Endemic and opportunistic infections in Brazilian solid organ transplant recipients

Clinical characteristics and outcome analysis of pulmonary nocardiosis in southern China: a two-center retrospective study

BACKGROUND

Pulmonary nocardiosis (PN) is a rare and opportunistic infection. This study aimed to analyze clinical, radiological, and microbiological features, treatment and outcome of PN in southern china.

METHODS

Clinical, laboratory, imaging, treatment and outcome data of PN patients at two tertiary hospitals from January 1, 2018, to January 1, 2024 were collected. Factors associated with clinical outcomes were determined by multivariate logistic regression analysis.

RESULTS

67 PN patients including 53 with clinical improvement and 14 with treatment failure were enrolled. Bronchiectasis was the most common respiratory disease in patients with PN (31.3%). The major symptoms of PN were cough (89.6%) and sputum (79.1%). Lung nodules, bronchiectasis, consolidation, pleural involvement, mass, cavity, and lymph node enlargement were the frequent computed tomography findings of PN. Among the Nocardia species detected, N. farcinica was the most common pathogen. Neutrophil-to-lymphocyte ratio (OR = 1.052, p = 0.010), concurrent bacterial infection (OR = 7.706, p = 0.016), and the use of carbapenems (OR = 9.345, p = 0.023) were independently associated with poor prognosis in patients with PN.

CONCLUSIONS

This study provides important insights into the clinical features of PN in southern china. neutrophil-to-lymphocyte ratio, concurrent bacterial infection, and the use of carbapenems were independently associated with poor prognosis in patients with PN.

Descriptive study on risk of increased morbidity of schistosomiasis and graft loss after liver transplantation

Solid-organ transplantation procedures have witnessed a surge in frequency. Consequently, increased attention to associated infections and their impact on graft success is warranted. The liver is the principal target for infection by the flatworm Schistosoma mansoni. Hence, rigorous screening protocols for this parasite should be implemented for liver transplantation donors and recipients. This study investigated the risks posed by schistosomiasis-infected liver tissues for successful liver transplantation (LT), considering donors and recipients, by analyzing reported cases. Among the 43 patients undergoing LT (donors = 19; recipients = 24), 32 were infected with S. mansoni, five were infected with other Schistosoma species, and no identification was made in four patients. Reported follow-up periods ranged from 1 to 132 months, and all patients achieved successful recovery. As these helminths do not replicate in their vertebrate hosts, immunosuppressive treatment is not expected to promote increased morbidity or reactivation. Moreover, suspected or confirmed schistosomiasis infections often have a benign course, and generally, should not prevent LT. The available literature was reviewed and a provisional screening protocol has been proposed.

Clinical Characteristics and Outcomes of Endemic Mycoses After Solid Organ Transplantation: A Comprehensive Review

Background

Geographically endemic fungi can cause significant disease among solid organ transplant (SOT) recipients. We provide an update on the epidemiology, clinical presentation, and outcomes of 5 endemic mycoses in SOT recipients.

Methods

Multiple databases were reviewed from inception through May 2023 using key words for endemic fungi (eg, coccidioidomycosis or Coccidioides, histoplasmosis or Histoplasma, etc). We included adult SOT recipients and publications in English or with English translation.

Results

Among 16 cohort studies that reported on blastomycosis (n = 3), coccidioidomycosis (n = 5), histoplasmosis (n = 4), and various endemic mycoses (n = 4), the incidence rates varied, as follows: coccidioidomycosis, 1.2%-5.8%; blastomycosis, 0.14%-0.99%; and histoplasmosis, 0.4%-1.1%. There were 204 reports describing 268 unique cases of endemic mycoses, including 172 histoplasmosis, 31 blastomycosis, 34 coccidioidomycosis, 6 paracoccidioidomycosis, and 25 talaromycosis cases. The majority of patients were male (176 of 261 [67.4%]). Transplanted allografts were mostly kidney (192 of 268 [71.6%]), followed by liver (n = 39 [14.6%]), heart (n = 18 [6.7%]), lung (n = 13 [4.9%]), and combined kidney-liver and kidney-pancreas (n = 6 [2.7%]). In all 5 endemic mycoses, most patients presented with fever (162 of 232 [69.8%]) and disseminated disease (179 of 268 [66.8%]). Cytopenias were frequently reported for histoplasmosis (71 of 91 [78.0%]), coccidioidomycosis (8 of 11 [72.7%]) and talaromycosis (7 of 8 [87.5%]). Graft loss was reported in 12 of 136 patients (8.8%). Death from all-causes was reported in 71 of 267 (26.6%); half of the deaths (n = 34 [50%]) were related to the underlying mycoses.

Conclusions

Endemic mycoses commonly present with fever, cytopenias and disseminated disease in SOT recipients. There is a relatively high all-cause mortality rate, including many deaths that were attributed to endemic mycoses.

Histoplasmosis in Solid Organ Transplantation

Histoplasma capsulatum, the etiological agent for histoplasmosis, is a dimorphic fungus that grows as a mold in the environment and as a yeast in human tissues. It has a broad global distribution with shifting epidemiology during recent decades. While in immunocompetent individuals infection is usually self-resolving, solid organ transplant recipients are at increased risk of symptomatic disease with dissemination to extrapulmonary tissue. Diagnosis of histoplasmosis relies on direct observation of the pathogen (histopathology, cytopathology, and culture) or detection of antigens, antibodies, or nucleic acids. All transplant recipients with histoplasmosis warrant therapy, though the agent of choice and duration of therapy depends on the severity of disease. In the present article, we describe the pathogenesis, epidemiology, clinical manifestations and management of histoplasmosis in solid organ transplant recipients.

Echinococcosis Is Associated with the Increased Prevalence of Intestinal Blastocystis Infection in Tibetans and Host Susceptibility to the Blastocystis in Mice

Blastocystis is a common human intestinal protozoan parasite. Little is known about its prevalence in echinococcosis. This study tested whether Echinococcus multilocularis infection would increase host susceptibility to Blastocystis. A total of 114 fecal samples (68 hydatid disease patients and 46 healthy people) were collected from Tibetans in the Qinghai province in China. The presence of Blastocystis was identified by sequencing of the small subunit (SSU) rRNA gene. Balb/c mice were co-infected with Blastocystis and E. multilocularis and tested for host susceptibility to Blastocystis. The overall Blastocystis prevalence was 12.3%; 16.2% in the patients and 4.4% in healthy people (p < 0.05). Sequence analysis identified three known Blastocystis genotypes, including ST1, ST2, and ST3, and one unknown genotype. Experimental dual infection significantly reduced mouse survival rate (20%), induced more severe signs, and increased intestinal damages with a higher intestinal colonization level of Blastocystis. The mouse model showed that E. multilocularis infection increases host susceptibility to Blastocystis. Our study shows a significantly higher prevalence of Blastocystis in patients with liver echinococcosis and reveals that non-intestinal E. multilocularis infection increases host susceptibility to the Blastocystis. Our results highlight that E. multilocularis infection is associated with Blastocystis. These findings remind us that more attention should be paid to the gut health of the patients with a helminth infection during clinical patient care.

