Ochrobactrum anthropi bacteremia in pediatric oncology patients.

Ochrobactrum anthropi is an emerging pathogen in immunocompromised hosts, particularly in patients with indwelling catheters. We report the characteristics of 14 O. anthropi bacteremic episodes in 11 children with Hickman-type central catheters. Children presented with fever and nonspecific clinical manifestations. Bacteremia was successfully treated with antibiotics, but catheter removal was necessary to achieve cure in four cases.     

Catheter-related bacteremia due to Roseomonas species in pediatric hematology/oncology patients

Roseomonas is a newly described genus of pink-pigmented, gram-negative bacteria. Human infections caused by Roseomonas species are very rare. We report two cases of central venous catheter-related bacteremia associated with Roseomonas species (one case with R. gilardii and one with R. fauriae), and review the clinical spectrum of previously reported cases in the literature. Clinicals should be aware that Roseomonas species may cause serious infections in children.     

Infections with viridans group streptococci in children with cancer

Infection with viridans group streptococci (VGS) causes morbidity and mortality in children with cancer. Incidence of these infections has increased over time. Neutropenic patients with acute myeloid leukemia and those receiving high-dose cytarabine or undergoing stem cell transplantation are at highest risk. One-third of infected patients develop a shock syndrome despite prompt antibiotic therapy. Host defense mechanisms contribute substantially to colonization and tissue damage, but the origin of the shock syndrome is not well understood. VGS infection may be accompanied by neurological complications, myocarditis, and acute respiratory distress syndrome. Routine systemic antimicrobial prophylaxis against VGS infection has not been proven effective. Current recommendations include appropriate antibiotic therapy and intensive supportive care.     

Polymicrobial bacteremia in pediatric patients

Of 1,352 positive pediatric blood cultures during a 3.6-year period, two or more microorganisms grew from 72 cultures (5.3%), representing 60 patients. Based on predefined operational criteria for clinical interpretation of blood cultures, these cases were retrospectively classified as polymicrobial bacteremia (each organism, ie, a pathogen, 30%), mixed bacteremia/contaminant (20%), or multiple contaminants (50%). Considered individually, gram-positive organisms were isolated more frequently but were more often judged to be contaminants than the less common gram-negative organisms, which were more often thought to be true pathogens. Although one child did have a combined Streptococcus pneumoniae/Hemophilus influenzae bacteremia, these more common pediatric pathogens were underrepresented in those patients with polymicrobial bacteremia, from whom Enterobacteriaceae, streptococci, staphylococci, and anaerobes were more commonly isolated. Hospitalization for a predisposing illness and/or a focus of infection occurred in 88% of the children with confirmed polymicrobial bacteremia.     

Low incidence of sepsis due to viridans streptococci in a ten-year retrospective study of pediatric acute myeloid leukemia

BACKGROUND: Infections remain an important cause of morbidity and mortality in children with acute myeloid leukemia (AML), and particularly viridans group streptococci (VGS) sepsis. The present study, conducted between 1993 and 2003 in children with AML, sought to assess the frequency and characteristics of infectious complications (ICs), the incidence of VGS sepsis, the interest of preventive decontamination, and a possible cytarabine dose-effect on the occurrence of ICs. METHODS: Medical charts of 78 children treated according to the EORTC 58921 clinical trial were analyzed retrospectively. Patients were isolated in laminar air flow rooms, received non-absorbable gut decontamination, gum decontamination with vancomycin mouthwash, and trimethoprim-sulfamethoxasole. ICs were categorized as microbiologically documented infections (MDI), clinically documented infections (CDI), or fever of unknown origin (FUO). RESULTS: Overall, 268 ICs occurred: 57.5% FUO, 8.5% CDI, and 34% MDI. Bloodstream infections occurred in 58 febrile episodes: Gram-positive bacteria represented 83% of the pathogens including 66.1% Staphylococcus species and 8.5% Streptococcus species (6.8% VGS), Gram-negative bacteria represented 13.5% of the pathogens and yeasts 3.5%. Five patients died of infection (6.4%). None died from bacterial infection and no case of VGS sepsis required intensive care. Invasive fungal infection was proven in four patients. Number of ICs was significantly different according to gum and gut decontamination status, and according to the cytarabine dose during the first intensification. No resistant strains were detected in spite of the use of local antibiotics. CONCLUSION: The low rate of VGS and enterobacteriaceae sepsis was probably due to the effective decontamination. Our supportive care strategy could potentially help enhance overall survival in children with AML.     

Pulmonary dysfunction in pediatric oncology patients

Children suffering from cancer may experience short episodes of respiratory distress and/or chronic impairment in pulmonary function. Pulmonary dysfunction may be primarily disease-related, but it may also result secondarily from treatment. Emergencies with critical respiratory dysfunction in childhood cancer include mechanical obstruction of vital anatomical structures and hyperleukocytosis syndrome. This paper focuses on the most relevant causes of respiratory distress and lung injury in pediatric oncology patients and bone marrow transplant patients. Infectious causes, lung disease resulting from anti-neoplastic agents, and bone marrow transplant-related pulmonary dysfunction are emphasized. A review of the literature pertinent to this subject is given.     

