Comparison of fungemia caused by Candida and non-Candida rare yeasts: a retrospective study from a tertiary care hospital.

Although Candida species are the most common cause of fungemia, non-Candida rare yeasts (NCY) have been increasingly reported worldwide. Although the importance of these yeast infections is recognized, current epidemiological information about these pathogens is limited, and they have variable antifungal susceptibility profiles. In this study, we aimed to evaluate the clinical characteristics for fungemia caused by NCY by comparing with candidemia. The episodes of NCY fungemia between January 2011 and August 2023 were retrospectively evaluated in terms of clinical characteristics, predisposing factor, and outcome. In addition, a candidemia group, including patients in the same period was conducted for comparison. Antifungal susceptibility tests were performed according to the reference method. A total of 85 patients with fungemia episodes were included: 25 with NCY fungemia and 60 with candidemia. Fluconazole had high minimal inhibitory concentration (MIC) values against almost all NCY isolates. The MIC values for voriconazole, posaconazole, and amphotericin B were ≤ 2 µg/ml, and for caspofungin and anidulafungin were ≥ 1 µg/ml against most of isolates. Hematological malignancies, immunosuppressive therapy, neutropenia and prolonged neutropenia, polymicrobial bacteremia/fungemia, preexposure to antifungal drugs, and breakthrough fungemia were associated with NCY fungemia, whereas intensive care unit admission, diabetes mellitus, urinary catheters, and total parenteral nutrition were associated with candidemia. In conclusion, the majority of fungemia due to NCY species was the problem, particularly in hematology units and patients with hematological malignancy. Preexposure to antifungal drugs likely causes a change in the epidemiology of fungemia in favor of non-albicans Candida and/or NCY.

Among all fungemia episodes, hematological malignancies, immunosuppressive therapy, neutropenia, and preexposure to antifungals were risk factors for non-Candida yeast fungemia; diabetes mellitus, urinary catheters, and total parenteral nutrition were risks for candidemia.

An inconspicuous identification: Isolation and identification of a novel Pichia species presenting as fungemia following cardiac surgery.

Fungemia is common in critically ill patient populations, and is associated with a high rate of mortality, especially when caused by nonalbicans Candida species. Herein, we describe a fatal case of fungemia following cardiothoracic surgery in which the organism, initially identified as Candida inconspicua, represents a novel species: Pichia alaskaensis.

[Lomentospora prolificans Fungemia in a Patient With T-Cell Large Granular Leukemia: A Rare Pathogen in Türkiye]. / T-hücreli Büyük Granüler Lösemili Bir Hastada Lomentospora prolificans Fungemisi: Türkiye'de Nadir Bir Etken.

Scedosporium/Lomentospora is an opportunistic fungal pathogen found worldwide. While Scedosporium apiospermum and Scedosporium boydii are commonly observed globally, Lomentospora prolificans, which mainly affects immunosuppressed individuals, is rarely encountered and is more prevalent in arid climates, particularly in Australia and Spain. L.prolificans is a fungus commonly found in environmental sources such as contaminated water and soil. This species is known as an opportunistic pathogen that can cause deep-seated fungal infections, especially in immunosuppressed individuals. In this case report, a fatal case of L.prolificans fungemia in a patient with T-cell large granular leukemia during profound neutropenia was presented. The patient admitted to the hospital with prolonged fever, neutropenia, and shortness of breath. Antibiotherapy was administered to the patient for febrile neutropenia, but the fever persisted and his clinical status rapidly deteriorated. L.prolificans was isolated from the blood culture, and considering its antifungal resistance, combination therapy of voriconazole and terbinafine was initiated. However, the patient died of septic shock and multiple organ failure. In conclusion, although L.prolificans infections are rare, they can be life-threatening, especially in immunosuppressed individuals. Diagnosis and treatment of such infections may be difficult, therefore rapid diagnostic methods and appropriate treatment protocols should be developed. Consideration of infections caused by rare fungal pathogens in patients with risk factors may be critical for patient care. The literature review revealed that the first case of L.prolificans fungemia from Türkiye was reported in 2023. This case presentation represents the second reported case. However, in our case, L.prolificans fungemia occurred in 2018, it can be considered that L.prolificans may have been an invasive fungal pathogen of significant concern in Türkiye much earlier than previously documented.