Association between Blastocystis sp. infection and immunocompromised patients: a systematic review and meta-analysis

The significance of opportunistic infections in immunocompromised patients and the enigmatic pathogenicity of Blastocystis directed us to conduct the first global systematic review and meta-analysis on Blastocystis prevalence, odds ratios (ORs), and subtypes distribution in various immunocompromised patients (HIV/AIDS, cancer and hemodialysis patients, as well as transplant recipients). The systematic searching procedure was done in Web of Science, PubMed, Scopus, and Google Scholar databases for relevant published literature until November 11, 2020. Random-effects model was utilized to calculate the weighted estimates and 95% confidence intervals (95% CIs). The computed pooled prevalence of Blastocystis inferred from 118 papers (128 datasets) on immunocompromised patients was 10.3% (95% CI: 8.7-12.2%), with 16.1% (95% CI: 11.3-22.2%), 12.5% (95% CI: 8.5-18%), 8.4% (95 % CI: 6.6-10.6%), and 6% (95% CI: 2.6-13.3%) for hemodialysis patients, cancer patients, HIV/AIDS patients, and transplant recipients, respectively. Based on 50 case-control studies (54 datasets), the highest ORs were associated with cancer [2.81 (95% CI: 1.24-6.38, P = 0.013)] and hemodialysis patients [2.78 (95% CI: 1.19-6.48, P = 0.018)]. The most frequent subtype being found in immunocompromised patients was ST3 [41.7% (95% CI: 31.4-52.7%)], followed by ST1 [31.7% (95% CI: 23.2-41.8%)] and ST2 [23.1% (95% CI: 14.8-34.1%)]. Also, the weighted frequency of Blastocystis in various subgroups (publication year, WHO regions, geographical distribution, continents, and country income) was analyzed separately. In total, the results of the present meta-analysis highlighted that one's immunodeficiency status is probably associated with an increased Blastocystis infection, underpinning strict preventive measures to be taken.

What Is the Part of Tropical Diseases Among Infectious Complications in Renal Transplant Recipients in the Amazon? A 12-Year Multicenter Retrospective Analysis in French Guiana

BACKGROUND

Infectious complications in kidney transplant recipients (KTRs) are well studied in temperate countries but remain barely known in tropical ones. The main objective of this study was to describe infection-related hospitalizations in patients living in the Amazon, where it has never been described.

METHODS

All KTRs residing in French Guiana between 2007 and 2018 were included retrospectively. Infection-related hospitalizations were collected in the main medical centers of the territory.

RESULTS

Eighty-two patients were included, and 42 were infected during the study period (51%). Eighty-seven infections were identified. The main sites of infection were urinary, in 29% of cases (25/87), and pulmonary, in 22% of cases (19/87). When documented (48/87), bacterial infections were predominant (35/48), followed by viral (8/48), fungal (4/48), and parasitic infections (1/48). Endemic so-called tropical infections accounted for 6% of infections (5/87). Histoplasma capsulatum was the most commonly isolated fungus (2/4).

CONCLUSIONS

This study suggests that the spectrum of infections in KTRs in French Guiana differs little from that of temperate countries. Nevertheless, some tropical infections are described. More studies on fungal infections in KTRs should be undertaken to clarify the weight of histoplasmosis in these patients.

Reactivation of latent infections in solid organ transplant recipients from sub-Saharan Africa: What should be remembered?

International migration from Sub-Saharan African countries to the European Union and the United States has significantly increased over the past decades. Although the vast majority of these immigrants are young and healthy people, a minority can be affected by chronic conditions eventually leading to solid organ transplantation (SOT). Importantly, these candidates can bear geographically restricted fungal and parasitic latent infections that can reactivate after the procedure. An appropriate evaluation before transplantation followed by treatment, whenever necessary, is essential to minimize such risk, as covered in the present review. In short, infection due to helminths (Schistosoma spp. and Strongyloides stercoralis) and intestinal protozoa (Entamoeba histolytica, Giardia lamblia or Cyclospora cayetanensis) can be diagnosed by multiple direct stool examination, serological assays and stool antigen testing. Leishmaniasis can be assessed by means of serology, followed by nucleic acid amplification testing (NAAT) if the former test is positive. Submicroscopic malaria should be ruled out by NAAT. Screening for Histoplasma spp. or Cryptococcus spp. is not routinely indicated. Consultation with an Infectious Diseases specialist is recommended in order to adjust preemptive treatment among Sub-Saharan African SOT candidates and recipients.

A case-control study to assess the role of polyomavirus in transplant complications: Where do we stand?

PURPOSE

The study's aim was to assess whether polyomavirus DNAemia screening was associated with different outcomes in patients with positive viremia compared with negative viremia.

METHODS

Case-control retrospective study of patients with polyomavirus DNAemia (viremia > 1000 copies/mL) matched 1:1 with controls. Control group consists of the patient who received a transplant immediately before or after each identified case and did have nil viremia.

FINDING

Ultimately, 120 cases of BK polyomavirus (BKPyV) were detected and matched with 130 controls. Of these, 54 were adult kidney transplant recipients (KTRs), 43 were pediatric KTRs, and 23 were undergoing hemato-oncologic therapy, of which 20 were undergoing hematopoietic stem cell transplantation. The odds ratio (OR) for overall risk of poorer outcomes in cases versus controls was 16.07 (95% CI: 5.55-46.54). The unfavorable outcome of switching the immunosuppressive drug (ISD) (14/40,35%) was no different from that of those treated with reduced ISD doses (31/71, 43.6%, P = .250). Acute rejection or graft-versus-host disease, previous transplant, and intensity of immunosuppression (4 ISDs plus induction or conditioning) were risk factors for BKPyV-DNAemia (OR: 13.96, 95% CI: 11.25-15.18, P < .001; OR: 6.14, 95% CI: 3.91-8.80, P < .001; OR: 5.53, 95% CI: 3.37-7.30, P < .001, respectively).

CONCLUSIONS

Despite viremia screening, dose reduction, and change in therapeutic protocol, patients with positive BKPyV-DNAemia present poorer outcomes and unfavorable results.

Visceral Leishmaniasis in a Liver Transplant Patient: A Case Report

Leishmaniasis is an infection caused by protozoa of the genus Leishmania, transmitted by sandflies and endemic to more than 88 countries. Visceral leishmaniasis in immunosuppressed patients is a growing concern. We report the case of a 61-year-old male patient with a previous history of alcoholic cirrhosis and portal vein thrombosis who underwent liver transplantation for the treatment of hepatocellular carcinoma. Thirty-six days after the procedure, the patient showed an increase in liver enzymes and was diagnosed with moderate acute rejection of the graft. He was treated with high-dose intravenous corticosteroids, and while showing improvement in biochemical markers, he became febrile 12 days after corticosteroid treatment. He presented daily episodes of fever, even after the use of several antimicrobial, antiviral, and antifungal agents, and a number of negative cultures from different sites were obtained. A bone marrow biopsy was then performed, showing a large number of amastigote forms of Leishmania spp. Treatment with liposomal amphotericin B was initiated; however, the patient progressed to refractory septic shock and death. This case highlights several aspects of visceral leishmaniasis in liver transplant recipients, such as the association of malnutrition to Leishmania infection and the challenges of diagnosing leishmaniasis in cirrhotic patients in which splenomegaly and pancytopenia, the hallmarks of leishmaniasis, may also be attributed to portal hypertension and end-stage liver disease. A high index of suspicion is necessary for the correct diagnosis and treatment of leishmaniasis in this group of patients. This study is compliant with the Helsinki Congress and the Istanbul Declaration.

