Pneumonia in solid organ transplant recipients: a prospective multicenter study

Clinical characteristics and outcomes of community-acquired pneumonia in solid organ transplant recipients

BACKGROUND

Pneumonia is a frequent complication of solid organ transplantation that adversely impacts both graft and recipient survival. There is a paucity of data on community-acquired pneumonia (CAP) in transplant recipients, particularly the long term outcomes. We conducted a study to compare the clinical characteristics and outcomes of pneumonia in solid organ transplant (SOT) recipients to those in non-transplant (NT) recipients.

MATERIAL AND METHODS

Clinical characteristics were abstracted from electronic medical records. Outcomes included time to hospital discharge, short and long-term mortality. Inverse-propensity score weights were assigned to account for between-group differences. Adjusted analysis included a weighted logistic regression. Results were reported as odds ratios with a corresponding 95 % confidence interval (CI).

RESULTS

A total of 7449 patients were admitted with CAP. Patients were divided into two groups: SOT recipients 42 (0.56 %) and NT recipients 7396 (99.2 %). SOT recipients were younger, more commonly males, with higher prevalence of comorbidities. After accounting for inverse-propensity score weighting, the odds of mortality were higher in SOT recipients in hospital, at 30 days and at 1 year. The magnitude of increase in mortality for SOT recipients was greatest at 1 year with 1.41 (95 % CI: 1.38-1.44) times higher odds.

CONCLUSION

In patients with CAP, SOT recipients are younger, more commonly male and have more co-morbidities compared with NT recipients. They also have higher 1 year mortality after adjustment. Clinicians must be vigilant toward the pronounced long-term mortality risk among these patients and ensure continued follow-up care for them.

Clinical Features, Diagnostics, Etiology, and Outcomes of Hospitalized Solid Organ Recipients With Community-Acquired Pneumonia: A Retrospective Cohort Analysis

BACKGROUND

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Limited evidence is available on the most effective diagnostic approaches, management strategies, and long-term outcomes for CAP in patients who have undergone solid organ transplantation.

RESEARCH QUESTION

What is the acute and long-term morbidity and mortality after CAP in organ transplant recipients?

STUDY DESIGN AND METHODS

We retrospectively analyzed hospitalizations for CAP in solid organ recipients at the largest German transplant center. The study included patients admitted between January 1, 2010, and May 31, 2021. The reported outcomes are in-hospital and 1-year mortality, risk of cardiovascular events during hospitalization and at 1 year, admission to the ICU, and risk of pneumonia with Pseudomonas aeruginosa. Multivariable binary logistic regression using stepwise forward selection was performed to determine predictive factors for pneumonia with P aeruginosa.

RESULTS

We analyzed data from 403 hospitalizations of 333 solid organ recipients. In > 60% of cases, patients had multiple comorbidities, with cardiovascular and chronic kidney disease being the most prevalent. More than one-half of the patients required oxygen supplementation after admission. In-hospital mortality (13.2%) and the death rate at 1 year postevent (24.6%) were higher than data reported from immunocompetent patients. We also observed high rates of acute cardiovascular events and events occurring 1 year after admission. Early blood cultures and bronchoscopy in the first 24 h significantly increased the odds of establishing an etiology. In our low-resistance setting, the burden of antimicrobial resistance was driven by bacteria from chronically colonized patients, mostly lung transplant recipients.

INTERPRETATION

This comprehensive analysis highlights the high morbidity associated with CAP after transplantation. It also emphasizes the need for prospective multicenter studies to guide evidence-based practices and improve outcomes for these vulnerable patients.

Focus on Pneumonia After Organ Transplantation: Is There a Need for Specific Medical Care in the Emergency Department?

BACKGROUND

Pneumonia is a major cause of hospitalization and has a substantial impact on health care costs. Diagnosis and treatment of pneumonia in solid organ transplant (SOT) patients remain a challenge for clinicians in the emergency department. This study aimed to evaluate demographic features, clinical patterns, history of hospitalization, and diagnosis of adult patients after organ(s) transplantation (liver, kidney, pancreas) with severe pneumonia requiring hospitalization. The aim is to determine whether patients undergoing SOT receive or require specific care and whether they need to be prioritized.

METHOD

This was a single-center observational study of adult patients after SOT with severe pneumonia requiring hospitalization. The data set for the analysis included only patients with pneumonia as the main reason for hospitalization. The diagnosis of pneumonia was suspected based on the American Thoracic Society criteria.

RESULTS

The study revealed that the standard of care for patients with a history of SOT did not significantly differ from care provided to the non-SOT patients with pneumonia admitted to the same hospital during a 94-week period.

CONCLUSION

There were notable differences, such as post-transplant patients being transferred more quickly to the hospital ward, having longer hospital stays, and receiving antibiotics earlier than the non-SOT group.

Monocentric, Retrospective Study on Infectious Complications within One Year after Solid-Organ Transplantation at a Belgian University Hospital

The epidemiology, diagnostic methods and management of infectious complications after solid-organ transplantation (SOT) are evolving. The aim of our study is to describe current infectious complications in the year following SOT and risk factors for their development and outcome. We conducted a retrospective study in adult SOT recipients in a Belgian university hospital between 2018 and 2019. We gathered demographic characteristics, comorbidities leading to transplantation, clinical, microbiological, surgery-specific and therapeutic data concerning infectious episodes, and survival status up to one year post-transplantation. Two-hundred-and-thirty-one SOT recipients were included (90 kidneys, 79 livers, 35 lungs, 19 hearts and 8 multiple organs). We observed 381 infections in 143 (62%) patients, due to bacteria (235 (62%)), viruses (67 (18%)), and fungi (32 (8%)). Patients presented a median of two (1-5) infections, and the first infection occurred during the first six months. Nineteen (8%) patients died, eleven (58%) due to infectious causes. Protective factors identified against developing infection were obesity [OR [IC]: 0.41 [0.19-0.89]; p = 0.025] and liver transplantation [OR [IC]: 0.21 [0.07-0.66]; p = 0.007]. Risk factors identified for developing an infection were lung transplantation [OR [IC]: 6.80 [1.17-39.36]; p = 0.032], CMV mismatch [OR [IC]: 3.53 [1.45-8.64]; p = 0.006] and neutropenia [OR [IC]: 2.87 [1.27-6.47]; p = 0.011]. Risk factors identified for death were inadequate cytomegalovirus prophylaxis, infection severity and absence of pneumococcal vaccination. Post-transplant infections were common. Addressing modifiable risk factors is crucial, such as pneumococcal vaccination.

