Visceral leishmaniasis in immunocompromised patients with and without AIDS: a comparison of clinical features and prognosis

Case Report: Leishmaniasis in a 33-Year-Old Man with Multiple Sclerosis

Leishmaniasis is a protozoan disease caused by species of genus Leishmania. Immunosuppression increases the risk of severe clinical forms and impairs response to treatment. The expansion of the use of immunomodulatory drugs for different conditions has raised the number of these cases. In this report, we present a case of visceral leishmaniasis in a patient with multiple sclerosis (MS) under fingolimod treatment. He presented with the triad of fever, visceromegaly, and pancytopenia and was diagnosed by the presence of amastigotes in a bone marrow sample. Furthermore, we discuss the previous published cases of MS patients under different immunosuppressant therapies to highlight its risk in endemic areas and suggest a therapeutic approach.

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.

Is Visceral Leishmaniasis Different in Immunocompromised Patients Without Human Immunodeficiency Virus? A Comparative, Multicenter Retrospective Cohort Analysis

Although visceral leishmaniasis (VL) can affect immunocompromised patients, data from the human immunodeficiency virus (HIV) infection context are limited, and the characteristics of VL in other immunosuppression scenarios are not well defined. A retrospective review of all cases of VL in immunocompromised patients from January 1997 to December 2014 in two Spanish hospitals on the Mediterranean coast was performed. We included 18 transplant recipients (kidney: 7, liver: 4, lung: 3, heart: 2, and blood marrow: 2), 12 patients with other causes of immunosuppression (myasthenia gravis: 3 and rheumatoid arthritis: 2), and 73 VL HIV-positive patients. Fever was more common in transplant patients (94.4%) and patients with other types of immunosuppression (100%) than in HIV-positive individuals (73.3%). Hepatomegaly was less common in transplant recipients (27.8%) and patients with other types of immunosuppression (41.7%) compared with HIV-positive patients (69.9%) (P = 0.01; P = 0.001, respectively). Patients with other types of immunosuppression had a median leukocyte count of 1.5 × 10⁹/L, significantly lower than HIV-positive patients (2.5 × 10⁹/L) (P = 0.04). Serology was more commonly positive in nontransplant immunosuppressed individuals (75%) and transplant recipients (78.6%) than in HIV-patients (13.8%) (P < 0.001). Antimonial therapy was rarely used in transplant recipients (1.9%) and never in patients with other immunosuppressive conditions, whereas 34.2% of HIV-positive patients received it (P = 0.05 and P = 0.01, respectively). Mortality was 16.7% in both transplant recipients and patients with other immunosuppressive conditions and 15.1% in HIV-positive patients. The features of VL may be different in immunosuppressed patients, with more fever and less hepatomegaly and leukopenia than in HIV-infected patients.

Visceral leishmaniasis and HIV/AIDS in Brazil: Are we aware enough?

Background

The urbanization of visceral leishmaniasis (VL) and the concurrent movement of the HIV infection to rural areas in Brazil are possible mechanisms associated with an increased number of Leishmania/HIV coinfected people. This study aimed to describe the clinical and epidemiological profile of VL/HIV coinfected patients and compare this profile to non-coinfected VL patients.

Methods

Cases of VL/HIV coinfection were obtained through a probabilistic record linkage of databases of VL and AIDS cases from the Brazilian Ministry of Health.

Results

We retrieved 760 cases of VL/HIV coinfection, most prevalent in adult males, with incidence ranging from 0.01 to 0.07 cases, per 100.000 population, in 2001 and 2010, respectively. Case-fatality rates were 27.3% in 2001 and 23.2% in 2010. Weakness, weight loss, cough, other associated infections and haemorrhagic phenomena were more commonly found among coinfected patients, which had a fatality rate three times higher as compared to the non-coinfected group. The relapse proportion was two times greater among coinfected (6.3%) than non-coinfected (3.1%).

Conclusions

The results found herein contribute to the increase of knowledge of the epidemiological situation of VL/HIV coinfection in Brazil and reinforce the necessity of implementing specific strategies to improve early case detection and efficacious and less toxic treatment in order to achieve lower case-fatality rates.