Linfohistiocitosis hemofagocítica por Histoplasma capsulatum en paciente con trasplante renal

La linfohistiocitosis hemofagocítica (LHH) por Histoplasma capsulatum, presentación rara de la histoplasmosis diseminada, es causada por la fagocitosis de las células hematopoyéticas por macrófagos tisulares. Presentamos el caso de un paciente masculino de 44 años con trasplante renal que asiste por fiebre sin otra sintomatología. Inicialmente se obtiene una gota gruesa positiva para P. vivax, iniciando manejo antimalárico. A los 2 días de tratamiento, el paciente presenta disfunción multiórganica, se rectifica diagnóstico en centro de referencia reportando en extendido de sangre periférica la presencia de levaduras de H. capsulatum en polimorfonucleares, resultado confirmado con prueba de inmunodifusión. Se ajusta manejo, pero el paciente fallece. El diagnóstico de infecciones por gérmenes inusuales con presentaciones inespecíficas es un reto en pacientes con inmunosupresión.

Prevalence of Blastocystis sp. infection in several hosts in Brazil: a systematic review and meta-analysis

BACKGROUND

Blastocystis sp. affects a wide variety of animals and is the most common protozoan in human fecal samples with potential pandemic distribution. In the present study, a systematic review and meta-analysis were conducted to determine the prevalence and distribution of Blastocystis sp. in different classes of hosts in Brazil.

METHODS

Studies that analyzed hosts of various classes, including humans, domestic animals, wild animals or captive animals, were considered. The pooled prevalence of Blastocystis sp. infection was estimated by random effects models.

RESULTS

For humans, similar prevalence rates were found for males (31.0%, 95% CI: 17.0-45.0%; weight 10%) and females (28.0%, 95% CI: 16.0-41.0%; weight 10%); the state of Mato Grosso do Sul showed the highest prevalence, with 41.0% positivity (95% CI: 36.0-46.0%; weight 2.9%). The prevalence among immunocompromised patients was 5.0% (95% CI: 3.0-7.0%; weight 10%), and the most common cause of immunosuppression was hemodialysis, with 23.0% (95% CI: 17.0-29.0%; weight 12.4%). Among classifications according to interaction with humans, wild and domestic animals presented values of 19.0% (95% CI: 7.0-31.0%; weight 42.6%) and 17.0% (95% CI: 13.0-21.0%; weight 29.6%), respectively. Among these animals, mammals (39.0%, 95% CI: 21.0-56.0%; weight 47.3%) and birds (18.0%, 95% CI: 10.0-27.0%; weight 39.3%) exhibited the highest prevalence. Phylogenetic analysis of Blastocystis sp. revealed greater genetic diversity for clades of subtypes (STs) ST1, ST2 and ST3.

CONCLUSIONS

The overall prevalence of Blastocystis sp. in the Brazilian human population was 24%, which reflects the reality in the South, Southeast and Midwest regions, where prevalence rates of up to 40% were found. Among animals, mammals and birds exhibited the highest prevalence.

Severe Strongyloides stercoralis infection in kidney transplant recipients: A multicenter case-control study

BACKGROUND

Severe Strongyloides stercoralis infection in kidney transplant recipients is associated with considerable morbidity and mortality, although little is known about the risk factors for such infection.

METHODOLOGY/PRINCIPAL FINDINGS

This was a retrospective, multicenter, case-control study in which we assessed the risk factors for and clinical outcomes of severe S. stercoralis infections in kidney transplant recipients in Brazil. We included 138 kidney transplant recipients: 46 cases and 92 controls. Among the cases, the median number of days from transplantation to diagnosis was 117 (interquartile range [IQR], 73.5-965) and the most common clinical findings were gastrointestinal symptoms (in 78.3%) and respiratory symptoms (in 39.1%), whereas fever and eosinophilia were seen in only 32.6% and 43.5%, respectively. The 30-day all-cause mortality among the cases was 28.3% overall and was significantly higher among the cases of infection occurring within the first three months after transplantation (47% vs. 17.2%, P = 0.04). The independent risk factors were receiving a transplant from a deceased donor (odds ratio [OR] = 6.16, 95% confidence interval [CI] = 2.05-18.5), a history of bacterial infection (OR = 3.04, 95% CI = 1.2-7.5), and a cumulative corticosteroid dose (OR = 1.005, 95% CI = 1.001-1.009). The independent predictors of mortality were respiratory failure (OR = 98.33, 95% CI = 4.46-2169.77) and concomitant bacteremia (OR = 413.00, 95% CI = 4.83-35316.61).

CONCLUSIONS/SIGNIFICANCE

Severe S. stercoralis infections are associated with considerable morbidity and mortality after kidney transplantation. In endemic areas, such infection may occur late after transplantation, although it seems to be more severe when it occurs earlier after transplantation. Specific risk factors and clinical manifestations can identify patients at risk, who should receive prophylaxis or early treatment.

T cell reconstitution after lymphocyte depletion features a different pattern of inhibitory receptor expression in ABO- versus HLA-incompatible kidney transplant recipients

Chronic antigen stimulation can lead to immune exhaustion (a state of T cell dysfunction). Several phenotypical signatures of T cell exhaustion have been described in various pathological situations, characterized by aberrant expression of multiple inhibitory receptors (IR). This signature has been barely studied in the context of allogenic organ transplantation. We undertook a cross-sectional analysis of the expression of IR [CD244, CD279, T cell immunoreceptor with immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibition motif (ITIM) domains (TIGIT) and CD57] and their correlation with cytokine-producing functions in T cells reconstituting after lymphocyte depletion in patients transplanted from living donors, with preformed donor-specific antibodies. After ABO incompatible transplantation, T cells progressively acquired a phenotype similar to healthy donors and the expression of several IR marked cells with increased functions, with the exception of TIGIT, which was associated with decreased cytokine production. In stark contrast, T cell reconstitution in patients with anti-human leukocyte antigen (HLA) antibodies was characterized with an increased co-expression of IR by T cells, and specifically by an increased expression of TIGIT. Furthermore, expression of these receptors was no longer directly correlated to cytokine production. These results suggest that T cell alloreactivity in HLA-incompatible kidney transplantation drives an aberrant T cell reconstitution with respect to IR profile, which could have an impact on the transplantation outcome.

Disseminated toxoplasmosis associated with hemophagocytic syndrome after kidney transplantation: A case report and review

Disseminated toxoplasmosis is infrequent after kidney transplant transmission but life-threatening because of a lack of diagnostic suspicion as well as specific chemoprophylaxis recommendations. Solid organ transplantation has resulted in few cases of disseminated toxoplasmosis presenting with associated hemophagocytic syndrome. Herein, we report, within the context of a donor/receiver mismatch, a case of a toxoplasmosis associated with hemophagocytic syndrome in a kidney transplant recipient. Molecular and serological investigations confirmed Toxoplasma gondii transmission through the kidney graft.

Toxoplasmosis in the non-orthotopic heart transplant recipient population, how common is it? Any indication for prophylaxis?

PURPOSE OF REVIEW

Unlike in orthotopic heart transplant (OHT) setting where toxoplasma prophylaxis is a standard practice in pretransplant toxoplasma seronegative recipients who have received donor hearts from seropositive donors (D+/R-), there is no consensus regarding prophylaxis in non-OHT recipients.

RECENT FINDINGS

The incidence of toxoplasma disease in non-OHT recipients is less than 1% but its true burden is underestimated. Among 31 cases of toxoplasma disease reported from 2004 through 2017, renal and liver transplant recipients comprised of 90% of cases. A total of 94% of 18 recipients with known pretransplant serology were seronegative recipients (mostly D+/R-). Out of 16 recipients with adequate information, 10 (63%) and five (31%) were deemed to be donor derived and nondonor-derived primary toxoplasmosis respectively. Tissue invasive reactivation was uncommon. Almost all cases were described in patients not on prophylaxis at the time of presentation. Universal screening of donor/recipient toxoplasma serology for risk stratification is beneficial as illustrated by reports of fatal cases of toxoplasmosis due to unavailability of positive donor serology results.

