Carriage of multidrug-resistant Gram-negative bacilli: duration and risk factors.

Identification of risk factors influencing the duration of carriage of multidrug-resistant Gram-negative bacilli (MDR-GNB) may be useful for infection control. The aim of this study is to estimate the impact of several factors collected for routine hospital surveillance on the duration of carriage of selected MDR-GNB. From January 2015 to July 2021, patients with at least two clinical/surveillance samples positive for MDR-GNB different from ESBL-producing E. coli or AmpC - exclusively producing Enterobacterales were assessed. Microorganisms, age, number of admissions, clinical or rectal sample, sex, and admission service were evaluated as risk factors. Multivariate analysis was performed by a Cox proportional hazard model. A total of 1981 episodes of colonization were included. Involved microorganisms were ESBL-Klebsiella pneumoniae (KP) in 1057 cases (53.4%), other ESBL-non-E. coli Enterobacterales in 91 (4.6%), OXA-48-KP in 263 (13.3%), KPC-KP in 90 (4.5%), VIM-KP in 29 (1.5%), carbapenemase-producing non-KP Enterobacterales (CP-non-KP) in 124 (6.3%), and MDR Pseudomonas aeruginosa (MDR-PAER) in 327 (16.5%). No differences in duration of colonization were observed among ESBL-KP (median colonization time 320 days), ESBL-non-E. coli Enterobacterales (226 days), OXA48-KP (305 days), and MDR-PAER (321 days). For each group, duration of colonization was significantly longer than that of KPC-KP (median colonization time 60 days), VIM-KP (138 days), and CP-non-KP (71 days). Male sex (HR = 0.88; 95% CI 0.78-0.99), detection in Hepatology-Gastroenterology (HR = 0.71; 95% CI 0.54-0.93), clinical sample (HR = 0.61; 95% CI 0.53-0.69), and > 2 admissions after first detection (HR = 0.47; 95% CI 0.42-0.52) were independent predictors of longer carriage, whereas VIM-KP (HR = 1.61; 95% CI 1.04-2.48), KPC-KP (HR = 1.85; 95% CI 1.49-2.3), and CP-non-KP (HR = 1.92; 95% CI 1.49-2.47) were associated with shorter colonization time. Duration of colonization was significantly longer for ESBL-KP, other ESBL-non-E. coli Enterobacterales, OXA-48-KP, and MDR-PAER. For these microorganisms, prolonging surveillance up to 2.5-3 years should be considered. Male sex, clinical sample, multiple readmissions, admission service, and type of microorganism are independent predictors of the duration of carriage.

Experience with the use of siltuximab in patients with SARS-CoV-2 infection.

OBJECTIVE: The study aims to describe characteristics and clinical outcome of patients with SARS-CoV-2 infection that received siltuximab according to a protocol that aimed to early block the activity of IL-6 to avoid the progression of the inflammatory flare. METHODS: Retrospective review of the first 31 patients with SARS-CoV-2 treated with siltuximab, in Hospital Clinic of Barcelona or Hospital Universitario Salamanca, from March to April 2020 with positive polymerase-chain reaction (PCR) from a nasopharyngeal swab. RESULTS: The cohort included 31 cases that received siltuximab with a median (IQR) age of 62 (56-71) and 71% were males. The most frequent comorbidity was hypertension (48%). The median dose of siltuximab was 800 mg ranging between 785 and 900 mg. 7 patients received siltuximab as a salvage therapy after one dose of tocilizumab. At the end of the study, a total of 26 (83.9) patients had been discharged alive and the mortality rate was 16.1% but only 1 out of 24 that received siltuximab as a first line option (4%). CONCLUSIONS: Siltuximab is a well-tolerated alternative to tocilizumab when administered as a first line option in patients with COVID-19 pneumonia within the first 10 days from symptoms onset and high C-reactive protein.

Tocilizumab reduces the risk of ICU admission and mortality in patients with SARS-CoV-2 infection.