Universal antifungal prophylaxis effectively prevents fungal bloodstream infection in pediatric liver transplant recipients: a retrospective real-world study.

OBJECTIVES: Fungal bloodstream infection (fBSI) following pediatric liver transplantation presents a significant challenge; however, there remains a paucity of guidance regarding antifungal prophylaxis in this population. This study aimed to evaluate the effectiveness of universal antifungal prophylaxis and propose a desirable strategy. METHODS: We enrolled 604 pediatric patients who underwent liver transplantation between 2020 and 2023, including 242 patients with empirical prophylaxis and 362 patients with universal prophylaxis. Univariate and multivariate logistic regression analyses were performed to identify independent factors for fBSI. RESULTS: Eight (2.2%) pediatric recipients in the universal prophylaxis group and 13 (5.4%) in the empirical group developed fBSI (P = 0.038). Universal prophylaxis was a protective factor (P = 0.044), while high-volume intraoperative plasma transfusion and deceased donor liver transplantation were independent risk factors for fBSI (P = 0.035 and 0.008, respectively). Universal antifungal strategy showed an increased overall survival trend after liver transplantation although without significant statistical difference (P = 0.217). Patients with fBSI had poorer survival than those without fBSI (P <0.001). CONCLUSIONS: Universal prophylaxis strategy for fBSI in pediatrics after liver transplantation is desirable as it could markedly decrease the occurrence of fBSI. Pediatric patients with deceased donors and high-volume intraoperative transfusion should be paid more attention to preventing fBSI.

Bloodstream infections: trends and evolution of incidence and etiology in a 12-year period (2010-2021).

INTRODUCTION: The epidemiological evolution of bloodstream infections (BSIs) in the last decade is not clearly defined. Our aim was to analyze the changes in the workload in our institution and to describe the evolution of the incidence and etiology of BSIs in a 12-year period, including the COVID-19 pandemic. METHODS: All blood cultures received in the laboratory of a tertiary general hospital between 2010 and 2021 were analyzed. Bloodstream infection episodes refer to each episode of bacteremia or fungemia in each patient. Incidence rates per 1000 admissions and per 100,000 population were calculated. RESULTS: No significant changes in the incidence of BSI episodes/1000 admissions were observed (mean, 31.1), while estimated population-based incidences showed declining trends (mean, 182.8/100,000 inhabitants). There was a slight increase in BSI episodes per 1000 admissions caused by Gram-negatives (mean, 16.6/1000 admissions) and E. coli was the most frequent pathogen (mean, 8.5/1000 admissions). There was no significant rise in episodes caused by ESBL- and carbapenemase-producing E. coli or K. pneumoniae, with a decline in those caused by methicillin-resistant S. aureus. A spike in BSI episodes, fungal BSIs and catheter-related infections was detected in 2020, during the COVID-19 outbreak. CONCLUSIONS: No clear increase in the incidence of BSI episodes was detected in our center over this period. Gram-negatives are the most frequent etiology, with no clear rise in antimicrobial resistance phenotypes. The COVID-19 pandemic accounted for a small increase in BSI episodes in 2020, probably related to the increase of catheter-related infections.

Case report: First case of fungemia caused by Papiliotrema laurentii in a patient with SARS-CoV-2 infection.

Previously considered saprobe and non-pathogenic, the fungus Papiliotrema laurentii (formerly known as Cryptococcus laurentii), is rarely associated with human infection. Nevertheless, there has been an increase in reported infections by non-neoformans cryptococci. After a literature search on the Cochrane Library, LILACS, SciELO, MEDLINE, PubMed, and PMC (PubMed Central) databases, we conclude that this is the first case report of fungemia and probable meningitis caused by Papiliotrema laurentii in a previously immunocompetent host with associated COVID-19.