SUMMARY

Toxoplasma disease in non-OHT predominantly occurs in pretransplant seronegative recipients- mostly in D+/R- group and is rare in seropositive recipients. Posttransplant prophylaxis should be targeted against the high-risk D+/R- group and should be considered in seropositive recipients in whom unusually high immunosuppression is implemented. Toxoplasma serologies and PCR should be used in combination for the diagnosis of toxoplasmosis in non-OHT patients.

Endemic fungal infections in solid organ transplant recipients-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention and management of blastomycosis, histoplasmosis, and coccidioidomycosis in the pre- and post-transplant period. Though each of these endemic fungal infections has unique epidemiology and clinical manifestations, they all share a predilection for primary pulmonary infection and may cause disseminated infection, particularly in immunocompromised hosts. Culture remains the gold standard for definitive diagnosis, but more rapid diagnosis may be achieved with direct visualization of organisms from clinical specimens and antigen-based enzyme immunoassay assays. Serology is of limited utility in transplant recipients. The mainstay of treatment for severe infections remains liposomal amphotericin followed by a step-down azole therapy. Cases of mild to moderate severity with no CNS involvement may be treated with azole therapy alone. The newer generation azoles provide additional treatment options, but supported currently with limited clinical efficacy data. Azole therapy in transplant recipients presents a unique challenge owing to the drug-drug interactions with immunosuppressant agents. Therapeutic drug monitoring of azole levels is an essential component of effective and safe therapy. Infection prevention centers around minimizing epidemiological exposures, early clinical recognition, and azole prophylaxis in selected individuals.

Long-Term Outcomes among Kidney Transplant Recipients and after Graft Failure: A Single-Center Cohort Study in Brazil

Background

The results of kidney transplantation are impacted by the categories of events responsible for patient death and graft failure. The objective of this study was to evaluate the causes of death and graft failure and outcomes after graft failure among kidney transplant recipients.

Methodology

A retrospective cohort study was conducted with 944 patients who underwent kidney transplantation. Outcomes were categorized in a managed and hierarchical manner.

Results

The crude mortality rate was 10.8% (n=102): in 35.3% cause of death was infection, in 30.4% cardiovascular disease, and in 15.7% neoplasia and in 6.8%, it was not possible to determine the cause of death. The rate of graft loss was 10.6%. The main causes of graft failure were chronic rejection (40%), acute rejection (18.3%), thrombosis (17.3%), and recurrence of primary disease (16.5%). Failures due to an acute rejection occurred earlier than those due to chronic rejection and recurrence (p<0.0001). As late causes of graft loss, death with the functioning kidney occurred earlier than recurrence and chronic rejection (p=0.008). The outcomes after graft failure were retransplantation in 26.1% and death in 21.4%, at a mean of 25.5 and 21.4 months, respectively.

Conclusion

It was possible to identify more than 90% of the events responsible for the deaths of transplanted patients, predominantly infectious and cardiovascular diseases. Among the causes of graft failure, chronic and acute rejections and recurrence were the main causes of graft failure which were followed more frequently by retransplantation than by death on dialysis.

IgG reactivity with 40-35 kDa soluble and membrane antigen of Strongyloides venezuelensis in immunocompromised patients

Immunocompromised patients constitute a risk group for the development of severe clinical forms of human strongyloidiasis. The diagnosis of this infection is primarily performed by parasitological techniques, but with low sensitivity. Serological techniques appear as an alternative, especially with heterologous antigens use. The aim of this study was to perform the Western blot technique by using S. venezuelensis infective third stage larva (iL3) soluble (TS) and membrane (TM) saline antigens to reveal immunoreactive bands in immunocompromised patients with strongyloidiasis. Serum samples from 117 parasitologically well-characterized patients were divided into four groups: S. stercoralis positive and immunocompetent (S + IC); S. stercoralis positive and immunocompromised (S + IP); negative and immunocompetent (S-IC); negative and immunocompromised (S-IP). A 40-35 kDa band was recognized by 100% of patients in the S + IC group in both antigenic fractions, and by 62.5% and 50% in the S + IP group using the TS and TM fractions, respectively. A 29 kDa band was recognized by 86.3% and 72.7% (for TS and TM, respectively) of patients in the S + IC group, and only by 12.5% of patients in the S + IP group on the TM antigen. Regardless of the patients' immunological condition, the 40-35 kDa band from S. venezuelensis was detected more frequently and can be used as an important marker to the immunodiagnosis of human strongyloidiasis.

Screening of Strongyloides infection using an ELISA test in transplant candidates

OBJECTIVES

Hyperinfection or disseminated strongyloidiasis has been frequently reported after transplants and is related to high mortality. This study aimed to screen for strongyloidiasis using serological diagnoses in transplant candidates.

METHODS

An ELISA test was performed with filariform larvae of Strongyloides venezuelensis as a source of antigen.

RESULTS

In the serum from transplant candidates, anti-Strongyloides IgG antibodies were detected in 35/150 (23.3%) samples by soluble fractions in phosphate buffered saline (PBS), 31/150 (20.7%) samples by soluble fractions in Tris-HCl, 27/150 (18.0%) samples by membrane fractions in PBS and 22/150 (14.7%) samples by membrane fractions in Tris-HCl.

CONCLUSIONS

The present results suggest the ELISA test, ideally using soluble fractions of filariform larvae S. venezuelensis in PBS, as an additional strategy for the diagnosis of strongyloidiasis in transplant candidates.

Infections in Liver Transplantation

Liver transplantation has become an important treatment modality for patients with end-stage liver disease/cirrhosis, acute liver failure, and hepatocellular carcinoma. Although surgical techniques and immunosuppressive regimens for liver transplantation have improved significantly over the past 20 years, infectious complications continue to contribute to the morbidity and mortality in this patient population. The use of standardized screening protocols for both donors and recipients, coupled with targeted prophylaxis against specific pathogens, has helped to mitigate the risk of infection in liver transplant recipients. Patients with chronic liver disease and cirrhosis have immunological deficits that place them at increased risk for infection while awaiting liver transplantation. The patient undergoing liver transplantation is prone to develop healthcare-acquired infections due to multidrug-resistant organisms that could potentially affect patient outcomes after transplantation. The complex nature of liver transplant surgery that involves multiple vascular and hepatobiliary anastomoses further increases the risk of infection after liver transplantation. During the early post-transplantation period, healthcare-acquired bacterial and fungal infections are the most common types of infection encountered in liver transplant recipients. The period of maximal immunosuppression that occurs at 1–6 months after transplantation can be complicated by opportunistic infections due to both primary infection and reactivation of latent infection. Severe community-acquired infections can complicate the course of liver transplantation beyond 12 months after transplant surgery. This chapter provides an overview of liver transplantation including indications, donor-recipient selection criteria, surgical procedures, and immunosuppressive therapies. A focus on infections in patients with chronic liver disease/cirrhosis and an overview of the specific infectious complications in liver transplant recipients are presented.

Epidemiology and outcomes of dengue in kidney transplant recipients: A 20-year retrospective analysis and comparative literature review

BACKGROUND

Kidney transplant (KT) recipients in dengue-endemic areas are at risk of exposure. We investigated the epidemiology and outcomes from dengue in KT recipients at our transplant center and conducted a literature review.

