Clinical Metagenomic Sequencing for Diagnosis of Meningitis and Encephalitis.

BACKGROUND: Metagenomic next-generation sequencing (NGS) of cerebrospinal fluid (CSF) has the potential to identify a broad range of pathogens in a single test. METHODS: In a 1-year, multicenter, prospective study, we investigated the usefulness of metagenomic NGS of CSF for the diagnosis of infectious meningitis and encephalitis in hospitalized patients. All positive tests for pathogens on metagenomic NGS were confirmed by orthogonal laboratory testing. Physician feedback was elicited by teleconferences with a clinical microbial sequencing board and by surveys. Clinical effect was evaluated by retrospective chart review. RESULTS: We enrolled 204 pediatric and adult patients at eight hospitals. Patients were severely ill: 48.5% had been admitted to the intensive care unit, and the 30-day mortality among all study patients was 11.3%. A total of 58 infections of the nervous system were diagnosed in 57 patients (27.9%). Among these 58 infections, metagenomic NGS identified 13 (22%) that were not identified by clinical testing at the source hospital. Among the remaining 45 infections (78%), metagenomic NGS made concurrent diagnoses in 19. Of the 26 infections not identified by metagenomic NGS, 11 were diagnosed by serologic testing only, 7 were diagnosed from tissue samples other than CSF, and 8 were negative on metagenomic NGS owing to low titers of pathogens in CSF. A total of 8 of 13 diagnoses made solely by metagenomic NGS had a likely clinical effect, with 7 of 13 guiding treatment. CONCLUSIONS: Routine microbiologic testing is often insufficient to detect all neuroinvasive pathogens. In this study, metagenomic NGS of CSF obtained from patients with meningitis or encephalitis improved diagnosis of neurologic infections and provided actionable information in some cases. (Funded by the National Institutes of Health and others; PDAID ClinicalTrials.gov number, NCT02910037.).

Use of hearts transplanted from donors with severe sepsis and infectious deaths.

BACKGROUND: The reluctance to use organs from donors who have died from severe infections is based on the potential transmission of an infectious agent to the recipient and on the uncertainty about allograft function in the setting of severe donor sepsis. METHODS: From 1999 to 2007, donor hospital records were reviewed which focused on microbiology cultures and sensitivity results; type and duration of antimicrobial therapy; hemodynamic data, results of echocardiogram, and imaging studies. Preliminary positive and negative results from pre-harvest blood, respiratory, urine, and cerebrospinal fluid cultures were verified with the procurement agency. The harvesting surgeon performed gross inspection of donor valvular structures. RESULTS: Nine donor hearts were transplanted from patients who expired from community onset infections with severe septic shock, meningitis, and/or pneumonia caused by Streptococcus pneumoniae (n = 4), Streptococcus milleri (n = 2), Neisseria meningitidis (n = 2), and unidentified gram- positive cocci (n = 1). Four donors had probable infection-induced intracranial hemorrhage, and all donors were vasopressor-dependent before organ procurement. No evidence of donor-transmitted infection, sepsis, or rejection was observed, and long-term function remained excellent; allograft dysfunction in three patients resolved after transplant. Our series of nine donors represents approximately 1.3% of successfully transplanted cardiac allografts during the respective period of review. CONCLUSIONS: Patients succumbing to severe infections (meningitis, pneumonia, and septic shock) should not be arbitrarily excluded for possible heart donation. Assessing the suitability of donors with severe infections requires flawless communication between the donor and transplant facility, including a comprehensive evaluation of donor infection and pathogen(s), severity of sepsis, adequacy of antimicrobial treatment, and the degree of sepsis-induced myocardial dysfunction.