Tissue and blood protozoa including toxoplasmosis, Chagas disease, leishmaniasis, Babesia, Acanthamoeba, Balamuthia, and Naegleria in solid organ transplant recipients- Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

Prophylaxis against Pneumocystis jirovecii pneumonia and toxoplasmosis with low-dose Trimethoprim-sulfamethoxazole (cotrimoxazole 20/100 mg) in heart transplant patients. The PAPTO-LOCO observational comparative study

OBJECTIVES

Practice concerning post-transplant Pneumocystis prophylaxis remains heterogeneous. SXT benefits must be balanced with frequent toxicity. We aimed to assess whether a low-dose SXT strategy might limit toxicities while maintaining an undisrupted prophylaxis compared with a standard dose in a retrospective cohort of heart transplant population.

METHODS

Patients undergoing heart transplant from two distinct centres, receiving daily SXT 20/100 mg versus daily SXT 80/400 mg between 2018 and 2020, were retrospectively included in the study. Demographic, immunosuppression and survival characteristics were collected to ensure group comparability. The occurrence of adverse effects and the rate of SXT discontinuation were compared between the two groups.

RESULTS

Overall, 359 patients were recruited in the study, 108 patients for the standard-dose group and 251 patients for the low-dose group. The leading cause of prophylaxis discontinuation was cytopenia. We observed significantly more discontinuation in the standard-dose compared with the low-dose group (24.1% and 6.4%, respectively, P < 0.001). No patient with ongoing prophylaxis presented Pneumocystis pneumonia or toxoplasmosis during the 2-year follow-up. Two Pneumocystis infections in the low-dose group occurred during prophylaxis breaks. The rate of toxoplasmosis seroconversion was similar in both groups.

CONCLUSIONS

This retrospective study suggests that a low-dose SXT Pneumocystis prophylaxis strategy might offer a more favourable safety/efficacy profile than standard-dose prophylaxis after heart transplantation. These results should be confirmed in an interventional trial. Caution remains for toxoplasmosis serology D+/R- profiles.

Reactivation of Chagas Disease in the Central Nervous System Among Heart Transplant Recipients: A Clinical Series From Brazil, 2006-2023

BACKGROUND

Chagas disease is a relevant cause of heart transplantation. The risk of reactivation is a potential concern. This study aimed to describe the reactivation of Trypanosoma cruzi in the central nervous system (CNS).

METHODS

We performed a retrospective study of all heart transplants for Chagas disease undertaken between 2006 and 2023 at a single institution in Brazil to define the prevalence of neurological reactivation and reviewed clinical characteristics and outcomes associated with CNS T. cruzi involvement.

RESULTS

Among 187 Chagas disease recipients, 11 episodes of neurologic reactivation were identified in nine patients, at a median of 160 days after transplant. Two patients had a relapse more than a year after the first episode. Three patients died and the remaining six had neurological sequelae. Of the 11 episodes of CNS reactivation, eight were confirmed based on finding T. cruzi parasites or DNA in cerebrospinal fluid or brain tissue biopsy, the remaining three episodes were considered probable by demonstrating parasites in blood and other tissues. Focal neurological manifestations (8 of 11 episodes) and a single lesion with the predominant involvement of white matter (6 of 11 episodes) were the most common features. Brain biopsy was the gold standard tool, detecting five of seven CNS reactivation. T. cruzi PCR in cerebrospinal fluid confirmed two of three cases, and direct examination has a low diagnostic yield, detecting only one of six episodes.

CONCLUSION

Neurological Chagas reactivation is a rare and severe posttransplant complication that should be considered in any at-risk heart recipient.

Diagnostic Approach to Pneumonia in Immunocompromised Hosts

In immunocompromised patients, pneumonia presents a diagnostic challenge due to diverse etiologies, nonspecific symptoms, overlapping radiological presentation, frequent co-infections, and the potential for rapid progression to severe disease. Thus, timely and accurate diagnosis of all pathogens is crucial. This narrative review explores the latest advancements in microbiological diagnostic techniques for pneumonia in immunocompromised patients. It covers major available microbiological tools for diagnosing both community-acquired and hospital-acquired pneumonia, encompassing a wide spectrum of pathogens including bacterial, viral, fungal, and parasitic. While traditional culture methods remain pivotal in identifying many pneumonia-causing etiologies, their limitations in sensitivity and time to results have led to the rise of non-invasive antigen tests and molecular diagnostics. These are increasingly employed alongside cultures and microscopy for more efficient diagnosis, mainly in viral and fungal infections. Lastly, we report the future of pneumonia diagnostics, exploring the potential of metagenomics and CRISPR/Cas13a for more precise and rapid pathogen detection in immunocompromised populations.

Serological Profile of Anti-Toxoplasma gondii Antibodies in Liver Transplant Recipients

Toxoplasma gondii (T. gondii), a globally distributed obligatory intracellular opportunistic parasite that has infected one third of the world population, has different transmission routes including via organ transplantation. The liver has emerged as a frequent transplanted organ in which the transmission of T. gondii can occur between seropositive donors and seronegative recipients. Allied with immunosuppressive therapy, the presence of latent infection in recipients elevates the risk of severe toxoplasmosis. The goal of this study was to evaluate the demographic, clinical, epidemiological, and anti-T. gondii antibody profiles in liver transplant recipients. All demographic, clinical, epidemiological, and serological data were obtained from the electronic medical records of liver transplant recipients from the Liver Transplantation Service of the Hospital de Base in São José do Rio Preto, Brazil, from 2008 to 2018. Data from 48 eligible recipients (females: n = 17; males: n = 31) were evaluated. The recipients were grouped according to their T. gondii serological profiles (G1: IgM-/IgG-; G2: IgM-/IgG+; G3: IgM+/IgG+; G4: IgM+/IgG-). The overall mean age was 55.3 (±15.3) years; the age difference between women (42.7 ± 17 years) and men (62.2 ± 10.9 years) was statistically significant (p-value > 0.0001). The percentages of the serological profiles were 20 (n = 41.7%), 26 (n = 54.1%), and 2 (n = 4.2%) for G1, G2, and G3, respectively. No recipient had a serological profile for G4. Hepatosplenomegaly (47.9%), fever (35.4%), encephalopathy (20.8%), and headache (16.7%) were commonly observed symptoms. No statistically significant differences were observed between the serological group and clinical data (p-value = 0.953). The percentages of coinfection by T. gondii with hepatitis A, B, and C were 47.9%, 20.8%, and 12.5%, respectively. About 41.7% of the recipients later died. The data demonstrate that infection by T. gondii is common in liver transplant recipients, and it is not associated with the analyzed demographic, clinical, and epidemiological data.

Alternative Pneumocystis Pneumonia Prophylaxis in Solid Organ Transplants

BACKGROUND

Despite limited data supporting use in solid organ transplant (SOT) recipients, atovaquone and dapsone are often used as alternatives to trimethoprim-sulfamethoxazole (TMP-SMX) for Pneumocystis jirovecii pneumonia (PJP) prophylaxis.