MATERIALS AND METHODS

We conducted a 20-year retrospective study of KT recipients who were diagnosed with laboratory-confirmed dengue from January 1997 to September 2017 according to the 2009 World Health Organization (WHO) classification. We analyzed clinical characteristics and treatment outcomes.

RESULTS

There were 13 (0.7%) dengue cases among 1917 KT recipients with a median age of 39 years (interquartile ranges [IQR], 22-46); 54% were males. Cases occurred with a median onset of 24 months (IQR, 6-122) after KT. Dengue was diagnosed via dengue NS1 antigen (85%), IgM antibodies (38.5%), or RT-PCR (15.4%). Patients were classified as having dengue without warning sign (30.8%), with warning sign (53.8%), or severe dengue (15.4%). All patients resolved without complications, except one had hemophagocytic lymphohistiocytosis. Ten (76.9%) patients experienced eGFR reduction with a median of 13.7 mL/min/1.73 m² (IQR, 8.3-20.5); eight (80%) had a full allograft function recovery.

CONCLUSIONS

Dengue in KT recipients in endemic areas is uncommon. Although a transient decline in allograft function can occur, the overall clinical and allograft outcomes seem to be favorable.

Prevalence of Cryptosporidium, Blastocystis, and other opportunistic infections in patients with primary and acquired immunodeficiency

Intestinal opportunistic infections are often caused by unicellular parasites. Individuals with decreased immunity are particularly susceptible to infection by said microorganisms, and when they are infected, diarrhea can be the main clinical manifestation. However, intestinal parasites have rarely been taken into account in intestinal disorders. In our study, an investigation was conducted to determine the prevalence of intestinal micro-pathogens, such as Cryptosporidium, Giardia, Blastocystis, and microsporidia, in hospitalized patients with different immunological statuses. The study at hand indicates that protozoan parasitic infections are rare among immunodeficient patients in Poland. The overall prevalence of micro-pathogens among participants was 4.6%; it was three times higher in adults (12.5%) than in children (2.3%). Cryptosporidium and Cyclospora species (Apicomplexa) were diagnosed as the main cause of heavy diarrhea. Accordingly, adult patients were positive mainly for Blastocystis and microsporidia, while children were more often infected with the Cryptosporidium species.

New insights into leishmaniasis in the immunosuppressed

Immunosuppression contributes significantly to the caseload of visceral leishmaniasis (VL). HIV coinfection, solid organ transplantation, malnutrition, and helminth infections are the most important immunosuppression-related factors. This review briefly describes the challenges of these associations. East Africa and the Indian subcontinent are the places where HIV imposes the highest burden in VL. In the highlands of Northern Ethiopia, migrant rural workers are at a greater risk of coinfection and malnutrition, while in India, HIV reduces the sustainability of a successful elimination programme. As shown from a longitudinal cohort in Madrid, VL is an additional threat to solid organ transplantation. The association with malnutrition is more complex since it can be both a cause and a consequence of VL. Different regimes for therapy and secondary prevention are discussed as well as the role of nutrients on the prophylaxis of VL in poverty-stricken endemic areas.

Mycobacterium tuberculosis after solid organ transplantation: A review of more than 2000 cases

BACKGROUND

Mycobacterium tuberculosis (TB) is a common pathogen worldwide, and it may cause significant infection after solid organ transplantation (SOT). We reviewed all reported TB cases to provide an update on its epidemiology, clinical presentation, management, and outcome after SOT.

METHODS

MEDLINE, EMBASE, and OVID were reviewed from January 1, 1998, to December 31, 2016, using keywords tuberculosis and solid organ transplant or transplantation.

RESULTS

There were 187 publications reporting 2082 cases of TB among kidney (n = 1719), liver (n = 253), heart (n = 77), lung (n = 25), and kidney-pancreas (n = 8) recipients. Among cohort studies, the median incidence was 2.37% (range, 0.05%-13.27%) overall. Most TB disease was considered reactivation of latent infection, occurring beyond the first year after SOT. Early-onset cases were seen among donor-derived TB cases. Fever was the most common symptom. Radiologic findings were highly variable. Extrapulmonary and disseminated TB occurred 29.84% and 15.96%, respectively. Multidrug-resistant TB was rare. Treatment using 4 or 5 drugs was commonly associated with hepatotoxicity and graft dysfunction. All-cause mortality was 18.84%.

CONCLUSIONS

This large review highlights the complexity of TB after SOT. Reactivation TB, donor-transmitted infection, extrapulmonary involvement, and disseminated disease are common occurrences. Treatment of TB is commonly associated with hepatotoxicity and graft dysfunction.

The liver as an organ at risk for Toxoplasma transmission during transplantation: myth or reality?

AIM

Toxoplasmosis following liver transplant with donor-recipient mismatch is rare, but is often life-threatening. However, there are no data on the frequency of cyst carriage in the liver, nor consensual chemoprophylaxis guidelines. This study aimed at describing frequency and localisation of Toxoplasma cysts in the liver in a mouse model of chronic infection to predict the risk in liver transplantation.

METHODS

Heart, brain and liver lobes of 21 mice chronically infected with Toxoplasma were collected for DNA extraction and amplification of Toxoplasma gondii rep529 sequence by real-time PCR.

RESULTS

Parasite DNA was detected in the liver of 19/21 mice (90.5%), with no preferential anatomical localisation, but with higher parasite loads in the papillary process. Parasite loads in the liver were far lower than in brain and heart. The number of infected lobes was inversely correlated to the total liver weight, but was independent of the brain parasite load and of the parasite strain.

CONCLUSIONS

The liver is a frequent site of cyst carriage, confirming that transplantation of an organ from a seropositive donor to seronegative recipient is at high risk for acquired toxoplasmosis. Systematic serological screening prior to transplantation and chemoprophylaxis in patients at risk are fully justified.

Does Toxoplasma gondii infection impact liver transplantation outcomes? A systematic review

PURPOSE

Approximately one-third of the world's population has Toxoplasma gondii infection, and one of the main routes of transmission is organ transplantation. The aim of this study was to evaluate the impact of Toxoplasma infection on liver transplantation patients.

METHODOLOGY

We searched PubMed, Lilacs, Medline, Science direct, Scielo, Ebsco, Springer, Wiley, Ovid and Google Scholar for reports published up to June 2017, and a systematic review was performed.

RESULTS

Twenty cases were analysed before and after liver transplantation. Primary and reactivated infections were investigated. Before transplantation, positive IgG antibodies were the predominant serological markers in donors and recipients: 40 % (D+/R-), 20 % (D+/R+) and 20 % (D-/R+). IgM was present in only 5 % of the donors (D+/R-). In four cases, the serological markers were not specified or were negative (D?/R? or D?/R-). After transplantation, IgM anti-Toxoplasma antibodies were found in 30 % of the recipients, and in 67 % of the seronegative recipients the presence of Toxoplasma DNA or tachyzoites was reported, suggesting a primary infection. Clinical symptoms were meningitis, massive cerebral oedema, encephalitis and seizures. Treatment was administered in 70 % of the patients, and 40 % died after presenting symptoms associated with Toxoplasma infection.

CONCLUSIONS

Although we review Toxoplasma infection and liver transplantation cases, problems associated with the parasite may be greater than identified. Hence, follow-up studies on Toxoplasma infection in liver transplantation patients are recommended.

