Hospital‐Onset Clostridium difficile Infection Among Solid Organ Transplant Recipients

Clostridium difficile infection (CDI) is a considerable health issue in the United States and represents the most common healthcare‐associated infection. Solid organ transplant recipients are at increased risk of CDI, which can affect both graft and patient survival. However, little is known about the impact of CDI on health services utilization posttransplantation. We examined hospital‐onset CDI from 2012 to 2014 among transplant recipients in the University HealthSystem Consortium, which includes academic medical center–affiliated hospitals in the United States. Infection was five times more common among transplant recipients than among general medicine inpatients (209 vs 40 per 10 000 discharges), and factors associated with CDI among transplant recipients included transplant type, risk of mortality, comorbidities, and inpatient complications. Institutional risk‐standardized CDI varied more than 3‐fold across high‐volume hospitals (infection ratio 0.54–1.82, median 1.04, interquartile range 0.78–1.28). CDI was associated with increased 30‐day readmission, transplant organ complications, cytomegalovirus infection, inpatient costs, and lengths of stay. Total observed inpatient days and direct costs for those with CDI were substantially higher than risk‐standardized expected values (40 094 vs 22 843 days, costs $198 728 368 vs $154 020 528). Further efforts to detect, prevent, and manage CDI among solid organ transplant recipients are warranted.     

Preventive Strategies Against Cytomegalovirus and Incidence of α‐Herpesvirus Infections in Solid Organ Transplant Recipients: A Nationwide Cohort Study

We assessed the impact of antiviral preventive strategies on the incidence of herpes simplex virus (HSV) and varicella‐zoster virus (VZV) infections in a nationwide cohort of transplant recipients. Risk factors for the development of HSV or VZV infection were assessed by Cox proportional hazards regression. We included 2781 patients (56% kidney, 20% liver, 10% lung, 7.3% heart, 6.7% others). Overall, 1264 (45%) patients received antiviral prophylaxis (ganciclovir or valganciclovir, n = 1145; acyclovir or valacyclovir, n = 138). Incidence of HSV and VZV infections was 28.9 and 12.1 cases, respectively, per 1000 person‐years. Incidence of HSV and VZV infections at 1 year after transplant was 4.6% (95% confidence interval [CI] 3.5–5.8) in patients receiving antiviral prophylaxis versus 12.3% (95% CI 10.7–14) in patients without prophylaxis; this was observed particularly for HSV infections (3% [95% CI 2.2–4] versus 9.8% [95% CI 8.4–11.4], respectively). A lower rate of HSV and VZV infections was also seen in donor or recipient cytomegalovirus‐positive patients receiving ganciclovir or valganciclovir prophylaxis compared with a preemptive approach. Female sex (hazard ratio [HR] 1.663, p = 0.001), HSV seropositivity (HR 5.198, p < 0.001), previous episodes of rejection (HR 1.95, p = 0.004), and use of a preemptive approach (HR 2.841, p = 0.017) were significantly associated with a higher risk of HSV infection. Although HSV and VZV infections were common after transplantation, antiviral prophylaxis significantly reduced symptomatic HSV infections.     

Clinical Presentation and Determinants of Mortality of Invasive Pulmonary Aspergillosis in Kidney Transplant Recipients: A Multinational Cohort Study

The prognostic factors and optimal therapy for invasive pulmonary aspergillosis (IPA) after kidney transplantation (KT) remain poorly studied. We included in this multinational retrospective study 112 recipients diagnosed with probable (75.0% of cases) or proven (25.0%) IPA between 2000 and 2013. The median interval from transplantation to diagnosis was 230 days. Cough, fever, and expectoration were the most common symptoms at presentation. Bilateral pulmonary involvement was observed in 63.6% of cases. Positivity rates for the galactomannan assay in serum and bronchoalveolar lavage samples were 61.3% and 57.1%, respectively. Aspergillus fumigatus was the most commonly identified species. Six‐ and 12‐week survival rates were 68.8% and 60.7%, respectively, and 22.1% of survivors experienced graft loss. Occurrence of IPA within the first 6 months (hazard ratio [HR]: 2.29; p‐value = 0.027) and bilateral involvement at diagnosis (HR: 3.00; p‐value = 0.017) were independent predictors for 6‐week all‐cause mortality, whereas the initial use of a voriconazole‐based regimen showed a protective effect (HR: 0.34; p‐value = 0.007). The administration of antifungal combination therapy had no apparent impact on outcome. In conclusion, IPA entails a dismal prognosis among KT recipients. Maintaining a low clinical suspicion threshold is key to achieve a prompt diagnosis and to initiate voriconazole therapy.     