Visceral leishmaniasis (VL) is an infectious disease present in 75 countries. Brazil is among the six countries that represent over 90% of the cases worldwide. AIDS is an emerging disease present in approximately 190 countries and a major public health problem worldwide due to its magnitude and damage extension. In Brazil, the recent alterations of the AIDS and VL distribution patterns, such as movement of the HIV infection to rural areas and the urbanization of VL associated to the rise of VL cases among the 20–49 years old age group, are possible factors associated with an increased risk of the population to present both infections. The coexistence of these diseases enhances the severity, seeing that VL accelerates the development of AIDS in HIV patients, and AIDS increases the risk of VL up to 100 to 1,000 times in endemic areas. Considering that the association of both infections is recent, however rising in several countries, our study contributes to the knowledge of the profile, magnitude and severity of VL/HIV coinfection, which can subsidize actions to overcome challenges related to both VL and AIDS and assist in guiding actions and decision-making processes.

Visceral leishmaniosis in immunocompromised host: an update and literature review

Visceral leishmaniasis (VL) is a chronic infectious disease endemic in tropical and sub-tropical areas including the Mediterranean basin, caused by a group of protozoan parasites of the genus Leishmania and transmitted by phlebotomine sandflies. Immunocompromised patients, in particular HIV positive, are considered at risk of VL. They report atypical signs and poor response to treatment due to impairment of T-helper and regulatory cells activity. Laboratory diagnosis is based on microscopy on bone marrow or spleen aspirates. Value of serology remains high in term of sensibility, but a positive test must be confirmed by microscopy or molecular tests. Treatment is based on Liposomal amphotericin B whose administration is associated to lower incidence of side effects, in respect to antimonials and other formulations of AmB. Use of Miltefosine needs further investigation when L. infantum is the causative agent. Frequent relapses are observed in co-infected HIV who can benefit of a second cycle.

Diagnosis and Treatment of Leishmaniasis: Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH)

It is important to realize that leishmaniasis guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. The IDSA and ASTMH consider adherence to these guidelines to be voluntary, with the ultimate determinations regarding their application to be made by the physician in the light of each patient's individual circumstances.

Clinical, hematological and biochemical alterations in hamster (Mesocricetus auratus) experimentally infected with Leishmania infantum through different routes of inoculation

Background

Leishmaniasis remains among the most important parasitic diseases in the developing world and visceral leishmaniasis (VL) is the most fatal. The hamster Mesocricetus auratus is a susceptible model for the characterization of the disease, since infection of hamsters with L. infantum reproduces the clinical and pathological features of human VL. In this context, it provides a unique opportunity to study VL in its active form. The main goal of this study was to evaluate the clinical, biochemical, and hematological changes in male hamsters infected through different routes and strains of L. infantum.

Methods

In the current study, hamsters (Mesocricetus auratus) were infected with the L. infantum strains (WHO/MHOM/BR/74/PP75 and MCAN/BR/2008/OP46) by intradermal, intraperitoneal and intracardiac routes. The animals were monitored for a nine  month follow-up period.

Results

The hamsters showed clinical signs similar to those observed in classical canine and human symptomatic VL, including splenomegaly, severe weight loss, anemia, and leucopenia. Therefore the OP46 strain was more infective, clinical signs were more frequent and more exacerbated in IC group with 80 to 100 % of the animals showing splenomegaly, in the last month infection. Additionally, desquamation, hair loss and external mucocutaneous lesions and ulcers localized in the snout, accompanied by swelling of the paws in all animals, were observed. Consequently, the animals presented severe weight loss/cachexia, hunched posture, an inability to eat or drink, and non-responsiveness to external stimuli. Furthermore, regardless of strain, route of inoculum and time assessed, the animals showed renal and hepatic alterations, with increased serum levels of urea and creatinine as well as elevated serum levels of aspartate aminotransferase and alanine aminotransferase.

Conclusions

These results strongly suggest that the inoculation through the intracardiac route resulted in a higher severity among infections, especially in the sixth and ninth month after infection via intracardiac, exhibited clinical manifestations and biochemical/hematological findings similar to human visceral leishmaniasis. Therefore, we suggest that this route must be preferentially used in experimental infections for pathogenesis studies of VL in the hamster model.