METHODS

This single-center, retrospective cohort study describes a multi-organ program's experience with alternative PJP prophylaxis. Adult SOT recipients transplanted November 13, 2020 to November 13, 2022 who received non-TMP-SMX PJP prophylaxis and had > 1 year follow-up were included.

RESULTS

Among 953 SOTs performed, 333 (34.9%) recipients received alternative PJP prophylaxis (319 [95.8%] atovaquone and 14 [4.2%] dapsone). Alternative prophylaxis was initiated in 76 (22.8%) recipients without starting TMP-SMX, mostly due to sulfa allergy (62, 81.6%). In 257 recipients who started TMP-SMX, common reasons for switching to alternatives were hyperkalemia (105, 40.9%) and leukopenia (77, 30.0%). While 79.8% of recipients had these adverse effects resolve, only 27.3% resumed TMP-SMX. Tolerance was high after resumption (85.7%). Barriers to accessing alternative prophylaxis included cost (25, 7.5%) and prior authorizations (26, 7.8%). There was one case of severe disseminated toxoplasmosis, one case of Nocardia infection, and no cases of PJP.

CONCLUSION

Alternative PJP prophylaxis carries risk of breakthrough infection and barriers to initiation. Since most recovered from adverse effects of TMP-SMX and tolerated resumption, providers should re-trial TMP-SMX when feasible.

Evaluation of the Incidence of Nocardia Infection in Solid Organ Transplant Recipients on Trimethoprim-Sulfamethoxazole for Opportunistic Infection Prophylaxis

BACKGROUND

Trimethoprim-sulfamethoxazole (TMP-SMX) is the preferred prophylactic agent for Pneumocystis jiroveci pneumonia (PJP) and toxoplasmosis after solid organ transplant (SOT). Compared with other agents, it has additional activity against Nocardia species.

OBJECTIVE

The purpose of this study was to evaluate the incidence of Nocardia infection in SOT patients receiving TMP-SMX or an alternative agent for opportunistic infection (OI) prophylaxis.

METHODS

This retrospective analysis included transplant recipients at a large urban medical center over a period of 4 years. All patients received either TMP-SMX or an alternative agent for PJP prophylaxis. The primary outcome was the incidence of Nocardia infection within 24 months posttransplant. Secondary outcomes included resistance rates of Nocardia isolates, usage rates of alternative prophylactic agents, reasons for using alternative agents, and rate of conversion from an alternative agent back to TMP-SMX.

RESULTS

A total of 791 adult SOT recipients who received PJP or toxoplasmosis prophylaxis were included. Mean age at transplantation was 60.9 years with the majority of patients being male (67.3%) lung transplant recipients (63.6%). TMP-SMX was the most commonly used initial prophylactic agent (84.6%), followed by atovaquone (15.4%). Of the 791 SOT recipients, 16 (2.0%) were diagnosed with nocardiosis within 24 months posttransplant. Patients receiving alternative agents had a higher incidence of infection compared with those receiving TMP-SMX prophylaxis (P < 0.001).

CONCLUSION AND RELEVANCE

Our findings suggest that OI prophylaxis with TMP-SMX may be protective against nocardiosis in SOT recipients. If possible, patients who are switched to an alternative agent due to TMP-SMX intolerance should be re-challenged when the adverse effect resolves. Most patients in our study were able to tolerate re-initiation, suggesting that the adverse effects associated with TMP-SMX may be temporary and may not warrant discontinuation.

Minimizing risk while maximizing opportunity: The infectious disease organ offer process survey

BACKGROUND

The purpose of this study was to understand how transplant infectious disease (TID) physicians assess a potential donor with known or suspected infection and describe posttransplant management.

METHODS

We designed a survey of 10 organ offer scenarios and asked questions pertaining to organ acceptability for transplantation and management posttransplant. The survey was distributed to TID clinicians via transplant society listservs and email. Responses were recorded in REDCap, and descriptive statistics were employed.

RESULTS

One hundred thirteen infectious disease physicians responded to the survey, of whom 85 completed all cases. Respondents were generally in agreement regarding organ acceptability, although some divergence was seen when evaluating lungs from donors with influenza, tuberculosis, or multidrug-resistant Acinetobacter infection. Posttransplant management showed more variation. Areas of optimization were identified: (1) Further understanding of where risk-mitigation strategies within the donor offer process may improve donor acceptability and therefore organ utilization; (2) importance of recipient considerations in assessing degree of infectious risk; and (3) gaps in evidenced-based data regarding optimal posttransplant management of recipients.

CONCLUSION

Evaluation of donor offers by TID clinicians is a complex process. Although the survey does not itself serve to make recommendations regarding best practices, it highlights areas where generation of data to inform acceptance and management practices may allow for improved organ utilization and recipient management.

Chagas disease in the immunocompromised host

PURPOSE OF REVIEW

To highlight recent advances in our understanding of Trypanosoma cruzi infection in immunocompromised individuals, a condition that is increasingly recognized as populations shift and use of immunosuppressive medications becomes more commonplace.

RECENT FINDINGS

Chagas disease screening programs should include people at risk for both Chagas disease and immunocompromise, e.g. people who have resided for ≥6 months in endemic Latin America who have an immunocompromising condition such as HIV or who are planned to start an immunosuppressive medication regimen. The goal of identifying such individuals is to allow management strategies that will reduce their risk of T. cruzi reactivation disease. For people with HIV- T. cruzi coinfection, strict adherence to antiretroviral therapy is important and antitrypanosomal treatment is urgent in the setting of symptomatic reactivation. People at risk for T. cruzi reactivation due to immunosuppression caused by advanced hematologic conditions or postsolid organ transplantation should be monitored via T. cruzi qPCR and treated with preemptive antitrypanosomal therapy if rising parasite load on serial specimens indicates reactivation. Reduction of the immunosuppressive regimen, if possible, is important.

SUMMARY

Chronic Chagas disease can lead to severe disease in immunocompromised individuals, particularly those with advanced HIV (CD4 + < 200 cells/mm 3 ) or peri-transplantation.

Infectious Disease Prophylaxis During and After Immunosuppressive Therapy

Immune-mediated renal diseases are a diverse group of disorders caused by antibody, complement, or cell-mediated autosensitization. Although these diseases predispose to infection on their own, a growing array of traditional and newer, more targeted immunosuppressant medications are used to treat these diseases. By understanding their mechanisms of action and the infections associated with suppression of each arm of the immune system, nephrologists can better anticipate these risks and effectively prevent and recognize opportunistic infections. Focusing specifically on nonkidney transplant recipients, this review discusses the infections that can be associated with each of the commonly used immunosuppressants by nephrologists and suggest interventions to prevent infectious complications in patients with immune-mediated renal disease.