OBJECTIVE: In some patients the immune response triggered by SARS-CoV-2 is unbalanced, presenting an acute respiratory distress syndrome which in many cases requires intensive care unit (ICU) admission. The limitation of ICU beds has been one of the major burdens in the management around the world; therefore, clinical strategies to avoid ICU admission are needed. We aimed to describe the influence of tocilizumab on the need of transfer to ICU or death in non-critically ill patients. METHODS: A retrospective study of 171 patients with SARS-CoV-2 infection that did not qualify as requiring transfer to ICU during the first 24h after admission to a conventional ward, were included. The criteria to receive tocilizumab was radiological impairment, oxygen demand or an increasing of inflammatory parameters, however, the ultimate decision was left to the attending physician judgement. The primary outcome was the need of ICU admission or death whichever came first. RESULTS: A total of 77 patients received tocilizumab and 94 did not. The tocilizumab group had less ICU admissions (10.3% vs. 27.6%, P=0.005) and need of invasive ventilation (0 vs 13.8%, P=0.001). In the multivariable analysis, tocilizumab remained as a protective variable (OR: 0.03, CI 95%: 0.007-0.1, P=0.0001) of ICU admission or death. CONCLUSIONS: Tocilizumab in early stages of the inflammatory flare could reduce an important number of ICU admissions and mechanical ventilation. The mortality rate of 10.3% among patients receiving tocilizumab appears to be lower than other reports. This is a non-randomized study and the results should be interpreted with caution.

Real-life use of remdesivir in hospitalized patients with COVID-19.

OBJECTIVE: Controversial results on remdesivir efficacy have been reported. We aimed to report our real-life experience with the use of remdesivir from its availability in Spain. METHODS: We performed a descriptive study of all patients admitted for ≥48 hours with confirmed COVID-19 who received remdesivir between the 1st of July and the 30th of September 2020. RESULTS: A total of 123 patients out of 242 admitted with COVID-19 at our hospital (50.8%) received remdesivir. Median age was 58 years, 61% were males and 56.9 % received at least one anti-inflammatory treatment. No adverse events requiring remdesivir discontinuation were reported. The need of intensive care unit admission, mechanical ventilation and 30-days mortality were 19.5%, 7.3% and 4.1%, respectively. CONCLUSIONS: In our real-life experience, the use of remdesivir in hospitalized patients with COVID-19 was associated with a low mortality rate and good safety profile.

Performance of differential time to positivity as a routine diagnostic test for catheter-related bloodstream infections: a single-centre experience.

OBJECTIVE: To assess the performance of differential time to positivity (DTP) for the diagnosis of catheter-related bloodstream infections (CRBSI). METHODS: From all episodes of bloodstream infections (BSI) diagnosed during a 15-year period (2003-17) those in which a paired set of blood cultures drawn from a catheter and a peripheral vein were positive for the same microorganism and had a clinically and/or microbiologically defined source were selected. To assess diagnostic discrimination ability and accuracy of DTP for CRBSI, area under the receiver operating characteristic curves (AUC) and performance characteristics of a DTP ≥2 h were computed. RESULTS: A total of 512 BSI were included, of which 302 (59%) were CRBSI. Discrimination ability of DTP was low for Staphylococcus aureus (AUC 0.656 ± 0.06), coagulase-negative staphylococci (AUC 0.618 ± 0.081), enterococci (AUC 0.554 ± 0.117) and non-AmpC-producing Enterobacteriaceae (AUC 0.653 ± 0.053); moderate for Pseudomonas aeruginosa (AUC 0.841 ± 0.073), and high for AmpC-producing Enterobacteriaceae (AUC 0.944 ± 0.039). For the entire sample, DTP had a low-to-moderate discrimination ability (AUC 0.698 ± 0.024). A DTP ≥2 h has a low sensitivity for coagulase-negative staphylococci (60%) and very low for S. aureus (34%), enterococci (40%) and non-AmpC-producing Enterobacteriaceae (42%). A DTP cut-off of 1 h improved sensitivity (90%) for AmpC-producing Enterobacteriaceae. CONCLUSIONS: Differential time to positivity performs well for diagnosing CRBSI only when AmpC-producing Enterobacteriaceae and P. aeruginosa are involved. Performance is low for common Gram-positive organisms and non-AmpC-producing enteric bacilli; a negative test should not be used to rule out CRBSI due to these microorganisms. A DTP ≥1 h may improve accuracy for AmpC-producing Enterobacteriaceae, particularly Enterobacter spp.

Skin infection by Corynebacterium diphtheriae and Streptococcus pyogenes: an unusual association / Infección cutánea por Corynebacterium diphtheriae y Streptococcus pyogenes: una asociación inusual

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The Impact of Culturing the Organ Preservation Fluid on Solid Organ Transplantation: A Prospective Multicenter Cohort Study.