Severe hypercalcemia as a result of disseminated Candida krusei infection.

Candida krusei disseminated infection is a rare complication of protracted neutropenia. Herein, we report a case of a 31-year-old male with relapsed acute myeloid leukemia who developed Candida krusei fungemia with cutaneous, ocular, splenic, renal, bone marrow and osseous involvement leading to severe hypercalcemia, treated with parenteral antifungals followed by oral ibrexafungerp.

Epidemiology and preventability of hospital-onset bacteremia and fungemia in 2 hospitals in India.

OBJECTIVE: Studies evaluating the incidence, source, and preventability of hospital-onset bacteremia and fungemia (HOB), defined as any positive blood culture obtained after 3 calendar days of hospital admission, are lacking in low- and middle-income countries (LMICs). DESIGN, SETTING, AND PARTICIPANTS: All consecutive blood cultures performed for 6 months during 2020-2021 in 2 hospitals in India were reviewed to assess HOB and National Healthcare Safety Network (NHSN) reportable central-line-associated bloodstream infection (CLABSI) events. Medical records of a convenience sample of 300 consecutive HOB events were retrospectively reviewed to determine source and preventability. Univariate and multivariable logistic regression analyses were performed to identify factors associated with HOB preventability. RESULTS: Among 6,733 blood cultures obtained from 3,558 hospitalized patients, there were 409 and 59 unique HOB and NHSN-reportable CLABSI events, respectively. CLABSIs accounted for 59 (14%) of 409 HOB events. There was a moderate but non-significant correlation (r = 0.51; P = .070) between HOB and CLABSI rates. Among 300 reviewed HOB cases, CLABSIs were identified as source in only 38 (13%). Although 157 (52%) of all 300 HOB cases were potentially preventable, CLABSIs accounted for only 22 (14%) of these 157 preventable HOB events. In multivariable analysis, neutropenia, and sepsis as an indication for blood culture were associated with decreased odds of HOB preventability, whereas hospital stay ≥7 days and presence of a urinary catheter were associated with increased likelihood of preventability. CONCLUSIONS: HOB may have utility as a healthcare-associated infection metric in LMIC settings because it captures preventable bloodstream infections beyond NHSN-reportable CLABSIs.

Coexistence of Cryptococcal Fungemia and Pneumocystis jirovecii Pneumonia in an HIV-Infected Patient: A Case Report.

INTRODUCTION: Opportunistic infections caused by bacteria and fungi are common in human immunodeficiency virus (HIV)-infected patients. Cryptococcus neoformans and Pneumocystis jirovecii are the most common opportunistic infections in immunosuppressed individuals, but their coexistence is rare. To our knowledge, this is the first case presented in Turkey involving the coexistence of C.neoformans fungemia and P.jirovecii pneumonia. CASE PRESENTATION: A 26-year-old male patient presented with a cachectic appearance, cough, sputum, weakness, shortness of breath, and a weight loss of 15 kg in the last three months. It was learned that the patient was diagnosed with HIV three years ago, did not go to follow-ups, and did not use the treatments. CD4 cell count was 7/mm3 (3.4%), CD8 cell count was 100 (54%) mm3, and HIV viral load was 5670 copies/mL. In thorax computed tomography (CT), increases in opacity in diffuse ground glass density in both lungs and fibroatelectasis in lower lobes were observed. With the prediagnosis of P. jiroveci pneumonia, the HIV-infected patient was given trimethoprim-- sulfamethoxazole 15 mg/kg/day intravenously (i.v.). On the 4th day of the patient's hospitalization, mutiplex PCR-based rapid syndromic Biofire (Film Array) blood culture identification 2 (BCID2) test (Biomerieux, France) was applied for rapid identification from blood culture. C. neoformans was detected in the blood culture panel. The treatment that the patient was taking with the diagnosis of C. neoformans fungemia was started at a dose of liposomal amphotericin B 5 mg/kg/- day + fluconazole 800 mg/day. CONCLUSION: While the incidence of opportunistic infections has decreased with antiretroviral therapy (ART), it remains a problem in patients who are unaware of being infected with HIV or who fail ART or refuse treatment. High fungal burden, advanced age, low CD4+ cell count, and being underweight are risk factors for mortality in HIV-positive patients. Our case was a cachectic patient with a CD4 count of 7 cells/mm3. Despite the early and effective treatment, the course was fatal.