Chagas disease in immunocompromised patients

SUMMARYAs Chagas disease remains prevalent in the Americas, it is important that healthcare professionals and researchers are aware of the screening, diagnosis, monitoring, and treatment recommendations for the populations of patients they care for and study. Management of Trypanosoma cruzi infection in immunocompromised hosts is challenging, particularly because, regardless of antitrypanosomal treatment status, immunocompromised patients with Chagas disease are at risk for T. cruzi reactivation, which can be lethal. Evidence-based practices to prevent and manage T. cruzi reactivation vary depending on the type of immunocompromise. Here, we review available data describing Chagas disease epidemiology, testing, and management practices for various populations of immunocompromised individuals, including people with HIV and patients undergoing solid organ and hematopoietic stem cell transplantation.

Interesting case from Argentina: Kidney transplant recipient with skin lesions-A Latin American perspective

This is a case of a kidney transplant recipient who presented with skin lesions, low-grade fevers, and pancytopenia 2 months after his transplant.

Skin and soft tissue infections in solid organ transplants

PURPOSE OF REVIEW

Skin and soft tissue infections (SSTI) in solid organ transplant (SOT) recipients may be a great challenge for clinicians caring for SOT due to the involvement of both common and opportunistic pathogens associated with a blunted immune response. The purpose of this review is to outline current literature and describe open issues on the management of SSTI in this special population.

RECENT FINDINGS

Clinical presentation in SOT recipients can manifest as isolated skin lesions after primary inoculation or be the sign of a disseminated infection. Tissue samples for microscopy and histopathology are crucial to making an accurate diagnosis given the nonspecific and heterogeneous appearance of skin lesions. Multidisciplinary teams are required for a comprehensive diagnosis and management.

SUMMARY

SSTI are frequent contributors to morbidity and mortality in SOT. Specific research focused on the clinical presentation, risk factors and management in this special population is needed.

Pre-Transplantation Strategies for Infectious Disease Mitigation and Prevention

Pediatric Infectious Disease (ID) clinicians play a critical role in helping prevent and mitigate infectious risks in children peri- and post-transplantation. Prevention starts during the pre-transplant evaluation and persists throughout the solid organ transplant and hematopoietic cell transplant continuum. The pre-transplant evaluation is an opportunity to screen for latent infections, plan preventative strategies, optimize immunizations, and discuss risk mitigation practices. An ideal pre-transplant evaluation establishes a relationship with the family that further promotes post-transplant infectious risk reduction. This manuscript builds on shared pediatric ID prevention strategies, introduces updated ID testing recommendations for transplant donors/candidates, highlights emerging data, and identifies ongoing knowledge gaps that are potential areas of research.

Pet safety guidelines for pediatric transplant recipients

Approximately 70% (90.5 million) of United States (US) households own at least one pet. Dogs are the most common, making up about 38% of all household pets, followed by cats, which make up 25%. Other pets such as fish, birds, reptiles, and small animals such as hamsters, gerbils, and rabbits are less common household members. Pets are often considered a part of the family and there are significant medical and psychosocial benefits to pet ownership; however, the possibility of disease transmission exists related to the type of animal and infectious organism, and specific human risk factors. Immunocompromised individuals may be at increased risk of serious illness from zoonotic infections. During the transplant evaluation and routinely posttransplant, the multidisciplinary team should inquire about pet ownership and animal exposures to guide on potential risks. This review discusses the most common diseases seen in various household pets including dogs, cats, birds, fish, and some farm animals. We will also present guidelines for pet safety and include strategies to decrease the risk of infection while supporting the benefits of pet ownership after transplant.

The etiological spectrum of multiple ring-enhancing lesions of the brain: a systematic review of published cases and case series

OBJECTIVE

Multiple ring-enhancing lesions of the brain are enigmatic neuroimaging abnormality. In this systematic review, we evaluated the etiological spectrum of these lesions.

METHODS

This systematic review adhered to the PRISMA guidelines. We searched PubMed, Embase, Scopus, and Google Scholar up until 15 June 2023. We included case reports and case series. Quality evaluation of each case was based on selection, ascertainment, causality, and reporting. The extracted information included demographic characteristics, clinical features, type and number of multiple enhancing brain lesions, diagnostic procedures, final diagnoses, treatments, and patient outcomes.

PROTOCOL REGISTRATION

PROSPERO CRD42023437081.

RESULTS

We analyzed 156 records representing 161 patients, 60 of whom were immunocompromised. The mean age was 42.6 years, and 67% of patients experienced symptoms for up to 1 month. A higher proportion of immunocompromised patients (42% vs. 30%) exhibited encephalopathy. Chest or CT thorax abnormalities were reported in 27.3% of patients, while CSF abnormalities were found in 31.7%, more frequently among the immunocompromised. Definitive diagnoses were established via brain biopsy, aspiration, or autopsy in 60% of cases, and through CSF examination or other ancillary tests in 40% of cases. Immunocompromised patients had a higher incidence of Toxoplasma gondii infection and CNS lymphoma, while immunocompetent patients had a higher incidence of Mycobacterium tuberculosis infection and immune-mediated and demyelinating disorders. The improvement rate was 74% in immunocompetent patients compared to 52% in the immunocompromised group.

CONCLUSION

Multiple ring-enhancing lesions of the brain in immunocompromised patients are more frequently caused by Toxoplasma gondii infections and CNS lymphoma. Conversely, among immunocompetent patients, Mycobacterium tuberculosis infection and immune-related demyelinating conditions are common.

Identification of asymptomatic Leishmania infection in patients undergoing kidney transplant using multiple tests

OBJECTIVES

In immunocompromised patients, asymptomatic Leishmania infection can reactivate, and evolve to severe disease. To date, no test is considered the gold standard for the identification of asymptomatic Leishmania infection. A combination of methods was employed to screen for Leishmania infection in patients undergoing kidney transplant (KT).

METHODS

We employed polymerase chain reaction for the detection of parasitic DNA in peripheral blood, Western blot to identify serum immunoglobulin G and whole blood assay to detect cytokines/chemokines after stimulation of whole blood with parasitic antigen.

RESULTS

One-hundred twenty patients residing in Italy were included in the study at the time of KT. Each patient that tested positive to at least one test was considered as Leishmania positive. Fifty out of 120 patients (42%) tested positive for one or more tests. The detection of specific cell-mediated response (32/111, 29%) was the most common marker of Leishmania infection, followed by a positive serology (24/120, 20%). Four patients (3%) harbored parasitic DNA in the blood.

CONCLUSION

Our findings underline the high prevalence of asymptomatic Leishmania infection in patients undergoing KT in Italy, who are potentially at-risk for parasite reactivation and can benefit from an increased vigilance. Understanding the clinical relevance of these findings deserves further studies.

Trypanosoma cruzi Reactivation After Chimeric Antigen Receptor T-Cell Therapy

https://tidbitapp.io/tidbits/trypanosoma-cruzi-reactivation-post-chimeric-antigen-receptor-t-cell-therapy/update.

Trypanosoma cruzi Central Nervous System Infection-Pathogenesis, Clinical Manifestations, Diagnosis, and Treatment

Purpose of Review

Chagas disease (CD) is a neglected tropical disease from the American continent that commonly causes cardiovascular disease. Some patients develop neurological manifestations. We discuss and summarize the pathogenesis, clinical characteristics, diagnosis, and treatment of the central nervous system manifestations of CD.