BACKGROUND: We analyzed the prevalence, etiology, and risk factors of culture-positive preservation fluid and their impact on the management of solid organ transplant recipients. METHODS: From July 2015 to March 2017, 622 episodes of adult solid organ transplants at 7 university hospitals in Spain were prospectively included in the study. RESULTS: The prevalence of culture-positive preservation fluid was 62.5% (389/622). Nevertheless, in only 25.2% (98/389) of the cases were the isolates considered "high risk" for pathogenicity. After applying a multivariate regression analysis, advanced donor age was the main associated factor for having culture-positive preservation fluid for high-risk microorganisms. Preemptive antibiotic therapy was given to 19.8% (77/389) of the cases. The incidence rate of preservation fluid-related infection was 1.3% (5 recipients); none of these patients had received preemptive therapy. Solid organ transplant (SOT) recipients with high-risk culture-positive preservation fluid receiving preemptive antibiotic therapy presented both a lower cumulative incidence of infection and a lower rate of acute rejection and graft loss compared with those who did not have high-risk culture-positive preservation fluid. After adjusting for age, sex, type of transplant, and prior graft rejection, preemptive antibiotic therapy remained a significant protective factor for 90-day infection. CONCLUSIONS: The routine culture of preservation fluid may be considered a tool that provides information about the contamination of the transplanted organ. Preemptive therapy for SOT recipients with high-risk culture-positive preservation fluid may be useful to avoid preservation fluid-related infections and improve the outcomes of infection, graft loss, and graft rejection in transplant patients.

Pyomyositis in a Patient with IgA Nephropathy and Kidney Transplant.

Infections are among the most common complications transplant physicians face when dealing with solid organ transplant recipients. We present a case of pyomyositis caused by Staphylococcus aureus in a patient with IgA nephropathy and a kidney transplant, under treatment with mTOR inhibitors and prednisone. This entity is a rare intramuscular infection, given the resistance of healthy muscle to colonization. We review the most frequent agents, the diagnostic algorithm, and therapeutic alternatives. We also comment on the role of mTOR inhibitors in this case as possible predisposing factor for the infection.

Severe Hepatitis C Recurrence as a Risk Factor for Opportunistic Infections in Liver Transplant Recipients.

OBJECTIVE: The aim of the study was to determine the clinical characteristics, frequency of opportunistic infections (OI), and the outcomes for liver transplant recipients with severe hepatitis C virus (HCV) recurrence. In addition, the objective was to evaluate HCV recurrence as a risk factor for developing an OI. METHODS: We conducted a retrospective observational study recording all liver transplant recipients from July 1, 2003, to December 31, 2012. Patients with liver disease due to HCV were selected. Active surveillance of infections was conducted periodically, and patients were classified according to presence of severe HCV recurrence. RESULTS: Three hundred seventy patients underwent liver transplantation because of chronic HCV. One hundred forty-seven patients presented severe recurrence (SR) (49%) and 50 (17%) of them had post-liver transplant cholestatic hepatitis C. Patients with SR presented OI, especially cytomegalovirus (CMV) infections and invasive fungal infections, more frequently than patients without SR (33% vs 13%; P < .001). From the diagnosis of SR to the presentation of OI, the median number of days was 169 (6-2083). Acute allograft rejection (OR 1.8 95% confidence interval [CI] 1.1-3.3) donor age ≥60 years (OR 2.9 95% CI 1.3-6.8), and SR (OR 2.8, 95% CI 1.6-5.1) were independently associated with the development of OI in liver transplant recipients. CONCLUSION: A high index of suspicion of opportunistic infections must be maintained when faced with severe HCV recurrence in liver transplant recipients. Moreover, active surveillance against CMV infection and other prophylactic strategies against opportunistic infections should be considered.

Brain abscess due to Listeria monocytogenes after HELLP syndrome in a patient with antiphospholipid syndrome.

Objective To illustrate an unusual case of Listeria cerebral abscess. Material and methods A 32-year-old pregnant woman with thrombotic antiphospholipid syndrome (APS) received corticotherapy for two weeks due to hemolysis, elevated liver enzymes, low platelet (HELLP) syndrome. After delivery she presented with neurological symptoms and fever. Results The MRI scan confirmed the presence of a brain abscess, and Listeria monocytogenes was isolated in blood cultures. After eight weeks of antibiotic treatment, the patient presented no sequelae. Conclusion L. monocytogenes should be included in the differential diagnosis of patients with fever and neurological dysfunction, especially in those with a recent history of corticotherapy.

