Clinical aspects of visceral leishmaniasis in HIV infection:

The Parasitemia has Contributed to the Severity of Cases of Visceral Leishmaniasis

Visceral leishmaniasis (VL) occurs due to the evolution, virulence, and adaptation of Leishmania, vector biology, host immune system evasion, and reservoir hosts. Parasitemia can be involved as a warning regarding the clinical severity of VL The present study aims to evaluate the relationship between parasitemia and the prognosis of individuals with VL. Blood and bone marrow samples from individuals with VL were analyzed to identify parasite and quantify or measure parasite burden. Individuals were classified in the clinical score model of risk of death by disease proposed by Coura-Vital et al. (PLoS Negl Trop Dis 8(12): e33742014, 2014). 39/74 individuals presented a better prognosis, and 35/74 individuals presented a worse prognosis. HIV + VL co-infection was present in 32 individuals, of which 12 were considered severe. The group aged 51 to 64 was classified as severe, with a decrease in leukocytes (p-value 0.0295) and neutrophils (p-value 0.0476). L. infantum DNA was identified in blood and bone marrow, in 69 individuals, and not detected in 5 individuals. The quantification of the parasite showed greater parasitemia in bone marrow (P = 0.0003) with an average of 4.70 × 104 Leishmanias/mL about blood, with 0.29 × 104 Leishmanias/mL. Individuals in the age group aged 51 to 64 co-infected with HIV + VL had higher parasitemia (p-value 0.0150) with 2.44 × 104 Leishmanias/mL in blood and bone marrow than in the group aged 20 to 50. Parasitemia, measured by molecular biology in blood and bone marrow, was related to the worst clinical prognosis of VL in the age group aged 51 to 64.

Touching Base with Some Mediterranean Diseases of Interest from Paradigmatic Cases at the "Magna Graecia" University Unit of Infectious Diseases: A Didascalic Review

Among infectious diseases, zoonoses are increasing in importance worldwide, especially in the Mediterranean region. We report herein some clinical cases from a third-level hospital in Calabria region (Southern Italy) and provide a narrative review of the most relevant features of these diseases from epidemiological and clinical perspectives. Further, the pathogenic mechanisms involved in zoonotic diseases are reviewed, focusing on the mechanisms used by pathogens to elude the immune system of the host. These topics are of particular concern for individuals with primary or acquired immunodeficiency (e.g., people living with HIV, transplant recipients, patients taking immunosuppressive drugs). From the present review, it appears that diagnostic innovations and the availability of more accurate methods, together with better monitoring of the incidence and prevalence of these infections, are urgently needed to improve interventions for better preparedness and response.

HIV pozitif hastalarda visseral leishmaniasis ve intestinal parazitlerin koenfeksiyonunun araştırılması

Parasitic infections are more frequently observed in immunosuppressed cases, such as those infected with human immunodeficiency virus (HIV). Furthermore, compared to immunocompetent cases, a more severe clinical course is observed in the immunosuppressed patient group. HIV-positive individuals have increased pathogenicity of parasites and may exhibit a wide range of clinical symptoms of varying severity that may result in mortality. Visceral leishmaisis (VL) is a vector-borne disease and an important opportunistic infection seen in HIV/AIDS cases, most notably in Southern Europe and Africa, where both infections are endemic. Several parasites namely toxoplasmosis, cryptosporidiosis, isosporiasis, cyclosporiasis, amebiasis, giardiasis, plasmodium, and strongyloidiasis are infections posing significant risk factors for these patient groups. In this study, visceral leishmaniasis was investigated serologically in serum samples and parasitic infections were analyzed by conventional methods in fecal samples from HIV-positive cases. 5 of the 42 cases included in the study were female. The mean age of these cases was 38.7 years (19-66). Blastocystis spp was detected in 5 fecal samples obtained from HIV-positive cases. The rK39 dipstick test with serum samples yielded a very weak band in one case, while none of the other tests yielded a positive band. As a result, the regional prevalence of these latent infections, which can be subclinical in HIV-positive patients, is important to know. However, the literature lacks sufficient data on the situation in Turkey. In this study, the prevalence of enteric parasitic infections in people with HIV infection in our region was found to be low and VL was not detected.

AmBisome monotherapy and combination AmBisome - miltefosine therapy for the treatment of visceral leishmaniasis in patients co-infected with HIV in India: a randomised open label, parallel arm, phase 3 trial

Background

Visceral leishmaniasis (VL) in patients with human immunodeficiency virus (HIV) presents an increasingly important patient cohort in areas where both infections are endemic. Evidence for treatment is sparce, with no high-quality studies from the Indian subcontinent.