Infection-Related Hospitalizations After Simultaneous Pancreas-Kidney Transplantation Compared to Kidney Transplantation Alone

The total burden of infections after transplantation has not been compared in detail between recipients of simultaneous pancreas-kidney transplantation (SPK) and kidney transplantation alone (KTA). We compared infection-related hospitalizations and bacteremias after transplantation during 1- and 5-year follow-up among 162 patients undergoing SPK. The control group consisted of 153 type 1 diabetics undergoing KTA with the inclusion criteria of donor and recipient age < 60, and BMI < 30. During the first year, SPK patients had more infection-related hospitalizations (0.54 vs. 0.31 PPY, IRR 1.76, p = <0.001) and bacteremias (0.11 vs. 0.01 PPY, IRR 17.12, p = <0.001) compared to KTA patients. The first infection-related hospitalizations and bacteremias occurred later during follow-up in KTA patients. SPK was an independent risk factor for infection-related hospitalization and bacteremia during the first year after transplantation, but not during the 5-year follow-up. Patient survival did not differ between groups, however, KTA patients had inferior kidney graft survival. SPK patients are at greater risk for infection-related hospitalizations and bacteremias during the first year after transplantation compared to KTA patients, however, at the end of the follow-up the risk of infection was similar between groups.

Association between Hospital-Acquired Pneumonia and In-Hospital Mortality in Solid Organ Transplant Admissions: An Observational Analysis in Spain, 2004-2021

(1) Background: To analyze the association between hospital-acquired pneumonia (HAP) and in-hospital mortality (IHM) during hospital admission for solid organ transplant in Spain during 2004-2021. (2) Methods: We used national hospital discharge data to select all hospital admissions for kidney, liver, heart, and lung transplants. We stratified the data according to HAP status. To examine time trends, we grouped data into three consecutive 6-year periods (2004-2009; 2010-2015; and 2016-2021). We assessed in-hospital mortality (IHM) in logistic regression analyses and obtained odds ratios (ORs) with their 95% confidence intervals (CIs). (3) Results: We identified a total of 71,827 transplants (45,262, kidney; 18,127, liver; 4734, heart; and 4598, lung). Two thirds of the patients were men. Overall, the rate of HAP during admission was 2.6% and decreased from 3.0% during 2004-2009 to 2.4% during 2016-2021. The highest rate of HAP corresponded to lung transplant (9.4%), whereas we found the lowest rate for kidney transplant (1.1%). Rates of HAP for liver and heart transplants were 3.8% and 6.3%, respectively. IHM was significantly lower during 2016-2021 compared to 2004-2009 for all types of transplants (ORs (CIs) = 0.65 (0.53-0.79) for kidney; 0.73 (0.63-0.84) for liver; 0.72 (0.59-0.87) for heart; and 0.39 (0.31-0.47) for lung). HAP was associated with IHM for all types of transplants (ORs (CIs) = 4.47 (2.85-9.08) for kidney; 2.96 (2.34-3.75) for liver; 1.86 (1.34-2.57) for heart; and 2.97 (2.24-3.94) for lung). (4) Conclusions: Rates of HAP during admission for solid organ transplant differ depending on the type of transplant. Although IHM during admission for solid organ transplant has decreased over time in our country, HAP persists and is associated with a higher IHM after accounting for potential confounding variables.

Patients with transplantation have reduced mortality in bacteraemia: analysis of data from a randomised trial

Objectives

Infection remains a major complication of organ transplantation. Paradoxically, epidemiological studies suggest better survival from serious infection. We analysed the relationship between organ transplantation and short -term mortality of patients with bloodstream infection.

Methods

Data on transplantation status was extracted from a large prospective, multi-centre clinical trial in bloodstream infection. Logistic regression for 28-day mortality was performed on the whole cohort and a propensity-matched cohort (3:1). Infective pathogen, focus of infection, and clinical variables were included in the model. Mediation analysis was performed on clinical variables to explore causation.

Results

4,178 participants were included in the full cohort, with 868 in the matched cohort, of which 217 received an organ transplant. Haematopoietic stem cell transplants (HSCT) were the most common transplant (n = 99), followed by kidney (n = 70). The most common pathogens were staphylococci and Enterobacterales. Transplantation status was associated with a reduced mortality in both the whole (Odds Ratio, OR 0.53; 95% CI 0.28, 0.77) and matched (OR 0.55, 95% CI 0.34, 0.90) cohort, while steroid use was robustly associated with increased mortality OR 4.4 (95% CI 3.12, 6.20) in the whole cohort and OR 5.24 (95% CI 2.79, 9.84) in the matched cohort. There was no interaction between steroid use and transplant status, so transplant patients on steroids generally had increased mortality relative to those without either.

Conclusions

Organ transplantation is associated with a near halving of short term mortality in bloodstream infection, including a cohort matched for comorbidities, infective pathogen and focus. Steroid usage is associated with increased mortality regardless of transplant status. Understanding the mechanism and causation of this mortality benefit should be a focus of future research.