Neuroinvasive St. Louis Encephalitis Virus Infection in Solid Organ Transplant Recipients

In summer 2015, three unrelated solid organ transplant recipients in Phoenix, Arizona, had meningoencephalitis suggestive of West Nile virus (WNV) infection. Testing was inconclusive but was later confirmed as St. Louis encephalitis (SLE). We retrospectively reviewed clinical manifestations, treatment, and outcomes of these transplant recipients. Common symptoms were fever, rigors, diarrhea, headache, and confusion. One patient died 3 days after hospitalization. Therapy for the other two patients was initiated with interferon α‐2b (IFN) and intravenous IgG (IVIG; IFN plus IVIG in combination). Both patients tested positive for WNV by serologic assay, but SLE virus (SLEV) infection was later confirmed by plaque reduction neutralization test at a reference laboratory. Clinical improvement was observed within 72 h after initiation of IFN plus IVIG. SLEV has been an uncommon cause of neuroinvasive disease in the United States. Accurate, timely diagnosis is hindered because of clinical presentation similar to neuroinvasive WNV and SLE, serologic cross‐reactivity, and lack of a commercially available serologic assay for SLEV. There is currently no approved therapy for flaviviral neuroinvasive disease. Anecdotal reports indicate varying success with IFN, IVIG, or IFN plus IVIG in WNV neuroinvasive disease. The same regimen might be of value for immunocompromised persons with neuroinvasive SLEV infection.     

CCL8 and the Immune Control of Cytomegalovirus in Organ Transplant Recipients

Monitoring of cytomegalovirus cell‐mediated immunity is a promising tool for the refinement of preventative and therapeutic strategies posttransplantation. Typically, the interferon‐γ response to T cell stimulation is measured. We evaluated a broad range of cytokine and chemokines to better characterize the ex vivo host‐response to CMV peptide stimulation. In a cohort of CMV viremic organ transplant recipients, chemokine expression—specifically CCL8 (AUC 0.849 95% CI 0.721–0.978; p = 0.003) and CXCL10 (AUC 0.841, 95% CI 0.707–0.974; p = 0.004)—was associated with control of viral replication. In a second cohort of transplant recipients at high‐risk for CMV, the presence of a polymorphism in the CCL8 promoter conferred an increased risk of viral replication after discontinuation of antiviral prophylaxis (logrank hazard ratio 3.6; 95% CI 2.077–51.88). Using cell‐sorting experiments, we determined that the primary cell type producing CCL8 in response to CMV peptide stimulation was the monocyte fraction. Finally, in vitro experiments using standard immunosuppressive agents demonstrated a dose‐dependent reduction in CCL8 production. Chemokines appear to be important elements of the cell‐mediated response to CMV infection posttransplant, as here suggested for CCL8, and translation of this knowledge may allow for the tailoring and improvement of preventative strategies.     

Donor‐Derived Strongyloides stercoralis Infection in Solid Organ Transplant Recipients in the United States, 2009–2013

Infection with Strongyloides stercoralis is typically asymptomatic in immunocompetent hosts, despite chronic infection. In contrast, immunocompromised hosts such as solid organ transplant recipients are at risk for hyperinfection syndrome and/or disseminated disease, frequently resulting in fatal outcomes. Infection in these recipients may result from reactivation of latent infection or infection through transmission from an infected donor. We describe the Centers for Disease Control and Prevention's experience with seven clusters of donor‐derived infection from 2009 to 2013. Six of the seven (86%) donors were born in Latin America; donor screening was not performed prior to organ transplantation in any of these investigations. Eleven of the 20 (55%) organ recipients were symptomatic, two of whom died from complications of strongyloidiasis. We also describe the New York Organ Donor Network (NYODN) experience with targeted donor screening from 2010 to 2013. Of the 233 consented potential donors tested, 10 tested positive for Strongyloides antibody; and 18 organs were transplanted. The majority (86%) of the donors were born in Central or South America. Fourteen recipients received prophylaxis after transplantation; no recipients developed strongyloidiasis. The NYODN experience provides evidence that when targeted donor screening is performed prior to transplantation, donor‐derived infection can be averted in recipients.     