CT findings of pulmonary nocardiosis: a report of 9 cases

Background

Pulmonary nocardiosis often occurs among immunocompromised patients, especially in those with impaired cell immunity related to AIDS and transplant. As the number of patients receiving transplant, the occurrence of pulmonary nocardiosis may also increase. Radiologic characteristics of this entity have not been well documented. In present study, CT findings of clinical confirmed pulmonary nocardiosis were retrospectively reviewed in order to understand CT features of pulmonary nocardiosis.

Methods

Electronic databases of Shenzhen People's Hospital, Shenzhen, China, and the Third People's Hospital of Longgang District, Shenzhen, China were searched for patients with definitive diagnosis of pulmonary nocardiosis and available CT images. Nine patients were founded and they were included in this retrospective analysis. Clinical presentations at diagnosis and related medical history were recorded. CT images were retrospectively reviewed by two radiologists in consensus.

Results

The patients consisted of seven men and two women with a median age of 47 years (range, 20-73 years). There were three immunocompromised patients and six immunocompetent patients. The latter included two patients had history of bronchiectasis. The symptoms at the diagnosis were nonspecific of fever, cough, sputum, dyspnea, chest pain, and hemoptysis. CT findings included: lung consolidation (n=8) with cavitation in three cases and foci of decreased enhancement in one patient who had contrast-enhanced CT, nodules/masses (n=6) with cavitation in two patients, ground-glass opacity (n=4), centrilobular nodules (n=4), pleural effusion (n=4), bronchiectasis (n=4), interlobular septal thickening (n=3), interlobular reticular opacity (n=3), lymph node enlargement (n=2), halo sign (n=2) and mucoid impaction (n=1).

Conclusions

Lung consolidation and nodules/masses are the most common findings, but CT findings of pulmonary nocardiosis are diverse and nonspecific. In some clinical background, such as immunocompromised patients or with some underlying lung diseases, consolidation or nodules/masses with cavitation may suggest the possibility of pulmonary nocardiosis.

Histoplasmosis in transplant recipients

Histoplasma capsulatum is a dimorphic fungus that most often causes asymptomatic infection in the immunocompetent population. In immunocompromised patients, including solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients, however, it is likely to cause severe life-threatening infection. Post-transplant histoplasmosis (PTH) in SOT is uncommon with an incidence of ≤1% and is even rarer in HCT patients. The majority of PTH in SOT is diagnosed in the first 2 years following transplantation. Histoplasmosis may result from endogenous reactivation of latent infection, de novo post-transplant acquisition, and donor-derived infection. Disseminated infection is common. Fever is the most common symptom and clinical features are often nonspecific, but patients with disseminated infection may present with a septic picture. Other features, including pancytopenia and hepatosplenomegaly, may not be prominent early in the course of illness. Contemporary histoplasma antigen assays are the most sensitive tests but cross-reactivity with antigens of other fungi, including with Aspergillus galactomannan, is not uncommon. Treatment should be continued for at least a year. Histoplasma antigen levels have prognostic value and can be used to monitor the response to therapy. The attributable mortality is approximately 10%. Routine screening of donors and recipients is not currently recommended.

Invasive Fungal Disease in Renal Transplant Recipients at a Brazilian Center: Local Epidemiology Matters

INTRODUCTION

Invasive fungal disease (IFD) is an important complication after solid organ transplantation (SOT). A marked geographic variation in the epidemiology of IFD after kidney transplantation (KT) has been suggested by the results of previous studies. Nevertheless, data from Latin American centers are scarce.

OBJECTIVE

This study sought to describe the epidemiology of IFD at a Brazilian KT center.

METHODS

This study was a retrospective single-center cohort study that included patients who underwent KT between 1998 and 2009 and were followed up until July 2015. Cases of simultaneous kidney-pancreas transplantation were excluded. The primary study outcome was the occurrence of proven or probable IFD.

RESULTS

Among 908 KT recipients, 44 cases of IFD occurred in 42 patients (4.6%). Cryptococcus spp. infection, diagnosed in 16 cases (36.3%), was the leading cause of IFD, followed by histoplasmosis in 10 cases (22.7%) and invasive candidiasis in 10 (22.7%). Sporotrichosis, mucormycosis, invasive aspergillosis, pulmonary Cladophialophora sp. infection, trichosporonosis and Saccharomyces cerevisiae fungemia occurred in 1 recipient each (2.3%). Two additional (4.5%) cases of unspecified mold infections were identified by histopathological analysis. Most cases of IFD (67%) occurred later than 6 months after transplantation. Previous use of antilymphocyte antibodies (P = .008) and corticosteroid pulse therapy (P < .001) were more frequent among cases of IFD occurring within the first 6 months after transplantation.

CONCLUSIONS

The epidemiology of IFD in this Brazilian cohort was characterized by a large predominance of late infections and a high proportion of cases of cryptococcosis and histoplasmosis. These results highlight the considerable geographic variability of IFD epidemiology after KT.

PCR-based molecular characterization of Blastocystis hominis subtypes in southwest of Iran

Blastocystis hominis is the most common intestinal parasite found in humans and many other hosts. Pathogenicity of Blastocystis sp. remains controversial and it has been suggested that it may be associated with certain subtypes of organism. The aim of this study was to evaluate the molecular epidemiology of B. hominis and its subtype distribution in Ahvaz, southwest of Iran. During 2012-2014, a total of 481 samples were collected from patients referred to the medical laboratory centers in Ahvaz for stool examination. Samples were examined by wet mount, and genomic DNA was extracted from 50 positive samples. PCR was performed using seven primer pairs targeting the SSU rDNA gene and sequenced. 69 (14.35%) samples were found to be positive for B. hominis and the subtypes of 50 samples were identified. Five subtypes (STs) were identified, including: ST1 (22%), ST2 (6%), ST3 (40%), ST4 (2%), and ST5 (8%). 11 (22%) mixed infections were found, of which 5 were a mixture of ST3/ST4. Mixtures of ST1/ST3 and ST1/ST4 were 3, respectively. In this study people infected with ST3 showed the most gastrointestinal symptoms. This is the first study in the population of Ahvaz and indicates the high prevalence of ST3 in this area. The results suggest a possible association between this subtype and pathogenic potential of parasite.

Infectious complications as the leading cause of death after kidney transplantation: analysis of more than 10,000 transplants from a single center

AIM

To identify specific causes of graft failure in a large sample of kidney transplant patients from a middle-income, developing country.

METHODS

Retrospective cohort study analyzing all consecutive single kidney transplants (KTs) performed at a single center in Brazil between January 1st 1998 and December 31st 2013. The database closing date was December 31st 2014.

RESULTS

Out of 10,400 KTs, there were 1191 (11.45%) deaths with a functioning graft, 40 cases (0.38%) of primary non-function (PNF) and 1417 cases (13.62%) of graft loss excluding death and PNF as the cause. Infectious complications (404 cases, 34% of all deaths) were the major cause of death. Most deaths due to infection occurred within the first year after transplantation (157 deaths, 38.86%). Immunologic mechanisms, comprising acute rejection and immune-mediated interstitial fibrosis/tubular atrophy (IF/TA), were responsible for 52% of all cases of graft failure not involving recipient death. Half of the losses by acute rejection occurred late after transplantation.

CONCLUSION

Contrary to what is observed in developed countries, infectious complications are the main challenge with kidney transplantation in Brazil. Non-adherence to treatment also appears to contribute significantly to long-term kidney graft loss. Strategies for improvement should focus on better compliance and a greater safety profile of immunosuppressive treatment.