Neonatal fungemia caused by Lodderomyces elongisporus: first case report in Latin America.

Premature hospitalized neonates have a greater risk for candidemia, however, fungemia due to rare opportunistic yeasts have been recently reported and is associated with high mortality rates. We herein report the first case in Latin America of Lodderomyces elongisporus fungemia in a premature neonate with a fatal outcome.

Geotrichosis: fungemia in a patient with acute lymphoblastic leukemia / Geotricosis: fungemia en paciente con leucemia linfoblástica aguda

Fungemia caused by Geotrichum spp. is rare and highly lethal. The Instituto Nacional de Cancerología in Bogotá reported just two cases: one in the period 2001-2007 and the other in 2012-2018. This type of infection is more common in any kind of immunocompromised patients, so it can occur in those with hematological malignancies. Here we present the case of a 27-year-old man, diagnosed with acute lymphoblastic leukemia in relapse and admitted with polyarthralgia for five days, febrile neutropenia, nonabscessed cellulitis, and bacteremia due to methicillin-sensitive Staphylococcus aureus. The patient received therapy with oxacillin and cefepime, but the febrile neutropenia persisted. A new set of blood cultures was taken, and antifungal treatment was started because of the suspicion of invasive fungal infection. Arthroconidia were identified in blood cultures and Geotrichum spp. was confirmed using matrix-assisted laser desorption-ionization mass spectrometry. The antifungal treatment was adjusted with amphotericin B deoxycholate for 14 days and voriconazole for four weeks, and after a prolonged stay, the patient was discharged. Although the incidence of fungemia caused by Geotrichum spp. is low, it must be considered in patients with hematological malignancies and persistent febrile neutropenia despite the broadspectrum antimicrobial treatment. The confirmation of fungemia causing agents, with proteomic tools such as the mentioned mass spectrometry, allows treatment adjustment and decreases complications, hospital stay, and mortality.

La fungemia por Geotrichum spp. es poco frecuente y altamente letal. En el Instituto Nacional de Cancerología de Bogotá solo se han reportado dos casos: uno entre el 2001 y el 2007, y el otro entre el 2012 y el 2018. Este tipo de infección es más común en pacientes con algún grado de compromiso del sistema inmunitario, por lo que puede presentarse en pacientes con neoplasias hematológicas malignas. Se presenta el caso de un hombre de 27 años con recaída de leucemia linfoblástica aguda, que ingresó con poliartralgias de cinco días de duración. También cursaba con neutropenia febril, celulitis sin abscesos y bacteriemia por Staphylococcus aureus resistente a la meticilina para lo cual recibió terapia con oxacilina y cefepime. Sin embargo, persistía la neutropenia febril por lo que se sospechó una infección fúngica invasora. Se tomó un nuevo set de hemocultivos y se inició tratamiento antifúngico. En los hemocultivos se identificaron artroconidias y mediante espectrometría de masas por láser de matriz asistida de ionización-desorción se confirmó la presencia de Geotrichum spp. Se ajustó el tratamiento antifúngico con deoxicolato de anfotericina B por 14 días y voriconazol por cuatro semanas. Luego de una estancia prolongada se le dio de alta. Aunque la incidencia de la fungemia por Geotrichum spp. es baja, en pacientes con neoplasias hematológicas malignas debe considerarse en el contexto de una neutropenia febril que es persistente a pesar del tratamiento antimicrobiano de amplio espectro.