Recent Findings

Cerebrospinal fluid quantitative polymerase chain reaction tests and next-generation sequencing in tissue samples have facilitated disease diagnosis and follow-up. Novel presentations, including retinitis, are now reported. A new MRI sign called "Bunch of açai berries appearance"-multiple hypointense nodular lesions-has been described recently. Treatment with benznidazole at higher doses and the role of therapeutic drug monitoring need to be further studied in this setting.

Summary

A high suspicion index is paramount to diagnosing Chagas' central nervous system involvement. Standardized molecular diagnostics can aid in the initial workup. Future development of new therapeutic drugs is crucial because of the toxicity profile of the currently available medications.

Parasitic infections in hematopoietic stem cell transplant recipients

INTRODUCTION

Hematopoietic stem cell transplantation (HSCT) is a vital treatment for various hematological disorders. However, HSCT recipients face increased risks of infectious complications due to immunosuppression. Parasitic infections are a significant concern in this vulnerable population and can lead to substantial morbidity and mortality. This review examines parasitic infections in HSCT recipients, focusing on major infections affecting different organ systems, including intestinal parasites (Giardia spp., Entamoeba histolytica, and Cryptosporidium spp.), hematologic parasites (Plasmodium spp. and Babesia spp.), and tissue/visceral parasites (Toxoplasma gondii, Leishmania spp., and Trypanosoma cruzi).

METHODS

A systematic search of relevant literature was conducted and included studies up to August 2023. Databases included PubMed, Google Scholar, were queried using specific keywords related to parasitic infections in HSCT patients. The epidemiology, risk factors, clinical presentation, diagnostic methods, and treatment approaches for each infection were evaluated.

RESULTS AND CONCLUSION

Knowing the epidemiology, risk factors, and clinical presentations are crucial for timely intervention and successful management. By emphasizing early detection, effective therapies, and the unique challenges posed by each of these infections, this review highlights the importance of tailored strategies for HSCT recipients. Future research can further refine management protocols to enhance care and outcomes for these patients.

Approach to suspected donor-derived infections

Prevention of donor-derived disease among pediatric solid organ transplant recipients requires judicious risk-benefit assessment. Comprehensive guidelines outline specific donor risk factors and post-transplant monitoring strategies to prevent and mitigate transmission of HIV, hepatitis B, and hepatitis C. However, elimination of unanticipated donor-derived infections remains challenging. The objectives of this review are to (1) define risk of anticipated vs. unanticipated disease transmission events in pediatric solid organ transplant recipients; (2) discuss donor presentations that confer greater risk of unanticipated disease transmission; (3) develop a matrix for consideration of donor acceptance; and (4) discuss limitations and future directions for donor screening. Although solid organ transplant confers inherent risk of infection transmission, the risk of significant disease transmission events may be mitigated by a comprehensive approach including donor assessment, consideration of recipient need, post-transplant monitoring, and early intervention.

South Asian Transplant Infectious Disease Guidelines for Solid Organ Transplant Candidates, Recipients, and Donors

These guidelines discuss the epidemiology, screening, diagnosis, posttransplant prophylaxis, monitoring, and management of endemic infections in solid organ transplant (SOT) candidates, recipients, and donors in South Asia. The guidelines also provide recommendations for SOT recipients traveling to this region. These guidelines are based on literature review and expert opinion by transplant physicians, surgeons, and infectious diseases specialists, mostly from South Asian countries (India, Pakistan, Bangladesh, Nepal, and Sri Lanka) as well as transplant experts from other countries. These guidelines cover relevant endemic bacterial infections (tuberculosis, leptospirosis, melioidosis, typhoid, scrub typhus), viral infections (hepatitis A, B, C, D, and E; rabies; and the arboviruses including dengue, chikungunya, Zika, Japanese encephalitis), endemic fungal infections (mucormycosis, histoplasmosis, talaromycosis, sporotrichosis), and endemic parasitic infections (malaria, leishmaniasis, toxoplasmosis, cryptosporidiosis, strongyloidiasis, and filariasis) as well as travelers' diarrhea and vaccination for SOT candidates and recipients including travelers visiting this region. These guidelines are intended to be an overview of each topic; more detailed reviews are being published as a special supplement in the Indian Journal of Transplantation .

The Medical Relevance of Toxoplasma Infections in Terms of the Safety of Blood Recipients under Immunosuppression-A Meta-Analysis

Laboratory diagnosis of Toxoplasma gondii infection plays a crucial role in ensuring the safety of blood recipients, especially in the case of immunosuppressed people, such as organ transplant patients. Toxoplasmosis, caused by the parasite Toxoplasma gondii, is a potential threat to people with weakened immune systems, and blood transfusions from infected donors can lead to severe complications. In this publication, we analyze the medical relevance of Toxoplasma infection in the context of the safety of blood recipients, focusing on the immunosuppressed patient population. We present various diagnostic methods, such as serological, molecular, and microscopic tests, which can detect the presence of Toxoplasma gondii in donors' blood. We also discuss the importance of adequately interpreting diagnostic results, considering risk factors, and detectability of the infection. We pay special attention to high-sensitivity and -specificity diagnostic techniques, which allow us to minimize the risk of Toxoplasma gondii transmission to blood recipients. Our findings have important implications for clinical practice and organ transplantation guidelines, emphasizing the need to diagnose and monitor Toxoplasma infections in blood donors and recipients.

Revisiting the Evidence Base for Modern-Day Practice of the Treatment of Toxoplasmic Encephalitis: A Systematic Review and Meta-Analysis

BACKGROUND

Toxoplasmic encephalitis (TE) is an opportunistic infection of people with human immunodeficiency virus (HIV) or other causes of immunosuppression. Guideline-recommended treatments for TE are pyrimethamine and sulfadiazine (P-S) or pyrimethamine and clindamycin (P-C); however, a substantial price increase has limited access to pyrimethamine. Consequently, some centers have transitioned to trimethoprim-sulfamethoxazole (TMP-SMX), an inexpensive alternative treatment. We aimed to review the evidence on the efficacy and safety of pyrimethamine-containing therapies vs TMP-SMX.

METHODS

We searched for and included randomized controlled trials (RCTs) and observational studies of TE treatments, regardless of HIV status. Data for each therapy were pooled by meta-analysis to assess the proportions of patients who experienced clinical and radiologic responses to treatment, all-cause mortality, and discontinuation due to toxicity. Sensitivity analyses limited to RCTs directly compared therapies.

RESULTS

We identified 6 RCTs/dose-escalation studies and 26 single-arm/observational studies. Identified studies included only persons with HIV, and most predated modern antiretroviral treatment. Pooled proportions of clinical and radiologic response and mortality were not significantly different between TMP-SMX and pyrimethamine-containing regimens (P > .05). Treatment discontinuation due to toxicity was significantly lower in TMP-SMX (7.3%; 95% confidence interval [CI], 4.7-11.4; I2 = 0.0%) vs P-S (30.5%; 95% CI, 27.1-34.2; I2 = 0.0%; P < .01) or P-C (13.7%; 95% CI, 9.8-18.8; I2 = 32.0%; P = .031). These results were consistent in analyses restricted to RCT data.