Hospital-Acquired Pneumonia

Pneumonia acquired during hospitalization is called nosocomial pneumonia (NP). Nosocomial pneumonia is divided into two types. Hospital-acquired pneumonia (HAP) refers to hospital-acquired pneumonia, whereas ventilator-associated pneumonia (VAP) refers to ventilator-associated pneumonia. Most clinical literature stresses VAP’s importance and associated mortality and morbidity, whereas HAP is not given enough attention even while being the most common cause of NP. HAP, like VAP, carries a high mortality and morbidity. HAP is the commonest cause of mortality from hospital-acquired infections. HAP is a common determinant for intensive care unit (ICU) admits with respiratory failure. Recent research has identified definite risk factors responsible for HAP. If these are prevented or modified, the HAP incidence can be significantly decreased with improved clinical outcomes and lesser utilization of the health care resources. The prevention approach will need multiple strategies to address the issues. Precise epidemiological data on HAP is deficient due to limitations of the commonly used diagnostic measures. The diagnostic modalities available in HAP are less invasive than VAP. Recent infectious disease society guidelines have stressed the importance of HAP by removing healthcare-associated pneumonia as a diagnosis. Specific differences exist between HAP and VAP, which are gleaned over in this chapter.

Rapid diagnostic tests in the management of pneumonia

INTRODUCTION

Pneumonia is one of the main causes of mortality associated with infectious diseases worldwide. Several challenges have been identified in the management of patients with pneumonia, ranging from accurate and cost-effective microbiological investigations, prompt and adequate therapeutic management, and optimal treatment duration.

AREAS COVERED

In this review, an updated summary on the current management of pneumonia patients is provided and the epidemiological issues of infectious respiratory diseases, which in the current pandemic situation are of particular concern, are addressed. The clinical and microbiological approaches to pneumonia diagnosis are reviewed, including discussion about the new molecular assays pointing out both their strengths and limitations. Finally, the current recommendations about antibiotic treatment are examined and discussed depending on the epidemiological contexts, including those with high prevalence of multidrug-resistant bacteria.

EXPERT OPINION

We claim that rapid diagnostic tests, if well-positioned in the diagnostic workflow and reserved for the subset of patients who could most benefit from these technologies, may represent an interesting and feasible tool to optimize timing of targeted treatments especially in terms of early de-escalation or discontinuation of antibiotic therapy.

Distinct Clinical and Laboratory Patterns of Pneumocystis jirovecii Pneumonia in Renal Transplant Recipients

Late post-transplant Pneumocystis jirovecii pneumonia (PcP) has been reported in many renal transplant recipients (RTRs) centers using universal prophylaxis. Specific features of PcP compared to other respiratory infections in the same population are not well reported. We analyzed clinical, laboratory, administrative and radiological data of all confirmed PcP cases between January 2009 and December 2014. To identify factors specifically associated with PcP, we compared clinical and laboratory data of RTRs with non-PcP. Over the study period, 36 cases of PcP were identified. Respiratory distress was more frequent in PcP compared to non-PcP (tachypnea: 59%, 20/34 vs. 25%, 13/53, p = 0.0014; dyspnea: 70%, 23/33 vs. 44%, 24/55, p = 0.0181). In contrast, fever was less frequent in PcP compared to non-PcP pneumonia (35%, 11/31 vs. 76%, 42/55, p = 0.0002). In both cohorts, total lymphocyte count and serum sodium decreased, whereas lactate dehydrogenase (LDH) increased at diagnosis. Serum calcium increased in PcP and decreased in non-PcP. In most PcP cases (58%, 21/36), no formal indication for restart of PcP prophylaxis could be identified. Potential transmission encounters, suggestive of interhuman transmission, were found in 14/36, 39% of patients. Interhuman transmission seems to contribute importantly to PcP among RTRs. Hypercalcemia, but not elevated LDH, was associated with PcP when compared to non-PcP.

Short-term experiences of a liver transplant centre before and after the COVID-19 pandemic

BACKGROUND/AIM

With the COVID-19 pandemic, managing the process of solid organ transplantation has become a significant matter for transplant centres. In this study, we report our experiences on evaluating the effects of COVID-19 in patients with recent liver transplants.

MATERIALS AND METHODS

We evaluated patients who received liver transplants during three close consecutive periods of time. For transplants conducted between October 1 and December 31, 2019, January 1 and March 10, 2020 and March 11 and June 22, 2020, the lung tomographies of patients were inspected for radiological signs of viral pneumonia. For patients after March 11, 2020, the hospital's electronic database system was scanned for preoperative and postoperative SARS-CoV-2 testing from Real-time Polymerase Chain Reaction (RT-PCR) of the respiratory tract samples.

RESULTS

A total of 149 patients over the age of 18 who received liver transplants at our centre between October 1, 2019 and June 22, 2020 were evaluated. During this time span, our centre conducted liver transplants on patients from 34 different provinces and also abroad. Within this time period, a total of nine patients had respiratory samples with a positive SARS-CoV-2 RT-PCR test. PCR of respiratory tract samples was performed in 21 (14%) patients to identify the other potential infective agents in the respiratory tracts; Rhinovirus and Influenza A were detected in two and respiratory syncytial virus (RSV) was detected in one patient. During the transplant periods, 99 (67.1%) patients were evaluated with computed tomography (CT). The CT findings of 18 (12%) patients were consistent with viral pneumonia. There was a statistically significant difference between the groups only in terms of air bronchogram findings (P = .012).

CONCLUSION

The clinical status of our short-term liver transplant patients was far better than we originally anticipated, but it remains obvious that the necessary precautions should continue to be taken.

Posttransplant Pneumonia Among Solid Organ Transplant Recipients Followed in Intensive Care Unit

OBJECTIVES

Pneumonia is a significant cause of morbidity and mortality in solid-organ transplant recipients. We studied the demographic characteristics, respiratory management, and outcomes of solid-organ transplant recipients with pneumonia in an intensive care unit.

MATERIALS AND METHODS

There have been 2857 kidney, 687 liver, and 142 heart transplants performed between October 16, 1985, and February 28, 2021, at our center. We retrospectively analyzed records for 51 of 193 recipients with pneumonia during the posttransplant period between January 1, 2016, and December 31, 2018.

