoperative fluid collection (P=0.0059).

Conclusion(s): The frequency of Strep anginosus among patients with ruptured appendicitis has risen over the past decade at Children’s Nebraska. These findings highlight the need to standardize antibiotic regimens for complicated appendicitis to decrease abscess formation and postoperative infections.

Table 1: Patient demographics and appendix histopathology.


Figure 1. Annual incidence of appendectomies with and without Strep anginosus positive cultures with postoperative fluid collection rates.


Figure 2. Annual rates of postoperative fluid collections in patients with and without Strep anginosus positive cultures.