Failure of voriconazole therapy due to acquired azole resistance in Aspergillus fumigatus in a kidney transplant recipient with chronic necrotizing aspergillosis

Invasive aspergillosis (IA) affects the lungs and disseminates mostly in patients with neutropenia and/or patients who are receiving immunosuppressive and steroid therapies. Despite progress in the diagnosis of and therapy for IA, it is still characterized by a high mortality rate. Currently, voriconazole is considered as the standard therapy for IA. Over recent years, triazole‐resistant Aspergillus fumigatus isolates have emerged in the environment due to the use of fungicidal agricultural products, with the risk of developing IA related to a resistant isolate. However, resistance may also develop in patients who are undergoing long‐term triazole therapy, particularly in the setting of chronic forms of pulmonary aspergillosis. Herein we describe a kidney transplant recipient who failed to respond to voriconazole therapy due to acquired resistance secondary to the appearance of a de novo mutation (Y121F) in the cyp51A gene during chronic necrotizing pulmonary aspergillosis. The infecting isolate acquired voriconazole resistance in 8 months despite plasma concentrations within the recommended range of the drug, necessitating lobectomy in association with a new antifungal strategy consisting of liposomal amphotericin and caspofungin with a good outcome over 36 months.     

Coccidioidomycosis Transmission Through Organ Transplantation: A Report of the OPTN Ad Hoc Disease Transmission Advisory Committee

Donor‐derived coccidioidomycosis has caused unexpected morbidity and mortality in transplant recipients. All proven or probable reports of donor‐derived coccidioidomycosis to the Disease Transmission Advisory Committee between 2005 and August 2012 were reviewed. Six reports of proven or probable coccidioidomycosis were discovered. In four of six, the infection was first detected at autopsy in the recipient. In two cases it was first identified in the donor. Twenty‐one recipients received organs from these six donors. Transmission occurred in 43% at a median of 30 days posttransplant with a mortality rate of 28.5%. Eleven recipients received preemptive antifungals, seven did not receive treatment, and treatment information was not reported for three recipients. Five of seven who did not receive prophylaxis/treatment died and all 11 who received early therapy survived. Six deaths occurred 14 to 55 days after transplant, with a median of 21 days. For exposed recipients, donor‐derived coccidioidomycosis is a significant cause of morbidity and mortality. Evidence of infection in one recipient should prompt immediate evaluation for treatment of all other recipients from the same donor as preemptive treatment was effective. Further studies are needed to decide whether all donors from endemic areas should have routine serologic screening.     

Cryptococcosis in solid organ transplantation—Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of cryptococcosis in the pre‐ and post‐transplant period. The current update now includes a discussion of cryptococcosis, which is the third most common invasive fungal infection in SOT recipients. Infection often occurs a year after transplantation; however, early infections occur and donor‐derived infections have been described within 3 months after transplant. There are two main species that cause infection, Cryptococcus neoformans and C gattii. Clinical onset may be insidious, but headaches, fevers, and mental status changes should warrant diagnostic testing. The lateral flow cryptococcal antigen assay is now the preferred test from serum and cerebrospinal fluid due to its rapidity, accuracy, and cost. A lumbar puncture with measurement of opening pressure is recommended for patients with suspected or proven cryptococcosis. Lipid amphotericin B plus 5‐flucytosine is used as initial treatment of meningitis, disseminated infection, and moderate‐to‐severe pulmonary infection, followed by fluconazole as consolidation therapy. Fluconazole is effective for mild‐to‐moderate pulmonary infection. Immunosuppression reduction as part of management may lead to immune reconstitution syndrome that may resemble active disease.     

Risk Factors Associated With Early Invasive Pulmonary Aspergillosis in Kidney Transplant Recipients: Results From a Multinational Matched Case–Control Study

Risk factors for invasive pulmonary aspergillosis (IPA) after kidney transplantation have been poorly explored. We performed a multinational case–control study that included 51 kidney transplant (KT) recipients diagnosed with early (first 180 posttransplant days) IPA at 19 institutions between 2000 and 2013. Control recipients were matched (1:1 ratio) by center and date of transplantation. Overall mortality among cases was 60.8%, and 25.0% of living recipients experienced graft loss. Pretransplant diagnosis of chronic pulmonary obstructive disease (COPD; odds ratio [OR]: 9.96; 95% confidence interval [CI]: 1.09–90.58; p = 0.041) and delayed graft function (OR: 3.40; 95% CI: 1.08–10.73; p = 0.037) were identified as independent risk factors for IPA among those variables already available in the immediate peritransplant period. The development of bloodstream infection (OR: 18.76; 95% CI: 1.04–339.37; p = 0.047) and acute graft rejection (OR: 40.73, 95% CI: 3.63–456.98; p = 0.003) within the 3 mo prior to the diagnosis of IPA acted as risk factors during the subsequent period. In conclusion, pretransplant COPD, impaired graft function and the occurrence of serious posttransplant infections may be useful to identify KT recipients at the highest risk of early IPA. Future studies should explore the potential benefit of antimold prophylaxis in this group.