725 - Influence of An Emerging Pathogen, Streptococcus anginosus, on Clinical Outcomes in Pediatric Appendiceal Abscess

Background: Escherichia Coli is the most common primary pathogen in appendiceal abscess, but an increasing number involve Streptococcus anginosus (SA) as the primary isolate. Ten years of data from a regional medical center was reviewed to track changes in the microbiology and outcomes of this condition. We believe that SA is emerging as a significant pathogen in appendiceal abscess in children and it is associated with increased morbidity compared to more commonly encountered pathogens.

Methods: A medical records search was done (IRB#5194) for patients below age 18 from 1/2008 to 12/2017 with acute appendicitis with local/generalized peritonitis or peritoneal abscess. There were 557 records retrieved, of which 201 had appendiceal abscess. The records were further divided based on the type of operation and timing of abscess development. There were 104 laparoscopic, 34 open, 4 drain alone, 53 interval management with a drain, and 6 interval without a drain. The focus of the study is laparoscopic and open post operative abscess. 56 of the laparoscopic cases developed a postoperative abscess of whom 45 had culture and sensitivity data. 25 of the open cases developed a postoperative abscess of whom 24 had culture and sensitivity data.

Results: Of the 45 postoperative abscesses following laparoscopic procedure, the most common isolate was E. coli (34) followed by SA (13). Of the 24 postoperative abscesses following open procedure, the most common isolate was also E. Coli (17) followed by SA (6). Patients are divided into those who had any culture of SA (SA group), vs those who did not (non-SA group). For laparoscopic cases there was no difference between additional procedures needed. However for open procedures, the SA group had an average of 2.33 additional procedures needed compared to the 0.94 additional procedures for the non-SA group (p=0.024). Major adverse outcomes included one death from sepsis, abdominal compartment syndrome, and one patient needing bilateral salpingectomy, all in the SA group.

Conclusion: SA has emerged as an important and virulent pathogen in complex appendicitis in pediatric patients.  It is sensitive to commonly used antibiotics, but is associated with increased risks of reoperation, additional drainage and adverse outcome for the sicker patients who require an open procedure.