Strongyloidiasis Current Status with Emphasis in Diagnosis and Drug Research

Strongyloidiasis is a parasitic neglected disease caused by the nematode Strongyloides stercoralis affecting 30 to 100 million people worldwide. Complications, strongly associated with alcoholism, organ transplants, and HTLV-1 virus, often arise due to late diagnosis, frequently leading to patient death. Lack of preemptive diagnosis is not the only difficulty when dealing with this parasite, since there are no gold standard diagnostic techniques, and the ones used have problems associated with sensitivity, resulting in false negatives. Treatment is also an issue as ivermectin and benzimidazoles administration leads to inconsistent cure rates and several side effects. Researching new anti-Strongyloides drugs is a difficult task since S. stercoralis does not develop until the adult stages in Mus musculus (with the exception of SCID mice), the main experimental host model. Fortunately, alternative parasite models can be used, namely, Strongyloides ratti and S. venezuelensis. However, even with these models, there are other complications in finding new drugs, which are associated with specific in vitro assay protocol steps, such as larvae decontamination. In this review, we highlight the challenges associated with new drug search, the compounds tested, and a list of published in vitro assay methodologies. We also point out advances being made in strongyloidiasis diagnosis so far.

The diagnostic yield and complications of open lung biopsies in kidney transplant patients with pulmonary disease

BACKGROUND

The purpose of this study was to assess the efficacy of open lung biopsy (OLB) in determining the specific diagnosis and the related complications in patients with undiagnosed diffuse pulmonary infiltrates.

METHODS

This single center, retrospective study included adult kidney transplant patients who underwent OLB. The patients had diffuse pulmonary infiltrates without definitive diagnoses and failed to respond to empiric antibiotic treatment. We analyzed the number of specific diagnoses, changes in treatment and the occurrence of complications in these patients. A logistic regression was used to determine which variables were predictors of hospital mortality.

RESULTS

From April 2010 to April 2014, 87 patients consecutively underwent OLB. A specific diagnosis was reached in 74 (85.1%) patients. In 46 patients (53%), their therapeutic management was changed after the OLB results. Twenty-five (28.7%) patients had complications related to the OLB. The hospital mortality rate was 25.2%. Age, SAPS3 score and complications related to the procedure were independent predictors of all-cause mortality.

CONCLUSIONS

OLB is a high-risk procedure with a high diagnostic yield in kidney transplant patients with diffuse pulmonary infiltrates who did not have a definitive diagnosis and who failed to respond to empiric antibiotic treatment. Complications related to OLB were common and were independently associated with intra-hospital mortality.

Leishmaniasis in solid organ and hematopoietic stem cell transplant recipients

Leishmaniasis occurs in <1% of solid organ and hematopoietic stem cell transplant recipients in endemic countries in which transplants are performed. Visceral leishmaniasis (VL) makes up the bulk of reported cases. The onset generally occurs months after transplantation and the mode of acquisition is often impossible to determine, but de novo vector-borne infection and reactivation of inapparent infection are thought to be the principal means. The potential role of clinically inapparent donor infection is uncertain and screening is not currently recommended, nor is it recommended for recipients from endemic areas, some of whom may have detectable circulating protozoan nucleic acid. While transplant recipients with VL often present with the non-specific findings of fever and cytopenia, the additional presence of hepatosplenomegaly in patients from endemic areas should lead to a directed diagnostic evaluation with bone marrow examination and PCR testing of marrow and peripheral blood having a high yield. Management may often be complicated by the presence of concomitant infections. A lipid formulation of amphotericin B is the preferred treatment, especially for VL, but the relapse rate in transplant recipients is approximately 25%. PCR monitoring of blood for either secondary prophylaxis or preemptive therapy requires further study.

Severe dengue in the early postoperative period after kidney transplantation: two case reports from Hospital Geral de Fortaleza

Dengue is an arbovirosis that ranges from an asymptomatic presentation to a more severe disease, which is characterized by a vascular leakage syndrome where abdominal pain is a major symptom. Transplant recipients are immunosuppressed and are less likely to develop a severe form of the disease because of a reduction in immune-mediated responses that trigger plasma extravasation events. Herein, we report two cases of severe dengue in the early postoperative period of two kidney transplant recipients. Considering the severity of the cases, we emphasize the importance of dengue screening immediately before transplantation in areas endemic for the disease.

High-resolution Computed Tomography Findings in Patients with Pulmonary Nocardiosis

RATIONALE AND OBJECTIVES

Nocardiosis is difficult to diagnose, and the diagnosis is thus frequently delayed. High-resolution computed tomography (HRCT) findings of patients with pulmonary nocardiosis have been documented in few reports. Our study objective was to assess HRCT findings of patients with pulmonary nocardiosis.

MATERIALS AND METHODS

This was a retrospective study of 20 consecutive patients with pulmonary Nocardia infections who underwent HRCT of the chest at our institutions from January 2011 to August 2014. After the exclusion of two patients with concurrent infections, the study group comprised 18 patients (11 men, 7 women; age range, 39-83 years; mean, 67.9 years) with pulmonary Nocardia infections. Parenchymal abnormalities, enlarged lymph nodes, and pleural effusion were evaluated on HRCT.

RESULTS

Underlying conditions included respiratory disease (n = 6, 33.3%), collagen diseases (n = 5, 27.8%), and diabetes mellitus (n = 4, 22.2%). All patients showed abnormal HRCT findings, including the presence of a nodule/mass (n = 17, 94.4%), ground-glass opacity (n = 14, 77.8%), interlobular septal thickening (n = 14, 77.8%), and cavitation (n = 12, 66.7%). Pleural effusion was seen in two patients. There were no cases of lymph node enlargement.

CONCLUSIONS

Among the HRCT findings in patients with pneumonia, a nodule/mass with interlobular septal thickening and/or cavitation are suggestive of pulmonary nocardiosis.

Transplantation in the tropics: lessons on prevention and management of tropical infectious diseases

Tropical infectious diseases (IDs) remain a rare complication in transplant recipients even in tropical settings, but this topic has become increasingly important during the last decade due to multiple factors. Interestingly, non-tropical countries report most of the experiences with tropical diseases. The reported experience from non-endemic regions, however, does not always reflect the experience of endemic areas. Most of the guidelines and recommendations in the literature may not be applicable in tropical settings due to logistical difficulties, cost, and lack of proven benefit. In addition, certain post-transplant prevention measures, as prophylaxis and reducing exposure risk, are not feasible. Nonetheless, risk assessment and post-transplant management of tropical IDs in tropical areas should not be neglected, and clinicians need to have a higher clinical awareness for tropical ID occurring in this population. Herein, we review the more significant tropical ID in transplant patients, focusing on relevant experience reported by tropical settings.

Dengue fever in a liver-transplanted patient: a case report

Introduction

Dengue fever is one of the commonest mosquito-borne diseases in the tropics, and Sri Lanka is no exception. Despite its commonness, dengue fever has rarely been described among patients who have undergone transplantation. We report the case of a patient with dengue fever after liver transplantation, which, to the best of our knowledge, is the first such reported case outside Brazil.