CONCLUSIONS

TMP-SMX appears to be as effective and safer than pyrimethamine-containing regimens for TE. These findings support modern RCTs comparing TMP-SMX to pyrimethamine-based therapies and a revisiting of the guidelines.

Chagas Disease

Chagas disease, which is caused by infection with the parasite Trypanosoma cruzi, is a leading neglected tropical disease in the United States. An estimated 240 000 to 350 000 persons in the United States are infected, primarily immigrants from Mexico, Central America, and South America, where the disease is endemic. The parasite is transmitted by the triatomine bug but can also be passed through blood transfusion, via organ transplant, or congenitally. Approximately 30% of infected persons later develop cardiac and/or gastrointestinal complications. Health care providers should consider screening at-risk patients with serologic testing. Early diagnosis and treatment with benznidazole or nifurtimox can help prevent complications.

Prevention, diagnosis, and management of donor derived infections in pediatric kidney transplant recipients

Donor derived infections (DDIs) in pediatric kidney transplant recipients remain challenging to diagnose and can result in serious morbidity and mortality. This review summarizes the current guidelines and recommendations for prevention, diagnosis, and treatment of unexpected DDIs in pediatric kidney transplant recipients. We provide a contemporary overview of DDI terminology, surveillance, epidemiology, and recommended approaches for assessing these rare events with an emphasis on the pediatric recipient. To address prevention and risk mitigation, important aspects of donor and pediatric candidate evaluations are reviewed, including current Organ Procurement and Transplantation Network (OPTN) and American Society of Transplantation (AST) recommendations. Common unexpected DDI encountered by pediatric transplant teams including multi-drug resistant organisms, tuberculosis, syphilis, West Nile Virus, toxoplasmosis, Chagas disease, strongyloidiasis, candidiasis, histoplasmosis, coccidioidomycosis, and emerging infections such as COVID-19 are discussed in detail. Finally, we consider the general challenges with management of DDIs and share our experience with a novel application of next generation sequencing (NGS) of microbial cell-free DNA that will likely define a future direction in this field.

Transplantation for chagas' disease: closing the knowledge gap

PURPOSE OF THE REVIEW

This review examines the most recent literature on the epidemiology and treatment of Chagas Disease and the risk of Chagas Disease Reactivation and donor-derived disease in solid organ transplant recipients.

RECENT FINDINGS

Chagas disease is caused by infection with the parasite Trypansoma cruzi . In nonendemic countries the disease is seen primarily in immigrants from Mexico, Central America and South America where the disease is endemic. Benznidazole or nifurtimox can be used for treatment. Posaconazole and fosravuconazole did not provide any additional benefit compared to benznidazole alone or in combination. A phase 2 randomized controlled trial suggests that shorter or reduced dosed regimes of benznidazole could be used. Based on a large randomized controlled trial, benznidazole is unlikely to have a significant preventive effect for established Chagas cardiomyopathy. Transplantation has become the treatment of choice for individuals with refractory Chagas cardiomyopathy. Cohort studies show similar posttransplant outcomes for these patients compared to other indications. Transplant candidates and donors with chronic T. cruzi infection are at risk for Chagas disease reactivation and transmitting infection. Screening them via serology is the first line of prevention. Recipients with chronic infection and those receiving organs from infected donors should undergo sequential monitoring with polymerase chain reaction for early detection of reactivation and preemptive treatment with antitrypanosomal therapy.

SUMMARY

Patients with chronic T. cruzi infection can be safely transplanted and be noncardiac organ donors.

Worldwide Control and Management of Chagas Disease in a New Era of Globalization: a Close Look at Congenital Trypanosoma cruzi Infection

Population movements have turned Chagas disease (CD) into a global public health problem. Despite the successful implementation of subregional initiatives to control vectorial and transfusional Trypanosoma cruzi transmission in Latin American settings where the disease is endemic, congenital CD (cCD) remains a significant challenge. In countries where the disease is not endemic, vertical transmission plays a key role in CD expansion and is the main focus of its control. Although several health organizations provide general protocols for cCD control, its management in each geopolitical region depends on local authorities, which has resulted in a multitude of approaches. The aims of this review are to (i) describe the current global situation in CD management, with emphasis on congenital infection, and (ii) summarize the spectrum of available strategies, both official and unofficial, for cCD prevention and control in countries of endemicity and nonendemicity. From an economic point of view, the early detection and treatment of cCD are cost-effective. However, in countries where the disease is not endemic, national health policies for cCD control are nonexistent, and official regional protocols are scarce and restricted to Europe. Countries of endemicity have more protocols in place, but the implementation of diagnostic methods is hampered by economic constraints. Moreover, most protocols in both countries where the disease is endemic and those where it is not endemic have yet to incorporate recently developed technologies. The wide methodological diversity in cCD diagnostic algorithms reflects the lack of a consensus. This review may represent a first step toward the development of a common strategy, which will require the collaboration of health organizations, governments, and experts in the field.

Toxoplasmosis: Current and Emerging Parasite Druggable Targets

Toxoplasmosis is a prevalent disease affecting a wide range of hosts including approximately one-third of the human population. It is caused by the sporozoan parasite Toxoplasma gondii (T. gondii), which instigates a range of symptoms, manifesting as acute and chronic forms and varying from ocular to deleterious congenital or neuro-toxoplasmosis. Toxoplasmosis may cause serious health problems in fetuses, newborns, and immunocompromised patients. Recently, associations between toxoplasmosis and various neuropathies and different types of cancer were documented. In the veterinary sector, toxoplasmosis results in recurring abortions, leading to significant economic losses. Treatment of toxoplasmosis remains intricate and encompasses general antiparasitic and antibacterial drugs. The efficacy of these drugs is hindered by intolerance, side effects, and emergence of parasite resistance. Furthermore, all currently used drugs in the clinic target acute toxoplasmosis, with no or little effect on the chronic form. In this review, we will provide a comprehensive overview on the currently used and emergent drugs and their respective parasitic targets to combat toxoplasmosis. We will also abridge the repurposing of certain drugs, their targets, and highlight future druggable targets to enhance the therapeutic efficacy against toxoplasmosis, hence lessening its burden and potentially alleviating the complications of its associated diseases.

Comprehensive Overview of Toxoplasma gondii-Induced and Associated Diseases

Toxoplasma gondii (T. gondii) is a prevalent protozoan parasite of medical and veterinary significance. It is the etiologic agent of toxoplasmosis, a neglected disease in which incidence and symptoms differ between patients and regions. In immunocompetent patients, toxoplasmosis manifests as acute and chronic forms. Acute toxoplasmosis presents as mild or asymptomatic disease that evolves, under the host immune response, into a persistent chronic disease in healthy individuals. Chronic toxoplasmosis establishes as latent tissue cysts in the brain and skeletal muscles. In immunocompromised patients, chronic toxoplasmosis may reactivate, leading to a potentially life-threatening condition. Recently, the association between toxoplasmosis and various diseases has been shown. These span primary neuropathies, behavioral and psychiatric disorders, and different types of cancer. Currently, a direct pre-clinical or clinical molecular connotation between toxoplasmosis and most of its associated diseases remains poorly understood. In this review, we provide a comprehensive overview on Toxoplasma-induced and associated diseases with a focus on available knowledge of the molecular players dictating these associations. We will also abridge the existing therapeutic options of toxoplasmosis and highlight the current gaps to explore the implications of toxoplasmosis on its associated diseases to advance treatment modalities.