RESULTS

Fifty-one of 193 recipients were followed in the intensive care unit. Mean age was 45.4 ± 16.6 years among 42 male (82.4%) and 9 female (17.6%) recipients. Twenty-six patients (51%) underwent kidney transplant, 14 (27.5%) liver transplant, 7 (13.7%) heart transplant, and 4 (7.8%) combined kidney and liver transplant. Most pneumonia episodes occurred 6 months after transplant (70.6%) with acute hypoxemic respiratory failure. Mean Acute Physiology and Chronic Health Evaluation System II score was 18.9 ± 7.7, and the Sequential Organ Failure Assessment score was 8.5 ± 3.9 at intensive care unit admission. Whereas 66.7% of pneumonia cases were nosocomial acquired, 33.3% were community acquired. The intensive care unit and 28-day mortality rates were 39.2% and 64.7%, respectively.

CONCLUSIONS

Solid-organ transplant recipients with pneumonia have been associated with poor prognosis. Our cohort followed in the intensive care unit comprised mostly patients with nosocomial pneumonia with acute hypoxemic respiratory failure, hospitalized 6 months after transplant with high Acute Physiology and Chronic Health Evaluation System II scores predictive of mortality. In this high-risk patient group, careful follow-up, early discovery of warning signs, and rapid treatment initiation could improve the outcomes in the intensive care unit.

Pneumococcal pneumonia in adult hospitalised solid organ transplant recipients: Nationwide, population-based surveillance

BACKGROUND

Pneumococcal disease poses a burden to the community in high risk population. Most early studies focused on invasive pneumococcal disease. However, the epidemiology of pneumococcal pneumonia (PP) requiring hospitalisation in solid organ transplant recipients (SOTRs) is poorly defined.

METHODS

We conducted a retrospective cohort study (January 1, 2000 and December 31, 2012) to evaluate the risk of PP requiring hospitalisation in SOTRs. SOTRs and non-SOT cohorts, propensity score-matched at a 1:1 ratio for age, sex, index date and underlying comorbidities, were identified from the National Health Insurance Research Database.

RESULTS

Each cohort consisted of 7507 patients. In the SOT cohort, 26 episodes of PP requiring hospitalisation were identified (incidence rate of 52.4 per 100,000 person-years). The risk of PP requiring hospitalisation in the SOT cohort was 1.50 times greater than in the non-SOT cohort [adjusted hazard ratio: 1.50, 95% confidence interval = 1.31-1.71, P < .001]. The nested case control study identified older age, kidney transplant, and concomitant chronic obstructive pulmonary disease, chronic kidney disease and heart failure as predictors of PP requiring hospitalisation in the SOT cohort. The highest risk period for PP requiring hospitalisation occurred within the first year of transplantation (36.47 per 1000 patients). Amongst kidney transplant recipients, patients with PP requiring hospitalisation exhibited higher cumulative incidences of graft failure than those without PP (log-rank test: P value = .004).

CONCLUSIONS

SOTRs are at risk of PP requiring hospitalisation with its attendant morbidity. Strategies to reduce risk of PP requiring hospitalisation using preventive vaccinations warrant further study.

Fungal pneumonia in kidney transplant recipients

Fungal pneumonia is a dreaded complication encountered after kidney transplantation, complicated by increased mortality and often associated with graft failure. Diagnosis can be challenging because the clinical presentation is non-specific and diagnostic tools have limited sensitivity and specificity in kidney transplant recipients and must be interpreted in the context of the clinical setting. Management is difficult due to the increased risk of dissemination and severity, multiple comorbidities, drug interactions and reduced immunosuppression which should be applied as an important adjunct to therapy. This review will focus on the main causes of fungal pneumonia in kidney transplant recipients including Pneumocystis, Aspergillus, Cryptococcus, mucormycetes and Histoplasma. Epidemiology, clinical presentation, laboratory and radiographic features, specific characteristics will be discussed with an update on diagnostic procedures and treatment.

High mortality associated with gram-negative bacterial bloodstream infection in liver transplant recipients undergoing immunosuppression reduction

BACKGROUND

Immunosuppression is an important factor in the incidence of infections in transplant recipient. Few studies are available on the management of immunosuppression (IS) treatment in the liver transplant (LT) recipients complicated with infection. The aim of this study is to describe our experience in the management of IS treatment during bacterial bloodstream infection (BSI) in LT recipients and assess the effect of temporary IS withdrawal on 30 d mortality of recipients presenting with severe infection.

AIM

To assess the effect of temporary IS withdrawal on 30 d mortality of LT recipients presenting with severe infection.

METHODS

A retrospective study was conducted with patients diagnosed with BSI after LT in the Department of Liver Surgery, Renji Hospital from January 1, 2016 through December 31, 2017. All recipients diagnosed with BSI after LT were included. Univariate and multivariate Cox regression analysis of risk factors for 30 d mortality was conducted in the LT recipients with Gram-negative bacterial (GNB) infection.

RESULTS

Seventy-four episodes of BSI were identified in 70 LT recipients, including 45 episodes of Gram-positive bacterial (GPB) infections in 42 patients and 29 episodes of GNB infections in 28 patients. Overall, IS reduction (at least 50% dose reduction or cessation of one or more immunosuppressive agent) was made in 28 (41.2%) cases, specifically, in 5 (11.9%) cases with GPB infections and 23 (82.1%) cases with GNB infections. The 180 d all-cause mortality rate was 18.5% (13/70). The mortality rate in GNB group (39.3%, 11/28) was significantly higher than that in GPB group (4.8%, 2/42) (P = 0.001). All the deaths in GNB group were attributed to worsening infection secondary to IS withdrawal, but the deaths in GPB group were all due to graft-versus-host disease. GNB group was associated with significantly higher incidence of intra-abdominal infection, IS reduction, and complete IS withdrawal than GPB group (P < 0.05). Cox regression showed that rejection (adjusted hazard ratio 7.021, P = 0.001) and complete IS withdrawal (adjusted hazard ratio 12.65, P = 0.019) were independent risk factors for 30 d mortality in patients with GNB infections after LT.