[Hemophagocytosis and disseminated intravascular coagulation in visceral leishmaniasis in adults: three new cases]

Les atteintes cliniques et biologiques communes au syndrome d'activation macrophagique (SAM) et à la leishmaniose viscérale (LV) rendent le diagnostic étiologique du SAM très difficile. Cette association est rare et grave. Nous rapportons trois nouvelles observations de SAM secondaire à une LV, compliquées de coagulation intravasculaire disséminée (CIVD). Il s'agissait de trois hommes, âgés respectivement de 31, 20 et 60 ans. Le tableau était fait de fièvre et de splénomégalie associés à une pancytopénie et une CIVD. Le diagnostic de LV était fait par le myélogramme, les sérologies et la polymerase chain reaction. Chez l'un de nos patients, une deuxième sérologie était nécessaire. Tous nos patients étaient traités par Glucantime^® avec une bonne évolution. Un cas de pancréatite aigue était noté. En en zones d'endémie, devant un SAM compliqué de CIVD, une LV doit être recherchée, en répétant si nécessaire certaines explorations initialement négatives. Le pronostic dépend de la rapidité du traitement spécifique.

Mucosal leishmaniasis mimicking squamous cell carcinoma in a liver transplant recipient

Organ transplant recipients living in endemic regions are at increased risk of Leishmania infections. Visceral leishmaniasis is the most common kind of presentation in the Mediterranean basin. Rarely, Leishmania infantum may cause localized mucosal disease. We present the first case, to our knowledge, of a liver transplant recipient with localized mucosal leishmaniasis. Twenty-two years after transplantation, a painless, very slow growing ulcer appeared on the inner side of the patient's upper lip. A biopsy performed in the community hospital showed non-specific chronic inflammation without neoplastic signs. Because of a high suspicion of malignancy, the patient was transferred to the referral hospital to consider complete excision. The excisional biopsy revealed a granulomatous inflammatory reaction together with intracellular Leishmania amastigotes within macrophages. Leishmaniasis was confirmed by the nested polymerase chain reaction assay. The clinical and laboratory findings did not suggest visceral involvement. The patient received meglumine antimoniate for 21 days without relevant adverse effects.

Is leishmaniasis an "unusual suspect" of infection in allogeneic transplantation?

Leishmaniasis is a disease of the immunocompetent population, more often affecting infants and young children. However, the number of leishmaniasis cases associated with immunosuppression has increased over the last 20 years. The visceral form of the disease, visceral leishmaniasis (VL), is identified as an opportunistic infection in immunosuppressed individuals, occurring mainly after solid organ transplantation, especially in renal transplant recipients. Limited data are available about VL after hematopoietic stem cell transplantation (HSCT). We report the cases of 3 patients with late VL after allogeneic HSCT, and review the literature.

Cell death in amastigote forms of Leishmania amazonensis induced by parthenolide

Background

Leishmania amazonensis infection results in diverse clinical manifestations: cutaneous, mucocutaneous or visceral leishmaniasis. The arsenal of drugs available for treating Leishmania infections is limited. Therefore, new, effective, and less toxic leishmaniasis treatments are still needed. We verified cell death in amastigote forms of Leishmania amazonensis induced by the sesquiterpene lactone parthenolide.

Results

The tested compound was able to concentration-dependently affect axenic and intracellular amastigotes, with IC₅₀ values of 1.3 μM and 2.9 μM, respectively after 72 h incubation. No genotoxic effects were observed in a micronucleus test in mice. Parthenolide induced morphological and ultrastructural changes in axenic amastigotes, including a loss of membrane integrity, swelling of the mitochondrion, cytoplasmic vacuoles, and intense exocytic activity in the region of the flagellar pocket. These results led us to investigate the occurrence of autophagic vacuoles with monodansylcadaverine and the integrity of the plasma membrane and mitochondrial membrane potential using flow cytometry. In all of the tests, parthenolide had positive results.

Conclusions

Our results indicate that the antileishmanial action of parthenolide is associated with autophagic vacuole appearance, a reduction of fluidity, a loss of membrane integrity, and mitochondrial dysfunction. Considering the limited repertoire of existing antileishmanial compounds, the products derived from medicinal plants has been one the greatest advances to help develop new chemotherapeutic approaches.

Leishmania-HIV co-infection: clinical presentation and outcomes in an urban area in Brazil

Background

Visceral leishmaniasis (VL) is an emerging condition affecting HIV-infected patients living in Latin America, particularly in Brazil. Leishmania-HIV coinfection represents a challenging diagnosis because the clinical picture of VL is similar to that of other disseminated opportunistic diseases. Additionally, coinfection is related to treatment failure, relapse and high mortality.

Objective

To assess the clinical-laboratory profile and outcomes of VL-HIV-coinfected patients using a group of non HIV-infected patients diagnosed with VL during the same period as a comparator.