Case presentation

Our patient was a 46-year-old Sri Lakan man who presented to our institution two years after undergoing an ABO-compatible cadaveric liver transplant. At presentation, he had typical symptoms of dengue fever. He was taking prednisolone 5mg daily and tacrolimus 3mg twice daily as immunosuppression. Initial investigations showed thrombocytopenia and neutropenia that reached a nadir by day 7 of his illness. He had elevated liver enzymes as well. The diagnosis was confirmed on the basis of NS1 antigen detection by enzyme-linked immunosorbent assay. His blood cultures and polymerase chain reaction tests for cytomegalovirus were negative. He made an uneventful recovery and was discharged by day 9 of his illness. However, normalization of liver function took nearly two weeks. In three previously reported Brazilian cases of dengue after liver transplantation, the patients presented with dengue shock syndrome, in contrast to the relatively milder presentation of our patient. Because of the lack of case reports in the literature, it is difficult to ascertain the risk factors for severe dengue infection in transplants, but dengue fever reported in renal transplants sheds some light on them. High-dose steroids increase the risk of thrombocytopenia, whereas tacrolimus has been reported to prolong the duration of symptoms. Otherwise, dengue fever is a relatively mild illness in patients who have undergone renal transplantation, and renal allograft survival has been reported to be 86% following dengue fever.

Conclusion

Dengue is a rarely reported infection in patients who have undergone transplantation. A high degree of suspicion is required for diagnosis. Dengue NS1 antigen detection is a useful addition to the already existing methods of diagnosis. Steroids and tacrolimus have effects on the morbidity of the disease. Graft outcomes following the infection has been excellent in all reported cases.

Reactivation of mucosal and cutaneous leishmaniasis in a renal transplanted patient

Mucosal leishmaniasis (ML) is a chronic form of tegumentary leishmaniasis, which causes destructive lesions of nasal, pharyngeal, and laryngeal mucosa. We describe a case of leishmaniasis reactivation with simultaneous cutaneous and mucosal forms in a renal transplanted patient with no history of prior leishmaniasis. Reactivation after renal transplantation was not reported in Brazil. A 67-year-old woman receiving prednisone 20 mg/day, tacrolimus 1 mg/day, and mycophenolic acid 360 mg/day presented with nose edema with erythema and cutaneous lesions. Amastigotes were identified on biopsies and the polymerase chain reaction confirmed Leishmania (Viannia) braziliensis. The patient was treated with liposomal amphotericin B but died 3 weeks after as a result of bacterial septic shock. In conclusion, tegumentary leishmaniasis can reactivate with simultaneous cutaneous and mucosal forms in a renal transplanted patient during the immunosuppressant therapy.

Children of Senegal River Basin show the highest prevalence of Blastocystis sp. ever observed worldwide

Background

Blastocystis sp. is currently the most common intestinal protist found in human feces and considered an emerging parasite with a worldwide distribution. Because of its potential impact in public health, we reinforced the picture of Blastocystis sp. prevalence and molecular subtype distribution in Africa by performing the first survey of this parasite in Senegal.

Methods

Stool samples from 93 symptomatic presenting with various gastrointestinal disorders or asymptomatic children living in three villages of the Senegal River Basin were tested for the presence of Blastocystis sp. by non-quantitative and quantitative PCR using primer pairs targeting the SSU rDNA gene. Positive samples were subtyped to investigate the frequency of Blastocystis sp. subtypes in our cohort and the distribution of subtypes in the symptomatic and asymptomatic groups of children.

Results

By the use of molecular tools, all 93 samples were found to be positive for Blastocystis sp. indicating a striking parasite prevalence of 100%. Mixed infections by two or three subtypes were identified in eight individuals. Among a total of 103 subtyped isolates, subtype 3 was most abundant (49.5%) followed by subtype 1 (28.2%), subtype 2 (20.4%) and subtype 4 (1.9%). Subtype 3 was dominant in the symptomatic group while subtypes 1 and 2 were detected with equal frequency in both symptomatic and asymptomatic groups. The distribution of subtypes was compared with those available in other African countries and worldwide. Comparison confirmed that subtype 4 is much less frequently detected or absent in Africa while it is commonly found in Europe. Potential sources of Blastocystis sp. infection including human-to-human, zoonotic, and waterborne transmissions were also discussed.

Conclusions

The prevalence of Blastocystis sp. in our Senegalese population was the highest prevalence ever recovered worldwide for this parasite by reaching 100%. All cases were caused by subtypes 1, 2, 3 and 4 with a predominance of subtype 3. More than half of the children infected by Blastocystis sp. presented various gastrointestinal disorders. Such high prevalence of blastocystosis in developing countries makes its control a real challenge for public health authorities.

Emerging Pathogens - How Safe is Blood?

During the last few decades, blood safety efforts were mainly focused on preventing viral infections. However, humanity's increased mobility and improved migration pathways necessitate a global perspective regarding other transfusion-transmitted pathogens. This review focuses on the general infection risk of blood components for malaria, dengue virus, Trypanosoma cruzi (Chagas disease) and Babesia spp. Approximately 250 million people become infected by Plasmodium spp. per year. Dengue virus affects more than 50 million people annually in more than 100 countries; clinically, it can cause serious diseases, such as dengue haemorrhagic fever and dengue shock syndrome. Chagas disease, which is caused by Trypanosoma cruzi, mainly occurs in South America and infects approximately 10 million people annually. Babesia spp. is a parasitic infection that infects red blood cells; although many infections are asymptomatic, severe clinical disease has been reported, especially in the elderly. Screening assays are available for all considered pathogens but make screening strategies more complex and more expensive. A general pathogen inactivation for all blood components (whole blood) promises to be a long-term, sustainable solution for both known and unknown pathogens. Transfusion medicine therefore eagerly awaits such a system.

Pulmonary nocardiosis associated with cerebral abscess successfully treated by co-trimoxazole: a case report

Nocardiosis is an acute or chronic infectious disease caused by the soil-borne filamentous bacteria belonging to the genus Nocardia. The organisms opportunistically infect both immunocompromised and immunocompetent individuals. The lungs are the primary site of infection and brain abscess is, by far, the most common complication following nocardial metastasis from pulmonary lesions. Although surgical intervention must always be considered in the treatment of nocardial brain abscess, it can obviously be cured by antibiotic therapy alone. This report describes a case infected by Nocardia cyriacigeorgica. Identification of the infectious agent was achieved by conventional and semi-nested PCR techniques. A 55-year-old woman with fever was referred to the infect disclinic of Imam Khomeini hospital in Tehran and was hospitalized after clinical assessment. She was a kidney transplant recipient for 4 years and was taking immunosuppressive treatment including azathioprine and methylprednisolone. Follow-up of the patient by CT scan revealed pulmonary infection and cerebral lesions. Specimens of the brain lesions contained filamentous bacteria. The patient received a combination of co-trimoxazole and ceftriaxone and brain abscesses as well as lung inflammation disappeared gradually during the course of antibiotic therapy within 3 months. The patient was discharged from the hospital after 2 months of therapy.

Gastrointestinal infections after transplantation

PURPOSE OF REVIEW

Recipients of both solid organ transplant and hematopoietic stem cell transplantation are at increased risk for infectious morbidity and mortality after transplantation due to on-going immunosuppression. Gastrointestinal infections have been increasingly reported in these populations.

RECENT FINDINGS

Increased reports of gastrointestinal infections including bacterial infection with Clostridium difficile, viral infection with norovirus and parasitic pathogens like cryptosporidium are emerging. Risk factors identified have focused on type of transplant, transplant immunosuppression regimens and exposures. Although many events are self-limiting, significant morbidity and rare mortality are reported.

SUMMARY

Improved diagnostic techniques have increased the reporting of several gastrointestinal infections after transplantation, affording improved understanding of the epidemiology of these diseases. Armed with this emerging data, prevention, recognition of infection and treatment strategies can be more thoroughly assessed in these at-risk populations.