CONCLUSION

IS reduction is more frequently associated with GNB infection than GPB infection in LT recipients. Complete IS withdrawal should be cautious due to increased risk of mortality in LT recipients complicated with BSI.

IS

Infectious Complications in Lung Transplant Recipients

Lung transplantation is a lifesaving intervention for patients with advanced lung disease. Due to a combination of immunosuppression, continuous exposure of the lungs to the environment, and complications at the anastomotic sites, lung transplant recipients are at high risk for infectious complications. The aim of this review is to summarize recent developments in the field of infectious diseases as it pertains to lung transplant recipients.

Identification of Streptococcus pneumoniae in hospital-acquired pneumonia in adults

Hospital-acquired pneumonia (HAP) is often more severe and life-threatening than community-acquired pneumonia (CAP). The role of Streptococcus pneumoniae in CAP is well-understood, but its role in HAP is unclear. The objective of this study was to summarize the available literature on the prevalence of S. pneumoniae in HAP episodes. We searched MEDLINE for peer-reviewed articles on the microbiology of HAP in individuals aged ≥18 years, published between 2008 and 2018. We calculated pooled estimates of the prevalence of S. pneumoniae in episodes of HAP using a random-effects, inverse-variance-weighted meta-analysis. Forty-seven of 1908 articles met the inclusion criteria. Bacterial specimen isolation techniques for microbiologically defined HAP episodes included bronchoalveolar lavage, protective specimen brush, tracheobronchial aspirate and sputum, as well as blood culture. Culture was performed in all studies; five studies also used urine antigen detection (5/47; 10.6%). S. pneumoniae was identified in 5.1% (95% confidence interval (CI): 3.8-6.6%) of microbiologically defined HAP episodes (N = 20), with 5.4% (95% CI: 4.3-6.7%, N = 29) in ventilator-associated HAP and 6.0% (95% CI: 4.1-8.8%, N = 6) in non-ventilator-associated HAP. S. pneumoniae was identified in 5.3% (95% CI: 4.5-6.3%) of HAP occurring in the intensive care unit (ICU, N = 41) and in 5.6% (95% CI: 3.3-9.5%, N = 5) outside the ICU. A higher proportion of early-onset HAP (10.3%; 95% CI: 8.3-12.8%, N = 16) identified S. pneumoniae as compared with late-onset HAP (3.3%; 95% CI: 2.5-4.4%, N = 16). In conclusion, S. pneumoniae was identified by culture in 5.1% of microbiologically defined HAP episodes. The importance of HAP as part of the disease burden caused by S. pneumoniae merits further research.

Infections in Lung Transplant Recipients during and after Prophylaxis

Background

The timeline of infections after lung transplantation has been changed with the introduction of new immunosuppressants and prophylaxis strategies. The study aimed to investigate the epidemiological characteristics of infectious diseases after lung transplantation in the current era.

Materials and Methods

All patients who underwent lung or heart–lung transplantation at our institution between October 29, 2008 and April 3, 2019 were enrolled. We retrospectively reviewed the patients' medical records till April 2, 2020.

Results

In total, 100 consecutive lung transplant recipients were enrolled. The median follow-up period was 28 months after lung transplantation. A total of 127 post–lung transplantation bacterial infections occurred. Catheter-related bloodstream infection (25/84, 29.8%) was the most common within 6 months and pneumonia (23/43, 53.5%) was the most common after 6 months. Most episodes (35/40, 87.5%) of respiratory viral infections occurred after 6 months, mainly as upper respiratory infections. The remaining episodes (5/40, 12.5%) mostly manifested as lower respiratory tract infections. Seventy cytomegalovirus infections observed in 43 patients were divided into 23 episodes occurring before and 47 episodes occurring after discontinuing prophylaxis. Of 10 episodes of cytomegalovirus disease, four occurred during prophylaxis and six occurred after prophylaxis. Of 23 episodes of post–lung transplantation fungal infection, 7 were aspergillosis and all occurred after the discontinuation of prophylaxis.

Conclusion

Lung transplant recipients experienced a high burden of infection even after 6 months, especially after the end of the prophylaxis period. Therefore, these patients should be continued to be monitored long-term for infectious disease.

Epidemiology and successful containment of a carbapenem-resistant Enterobacteriaceae outbreak in a Southern Italian Transplant Institute

INTRODUCTION

Carbapenem-resistant enterobacteriaceae (CRE) infections are difficult to treat and pose a serious threat to solid organ transplant (SOT) recipients. At our institute we observed an infection burden in 2012.

METHODS

In order to contain the spread of CRE infections, we established a taskforce to implement guidelines suggested by the Centers for Disease Control and Prevention (CDC) for this type of outbreak. Here, we describe the epidemiology of the outbreak in our SOT population, and the effectiveness of such interventions, by comparing levels of CRE hospital-acquired infection (HAI) pre- and post-task force intervention (from January 2009 to December 2012, and from September 2013 to December 2016, respectively) through a linear regression model.

RESULTS

In this study, we included 933 patients who underwent a total of 1017 SOT procedures, 286 of whom had a CRE-positive culture (28.8%), of which 65 (22.7% of CRE positive) developed infection. One-year mortality post-SOT was significantly higher in patients with CRE infection. After the taskforce intervention, the CRE HAI rate in SOT showed a significant inverse trend (event rate: -1.28, CI -1.70 to 0.86; P < 0.01).

CONCLUSION

In the paucity of treatment options, the application of CDC measures in our SOT institute contributed significantly to containing CRE infections.