Methods

The study was conducted at a reference center for infectious diseases in Brazil. All patients with suspected VL were evaluated in an ongoing cohort study. Confirmed cases were divided into two groups: with and without HIV coinfection. Patients were treated according to the current guidelines of the Ministry of Health of Brazil, which considers antimony as the first-choice therapy for non HIV-infected patients and recommends amphotericin B for HIV-infected patients. After treatment, all patients with CD4 counts below 350 cells/mm³ received secondary prophylaxis with amphotericin B.

Results

Between 2011 and 2013, 168 patients with suspected VL were evaluated, of whom 90 were confirmed to have VL. In total, 51% were HIV coinfected patients (46 patients). HIV-infected patients had a lower rate of fever and splenomegaly compared with immunocompetent patients. The VL relapse rate in 6 months was 37% among HIV-infected patients, despite receiving secondary prophylaxis. The overall case-fatality rate was 6.6% (4 deaths in the HIV-infected group versus 2 deaths in the non HIV-infected group). The main risk factors for a poor outcome at 6 months after the end of treatment were HIV infection, bleeding and a previous VL episode.

Conclusion

Although VL mortality rates among HIV-infected individuals are close to those observed among immunocompetent patients treated with amphotericin B, HIV coinfection is related to a low clinical response and high relapse rates within 6 months.

Visceral leishmaniasis (VL) is of a higher clinical importance as an opportunistic infection in individuals infected with HIV (human immunodeficiency virus type-1) in areas where both infections are endemic. Co-infected patients classically present a chronic clinical course, with high rates of treatment failure and relapse. Differences in the clinical presentation of VL between HIV-infected and uninfected patients and the factors related to an unfavorable outcome remain rarely studied. In this work, the clinical and laboratory characteristics of patients with VL were compared according to HIV infection status, and the main determinants of a poor outcome at 6 months were identified.

The prevention of canine leishmaniasis and its impact on public health

Canine leishmaniasis (CanL) caused by Leishmania infantum is a vector-borne disease of great veterinary and medical significance. Prevention of CanL requires a combined approach including measures focused on dogs and the environment where the vectors perpetuate. Over past decades, considerable effort has been put towards developing novel and cost-effective strategies against CanL. Vaccination is considered among the most promising tools for controlling CanL, and synthetic pyrethroids are useful and cost-effective in reducing risk of L. infantum infection in dogs. The effectiveness of the use of vaccines plus repellents in preventing L. infantum infection and subsequent disease development should be assessed by means of large-scale, randomized controlled field trials because this combined strategy may become the next frontier in the control of CanL.

Parasitic infections in solid organ transplant recipients

Parasitic diseases are rare infections after a solid organ transplant (SOT). Toxoplasmosis, Trypanosoma cruzi, and visceral leishmanias are the 3 main opportunistic protozoal infections that have the potential to be lethal if not diagnosed early and treated appropriately after SOT. Strongyloides stercoralis is the one helminthic disease that is life-threatening after transplant. This review addresses modes of transmission, methods of diagnosis, and treatment of the most serious parasitic infections in SOT. The role of targeted pretransplant screening of the donor and recipient for parasitic diseases is also discussed.

Involvement of CD4⁺ Foxp3⁺ regulatory T cells in persistence of Leishmania donovani in the liver of alymphoplastic aly/aly mice

Visceral leishmaniasis (VL) is a chronic and fatal disease in humans and dogs caused by the intracellular protozoan parasites, Leishmania donovani and L. infantum (L. chagasi). Relapse of disease is frequent in immunocompromised patients, in which the number of VL cases has been increasing recently. The present study is aimed to improve the understanding of mechanisms of L. donovani persistence in immunocompromised conditions using alymphoplastic aly/aly mice. Hepatic parasite burden, granuloma formation and induction of regulatory T cells were determined for up to 7 months after the intravenous inoculation with L. donovani promastigotes. While control aly/+ mice showed a peak of hepatic parasite growth at 4 weeks post infection (WPI) and resolved the infection by 8 WPI, aly/aly mice showed a similar peak in hepatic parasite burden but maintained persistent in the chronic phase of infection, which was associated with delayed and impaired granuloma maturation. Although hepatic CD4⁺Foxp3⁺ but not CD8⁺Foxp3⁺ T cells were first detected at 4 WPI in both strains of mice, the number of CD4⁺Foxp3⁺ T cells was significantly increased in aly/aly mice from 8 WPI. Immunohistochemical analysis demonstrated the presence of Foxp3⁺ T cells in L. donovani–induced hepatic granulomas and perivascular neo-lymphoid aggregates. Quantitative real-time PCR analysis of mature granulomas collected by laser microdissection revealed the correlation of Foxp3 and IL-10 mRNA level. Furthermore, treatment of infected aly/aly mice with anti-CD25 or anti-FR4 mAb resulted in significant reductions in both hepatic Foxp3⁺ cells and parasite burden. Thus, we provide the first evidence that CD4⁺Foxp3⁺ Tregs mediate L. donovani persistence in the liver during VL in immunodeficient murine model, a result that will help to establish new strategies of immunotherapy against this intracellular protozoan pathogen.