Impact of urinary tract infections on short-term kidney graft outcome.

Urinary tract infections (UTIs) are frequent after renal transplantation, but their impact on short-term graft outcome is not well established. All kidney transplants performed between July 2003 and December 2010 were investigated to evaluate the impact of UTI on graft function at 1 year after transplantation. Of 867 patients who received a kidney transplant, 184 (21%) developed at least one episode of UTI, at a median of 18 days after transplantation. The prevalence of acute graft pyelonephritis (AGP) was 15%. The most frequent pathogens identified were Escherichia coli, Klebsiella species, and Pseudomonas aeruginosa, 37% of which were considered to be multidrug-resistant strains. Thirty-eight patients (4%) lost their grafts, 225 patients (26%) had graft function impairment and the 1-year mortality rate was 3%; however, no patient died as a consequence of a UTI. Surgical re-intervention and the development of at least one episode of AGP were independently associated with 1-year graft function impairment. Moreover, the development of at least one episode of AGP was associated with graft loss at 1 year. Patients with AGP caused by a resistant strain had graft function impairment more frequently, although this difference did not reach statistical significance (53% vs. 36%, p 0.07). Neither asymptomatic bacteriuria nor acute uncomplicated UTI were associated with graft function impairment in multivariate analysis. To conclude, UTIs are frequent in kidney transplant recipients, especially in the early post-transplantation period. Although AGP was significantly associated with kidney graft function impairment and 1-year post-transplantation graft loss, lower UTIs did not affect graft function.

Impact of antibiotic resistance on the development of recurrent and relapsing symptomatic urinary tract infection in kidney recipients.

We sought to determine the frequency, risk factors, and clinical impact of recurrent urinary tract infections (UTI) in kidney transplant recipients. Of 867 patients who received a kidney transplant between 2003 and 2010, 174 (20%) presented at least one episode of UTI. Fifty-five patients presented a recurrent UTI (32%) and 78% of them could be also considered relapsing episodes. Recurrent UTI was caused by extended-spectrum betalactamase (ESBL)-producing Klebsiella pneumoniae (31%), followed by non-ESBL producing Escherichia coli (15%), multidrug-resistant (MDR) Pseudomonas aeruginosa (14%), and ESBL-producing E. coli (13%). The variables associated with a higher risk of recurrent UTI were a first or second episode of infection by MDR bacteria (OR 12; 95%CI 528), age >60 years (OR 2.2; 95%CI 1.15.1), and reoperation (OR 3; 95%CI 1.37.1). In addition, more relapses were recorded in patients with UTI caused by MDR organisms than in those with susceptible microorganisms. There were no differences in acute rejection, graft function, graft loss or 1 year mortality between groups. In conclusion, recurrent UTI is frequent among kidney recipients and associated with MDR organism. Classic risk factors for UTI (female gender and diabetes) are absent in kidney recipients, thus highlighting the relevance of uropathogens in this population.

Legionellosis and biologic therapies.

BACKGROUND: Biologic therapies are widely used in inflammatory diseases, and they are associated to an increased infection risk, especially to granulomatous and intracellular infections such as Legionella. RESULTS: A review of the literature revealed 105 cases of Legionella pneumonia in patients taking biologic therapies. Sixty-four patients (65.3%) were treated with infliximab, 23 (23.5%) with adalimumab, 5 (5%) with etanercept and 3 (3%) with rituximab. Seventy-one per cent of the patients were treated for rheumatologic diseases and 16% for inflammatory bowel diseases. The majority of the patients received one or more concomitant immunosuppressive drugs, especially steroids (43%). Overall mortality was 19%. Legionella pneumonia might complicate therapy with biologic therapies, especially in patients being treated with infliximab or adalimumab given concomitantly with other immunosuppressive medications during their first 6 months of treatment. CONCLUSION: Physicians should be aware of this potentially severe association. Early recognition and treatment would likely result in reduced morbidity and mortality.

Candida arteritis occurring in a liver transplant recipient.

We report the first case, to our knowledge, of Candida arteritis in a liver transplant recipient. The patient presented with hemorrhagic shock requiring emergency arterial repair. As Candida albicans, Candida tropicalis, and Candida glabrata were growing in the arterial tissue, the patient received antifungal therapy for 5 months, but died because of chronic graft dysfunction. No evidence of fungal infection was found in the tissue on postmortem examination.