Distribution of fungemia agents in five years and antifungal resistance.

OBJECTIVE: Recent research has suggested that fungemia may demonstrate an epidemiologic shift in etiologic agents. This study focuses on the agents causing fungemia and antifungal resistance in a tertiary hospital. PATIENTS AND METHODS: We evaluated all-age fungemia cases admitted to Balikesir Ataturk City Hospital in 2017-2021. Blood cultures (BC) were studied using BacT/Alert® 3D (bioMérieux, Marcyl'Etoile, France) and Render BC128 System (Render Biotech Co. Ltd., Shenzhen, China). On the data, we explored only the first fungal positive samples or the first isolates in different episodes of the same patients. Upon The Clinical and Laboratory Standards Institute (CLSI) disk diffusion guidelines, conventional methods and the Phoenix™ 100 System (Becton Dickinson, Franklin Lakes, NJ, USA) were utilized for antifungal susceptibility identifications. RESULTS: The findings showed that 325 (0.84%) of 38,682 BC sets were positive for fungal growth. Except for four cases (1.2%) [Saprochaete capitata (n = 2); Trichosporon asahii (n = 1), and Saccharomyces cerevisiae (n = 1)], all positive cases yielded Candida spp. (98.8%) growth. In these patients, the following Candida spp. were isolated: Candida albicans complex (n = 155; 47.7%), Candida parapsilosis complex (n = 127; 39.1%), Candida glabrata complex (n = 19; 5.85%), Candida tropicalis (n = 12; 3.7%), Candida kefyr (n = 5; 1.54%), Candida krusei (n = 2; 0.62%), and Candida guilliermondii complex (n = 1; 0.31%). We also realized that while none of the Candida spp. had echinocandin resistance, 8 C. parapsilosis complex isolates were resistant to fluconazole, and 17 C. parapsilosis complex and 2 C. tropicalis isolates were susceptible dose-dependent to fluconazole. CONCLUSIONS: In brief, antifungal resistance is more likely to restrict therapeutic options, albeit it is, fortunately, not prevalent in Turkey despite a few recent reports. Yet, a robust detection or management of antifungal resistance requires species-level identification and strict compliance with relevant management guidelines. Besides, challenges in research may be compensated with a national data set built with data from local laboratories.

Scedosporium species and Lomentospora prolificans fungaemia is uniformly fatal in patients with haematological malignancy.

Scedosporium and Lomentospora species are environmental moulds that are virulent in immunocompromised hosts and rarely cause bloodstream infection (BSI). Patients with Scedosporium and Lomentospora species BSI were identified by the state public laboratory service in Queensland, Australia, over a 20-year period. Twenty-two incident episodes occurred among 21 residents; one patient had a second episode 321 days following the first. Of these, 18 were Lomentospora prolificans, three were Scedosporium apiospermum complex and one was a nonspeciated Scedosporium species. Seventeen (81%) patients died during their index admission, and all-cause mortality at 30, 90 and 365 days was 73%, 82% and 91% respectively. All 20 patients with haematological malignancy died within 365 days of follow-up with a median time to death of 9 days (interquartile range, 6-20 days) following diagnoses of BSI.

Fatal panresistant Lomentospora prolificans fungemia in a patient with aplastic anemia: First report from Türkiye.

Lomentospora prolificans is an opportunistic pathogen that can cause invasive lomentosporiosis in immunocompromised patients. Patients with hematological malignancies and those who have undergone stem cell or solid organ transplantations are in the highest risk group. In addition to the limitations and delays in diagnostic possibilities, L. prolificans has a high mortality due to its resistance to all available antifungal drugs. In a patient diagnosed with aplastic anemia, we described the first case of L. prolificans in Türkiye. L. prolificans was identified in the blood culture, and despite the initiation of antifungal treatments, the fungemia resulted in mortality on the 7th day of intensive care hospitalization. This case highlights the importance of early recognition and prompt initiation of appropriate antifungal therapy to improve the outcome of patients with rare mold infections.