The protozoan parasite Leishmania donovani is the causative agent of visceral leishmaniasis (VL) with a variety of outcomes ranging from asymptomatic to fatal infection. In the last decade, an increasing number of VL cases in immunocompromised conditions have been reported. Loss of the control of parasite persistence causes relapse of the disease in these patients. To clarify why parasite persistence and disease are caused in an immunocompromised condition, we examined L. donovani infection in alymphoplastic aly/aly mice that completely lack lymph nodes and have disturbed spleen architecture. Although parasites grew in the liver of aly/+ mice for the first 4 weeks post infection (WPI) and parasites were eliminated by 8 WPI, we found that parasites persisted in the liver of aly/aly mice with the ineffective of granuloma formation to kill the parasites. These aly/aly mice showed significant increases in CD4⁺Foxp3⁺ regulatory T cells in the liver. Consequently, we treated infected mice with anti-CD25 or anti-FR4 mAb to inhibit the function of Tregs, and found significant reductions in both hepatic Foxp3⁺ cells and parasite burden. These results clearly demonstrated for the first time that the expansion of CD4⁺Foxp3⁺ Tregs is involved in hepatic L. donovani persistence in immunodeficient murine model.

Parasitic infections in solid-organ transplant recipients

PURPOSE OF REVIEW

To provide an updated perspective of the most common parasitic infections occurring in solid-organ transplant (SOT) recipients.

RECENT FINDINGS

Parasitic infections are an emerging problem in SOT programs and represent a diagnostic and therapeutic challenge. Transplantation in endemic areas - including medical tourism, international travel and migration - justify the necessity of considering parasitic infections in the differential diagnosis of posttransplant complications. Molecular techniques, such as PCR, may improve the diagnostic accuracy and help during the follow-up.

SUMMARY

Parasitic infections are an uncommon but potentially severe complication in SOT recipients. An increase of donors emigrated from tropical areas and more posttransplant patients traveling to endemic areas have led to a rise in parasitic infections reported among SOT recipients. Transplant physicians should get familiar with parasitic infections and promote adherence to preventive measures in SOT recipients.

DNA vaccination with KMP11 and Lutzomyia longipalpis salivary protein protects hamsters against visceral leishmaniasis

It was recently shown that immunization of hamsters with DNA plasmids coding LJM19, a sand fly salivary protein, partially protected against a challenge with Leishmania chagasi, whereas immunization with KMP11 DNA plasmid, a Leishmania antigen, induced protection against L. donovani infection. In the present study, we evaluated the protective effect of immunization with both LJM19 and KMP11 DNA plasmid together. Concerning the protection against an infection by L. chagasi, immunization with DNA plasmids coding LJM19 or KMP11, as well as with both plasmids combined, induced IFN-γ production in draining lymph nodes at 7, 14 and 21 days post-immunization. Immunized hamsters challenged with L. chagasi plus Salivary Gland Sonicate (SGS) from Lutzomyia longipalpis showed an enhancement of IFN-γ/IL-10 and IFN-γ/TGF-β in draining lymph nodes after 7 and 14 days of infection. Two and five months after challenge, immunized animals showed reduced parasite load in the liver and spleen, as well as increased IFN-γ/IL-10 and IFN-γ/TGF-β ratios in the spleen. Furthermore, immunized animals remained with a normal hematological profile even five months after the challenge, whereas L. chagasi in unimmunized hamsters lead to a significant anemia. The protection observed with LJM19 or KMP11 DNA plasmids used alone was very similar to the protection obtained by the combination of both plasmids.

New challenges in the epidemiology and treatment of visceral leishmaniasis in periurban areas

Visceral leishmaniasis [VL] represents a major public health problem in many areas of the world. This review focuses on the impact of periurbanization on the epidemiology and treatment of VL, using Brazil as an example. VL continues to be mostly a disease of poverty with impact on families. However, the disease has expanded in Latin America, with foci reported as far south as Argentina. There is an increasing overlap of Leishmania infantum chagasi and HIV infections and other immunosuppressive conditions, resulting in VL emerging as an opportunistic infection. This new setting poses new challenges for VL disease control and patient management.