Listeriosis in patients receiving biologic therapies.

The evolution of inflammatory diseases has radically changed since the introduction of biologic therapies, such as tumour necrosis factor alpha inhibitors (anti-TNFα). They, therefore, represent a widely used therapeutic modality. Nevertheless, post-marketing studies reveal an increased risk of infection in patients taking these drugs, especially granulomatous infections such as listeriosis. We aimed to evaluate the reported cases of listeriosis in patients treated with biologic treatments. We used the United States Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) from 2004 to 2011. We also perform a literature review of previously reported cases of listeriosis in patients taking biologic therapies. We identified 266 cases of Listeria monocytogenes infection associated with biologic therapies. The majority of patients were receiving infliximab (77.1 %), followed by etanercept (11.7 %), adalimumab (9.8 %), rituximab (4.1 %), abatacept (0.4 %) and golimumab (0.4 %). Indications for the use of biologics were as follows: 47.7 % for rheumatologic diseases, 38 % for inflammatory bowel diseases, 3.4 % for haematological diseases and 10.5 % for other indications. Seventy-three percent of the patients were receiving concomitant immunosuppressant drugs, especially steroids (56 %) and methotrexate (31.6 %). The median time to the onset of infection was 184 days. Mortality rates range from 11.1 % in adalimumab-treated patients to 27.3 % in rituximab-treated patients (p = 0.7). Listeriosis is common in biologics-treated patients, especially related to infliximab use given concomitantly with other immunosuppressive therapies. Infections after treatment with biologics mostly occurred in the first year after initiating treatment.

Changing aetiology, clinical features, antimicrobial resistance, and outcomes of bloodstream infection in neutropenic cancer patients.

Recent changes in the management of patients with haematological malignancies might have influenced the aetiology, characteristics, antimicrobial resistance and outcomes of bloodstream infection (BSI) during neutropenia. We compared 272 episodes of BSI in adult neutropenic patients with cancer prospectively collected from January 1991 to December 1996 (first period), when quinolone prophylaxis was used, with 283 episodes recorded from January 2006 to March 2010 (second period), when antibacterial prophylaxis was stopped. Patients in the second period were significantly older and were more likely to have graft-versus-host disease and a urinary catheter in place, whereas the presence of a central venous catheter, parenteral nutrition, corticosteroids and antifungal and quinolone prophylaxis, were more frequent in the first period. More patients in the first period had mucositis and soft-tissue infection as the origin of BSI, but an endogenous source was more common during the second. Gram-positive BSI was more frequent in the first period (64% versus 41%; p <0.001), mainly due to coagulase-negative staphylococci and viridans group streptococci. In the second period gram-negative BSI increased (28% versus 49%; p <0.001), quinolone susceptibilities were recovered, but multidrug-resistant gram-negative BSI also increased (1% versus 6%; p <0.001). Although patients in the second period were more likely to need admission to the intensive-care unit, overall case-fatality rate was similar in the two periods (19% versus 15%). The aetiology of BSI in neutropenic patients with cancer has shifted from gram-positive to gram-negative organisms. Multidrug resistance among gram-negative bacilli is emerging as a therapeutic challenge. Overall case-fatality rate remains high.

Risk factors, clinical characteristics, and outcomes of invasive fungal infections in solid organ transplant recipients.

BACKGROUND: Invasive fungal infection (IFI) is an important cause of morbidity and mortality among solid organ transplant (SOT) recipients. We sought to assess risk factors, clinical characteristics, and current outcomes of IFI in SOT recipients. METHODS: We reviewed all episodes of IFI occurring among SOT recipients in a university hospital from 2008 to 2011. To determine risk factors for IFI we carried out a matched case-control study (1:2 ratio). Control subjects were matched for transplant type and timing. RESULTS: We documented 20 episodes of IFI among 744 SOT recipients (2.7%). Sixty-five percent of cases were proven IFI and 35% were probable IFI. The types of IFI documented were aspergillosis in 8 cases, candidiasis in 7, pneumocystosis in 3, Emmonsia species in infection 1, and disseminated cryptococcosis in 1. Ninety-nine percent of the patients had received a prior antibiotic therapy (3 months), 40% presented allograft rejection (3 months), and 40% had prior kidney injury. Complications of IFI included septic shock (50%), respiratory failure (55%), multiple-organ dysfunction (55%), and intensive care unit (ICU) admission (50%). Median days from transplantation to diagnosis was 103 for candidiasis (range, 27-4644) and 1195 for aspergillosis (range, 0-4319). In a comparison of case patients with 40 matched control subjects, case patients more frequently presented prior ICU stay (3 months; P = .05), hemodialysis requirement (P = .02), receipt of high-dose prednisone (6 months; P = .006), and prior antibiotic therapy (P < .001). Prior use of antibiotic treatment was the only risk factor for IFI (odds ratio [OR] 93; 95% confidence interval [CI], 8.3-1042). Case-fatality rate was 60%. CONCLUSIONS: In our recent experience, 2.7% of SOT recipients developed IFI, mainly aspergillosis followed by candidiasis. Prior ICU admission, hemodialysis, receipt of high-dose prednisone, and prior antibiotic use were more frequent in cases when compared with control subjects, with the latter factor being the only independent risk factor for developing IFI. Case-fatality rate was high (60%).