Pneumonia in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the AST Infectious Diseases Community of Practice review the diagnosis and management of pneumonia in the post-transplant period. Clinical presentations and differential diagnosis for pneumonia in the solid organ transplant recipient are reviewed. A two-tier approach is proposed based on the net state of immunosuppression and the severity of presentation. With a lower risk of opportunistic, hospital-acquired, or exposure-specific pathogens and a non-severe presentation, empirical therapy may be initiated under close clinical observation. In all other patients, or those not responding to the initial therapy, a more aggressive diagnostic approach including sampling of tissue for microbiological and pathological testing is warranted. Given the broad range of potential pathogens, a microbiological diagnosis is often key for optimal care. Given the limited literature comparatively evaluating diagnostic approaches to pneumonia in the solid organ transplant recipient, much of the proposed diagnostic algorithm reflects clinical experience rather than evidence-based data. It should serve as a template which may be modified according to local needs. The same holds true for the suggested empiric therapies, which need to be adapted to the local resistance patterns. Further study is needed to comparatively evaluate diagnostic and empiric treatment strategies in SOT recipients.

Is hospital-acquired pneumonia different in transplant recipients?

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are serious complications in transplant patients. The aim of this review is to summarize the evidence regarding nosocomial pneumonia in transplant recipients, including HAP in non-ventilated patients and VAP, and to identify future directions for improvement.A comprehensive literature search in the PubMed/MEDLINE database was performed. Articles written in English and published between 1990 and November 2018 were included. HAP/VAP in transplant patients usually occurs early post-transplant, particularly during neutropenia in haematopoietic stem cell transplant recipients. Bacteria are the leading cause of nosocomial pneumonia for both immunocompetent and transplant recipients, being Gram negative organisms, and especially Pseudomonas aeruginosa, highly prevalent. Multidrug-resistant bacteria are of special concern. Pneumonia in the transplant setting may be caused by opportunistic pathogens, and the differential diagnosis needs to be extended to other non-infectious complications. The most relevant opportunistic pathogens are Aspergillus fumigatus, Pneumocystis jirovecii and cytomegalovirus. Nevertheless, they are an exceptional cause of nosocomial pneumonia, and usually occur in severely immunosuppressed patients not receiving antimicrobial prophylaxis. Performing bronchoalveolar lavage may improve the rate of aetiological diagnosis, leading to a change in therapeutic management and improved outcomes. The optimal length of antibiotic therapy for bacterial HAP/VAP has not been well defined, but it should perhaps be longer than in the general population. Mortality associated with HAP/VAP is high. HAP/VAP in transplant patients is frequent and is associated with increased mortality. There is room for improvement in gaining knowledge about the management of HAP/VAP in this population.

Indian Antimicrobial Prescription Guidelines in Critically Ill Immunocompromised Patients

How to cite this article: Kulkarni AP, Sengar M, Chinnaswamy G, Hegde A, Rodrigues C, Soman R, Khilnani GC, Ramasubban S, Desai M, Pandit R, Khasne R, Shetty A, Gilada T, Bhosale S, Kothekar A, Dixit S, Zirpe K, Mehta Y, Pulinilkunnathil JG, Bhagat V, Khan MS, Narkhede AM, Baliga N, Ammapalli S, Bamne S, Turkar S, Bhat KV, Choudhary J, Kumar R, Divatia JV. Indian Journal of Critical Care Medicine 2019;23(Suppl 1): S64-S96.

Patients immunodéprimés, quel pathogène pour quel déficit immunitaire ? (en dehors de l’infection à VIH)

Le nombre de patients immunodéprimés ne cesse d’augmenter en raison de l’amélioration du pronostic global du cancer et de l’utilisation croissante d’immunosuppresseurs tant en transplantation qu’au cours des maladies auto-immunes. Les infections sévères restent la première cause d’admission en réanimation dans cette population et sont dominées par les atteintes respiratoires. On distingue les déficits primitifs, volontiers révélés dans l’enfance, des déficits secondaires (médicamenteux ou non), les plus fréquents. Dans tous les cas, les sujets sont exposés à des infections inhabituelles de par leur fréquence, leur type et leur sévérité. À côté des pyogènes habituels, les infections opportunistes et la réactivation d’infections latentes font toute la complexité de la démarche diagnostique. Celle-ci doit être rigoureuse, orientée par le type de déficit, les antécédents, les prophylaxies éventuelles et la présentation clinicoradiologique. Elle permettra seule de guider le traitement probabiliste et les examens étiologiques, l’absence de diagnostic étant associée à une mortalité élevée.

Management of immunosuppressive therapy in liver transplant recipients who develop bloodstream infection

BACKGROUND

Data about the optimal management of immunosuppressive therapy in liver transplant (LT) recipients with bloodstream infection (BSI) are missing. We aimed to describe the management of immunosuppressive therapy at diagnosis of BSI in LT recipients and to assess its impact on 28-day mortality.

METHODS

We performed a single-center retrospective study of all LT recipients diagnosed with BSI, over 10-year period. Multivariate Cox regression analysis of risk factors for all cause 28-day mortality was adjusted for the propensity score of being managed with "any reduction" in immunosuppressive therapy at the diagnosis of BSI.

RESULTS

We identified 209 episodes of BSI in 157 LT recipients: 107 (68%) male, median age 54 (IQR 48-63) years. "Any reduction" was made in 90 (43%) cases including: dosage reduction of ≥1 immunosuppressive drug in 31 (15%), discontinuation of ≥1 immunosuppressive drug in 28 (13%), both dosage reduction and discontinuation in 13 (6%), complete withdrawal of immunosuppressive therapy in 18 (9%) cases. All-cause 28-day mortality rate was 13.4%, varying from 22% to 7% (P = .002) in cases with and without "any reduction". Cox regression showed septic shock (aHR 3.15, P = .007) and "any reduction" (aHR 2.50, P = .02) as independent risk factors for all-cause 28-day mortality, while Escherichia coli (aHR 0.38, P = .03) and source control (aHR 0.43, P = .04) were protective factors. The final model did not change after the introduction of the propensity score for "any reduction".