Polyfungal systemic infections in pediatric oncology patients

Three cases of two fungal agents causing simultaneous systemic infection in immunocompromised pediatric patients are presented and the literature is reviewed. All three patients had several underlying factors that predispose to systemic fungal infections. A species of candida was identified initially as an etiologic agent in all of the three patients causing subcutaneous abscesses, urinary tract infections, fungemia, catheter exit site infection, or pneumonia. However, a few days later blood cultures grew aspergillus species in two of the three patients; in the third patient aspergillus was identified on microscopic examination of the spleen. All three patients had an associated bacteremia with either Staphylococcus aureus or S. epidermidis requiring vancomycin therapy. Presence of aspergillus infection required treatment with amphotericin. Difficulties in making a definitive diagnosis of systemic fungal disease may explain paucity of reports in the literature with simultaneous polyfungal systemic infection.     

Transient bacteremia in pediatric patients after dental extraction.

The incidence of bacteremia in a group of well children undergoing dental extraction of both normal and abscessed teeth was determined. Blood samples were obtained from each child before and immediately after dental instrumentation and then cultured aerobically and anaerobically. Eleven of 36 (30%) of the postextraction cultures were positive, and Streptococcus viridans grew from all of them. Bacteremia was more common after the extraction of diseased teeth, and there was no relationship between bacteremia and the number or species of teeth removed.     

Phase I trial of trimetrexate in pediatric solid tumors: A pediatric oncology group study

Trimetrexate (TMTX), a lipophilic antifol, was evaluated in a Pediatric Oncology Group (POG) Phase I trial in children with refractory solid tumors. TMTX was administered intravenously daily × 5 every three weeks. Starting dose was 6.4 mg/m²/day. Dose was escalated by 20% until the maximal tolerated dose was reached. A total of 75 courses were administered to 26 children. The major toxicity was myelosuppression, of which neutropenia and thrombocytopenia were most prominent. Rash, mucositis, and transient liver enzyme elevations were infrequently seen. Responses were observed in children with brainstem glioma, neuroblastoma, and renal cell carcinoma. The recommended Phase II dose using this schedule is 9.2–11 mg/m²/day depending on how heavily the patient has been treated prior to initiating this therapy. © 1993 Wiley-Liss, Inc.     

Evaluation of persistent pulmonary infiltrates in pediatric oncology patients

PURPOSE: To evaluate the role of bronchoalveolar lavage (BAL), computed-tomography-guided biopsy (CTB), and open lung biopsy (OLB) in the management of persistent pulmonary infiltrates in pediatric oncology patients. METHODS: Retrospective review of clinical records of pediatric oncology patients who underwent BAL, CTB, and OLB over a 7-year period. Data was compared across the three procedures using chi-square analysis. Logistic regression was used to adjust potential confounding variables for diagnostic yield. RESULTS: There were 113 consecutive patients who underwent 140 separate procedures during their hospitalization. Thirty (26%) patients had a previous BMT. BALs were more likely to occur as the first line of investigation (98% vs. 47%, 45%; P < 0.01) and in patients with diffuse infiltrates (64% vs. 6%, 26%; P < 0.01) when compared to CTB and OLB, respectively. OLBs were performed less frequently in neutropenic patients (26% vs. 53%, 54%; P < 0.05), more often led to change in management directly because of procedure (61% vs. 12%, 33%; P < 0.01), and had higher diagnostic yield (61% vs. 24%, 36%; P < 0.01) when compared to CTB and BAL, respectively. Diagnostic yield of OLB was significantly higher regardless of diffuse or focal nature of infiltrate. Major adverse events after a procedure were not significantly different across the three procedures. Logistic regression demonstrated that having an OLB was independently associated with identifying the cause of pulmonary infiltrate. CONCLUSION: OLB appears to be safe, has the best diagnostic yield, and leads to change in management more often than CTB or BAL in pediatric oncology patients with persistent pulmonary infiltrates.     

Imaging findings of hemorrhagic cystitis in pediatric oncology patients

In pediatric oncology patients, hemorrhagic cystitis may be a life-threatening complication of bone-marrow transplantation, chemotherapy, and/or radiation therapy. The inciting agent in urine can affect the entire urothelium from the renal collecting system to the bladder, and the severity of disease can vary. The radiologist often plays a key role in the diagnosis, follow-up, and occasionally the treatment of hemorrhagic cystitis and its complications. This review discusses the imaging findings in the kidneys and bladder in patients with hemorrhagic cystitis both before and after treatment for this disease. Findings on two-dimensional sonography, color Doppler and power Doppler sonography, computed tomography, magnetic resonance imaging, antegrade pyleography, and cystography are presented. Received: 24 May 1999/Accepted: 20 September 1999