Predictors of visceral leishmaniasis relapse in HIV-infected patients: a systematic review

BACKGROUND AND OBJECTIVES

Visceral leishmaniasis (VL) is a common complication in AIDS patients living in Leishmania-endemic areas. Although antiretroviral therapy has changed the clinical course of HIV infection and its associated illnesses, the prevention of VL relapses remains a challenge for the care of HIV and Leishmania co-infected patients. This work is a systematic review of previous studies that have described predictors of VL relapse in HIV-infected patients.

REVIEW METHODS

We searched the electronic databases of MEDLINE, LILACS, and the Cochrane Central Register of Controlled Trials. Studies were selected if they included HIV-infected individuals with a VL diagnosis and patient follow-up after the leishmaniasis treatment with an analysis of the clearly defined outcome of prediction of relapse.

RESULTS

Eighteen out 178 studies satisfied the specified inclusion criteria. Most patients were males between 30 and 40 years of age, and HIV transmission was primarily via intravenous drug use. Previous VL episodes were identified as risk factors for relapse in 3 studies. Two studies found that baseline CD4+ T cell count above 100 cells/mL was associated with a decreased relapse rate. The observation of an increase in CD4+ T cells at patient follow-up was associated with protection from relapse in 5 of 7 studies. Meta-analysis of all studies assessing secondary prophylaxis showed significant reduction of VL relapse rate following prophylaxis. None of the five observational studies evaluating the impact of highly active antiretroviral therapy use found a reduction in the risk of VL relapse upon patient follow-up.

CONCLUSION

SOME PREDICTORS OF VL RELAPSE COULD BE IDENTIFIED: a) the absence of an increase in CD4+ cells at follow-up; b) lack of secondary prophylaxis; and c) previous history of VL relapse. CD4+ counts below 100 cells/mL at the time of primary VL diagnosis may also be a predictive factor for VL relapse.

Recent advances in leishmaniasis treatment

About 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis occur each year around the world. For over half a century, the clinical forms of the disease have been treated almost exclusively with pentavalent antimonial compounds. In this review, we describe the arsenal available for treating Leishmania infections, as well as recent advances from research on plants and synthetic compounds as source drugs for treating the disease. We also review some new drug-delivery systems for the development of novel chemotherapeutics. We observe that the pharmaceutical industry should employ its modern technologies, which could lead to better use of plants and their extracts, as well as to the development of synthetic and semi-synthetic compounds. New studies have highlighted some biopharmaceutical technologies in the design of the delivery strategy, such as nanoparticles, liposomes, cochleates, and non-specific lipid transfer proteins. These observations serve as a basis to indicate novel routes for the development and design of effective anti-Leishmania drugs.

Effect of elatol, isolated from red seaweed Laurencia dendroidea, on Leishmania amazonensis

In the present study, we investigated the antileishmanial activity of sesquiterpene elatol, the major constituent of the Brazilian red seaweed Laurencia dendroidea (Hudson) J.V. Lamouroux, against L. amazonensis. Elatol after 72 h of treatment, showed an IC(50) of 4.0 μM and 0.45 μM for promastigote and intracellular amastigote forms of L. amazonensis, respectively. By scanning and transmission electron microscopy, parasites treated with elatol revealed notable changes compared with control cells, including: pronounced swelling of the mitochondrion; appearance of concentric membrane structures inside the organelle; destabilization of the plasma membrane; and formation of membrane structures, apparently an extension of the endoplasmic reticulum, which is suggestive of an autophagic process. A cytotoxicity assay showed that the action of the isolated compound is more specific for protozoa, and it is not toxic to macrophages. Our studies indicated that elatol is a potent antiproliferative agent against promastigote and intracellular amastigote forms, and may have important advantages for the development of new anti-leishamanial chemotherapies.

Visceral Leishmaniasis Revealing Chronic Granulomatous Disease in a Child

We report the first description of visceral leishmaniasis (VL) infection as a harbinger of chronic granulomatous disease (CGD) in a 3-year old child. Although VL is not frequently suspected in CGD patients, our case emphasises the importance of a complete evaluation of the immune system in children presenting with VL in order to exclude underlying immunodeficiency states. As the prognosis of CGD is poor, with high morbidity and mortality, establishing an early diagnosis has important practical implications in the successful treatment of these patients. Following the diagnosis, the patient received Human Leukocyte Antigen (HLA) identical sibling bone marrow transplantation (BMT). The child is now 2 years post-transplant and is in good general conditions with normal blood counts, and evidence of full-donor chimerism in repeated fluorescence in situ hybridization (FISH) studies.