Methods

This is a randomized, open-label, parallel-arm, phase 3 trial conducted within a single hospital in Patna, India. One hundred and fifty patients aged ≥18 years with serologically confirmed HIV and parasitologically confirmed VL were randomly allocated to 1 of 2 treatment arms, either a total 40 mg/kg intravenous liposomal amphotericin B (AmBisome; Gilead Pharmaceuticals) administered in 8 equal doses over 24 days or a total 30 mg/kg intravenous AmBisome administered in 6 equal doses given concomitantly with a total 1.4 g oral miltefosine administered through 2 daily doses of 50 mg over 14 days. The primary outcome was intention-to-treat relapse-free survival at day 210, defined as absence of signs and symptoms of VL or, if symptomatic, negative parasitological investigations.

Results

Among 243 patients assessed for eligibility, 150 were recruited between 2 January 2017 and 5 April 2018, with no loss to follow-up. Relapse-free survival at day 210 was 85% (64/75; 95% CI, 77–100%) in the monotherapy arm, and 96%, (72/75; 90–100%) in the combination arm. Nineteen percent (28/150) were infected with concurrent tuberculosis, divided equally between arms. Excluding those with concurrent tuberculosis, relapse-free survival at day 210 was 90% (55/61; 82–100%) in the monotherapy and 97% (59/61; 91–100%) in the combination therapy arm. Serious adverse events were uncommon and similar in each arm.

Conclusions

Combination therapy appears to be safe, well tolerated, and effective, and halves treatment duration of current recommendations.

Clinical Trials Registration

Clinical Trial Registry India (CTRI/2015/05/005807; the protocol is available online at https://osf.io/avz7r).

Knowledge, attitude and practices towards visceral leishmaniasis among HIV patients: A cross-sectional study from Bihar, India

Background

In the Indian state of Bihar, visceral leishmaniasis (VL) is a major public health issue that has been aggravated by the rising incidence of new Human immunodeficiency virus (HIV) infections. In endemic areas, the risk of VL infections in patients living with HIV (PLHIV) is higher. It is important to investigate the disease-related knowledge, attitude, and practices (KAP) of PLHIV in Bihar in order to monitor HIV/VL co-infection. Adequate knowledge, a positive attitude, and good practices for VL control are essential to stamp out the disease. This study investigated the KAP towards VL in HIV patients attending antiretroviral therapy (ART) clinic at ICMR-RMRIMS, Patna.

Methods

A questionnaire based cross-sectional study was performed among 120 HIV patients aged ≥18 years, to evaluate their KAP regarding visceral leishmaniasis. For the KAP indicators, each correct answer received a score of 1, while unsure and incorrect responses received a score of 0. Descriptive statistics and logistic regression were used for the analysis. Data analysis was performed using Statistical Package for the Social Sciences (SPSS) version 27.

Results

The study population had a male (68.30%) preponderance with a mean age of 37.03 years ± 9.80 years of standard deviation. The majority (93.30%) of the study participants had previously heard about VL. Only 32.10% of those who had heard about VL knew that the disease was transmitted by the sandfly. Most (80.40%) of the study respondents were ignorant of the sandfly breeding grounds. The vast majority (75.90%) had no idea how to recognize sandflies and were unaware of their biting time, leishmaniasis transmission season, and preventive practices. Although PLHIV are vulnerable to VL, only 27.70% of them agreed that VL is a fatal disease if untreated, and 42.90% believed they wear not at risk of developing the disease. Regarding the control methods of sandflies, 28.60% of participants did not use any methods to avoid sandfly bites. The multivariable analysis revealed that occupation and family history were the two independent predictor variables of the knowledge index. Age and gender were significantly associated with attitude towards VL. Participants working as laborers had significantly lesser odds (AOR: 0.248, 95% CI: 0.073–0.844) to follow good preventive practices. There were significantly higher odds of having good practice among participants aged 18–40 years (AOR: 6.866, 95% CI: 1.694–27.834) and those residing in urban areas (AOR: 4.159, 95% CI: 1.317–13.139) than their peers. Overall, 27.7% of respondents were knowledgeable, 41.1% had a positive mindset, and 33.9% had strong VL preventive habits, according to the study.

Conclusion

The study determined a remarkable gap in the knowledge attitude and practices towards VL among PLHIV. This underscores the need of augmented health education initiatives for PLHIV in endemic areas for good VL awareness and preventive practices.