Clinical features and outcomes of tuberculosis in solid organ transplant recipients.

BACKGROUND: Tuberculosis (TB) remains a significant opportunistic infection in solid organ transplant (SOT) recipients. Moreover, its optimal treatment in SOT recipients is challenging due to the toxicity and potential drug-drug interactions of antituberculus drugs. We sought to assess the frequency, clinical characteristics, treatments, and outcomes of TB among SOT recipients. METHODS: We reviewed retrospectively the medical charts of all TB cases occurring among SOT recipients from January 2000 to December 2011, retrieving data regarding baseline and clinical features, as well as treatment and outcomes. RESULTS: Eighteen of 2005 SOT recipients developed TB (0.9%). The frequency according to the type of allograft was 0.9% (10 of 1120) for kidney, 1% (7 of 701) for liver, and 0.5% (1 of 184) for heart recipients. Six patients (33%) had prior exposure to TB: a positive tuberculin test (n = 3), a positive quantiferon-TB (n = 1) for a prior history of TB (n = 3). None of them received antituberculus prophylaxis. The mean time after transplantation to TB diagnosis was 64 months (range 2-169). Five patients (28%) developed TB within the first year posttransplantation. The mean duration of symptoms before diagnosis was 30 days (range 1-180). Nine patients (50%) displayed pulmonary TB; 7 (39%) had disseminated infections, and 2 (11%) had lymph node involvement. None of the Mycobacterium tuberculosis isolates were resistant to first-line antituberculus drugs. All patients were given isoniazide. Most of them received a 3-drug regimen. Rifampin was prescribed in 11 cases. Seven patients (5 liver and 2 kidney recipients) developed hepatotoxicity. One patient developed rejection without allograft loss. Mortality during antituberculus treatment was 17% (3/18). CONCLUSIONS: In this study, 0.9% of SOT recipients developed TB, which frequently presented with extrapulmonary involvement, causing considerable mortality. Hepatotoxicity mainly among liver transplant recipients was a significant therapeutic drawback.

Reduced incidence of pneumonia in influenza-vaccinated solid organ transplant recipients with influenza disease.

Whether influenza vaccination influences the severity of illness in cases of clinical failure in solid organ transplant (SOT) recipients receiving influenza vaccine has not been extensively studied. Our goal was to evaluate the frequency of influenza vaccination among SOT recipients with influenza disease and its impact on the illness severity during the 2010-2011 season. Adult SOT recipients with confirmed influenza infection were included from December 2010 to April 2011. Follow-up data were recorded and antibody titres were determined using a microneutralization assay. Sixty-four SOT recipients were included in the study, ten (15.6%) with severe disease, requiring admission to intensive care units, of whom four (6.3%) died. In all, 34 (53.1%) received the 2010-2011 seasonal influenza vaccine and 32 (50.0%) received the 2009-H1N1 pandemic vaccine, and none had detectable antibodies against influenza at the time of diagnosis of influenza infection. Twenty-three (67.6%) of the patients that received the vaccine required hospital admission and presented less dyspnoea (10, 29.4% versus 14 (50.0%), p 0.09) and pneumonia (8, 23.8% versus 15, 50.0%, p 0.03, relative risk 0.3, 95% CI 0.1-0.9) than unvaccinated patients, with relative risk reductions of 60% and 70%, respectively. Although influenza vaccination confers protection on SOT recipients against developing influenza pneumonia, the rate of clinical failure is still high. New strategies to improve influenza immunization are needed for this group of patients.