CONCLUSIONS

Any reduction in the immunosuppressive therapy was common and was associated with worse outcome in LT recipients developing BSI.

Utility of Mean Platelet Volume to Diagnose Pneumonia in Patients With Solid-Organ Transplant

OBJECTIVES

Despite improved success with solid-organ transplant procedures, recipients remain at risk for infections, including pneumonia, due to their immunosuppressive regimens. In solid-organ transplant patients, clinical findings of pneumonia can be nonspecific, and diagnosis of pneumonia may be difficult as several conditions (drug lung, hypervolemia, infections, hemorrhage) can led to pulmonary infiltrates, mimicking pneumonia in these patients. The role of mean platelet volume, a predictor of inflammatory disease, with elevated values inversely correlated with inflammatory problems, in the diagnosis of pneumonia has not yet been investigated in solid-organ transplant patients. Here, we retrospectively investigated mean platelet volume in diagnosis of pneumonia in transplant patients.

MATERIALS AND METHODS

Medical records of solid-organ transplant patients from 2011 to 2016 were reviewed for demographic, clinical, radiographic, laboratory, and microbiology data. Transplant type, immunosuppressive drugs, and clinical outcomes were noted. Pneumonia diagnosis was based on clinical respiratory symptoms and signs, imaging findings, positive microbiological tests, pathologic findings, laboratory findings, or effective clinical treatment trials.

RESULTS

Our study included 70 patients (47 male/23 female; mean age of 46 ± 14 years), comprising 26 liver and 44 renal transplant recipients. Pneumonia was diagnosed radiologically in 30 patients (42.9%), with procalcitonin positive in 11 patients (36.7%), C-reactive protein elevated in 29 patients (96.7%), and leukocytes increased in 6 patients (20%). When laboratory measurements were compared with mean platelet volume, mean platelet volume values were significantly lower in patients with pneumonia who had elevated procalcitonin levels (P = .038).

CONCLUSIONS

We found that mean platelet volume for diagnosis of pneumonia in solid-organ transplant patients was not a promising tool. Considering the difficulties in caring for transplant patients with pulmonary infiltrates, clinical decisions should be based on clinical, laboratory, microbiological, and radiologic findings.

Burden of pneumococcal community-acquired pneumonia in adults across Europe: A literature review

BACKGROUND

The burden of community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae (pneumococcus) among adults in Europe is poorly defined.

METHODS

Structured searches of PubMed were conducted to identify the incidence of pneumococcal CAP among adults across Europe.

RESULTS

The overall incidence rates for CAP was 68-7000 per 100,000 and the incidence in hospitalised CAP cases of all causes was 16-3581 per 100,000. In general the incidence of CAP increased consistently with age. Available data indicated higher burdens of pneumococcal CAP caused in groups with more comorbidities. Most cases of pneumococcal CAP (30%-78%) were caused by serotypes covered by PCV13 vaccine; the incidence of PCV13-related pneumonia decreased after the introduction of childhood vaccination.

CONCLUSIONS

We observed a high burden adult pneumococcal CAP in Europe despite use of the 23-valent pneumococcal polysaccharide vaccine, particularly in elderly patients with comorbidities. CAP surveillance presented wide variations across Europe. Pneumococcal CAP has to be monitored very carefully due to the possible effect of current vaccination strategies.

Infections in liver and lung transplant recipients: a national prospective cohort

Infections are a major complication of solid organ transplants (SOTs). This study aimed to describe recipients' characteristics, and the frequency and etiology of infections and transplant outcome in liver and lung SOTs, and to investigate exposures associated to infection and death in liver transplant recipients. The study population included recipients of SOTs performed in Italy during a 1-year period in ten Italian lung transplant units and eight liver transplant units. Data on comorbidities, infections, retransplantation, and death were prospectively collected using a web-based system, with a 6-month follow-up. The cumulative incidence of infection was 31.7% and 47.8% in liver and lung transplants, respectively, with most infections occurring within the first month after transplantation. Gram-negatives, which were primarily multidrug-resistant, were the most frequent cause of infection. Death rates were 0.42 per 1000 recipient-days in liver transplants and 1.41 per 1000 recipient-days in lung transplants. Infection after SOT in adult liver recipients is associated to an increased risk of death (OR = 13.25; p-value < 0.001). Given the frequency of infection caused by multidrug-resistant microorganisms in SOT recipients in Italy and the heavy impact of infections on the transplant outcome, the reinforcement of surveillance and control activities to prevent the transmission of multidrug-resistant microorganisms in SOT recipients represents a priority. The implementation of the study protocol in liver and lung transplant units and the sharing of results have increased the awareness about the threat due to antimicrobial resistance in the country.

Antibiotic-Resistant Infections and Treatment Challenges in the Immunocompromised Host

This article reviews antibiotic resistance and treatment of bacterial infections in the growing number of patients who are immunocompromised: solid organ transplant recipients, the neutropenic host, and persons with human immunodeficiency virus and AIDS. Specific mechanisms of resistance in both gram-negative and gram-positive bacteria, as well as newer treatment options are addressed elsewhere, and are only briefly discussed in the context of the immunocompromised host.

Solid organ transplant patients: are there opportunities for antimicrobial stewardship?

OBJECTIVE

Rising incidence of Clostridium difficile and multidrug-resistant organisms' infections and a dwindling development of new antimicrobials are an impetus for antimicrobial stewardship in organ transplant recipients. We sought to understand antimicrobial prescribing practices and identify opportunities for interdisciplinary collaboration among the transplant, antimicrobial stewardship, and infectious diseases teams.

METHODS

In 2013, two assessors conducted four real-time audits on all antimicrobial therapy in transplant patients, assessing each regimen against stewardship principles established by the Centers for Disease Prevention and Control, supplemented by applicable transplant-specific infection guidelines. Chi-square test was used to compare stewardship-concordant and stewardship-discordant audit results relative to transplant infectious diseases consultation.

