The majority of children and adolescents diagnosed with cancer will experience one or more episodes of fever or infection during their course of therapy. The most common microbiologically documented infection is bloodstream infection (BSI), which can be associated with severe sepsis or death. Current methods of diagnosis require a significant load of live bacteria in the blood making early detection difficult. Delayed diagnosis and delayed optimal therapy of BSIs are associated with increased morbidity and mortality.

This study seeks to identify whether next generation sequencing (NGS) of pathogens can identify patients with impending bloodstream infection. This would enable preemptive targeted therapy to replace antibacterial prophylaxis which often leads ot high-density broad-spectrum antibiotic exposure and contributes to subsequent development of antibiotic resistance.

PRIMARY OBJECTIVE:

• To estimate the sensitivity and specificity of next generation pathogen sequencing for prediction of bloodstream infection in children with cancer at high risk of infection.

Plasma samples collected but not required for clinical care (discarded samples) will be collected and stored. Results of NGS will be compared between patients who develop BSI immediately (within 72 hours) after sample collection, those who develop other infectious syndromes, and those who remain well. Clinical data describing baseline information about the patient and malignancy, antibiotic and chemotherapy exposure, microbiology testing, hematology results, and infection-related events will be collected prospectively from the electronic medical record.

An initial exploratory phase will examine approximately 50 participants to determine whether the effectiveness of predicting infections. The study may then enroll up to 200 participants to collection additional data for analysis.

Inclusion Criteria:

• Under 25 years of age at time of study enrollment
• Undergoing care for cancer at St. Jude
• In a category of patients who are considered by the investigator to be at high risk of infection
• Expected to receive care at St. Jude for at least 7 days

Exclusion Criteria:

• Any condition that would, in the opinion of the investigator, place the subject at an unacceptable risk of injury or render the subject unable to meet the requirements of the protocol.

Participants who are being treated at St. Jude Children's Research Hospital and who have a high risk of infection.