Geotricosis: fungemia en paciente con leucemia linfoblástica aguda / Geotrichosis: fungemia in a patient with acute lymphoblastic leukemia

La fungemia por Geotrichum spp. es poco frecuente y altamente letal. En el Instituto Nacional de Cancerología de Bogotá solo se han reportado dos casos: uno entre el 2001 y el 2007, y el otro entre el 2012 y el 2018. Este tipo de infección es más común en pacientes con algún grado de compromiso del sistema inmunitario, por lo que puede presentarse en pacientes con neoplasias hematológicas malignas. Se presenta el caso de un hombre de 27 años con recaída de leucemia linfoblástica aguda, que ingresó con poliartralgias de cinco días de duración. También cursaba con neutropenia febril, celulitis sin abscesos y bacteriemia por Staphylococcus aureus resistente a la meticilina para lo cual recibió terapia con oxacilina y cefepime. Sin embargo, persistía la neutropenia febril por lo que se sospechó una infección fúngica invasora. Se tomó un nuevo set de hemocultivos y se inició tratamiento antifúngico. En los hemocultivos se identificaron artroconidias y mediante espectrometría de masas por láser de matriz asistida de ionización-desorción se confirmó la presencia de Geotrichum spp. Se ajustó el tratamiento antifúngico con deoxicolato de anfotericina B por 14 días y voriconazol por cuatro semanas. Luego de una estancia prolongada se le dio de alta. Aunque la incidencia de la fungemia por Geotrichum spp. es baja, en pacientes con neoplasias hematológicas malignas debe considerarse en el contexto de una neutropenia febril que es persistente a pesar del tratamiento antimicrobiano de amplio espectro. La identificación de los agentes causantes de fungemias con herramientas de proteómica, como la espectrometría de masas mencionada, permite ajustar el tratamiento dirigido y reducir las complicaciones, la estancia hospitalaria y la mortalidad.

Fungemia caused by Geotrichum spp. is rare and highly lethal. The Instituto Nacional de Cancerología in Bogotá reported just two cases: one in the period 2001-2007 and the other in 2012-2018. This type of infection is more common in any kind of immunocompromised patients, so it can occur in those with hematological malignancies. Here we present the case of a 27-year-old man, diagnosed with acute lymphoblastic leukemia in relapse and admitted with polyarthralgia for five days, febrile neutropenia, non- abscessed cellulitis, and bacteremia due to methicillin-sensitive Staphylococcus aureus. The patient received therapy with oxacillin and cefepime, but the febrile neutropenia persisted. A new set of blood cultures was taken, and antifungal treatment was started because of the suspicion of invasive fungal infection. Arthroconidia were identified in blood cultures and Geotrichum spp. was confirmed using matrix-assisted laser desorption-ionization mass spectrometry. The antifungal treatment was adjusted with amphotericin B deoxycholate for 14 days and voriconazole for four weeks, and after a prolonged stay, the patient was discharged. Although the incidence of fungemia caused by Geotrichum spp. is low, it must be considered in patients with hematological malignancies and persistent febrile neutropenia despite the broadspectrum antimicrobial treatment. The confirmation of fungemia causing agents, with proteomic tools such as the mentioned mass spectrometry, allows treatment adjustment and decreases complications, hospital stay, and mortality.