Leishmaniasis among organ transplant recipients

Leishmaniasis is a rarely reported disease among transplant recipients; however, the number of published cases has quadrupled since the beginning of the 1990s. Most cases have been observed in patients living in countries of the Mediterranean basin. Leishmaniasis is most commonly associated with kidney transplantation (77%), and cases are also recorded among patients undergoing liver, heart, lung, pancreas, and bone marrow transplantation. Visceral leishmaniasis (VL) is the most frequently observed clinical presentation, followed by mucosal leishmaniasis and more rarely cutaneous leishmaniasis. Transplant recipients with VL develop the classic clinical form of the disease, which is a febrile hepatosplenic and pancytopenic syndrome. Immunodepression seems to predispose to development of mucosal leishmaniasis caused by viscerotropic strains. Early diagnosis of VL is crucial for patient therapy and outcome; however, this is frequently overlooked or delayed in transplant patients. Pentavalent antimonials are the most commom form of treatment for VL, but have a high incidence of toxicity (34%). Although used in fewer patients, liposomal amphotericin B seems to be better tolerated and should be considered as first-line therapy in transplant recipients.

Liver transplant recipient with concomitant cutaneous and visceral leishmaniasis

Diagnosis of leishmaniasis in immunosuppressed patients may be a serious challenge for physicians because of the major clinical and laboratory differences with immunocompetent patients. In immunosuppressed patients, the disease is characterized usually by disseminated visceral involvement, atypical cutaneous lesions and persistent negativity of diagnostic tests. Here, we report an eight-yr-old liver transplant recipient with concomitant cutaneous and visceral leishmaniasis in whom the cutaneous lesion led to the diagnosis of systemic involvement.

Efficacy of a combination of 10% imidacloprid/50% permethrin for the prevention of leishmaniasis in kennelled dogs in an endemic area

The efficacy of imidacloprid 10%and permethrin 50% (Advantix; Bayer AG, Germany) in a spot-on formulation was evaluated in the field as a control measure to prevent canine leishmaniasis (CanL) in dogs in an endemic area of southern Italy. In February 2005, out of 845 dogs initially tested for CanL, 631 dogs which tested negative (315 from a kennel in Bari (KB) and 316 from a kennel in Ginosa (KG)) in a serological and a parasitological examination were allocated to one of three groups: Group A-treated with imidacloprid 10% and permethrin 50% once a month; Group B-treated every 2 weeks; and Group C-untreated control animals. All the dogs were examined serologically and parasitologically for CanL prior to the start of the study, in November 2005 (end of the sandfly season) and in March 2006 (end of the study). An initial CanL seroprevalence of 24.7% (209 dogs) was detected in KB and KG. In KB Leishmania infection, inferred by positivity in at least one of the three tests performed at the interim or final follow-up, was found in one animal from Group A and in nine from Group C. No positive animals were detected in Group B, thus giving a final protection efficacy of 88.9% in Group A and 100% in Group B. In KG Leishmania infection was identified in one animal from Groups A and B, respectively, and 11 from Group C (protection efficacy of 90.36% in Group A and 90.73% in Group B). The incidence density rates (IDRs) of infection in both Groups A and B at each kennel were statistically significantly lower than that registered in Group C (KB p<0.05 and KG p<0.01). The results clearly show that a combination of imidacloprid 10% and permethrin 50%, by virtue of its repellent activity against sandflies, is effective under both application regimes in preventing CanL in the field in endemic areas.

[Intestinal leishmaniasis and Sézary syndrome: endoscopic diagnosis]

Sézary syndrome is a non-Hodgkin's lymphoma of cutaneous origin that provokes severe cellular immunosuppression leading to greater susceptibility to opportunistic infections. We present the case of a male patient with a diagnosis of Sézary syndrome complicated by visceral leishmaniasis and Mycobacterium avium complex coinfection, with intestinal involvement of both pathogens -an exceptional finding in the absence of HIV infection. The diagnosis was confirmed by bone marrow biopsy and oral endoscopy with intestinal biopsy. Because of the severity of the infection and the failure of conventional treatment, miltefosine, a new antiparasitic agent still under investigation, was administered with favorable response. However the patient developed fatal pneumonia.

