Outcomes in influenza and RANBP2 mutation-associated acute necrotizing encephalopathy of childhood

AIM

To evaluate clinical and imaging features in patients with acute necrotizing encephalopathy of childhood (ANEC) to identify predictors of RANBP2 mutations, influenza association, and long-term outcomes.

METHOD

A retrospective chart review in patients with ANEC (2012-2020) seen at a tertiary pediatric center was performed. Children were included if they had acute inflammatory lesions in the basal ganglia and pons. Variables included presenting features, imaging characteristics, RANBP2 gene testing, nasopharyngeal swab findings, therapies, and long-term outcomes.

RESULTS

Twenty patients were included (average age at presentation 3y 6mo, interquartile range  3y 7mo, SD  2y 8mo; 14 females, six males). Three of the 20 experienced recurrences; one of the 20 died. Ten patients were influenza positive. Seven patients were RANBP2 mutation positive. A higher likelihood of hemorrhage was observed in patients who were influenza positive compared to influenza negative (p=0.048). Patients with influenza had a higher degree of thalamic hemorrhage (2, p=0.035) and greater extent of diffusion restriction (3, p=0.035) in semiquantitive analysis.

INTERPRETATION

Children with ANEC who are positive for influenza are more likely to have hemorrhage and greater thalamic swelling. RANBP2 status was predictive of relapse but not predictive of overall outcome.

A67 DELAYED PRESENTATION AND SURGICAL MANAGEMENT OF PRIMARY PNEUMOCOCCAL PERITONITIS

Background

S. pneumoniae intraabdominal infections are rare in healthy individuals, but the literature reveals a female dominance for primary peritonitis in the early post-partum period. Limited studies exist evaluating the timing of surgical management.

Aims

We present a case of primary pneumococcal peritonitis in which the presentation and surgical intervention was delayed.

Methods

A case chart review and literature review was conducted.

Results

A 41-year-old female with a spontaneous vaginal delivery 4 months prior presented with progressive abdominal pain, distention, and emesis over 10 days. She was septic with a firm, distended abdomen and rebound tenderness. A CT revealed significant panenteritis and ascites. She received intravenous fluids and was empirically started on ceftriaxone, vancomycin and metronidazole. The gastrointestinal virus panel, stool cultures and C. difficile toxin were negative. However, her blood cultures revealed Strep. pneumoniae and the purulent peritoneal fluid contained gram-positive cocci. Despite sensitivity to ceftriaxone, and several paracenteses, her ascites, pain and new fever continued. Twenty-eight days after admission, she underwent a laparoscopic abdominal lysis of adhesions and drainage of three intraabdominal abscess collections. Cultures of the purulent peritoneal fluid were negative. She was stepped down to amoxicillin-clavulanate and discharged six weeks after symptom onset.

Despite the development of pneumococcal vaccines, worldwide S. pneumoniae is a common pathogen with high morbidity and mortality. It is a rare cause of intraabdominal infections; however, primary peritonitis has been widely recognized in children. Prior to antibiotics, the mortality of pneumococcal peritonitis was 31.5–100%. Secondary pneumococcal peritonitis is established in adult patients with cirrhosis, nephrotic syndrome and immunocompromised conditions. In healthy individuals, pneumococcal peritonitis often mimics appendicitis and is diagnosed with positive blood cultures. The majority of primary pneumococcal peritonitis cases occur in females, are associated with the early post-partum period (less than two months), IUD placement, and pelvic inflammatory disease. Theories of pathogenesis include direct hematogenous spread or translocation. Transient colonization of the genital tract after IUD placement or during the post-partum period may allow for ascension from the fallopian tubes into the peritoneum. The majority of cases undergo surgery within one week of symptom onset. While it has not been studied in randomized trials, early surgical intervention for source control may decrease morbidity and hospital stay.

Conclusions

Primary pneumococcal peritonitis has a female predominance and can occur later in the post-partum period than previously reported. Surgery should be considered early to achieve source control and improve patient outcomes.

Funding Agencies

None

Escherichia coli 0157 enterohaemorrhagic colitis associated with pyelonephritis: CT findings

Escherichia coli 0157:H7 is increasingly being recognized as a cause of infectious colitis, which typically results in bloody diarrhoea in an afebrile patient. The absence of fever often means that an infectious process is not considered in the differential diagnosis, particularly as this organism will not be detected in routine stool cultures. Inappropriate antibiotic therapy may increase the risk of development of haemolytic uraemic syndrome, a potentially fatal complication of this form of colitis, hence the importance of accurate diagnosis. On CT, it is characterized by severe diffuse colonic wall thickening, with little or no pericolic inflammatory changes. The radiologist may be the first to suspect the correct diagnosis and so should be aware of its imaging appearances. We report the case of a 19-year-old man who presented with typical radiological findings of enterohaemorrhagic colitis and whose CT also showed evidence of acute pyelonephritis; we suggest that this combination of abnormalities should further heighten radiologists' suspicions of infection due to E. coli 0157:H7, despite the absence of fever.