Fusariosis en pacientes con cáncer: serie de 13 casos y revisión de la literatura / Fusariosis in cancer patients: 13 case series report and literature review

La fusariosis es una micosis oportunista producida por Fusarium spp. Su presentación clínica depende del estado inmunológico del huésped, especialmente, el de aquellos con enfermedades hematooncológicas, cuyas manifestaciones varían desde formas localizadas hasta infección fúngica invasora. El cultivo de piel o de sangre permite orientar el tratamiento antifúngico combinado con anfotericina B y voriconazol. Se presentan 13 casos de pacientes con cáncer en un periodo de once años que desarrollaron fusariosis diseminada; asimismo, se hizo con una revisión extensa de la literatura. En esta serie de casos, la mortalidad fue del 61,5 % (8/13), a pesar del uso del antifúngico. De los 13 pacientes, 11 tenían neoplasia hematológica y 2 neoplasia sólida. El factor de riesgo más importante fue la neutropenia profunda. El compromiso de la piel y los hemocultivos positivos facilitaron la prescripción del tratamiento combinado en la mayoría de los casos. La neutropenia febril persistente asociada a lesiones cutáneas, la onicomicosis, los nódulos o las masas pulmonares permitieron sospechar una infección fúngica invasora por Fusarium spp. El objetivo de la presentación de esta serie de casos es recordar el diagnóstico de fusariosis a la comunidad médica en contacto con pacientes oncológicos, con neutropenia febril profunda y persistentes.

The fusariosis is an opportunistic mycosis caused by Fusarium spp. Its clinical presentation depends on the immunological status of the host, especially in patients with hemato-oncological diseases, whose manifestations vary from localized to invasive fungal infections. Skin or blood culture helps to guide combined antifungal treatment with amphotericin B and voriconazole. Here, we present 13 cases in a period of eleven years of patients with cancer who developed disseminated fusariosis and their outcomes, together with a review of the related literature. In this series of cases, mortality was 61.5 % (8/13), despite the use of the antifungal. Out of the 13 cases, 11 had hematological neoplasia and 2 solid neoplasia. The most determinant risk factor was profound neutropenia. Skin involvement and positive blood cultures in most cases allowed combined treatment prescription. Persistent febrile neutropenia associated with skin lesions, onychomycosis, nodules, or lung masses lead to suspicion of Fusarium spp. fungal invasive infection. The aim of this series of cases is to remind healthcare professionals that oncological patients with deep and persistent febrile neutropenia can develop fusariosis.

Characteristics, costs, and outcomes associated with central-line-associated bloodstream infection and hospital-onset bacteremia and fungemia in US hospitals.

OBJECTIVES: To compare characteristics and outcomes associated with central-line-associated bloodstream infections (CLABSIs) and electronic health record-determined hospital-onset bacteremia and fungemia (HOB) cases in hospitalized US adults. METHODS: We conducted a retrospective observational study of patients in 41 acute-care hospitals. CLABSI cases were defined as those reported to the National Healthcare Safety Network (NHSN). HOB was defined as a positive blood culture with an eligible bloodstream organism collected during the hospital-onset period (ie, on or after day 4). We evaluated patient characteristics, other positive cultures (urine, respiratory, or skin and soft-tissue), and microorganisms in a cross-sectional analysis cohort. We explored adjusted patient outcomes [length of stay (LOS), hospital cost, and mortality] in a 1:5 case-matched cohort. RESULTS: The cross-sectional analysis included 403 patients with NHSN-reportable CLABSIs and 1,574 with non-CLABSI HOB. A positive non-bloodstream culture with the same microorganism as in the bloodstream was reported in 9.2% of CLABSI patients and 32.0% of non-CLABSI HOB patients, most commonly urine or respiratory cultures. Coagulase-negative staphylococci and Enterobacteriaceae were the most common microorganisms in CLABSI and non-CLABSI HOB cases, respectively. In case-matched analyses, CLABSIs and non-CLABSI HOB, separately or combined, were associated with significantly longer LOS [difference, 12.1-17.4 days depending on intensive care unit (ICU) status], higher costs (by $25,207-$55,001 per admission), and a >3.5-fold increased risk of mortality in patients with an ICU encounter. CONCLUSIONS: CLABSI and non-CLABSI HOB cases are associated with significant increases in morbidity, mortality, and cost. Our data may help inform prevention and management of bloodstream infections.