Multiplex analysis of circulating cytokines in the sera of patients with different clinical forms of visceral leishmaniasis

BACKGROUND

The clinical spectrum of visceral leishmaniasis (VL), a chronic intracellular parasitic disease, ranges from a subclinical, asymptomatic infection to severe clinical disease (kala-azar). In experimental leishmaniasis, mice that have a Th1 response to infection tend to have limited disease while a Th2 response is associated with disease progression. Humans with VL most often have mixed rather than polarized responses. However, most clinical studies have used methods that require a relatively large sample volume, thus limiting their scope. Measuring multiple cytokine levels in blood samples using a multiplexed microsphere assay (MMA) may be useful to further evaluate the Th1/Th2 paradigm in humans.

METHODS

Bangladeshi individuals (n=120) living in an area endemic for VL were categorized into one of the five clinical categories. Sera from these individuals were measured for levels of IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IFN-gamma, and TNF-alpha by multiplexed microsphere cytokine immunoassay.

RESULTS

Circulating IL-8, IL-10, and IL-12 differed significantly among the clinical groups. Persons with kala-azar demonstrated the highest median levels of IL-8 and IL-10 but lower median levels of IL-12.

CONCLUSIONS

The MMA for cytokines is an extremely time-and sample-efficient method for characterizing circulating cytokine levels in visceral leishmaniasis patients.

Parasitic central nervous system infections in immunocompromised hosts: malaria, microsporidiosis, leishmaniasis, and African trypanosomiasis

Immunosuppression associated with HIV infection or following transplantation increases susceptibility to central nervous system (CNS) infections. Because of increasing international travel, parasites that were previously limited to tropical regions pose an increasing infectious threat to populations at risk for acquiring opportunistic infection, especially people with HIV infection or individuals who have received a solid organ or bone marrow transplant. Although long-term immunosuppression caused by medications such as prednisone likely also increases the risk for acquiring infection and for developing CNS manifestations, little published information is available to support this hypothesis. In an earlier article published in Clinical Infectious Diseases, we described the neurologic manifestations of some of the more common parasitic CNS infections. This review will discuss the presentation, diagnosis, and treatment of the following additional parasitic CNS infections: malaria, microsporidiosis, leishmaniasis, and African trypanosomiasis.

Risk factors in the spread of leishmaniases: towards integrated monitoring?

Environmental changes, immune status and treatment failure constitute the three major risk factors for the (re-)emergence and spread of leishmaniases. Except for Leishmania-HIV co-infection, these risk factors are not systematically monitored and their interaction is poorly studied and understood. Recently, the multidisciplinary network Leish-Med was launched to document this issue around the Mediterranean and to promote transborder control strategies.

Advances in leishmaniasis

Governed by parasite and host factors and immunoinflammatory responses, the clinical spectrum of leishmaniasis encompasses subclinical (inapparent), localised (skin lesions), and disseminated infection (cutaneous, mucosal, or visceral). Symptomatic disease is subacute or chronic and diverse in presentation and outcome. Clinical characteristics vary further by endemic region. Despite T-cell-dependent immune responses, which produce asymptomatic and self-healing infection, or appropriate treatment, intracellular infection is probably life-long since targeted cells (tissue macrophages) allow residual parasites to persist. There is an epidemic of cutaneous leishmaniasis in Afghanistan and Pakistan and of visceral infection in India and Sudan. Diagnosis relies on visualising parasites in tissue or serology; culture and detection of parasite DNA are useful in the laboratory. Pentavalent antimony is the conventional treatment; however, resistance of visceral infection in India has spawned new treatment approaches--amphotericin B and its lipid formulations, injectable paromomycin, and oral miltefosine. Despite tangible advances in diagnosis, treatment, and basic scientific research, leishmaniasis is embedded in poverty and neglected. Current obstacles to realistic prevention and proper management include inadequate vector (sandfly) control, no vaccine, and insufficient access to or impetus for developing affordable new drugs.

Emerging parasitic infections

Parasitic infections are felt by most individuals to have little impact on the health and well being of most inhabitants of Canada, Western Europe, and the United States. As the authors show in this article, parasites are always "emerging" somewhere and have a significant impact on those areas of the world. Moreover, as we are becoming an ever-smaller global village, catastrophes and instability in the Third World affect control of parasitic diseases endemic to those areas, ensuring greater chances of transmission to visitors there. The foundation of successful limitation of parasitic diseases in both developing and developed regions is still accurate and rapid diagnosis.