Isolation and molecular identification of Acanthamoeba spp. from hospital dust and soil of Khomein, Iran, as reservoir for nosocomial infection

Background

Acanthamoeba spp. are commonest opportunistic amoebae, which ubiquitous in various environmental resources. Acanthamoeba species are the causative agents of amoebic keratitis, granulomatous amoebic encephalitis and i.e. in immunocompromised and immunocompetent patients. Moreover Acanthamoeba spp. can act as reservoir and transmission agent of bacterial pathogens. Due to this issue the aim of this study was to characterized Acanthamoeba spp. genotypes in dust and soil of hospital samples from Khomein of Iran.

Methods

In a cross sectional study, a total of 100 soil and dust samples were collected from hospital environment of Khomein Iran, and analyzed for the presence of Acanthamoeba spp. based on phenotypic and molecular methods including PCR amplification and sequence analysis of 18SrRNA. A total of 5 Acanthamoeba isolates were sequenced, and different genotypes of isolates were detected via direct sequence analysis.

Results

The results showed that 20% of samples (20/100) were positive for Acanthamoeba, while only 5 cases were successfully cultured in NNM medium and were subjected to molecular assay. A. lenticulata, A. castellanii and A. quina were the prevalent identified species that were belonged to T4 and T5 genotypes.

Conclusions

Acanthamoeba spp. are the most prevalent free living amoeba in the dust and soil of hospital environment. Moreover, due to the presence of potentially pathogenic T4 genotypes in our hospital, it is recommended that in health and hygienic programs elimination of FLA should be considered.

Central nervous system infections after solid organ transplantation

PURPOSE OF REVIEW

Significant advances to our understanding of several neuroinfectious complications after a solid organ transplant (SOT) have occurred in the last few years. Here, we review the central nervous system (CNS) infections that are relevant to SOT via a syndromic approach with a particular emphasis on recent updates in the field.

RECENT FINDINGS

A few key studies have advanced our understanding of the epidemiology and clinical characteristics of several CNS infections in SOT recipients. Risk factors for poor prognosis and protective effects of standard posttransplant prophylactic strategies have been better elucidated. Newer diagnostic modalities which have broad clinical applications like metagenomic next-generation sequencing, as well as those that help us better understand esoteric concepts of disease pathogenesis have been studied. Finally, several studies have provided newer insights into the treatment of these diseases.

SUMMARY

Recent findings reflect the steady progress in our understanding of CNS infections post SOT. They provide several avenues for improvement in the prevention, early recognition, and therapeutic outcomes of these diseases.

Endemic parasitic infections in donors and recipients of stem cell and solid organ transplants: focus on strongyloidiasis and Chagas disease

PURPOSE OF REVIEW

The aim of the article is to review recent recommendations on the management of Strongyloidiasis and Chagas disease (ChD) in the context of stem-cell or solid-organ transplantation.

RECENT FINDINGS

An update on laboratory screening, detection of acute disease or reactivation and recommended preventive or therapeutic options in the transplant recipients and donors is presented. Recent epidemiological data showing new estimates on the worldwide burden of both diseases and changes in the classical distribution around the globe should increase awareness and will impact the evaluation and management of transplant recipients and donors in endemic and nonendemic regions.

SUMMARY

Strongyloidiasis and ChD are potentially life threatening if unnoticed in the context of stem-cell or solid-organ transplantation and should be considered in endemic and nonendemic areas. Effective strategies for detection, monitoring, prevention and management are available for both diseases.

Prevention of infection and optimizing vaccination in the solid organ transplant candidate and recipient

PURPOSE OF REVIEW

Infections can result in serious complications in solid organ transplant (SOT) patients. The need to remain up to date on recommendations on screening, vaccinations, and chemoprophylaxis is paramount in the management of SOT patients. The goal of this review is to provide an overview of current recommendations for the prevention of infections and optimization of vaccinations from the pretransplant through posttransplant periods.

RECENT FINDINGS

There is an emphasis on thorough pretransplant evaluation to guide clinicians and pretransplant testing based on epidemiological and endemic risk factors. Additionally, recent studies on vaccine safety and efficacy of newer vaccine formulations in SOT recipients are addressed.

SUMMARY

This review provides insight on updated recommendations for pretransplant screening, new data on vaccine optimization in SOT recipients and posttransplant prophylaxis. Further research is needed in order to improve preventive measures including screening tests, vaccines, and chemoprophylaxis.

Experiences with Diagnosis and Treatment of Chagas Disease at a United States Teaching Hospital-Clinical Features of Patients with Positive Screening Serologic Testing

Chagas disease (CD) is the third most common parasitic infection globally and can cause cardiac and gastrointestinal complications. Around 300,000 carriers of CD live in the U.S., with about 3000 of those in Colorado. We described our experience in diagnosing CD at a Colorado teaching hospital to revise screening eligibility criteria. From 2006 to 2020, we reviewed Trypanosoma cruzi (TC) IgG serology results for 1156 patients in our institution. We identified 23 patients (1.99%) who had a positive test. A total of 14/23 (60%) of positive serologies never had confirmatory testing, and 7 of them were lost to follow up. Confirmatory testing, performed in 9 patients, resulted in being positive in 3. One additional case of CD was identified by positive tissue pathology. All four confirmed cases were among patients born in Latin America. While most of the testing for CD at our institution is part of the pretransplant screening, no confirmed cases of CD derived from this strategy. Exposure risk in this population is not always documented, and initial positive results from screening are not always confirmed. The lack of standardized screening protocols for CD in our institution contributes to underdiagnosis locally and in health systems nationwide. Given a large number of individuals in the U.S. with chronic CD, improved screening is warranted.

Transmission of malaria from donors to solid organ transplant recipients: A case report and literature review

Malaria is a febrile and potentially fatal infection. It is typically transmitted to humans through the bite of Anopheles mosquitoes and less frequently can be contracted through blood transfusions, sharing contaminated needles and syringes, mother-to-child transmission, or after solid organ transplantation. Posttransplant malaria has rarely been reported in the literature, even in endemic areas. We report the cases of three solid organ recipients in which Plasmodium vivax infection was documented during postsurgical evaluation 30 days after transplant surgery. The diagnosis of donor-derived malaria was confirmed in all patients by demonstrating Plasmodium in a peripheral blood smear and by polymerase chain reaction (PCR). All recipients had symptoms. The liver transplant recipient had myalgia, arthralgia, and thrombocytopenia; the kidney transplant recipient developed acute renal failure; and the heart transplant recipient had fever, cephalalgia, and tonic-clonic seizures. Pre-transplant screening of donors and recipients from endemic regions may not be sufficient to safely rule out persistent malaria. In Colombia, according to legislation, no mandatory testing is required for the diagnosis of malaria in organ donors in nonendemic areas. Therefore, donor screening by questionnaire is the only tool for preventing transplant-borne malaria. The migratory trend from Venezuela to Colombia has increased the number of imported cases of malaria, and the infection may be present in endemic and nonendemic regions. Although donor evaluation is not standardized in current guidelines, we suggest that donors be tested for malaria with a peripheral blood smear, detection of specific IgG antibodies against Plasmodium, and techniques such as PCR, if possible.