Evaluation of qPCR on blood and skin microbiopsies, peripheral blood buffy coat smear, and urine antigen ELISA for diagnosis and test of cure for visceral leishmaniasis in HIV-coinfected patients in India: a prospective cohort study

INTRODUCTION

HIV coinfection presents a challenge for diagnosis of visceral leishmaniasis (VL). Invasive splenic or bone marrow aspiration with microscopic visualisation of Leishmania parasites remains the gold standard for diagnosis of VL in HIV-coinfected patients. Furthermore, a test of cure by splenic or bone marrow aspiration is required as patients with VL-HIV infection are at a high risk of treatment failure. However, there remain financial, implementation and safety costs to these invasive techniques which severely limit their use under field conditions.

METHODS AND ANALYSIS

We aim to evaluate blood and skin qPCR, peripheral blood buffy coat smear microscopy and urine antigen ELISA as non-invasive or minimally invasive alternatives for diagnosis and post-treatment test of cure for VL in HIV-coinfected patients in India, using a sample of 91 patients with parasitologically confirmed symptomatic VL-HIV infection.

ETHICS AND DISSEMINATION

Ethical approval for this study has been granted by The Liverpool School of Tropical Medicine, The Institute of Tropical Medicine in Antwerp, the University of Antwerp and the Rajendra Memorial Research Institute of Medical Science in Patna. Any future publications will be published in open access journals.

TRIAL REGISTRATION NUMBER

CTRI/2019/03/017908.

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

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

Frequency of Leishmania spp. infection among HIV-infected patients living in an urban area in Brazil: a cross-sectional study

Background

There is little information about the frequency of Leishmania infection in asymptomatic people living with HIV (PLWH) and about the performance of laboratory diagnostic methods in coinfected patients in Latin America. The main objective of this study is to evaluate the frequency of Leishmania spp. infection in HIV-infected patients living in an urban area in Brazil.

Methods

To detect Leishmania infection, diagnostic tests were performed to detect anti-Leishmania antibodies (ELISA using Leptomonas seymouri antigens; ELISA using rK39 antigens; ELISA using rK28 antigens; indirect fluorescent-antibody test (IFAT); direct agglutination test (DAT)) and Leishmania DNA (polymerase chain reaction (PCR) with the target genes kDNA and ITS-1).

Results

The frequency of at least one positive test was 15%. For ELISA using Leptomonas antigens and IFAT, there was an association between CD4+ T lymphocyte counts and test positivity, with a higher positivity of these tests in more immunosuppressed patients (CD4+ T cell count < 200/mm³).

Conclusions

According to our data, there was a high prevalence of Leishmania spp. infections in this population living with HIV. Although there is the possibility of cross-reaction, some tests that are considered highly specific for the diagnosis of Leishmania infection were positive. There was also an association between the positivity of some tests studied and lower values of CD4+ T lymphocytes.

Laboratory Diagnosis of Cutaneous and Visceral Leishmaniasis: Current and Future Methods

Leishmaniasis is a neglected tropical disease with two main clinical forms: cutaneous and visceral leishmaniasis. Diagnosis of leishmaniasis is still a challenge, concerning the detection and correct identification of the species of the parasite, mainly in endemic areas where the absence of appropriate resources is still a problem. Most accessible methods for diagnosis, particularly in these areas, do not include the identification of each one of more than 20 species responsible for the disease. Here, we summarize the main methods used for the detection and identification of leishmaniasis that can be performed by demonstration of the parasite in biological samples from the patient through microscopic examination, by in vitro culture or animal inoculation; by molecular methods through the detection of parasite DNA; or by immunological methods through the detection of parasite antigens that may be present in urine or through the detection of specific antibodies against the parasite. Potential new methods that can be applied for laboratory diagnosis of leishmaniasis are also discussed.

Nano- and Microformulations to Advance Therapies for Visceral Leishmaniasis

Visceral leishmaniasis (VL) is a deadly, vector-borne, neglected tropical disease endemic to arid parts of the world and is caused by a protozoan parasite of the genus Leishmania. Chemotherapy is the primary treatment for this systemic disease, and multiple potent therapies exist against this intracellular parasite. However, several factors, such as systemic toxicity, high costs, arduous treatment regimen, and rising drug resistance, are barriers for effective therapy against VL. Material-based platforms have the potential to revolutionize chemotherapy for leishmaniasis by imparting a better pharmacokinetic profile and creating patient-friendly routes of administration, while also lowering the risk for drug resistance. This review highlights promising drug delivery strategies and novel therapies that have been evaluated in preclinical models, demonstrating the potential to advance chemotherapy for VL.

Can We Harness Immune Responses to Improve Drug Treatment in Leishmaniasis?

