A49-43 Unusual Suspects: Streptococcus Pneumoniae Bacteremia From a Tubo-ovarian Abscess

Abstract Introduction Streptococcus pneumoniae is a pathogen frequently implicated in pneumonia, sinusitis, and otitis media.1 Invasive pneumococcal infections typically occur when a pulmonary infection spreads to the bloodstream.1 We describe a unique case of a primary tubo-ovarian abscess (TOA) caused by S. pneumoniae, which progressed to secondary bacterial peritonitis and bacteremia. While invasive S. pneumoniae infections starting in the lungs are common, primary intra-abdominal infections with secondary bacteremia are rare.2-5 This case illustrates this rare occurrence of a primary intra-abdominal infection as the source of invasive disease. Case A 54-year-old female with heart failure, diabetes mellitus, and hypertension presented with two days of abdominal pain, nausea, vomiting, and diarrhea. She denied respiratory symptoms. On admission, she was found to be in shock, and the physical exam was notable for abdominal tenderness and ascites. GI PCR was positive for Clostridioides difficile, which was treated with oral vancomycin. Blood cultures were positive for gram positive cocci on hospital day (HD) 1 with multiplex PCR identifying Streptococcus pneumoniae. CT imaging of the abdomen and pelvis demonstrated colitis and left adnexal multiloculated cystic lesions (Image 1) initially concerning for a malignancy. Chest imaging did not show signs of pneumonia. Frank pus was visualized on diagnostic paracentesis on HD1 with the gram stain demonstrating only gram-positive cocci. She underwent exploratory laparotomy on HD2, where a TOA was drained. Pathology from the adnexa was consistent with an abscess. An exhaustive evaluation with infectious disease revealed no alternative source for pneumococcal bacteremia. She was treated for a primary S. pneumoniae TOA complicated by secondary bacterial peritonitis and secondary bacteremia with metronidazole, ceftriaxone, and doxycycline with clinical improvement. She was discharged with an extended course of levofloxacin and metronidazole. Discussion Cases of primary pneumococcal intra-abdominal infections with secondary peritonitis and bacteremia are exceedingly rare.2-5 Post-menopausal women with comorbidities, such as diabetes, are at increased risk for pneumococcal pelvic infections.6 It is hypothesized that lower genital tract pneumococcal infections ascend, translocate through the uterine wall, and cause peritonitis and then bacteremia. Menopausal estrogen changes may mediate this process.2-3,6 It is crucial to include TOA in the differential diagnosis for post-menopausal women presenting with pneumococcal bacteremia, particularly when respiratory symptoms are absent. Recognizing this presentation early allows for timely treatment and improved outcomes. It also helps distinguish these ovarian changes from a pelvic malignancy.7 Treatment of this condition includes source control and a 14-day antibiotic course tailored to available antimicrobial sensitivities. This abstract is funded by: None