Leishmaniasis in the United States: Emerging Issues in a Region of Low Endemicity

Leishmaniasis, a chronic and persistent intracellular protozoal infection caused by many different species within the genus Leishmania, is an unfamiliar disease to most North American providers. Clinical presentations may include asymptomatic and symptomatic visceral leishmaniasis (so-called Kala-azar), as well as cutaneous or mucosal disease. Although cutaneous leishmaniasis (caused by Leishmania mexicana in the United States) is endemic in some southwest states, other causes for concern include reactivation of imported visceral leishmaniasis remotely in time from the initial infection, and the possible long-term complications of chronic inflammation from asymptomatic infection. Climate change, the identification of competent vectors and reservoirs, a highly mobile populace, significant population groups with proven exposure history, HIV, and widespread use of immunosuppressive medications and organ transplant all create the potential for increased frequency of leishmaniasis in the U.S. Together, these factors could contribute to leishmaniasis emerging as a health threat in the U.S., including the possibility of sustained autochthonous spread of newly introduced visceral disease. We summarize recent data examining the epidemiology and major risk factors for acquisition of cutaneous and visceral leishmaniasis, with a special focus on implications for the United States, as well as discuss key emerging issues affecting the management of visceral leishmaniasis.

Visceral Dissemination of Mucocutaneous Leishmaniasis in a Kidney Transplant Recipient

Intracellular protozoan of the genus Leishmania, endemic in the Mediterranean basin, are the cause of cutaneous (CL), mucocutaneous (MCL), and visceral leishmaniasis (VL). A 75-year-old woman was admitted nine years after a second kidney transplant (KT), due to persistent pancytopenia and fever. She presented edema and erythema of the nose in the last two years and an exophytic nodular lesion located on the left arm, with areas of peripheral necrosis and central ulceration in the last 18 months. A bone marrow biopsy revealed features compatible with Leishmania amastigotes, and polymerase chain reaction test (PCR) for Leishmania infantum was positive. Moreover, biopsy and PCR for L. infantum of the cutaneous lesion on the patient's left arm and nose and PCR from peripheral blood were positive. Thus, a diagnosis of CL, MCL, and VL was made, and liposomal amphotericin B was initiated, but the patient had an unfavorable outcome and died. This is the first report of a KT recipient presenting with the entire spectrum of leishmaniasis. In Portugal, this infection is rare-so a high degree of clinical suspicion is required for its diagnosis, especially in endemic regions, as visceral leishmaniasis is a potentially life-threatening infection.

Application of Quantitative PCR in the Diagnosis and Evaluating Treatment Efficacy of Leishmaniasis

Leishmaniasis is still a serious neglected tropical disease that may cause death in infected individuals. At present, the clinical diagnosis and treatment monitoring still rely on parasitological culture and microscopy that needs experienced technicians. The low sensitivity and inconvenience of microscopic examination could cause misdiagnosis and relapse of leishmaniasis. There is an urgent need for developing a sensitive and easily operated diagnostic method for the diagnosis and disease management of leishmaniasis. Thus, a quantitative real-time PCR (qPCR) based on the conversed regions of kinetoplast minicircle DNA (mkDNA) of Leishmania spp. was developed to detect different species of Leishmania. The designed mkDNA-based qPCR was able to detect as low as one copy of Leishmania mkDNA or DNA from single parasite. It also detected Pan-Leishmania protozoa including Leishmania donovani, Leishmania infantum and Leishmania major without cross-reaction with other pathogen DNAs available in our lab. This method was clinically applied to quantitatively detect skin lesion samples from 20 cutaneous leishmaniasis (CL) and bone marrow and/or PBMC samples from 30 current and cured visceral leishmaniasis (VL) patients, and blood samples from 11 patients with other infections and 5 normal donors as well. Total 20 skin lesion samples from current CL patients and 20 bone marrow and/or PBMC samples from current VL patients were all detected as positive with qPCR without cross-reaction with samples from patients with malaria, brucellosis and dengue or normal donors. Two VL patients with parasite converted to microscopically negative after treatment were detected positive with qPCR. The patients with bigger skin lesion in CL and higher level of immunoglobulin or splenomegaly in VL, had the higher parasite load detected by qPCR. The parasite load was significantly reduced after treatment. In conclusion, the mkDNA-based qPCR assay that we developed in this study can be used not only for diagnosis of both cutaneous and visceral leishmaniasis with high sensitivity and specificity, but also for evaluating the severity and treatment efficacy of this disease, presenting a rapid and accurate tool for clinical surveillance, treatment monitoring and the end point determination of leishmaniasis.

Aryl Quinazolinone Derivatives as Novel Therapeutic Agents against Brain-Eating Amoebae

Naegleria fowleri and Balamuthia mandrillaris are protist pathogens that infect the central nervous system, causing primary amoebic meningoencephalitis and granulomatous amoebic encephalitis with mortality rates of over 95%. Quinazolinones and their derivatives possess a wide spectrum of biological properties, but their antiamoebic effects against brain-eating amoebae have never been tested before. In this study, we synthesized a variety of 34 novel arylquinazolinones derivatives (Q1-Q34) by altering both quinazolinone core and aryl substituents. To study the antiamoebic activity of these synthetic arylquinazolinones, amoebicidal and amoebistatic assays were performed against N. fowleri and B. mandrillaris. Moreover, amoebae-mediated host cells cytotopathogenicity and cytotoxicity assays were performed against human keratinocytes cells in vitro. The results revealed that selected arylquinazolinones derivatives decreased the viability of B. mandrillaris and N. fowleri significantly (P < 0.05) and reduced cytopathogenicity of both parasites. Furthermore, these compounds were also found to be least cytotoxic against HaCat cells. Considering that nanoparticle-based materials possess potent in vitro activity against brain-eating amoebae, we conjugated quinazolinones derivatives with silver nanoparticles and showed that activities of the drugs were enhanced successfully after conjugation. The current study suggests that quinazolinones alone as well as conjugated with silver nanoparticles may serve as potent therapeutics against brain-eating amoebae.