RESULTS

Analysis was performed on 176 audits. Fifty-eight percent (103/176) received at least one antimicrobial, of which 69.9% (72/103) were stewardship-concordant. Infections were confirmed or suspected in 52.3% (92/176). Of those, 98.9% (91/92) received antimicrobials, and 41.8% (38/91) were prescribed by transplant clinicians. Infectious diseases consultation was associated with more stewardship-concordant prescriptions (78.5% vs. 59.6%, p = 0.03). The most common stewardship-discordant categories were lack of de-escalation, empiric antimicrobial spectrum being too broad, and therapy duration being too long.

CONCLUSIONS

Opportunities exist for antimicrobial stewardship in transplant recipients, especially those who do not require infectious diseases consultation.

Approach to the Solid Organ Transplant Patient with Suspected Fungal Infection

In solid organ transplant (SOT) recipients, invasive fungal infections (IFIs) are associated with significant morbidity and mortality. Detection of IFIs can be difficult because the signs and symptoms are similar to those of viral or bacterial infections, and diagnostic techniques have limited sensitivity and specificity. Clinicians must rely on knowledge of the patient's risk factors for fungal infection to make a diagnosis. The authors describe their approach to the SOT recipient with suspected fungal infection. The epidemiology of IFIs in the SOT population is reviewed, and a syndromic approach to suspected IFI in SOT recipients is described.

Pleural effusion as the initial clinical presentation in disseminated cryptococcosis and fungaemia: an unusual manifestation and a literature review

BACKGROUND

Cryptococcus neoformans infection usually presents as chronic meningitis and is increasingly being recognized in immunocompromised patients. Presentation with pleural effusion is rare in cryptococcal disease; in fact, only 4 cases of pleural effusion as the initial clinical presentation in cryptococcosis have been reported in English-language literature to date. We report the first case of pleural effusion as the initial clinical presentation in a renal transplant recipient who was initially misdiagnosed with tuberculous pleuritis but who then developed fungaemia and disseminated cryptococcosis. The examination of this rare manifestation and the accompanying literature review will contribute to increased recognition of the disease and a reduction in misdiagnoses.

CASE PRESENTATION

We describe a 63-year-old male renal transplant recipient on an immunosuppressive regimen who was admitted for left pleural effusion and fever. Cytological examinations and pleural fluid culture were nonspecific and negative. Thoracoscopy only found chronic, nonspecific inflammation with fibrosis in the pleura. After empirical anti-tuberculous therapy, the patient developed an elevated temperature, a severe headache and vomiting and fainted in the ward. Cryptococci were specifically found in the cerebrospinal fluid following lumbar puncture. Blood cultures were twice positive for C. neoformans one week later. He was transferred to the respiratory intensive care unit (RICU) immediately and was placed on non-invasive ventilation for respiratory failure for 2 days. He developed meningoencephalitis and fungaemia with C. neoformans during hospitalization. He was given amphotericin B liposome combined with 5-flucytosine and voriconazole for first 11 days, then amphotericin B liposome combined with 5-flucytosine sustained to 8 weeks, after that changed to fluconazole for maintenance. His condition improved after antifungal treatment, non-invasive ventilation and other support. Further pathological consultation and periodic acid-Schiff staining revealed Cryptococcus organisms in pleural sections, providing reliable evidence for cryptococcal pleuritis.

CONCLUSION

Pleural effusion is an unusual manifestation of cryptococcosis. Cryptococcal infection must be considered in the case of patients on immunosuppressives, especially solid-organ transplant recipients, who present with pleural effusion, even if pleural fluid culture is negative. Close communication between the pathologist and the clinician, multiple special biopsy section stains and careful review are important and may contribute to decreasing misdiagnosis.

Primary Care of the Solid Organ Transplant Recipient

Solid organ transplantation (SOT) is one of the major advances in medicine. Care of the SOT recipient is complex and continued partnership with the transplant specialist is essential to manage and treat complications and maintain health. The increased longevity of SOT recipients will lead to their being an evolving part of primary care practice, with ever more opportunities for care, education, and research of this rewarding patient population. This review discusses the overall primary care management of adult SOT recipients.

An Approach to a Pulmonary Infiltrate in Solid Organ Transplant Recipients

The onset of a pulmonary infiltrate in a solid organ transplant (SOT) recipient is both a challenging diagnostic and therapeutic challenge. We outline the potential aetiologies of a pulmonary infiltrate in a SOT recipient, with particular attention paid to fungal pathogens. A diagnostic and empirical therapy approach to a pulmonary infiltrate, especially invasive fungal disease (IFD) in SOT recipients, is provided.

Pneumococcal disease in adult solid organ transplantation recipients

In solid organ transplant (SOT) recipients, Streptococcus pneumoniae can cause substantial morbidity and mortality ranging from non-invasive to invasive diseases, including pneumonia, bacteremia, and meningitis, with a risk of invasive pneumococcal disease 12 times higher than that observed in non-immunocompromised patients. Moreover, pneumococcal infection has been related to graft dysfunction. Several factors have been involved in the risk of pneumococcal disease in SOT recipients, such as type of transplant, time since transplantation, influenza activity, and nasopharyngeal colonization. Pneumococcal vaccination is recommended for all SOT recipients with 23-valent pneumococcal polysaccharides vaccine. Although immunological rate response is appropriate, it is lower than in the rest of the population, decreases with time, and its clinical efficacy is variable. Booster strategy with 7-valent pneumococcal conjugate vaccine has not shown benefit in this population. Despite its relevance, there are few studies focused on invasive pneumococcal disease in SOT recipients. Further studies addressing clinical, microbiological, and epidemiological data of pneumococcal disease in the transplant setting as well as new strategies for improving the protection of SOT recipients are warranted.