Duffy blood group system and ocular toxoplasmosis

Duffy blood group phenotypes [Fy(a + b-), Fy(a-b+), Fy(a + b+), Fy(a-b-)], characterized by the expression of Fy^a, and Fy^b antigens, are present in red blood cells. Therefore, we hypothesize that the non-hematopoietic expression of these antigens might influence cell invasion by T. gondii. 576 consecutive patients from both genders were enrolled. The presumed OT clinical diagnosis was performed. Duffy phenotyping was performed by hemagglutination in gel columns and for the correct molecular characterization Fy(a-b-) phenotype, using PCR-RFLP. Anti-T. gondii IgG antibodies were detected by ELISA. Chi-square, Fisher's exact tests were used to compare the proportions. OT was present in 22.9% (n = 132) and absent in 77.1% (n = 444) of patients. The frequencies of anti-T. gondii IgG antibodies were higher in OT (127/132, 96.2%) than those without this disease (321/444, 72.3%) (p < .0001). None of the Duffy antigens or phenotypes were associated with T. gondii infection (χ2: 2.222, GL: 3, p = .5276) as well as the risk of OT (χ2: 0.771, GL: 3, p = .8566). Duffy blood group system phenotypes and their antigens do not constitute risk factors for infection by T. gondii infection and the development of OT.

Chagas Disease in the New York City Metropolitan Area

Background

Chagas disease, caused by the parasite Trypanosoma cruzi, once considered a disease confined to Mexico, Central America, and South America, is now an emerging global public health problem. An estimated 300 000 immigrants in the United States are chronically infected with T. cruzi. However, awareness of Chagas disease among the medical community in the United States is poor.

Methods

We review our experience managing 60 patients with Chagas disease in hospitals throughout the New York City metropolitan area and describe screening, clinical manifestations, EKG findings, imaging, and treatment.

Results

The most common country of origin of our patients was El Salvador (n = 24, 40%), and the most common detection method was by routine blood donor screening (n = 21, 35%). Nearly half of the patients were asymptomatic (n = 29, 48%). Twenty-seven patients were treated with either benznidazole or nifurtimox, of whom 7 did not complete therapy due to side effects or were lost to follow-up. Ten patients had advanced heart failure requiring device implantation or organ transplantation.

Conclusions

Based on our experience, we recommend that targeted screening be used to identify at-risk, asymptomatic patients before progression to clinical disease. Evaluation should include an electrocardiogram, echocardiogram, and chest x-ray, as well as gastrointestinal imaging if relevant symptoms are present. Patients should be treated if appropriate, but providers should be aware of adverse effects that may prevent patients from completing treatment.

Pneumocystis jirovecii and toxoplasmosis prophylaxis strategies among pediatric organ transplantation recipients: A US National Survey

There is a paucity of pediatric-specific data to guide consensus recommendations for the prevention of Pneumocystis jirovecii pneumonia (PCP) and toxoplasmosis after solid organ transplantation. We surveyed pediatric transplantation providers and found considerable variability in prophylaxis strategies, despite current guideline recommendations that are based primarily on adult data.

Novel Azoles as Antiparasitic Remedies against Brain-Eating Amoebae

Balamuthia mandrillaris and Naegleria fowleri are opportunistic protozoan pathogens capable of producing infection of the central nervous system with more than 95% mortality rate. Previously, we have synthesized several compounds with antiamoebic properties; however, synthesis of compounds that are analogues of clinically used drugs is a highly desirable approach that can lead to effective drug development against these devastating infections. In this regard, compounds belonging to the azole class possess wide range of antimicrobial properties and used clinically. In this study, six novel benzimidazole, indazole, and tetrazole derivatives were synthesized and tested against brain-eating amoebae. These compounds were tested for their amoebicidal and static properties against N. fowleri and B. mandrillaris. Furthermore, the compounds were conjugated with silver nanoparticles and characterized. The synthetic heterocyclic compounds showed up to 72% and 65% amoebicidal activities against N. fowleri and B. mandrillaris respectively, while expressing up to 75% and 70% amoebistatic activities, respectively. Following conjugation with silver nanoparticles, amoebicidal activities of the drugs increased by up to 46 and 36% versus B. mandrillaris and N. fowleri. Minimal effects were observed when the compounds were evaluated against human cells using cytotoxicity assays. In summary, azole compounds exhibited potent activity against N. fowleri and B. mandrillaris. Moreover, conjugation of the azole compounds with silver nanoparticles further augmented the capabilities of the compounds against amoebae.

Screening of donors and recipients for infections prior to solid organ transplantation

PURPOSE OF REVIEW

This review is a brief overview of current guidelines on screening donors and candidates for bacterial, fungal, parasitic and viral infections prior to solid organ transplantation. The pretransplant period is an important time to evaluate infection exposure risk based on social history as well as to offer vaccinations.

RECENT FINDINGS

One of the major changes in the past few years has been increased utilization of increased Public Health Service risk, HIV positive, and hepatitis C-positive donors. There has also been increased attention to donor and recipient risks for geographically associated infections, such as endemic fungal infections and flaviviruses.

SUMMARY

Screening for donors and candidates prior to organ transplantation can identify and address infection risks. Diagnosing infections in a timely manner can help guide treatment and additional testing. Use of necessary prophylactic treatment in organ recipients can prevent reactivation of latent infections and improve posttransplant outcomes.

What's Hot in Clinical Infectious Diseases? 2019 IDWeek Summary

The year 2019 brought about a multitude of innovations in clinical infectious diseases. With the continued rise of antimicrobial resistance (AMR), advances in diagnostics and newly available antibiotics offer additional strategies for combating this threat, but the broken antibiotic market serves as an impediment to further developments. The IDSA and other stakeholders are working to create novel pull incentives to stabilize the pipeline. Ongoing needs include developing optimal stewardship practices, including by using narrow-spectrum antibiotics and shorter durations of therapy. In the area of solid organ transplantation, early data from transplanting Hepatitis C virus (HCV)-infected organs are encouraging and the American Society of Transplantation (AST) released new guidelines addressing several key issues. Lastly, 2019 saw a resurgence in Measles emphasizing the importance of vaccination.

Diagnosis of severe respiratory infections in immunocompromised patients

An increasing number of critically ill patients are immunocompromised. Acute hypoxemic respiratory failure (ARF), chiefly due to pulmonary infection, is the leading reason for ICU admission. Identifying the cause of ARF increases the chances of survival, but may be extremely challenging, as the underlying disease, treatments, and infection combine to create complex clinical pictures. In addition, there may be more than one infectious agent, and the pulmonary manifestations may be related to both infectious and non-infectious insults. Clinically or microbiologically documented bacterial pneumonia accounts for one-third of cases of ARF in immunocompromised patients. Early antibiotic therapy is recommended but decreases the chances of identifying the causative organism(s) to about 50%. Viruses are the second most common cause of severe respiratory infections. Positive tests for a virus in respiratory samples do not necessarily indicate a role for the virus in the current acute illness. Invasive fungal infections (Aspergillus, Mucorales, and Pneumocystis jirovecii) account for about 15% of severe respiratory infections, whereas parasites rarely cause severe acute infections in immunocompromised patients. This review focuses on the diagnosis of severe respiratory infections in immunocompromised patients. Special attention is given to newly validated diagnostic tests designed to be used on non-invasive samples or bronchoalveolar lavage fluid and capable of increasing the likelihood of an early etiological diagnosis.