Leishmaniasis is a vector-borne parasitic disease that has been neglected in priority for control and eradication of malaria, tuberculosis, and HIV/AIDS. Collectively, over one seventh of the world’s population is at risk of being infected with 0.7–1.2 million new infections reported annually. Clinical manifestations range from self-healing cutaneous lesions to fatal visceral disease. The first anti-leishmanial drugs were introduced in the 1950′s and, despite several shortcomings, remain the mainstay for treatment. Regardless of this and the steady increase in infections over the years, particularly among populations of low economic status, research on leishmaniasis remains under funded. This review looks at the drugs currently in clinical use and how they interact with the host immune response. Employing chemoimmunotherapeutic approaches may be one viable alternative to improve the efficacy of novel/existing drugs and extend their lifespan in clinical use.

A spotlight on the diagnostic methods of a fatal disease Visceral Leishmaniasis

Leishmania donovani (a causative agent of visceral leishmaniasis) poses a serious health threat to the human population which is fatal if left untreated. The life cycle of Leishmania alternates between vertebrate host and Phlebotomine fly as intermediate ones. Due to the difficulties linked to vector (sandfly) control and the lack of an effective vaccine, the control of leishmaniasis relies mostly on chemotherapy. Unfortunately, the prevalence of parasites becoming resistant to the first-line drug pentavalent antimonial (Sb^V )/sodium antimony gluconate (SAG) and some other anti-leishmanial drug is increasing in several parts of the world. With the alarming rise of drug resistance and other issues related to VL, there is an urgent need to focus on early detection and quick diagnosis of VL case. Therefore, we have reviewed most of the methods used in the diagnostic process of VL. Along with existing diagnostic methods, developing more effective and sensitive diagnostic methods and biomarkers is also vital for enhancing VL identification and control programs. This review gathers the comprehensive information on diagnostics methods of VL under a single umbrella that could be the prominent tools for the development of rapid, accurate and cost-effective diagnostic kits for VL which can be used in field conditions.

Quality of life perceptions amongst patients co-infected with Visceral Leishmaniasis and HIV: A qualitative study from Bihar, India

Background

Co-infection with Visceral Leishmaniasis (commonly known as Kala Azar, KA) and Human Immunodeficiency Virus (HIV) is increasingly being diagnosed among patients in Bihar. This qualitative study is the first assessment of self-reported quality of life among patients co-infected with KA-HIV in the Asian context.

Methods

We conducted semi-structured, in-depth interviews and adopted an inductive thematic analysis to generate evidence on the quality of life of patients co-infected with KA and HIV. Patients were purposively sampled until saturation was attained.

Results

We found that patients highly valued income or livelihood potential and health as indicators of a good quality life, and routinely went into debt accessing care in the private setup. This was due to perceptions of poor quality of care in the government setup and a lack of knowledge regarding available government services at the district level. KA symptoms were often misdiagnosed in the private sector as seasonal fever, while care providers found it difficult to disentangle the clinical symptoms of KA and HIV; hence, patients presented late to district hospitals. Patients perceived a high level of stigma, largely due to their HIV status, and routinely reported that HIV had “destroyed” their life.

Conclusions

Inadequate social support and referral pathways that were not conducive to patient needs negatively impacted patients’ quality of life. The dual burden of poverty interacting with the severity and chronicity of KA-HIV co-infection means financial support, increased community engagement, and collaborative decision making are crucial for co-infected patients. Increased provider awareness of co-infection and effective stigma-reduction interventions should be integrated to ensure that appropriate and effective access to care is possible for this vulnerable population. A sustainable long-term strategy requires a people-centered approach wherein the perceptions and life circumstances of patients are taken into account in the medical decision making process.

Risk mapping of human HIV-Leishmaniasis co-infection in Morocco

Background

HIV/AIDS is frequently associated with opportunistic diseases such as leishmaniasis. Hence, the co-infection HIV-Leishmania spp. is the result of the geographical overlap between leishmaniasis and HIV/AIDS cases. To the best of our knowledge, this is the first report describing the spatial distribution of HIV-Leishmaniasis co-infection in Morocco where both infections are endemic.

Methods

In the current study, we discuss the HIV-Leishmania spp. co-infection vulnerability in Morocco by using the cartography tools. Thus, epidemiological data of both infections (Leishmaniasis and HIV/AIDS) in different administrative regions of Morocco were collected and co-registered for Digital maps making.

Results & conclusion

The results showed a high risk of HIV-Leishmania infantum co-infection in northern and central regions in Morocco. These results should be taken into account for efficient control strategies and epidemiological surveillance of HIV –Leishmania spp. co-infection in Morocco.

Identifying miltefosine-resistant key genes in protein-protein interactions network and experimental verification in Iranian Leishmania major

Drug resistance is a complex phenomenon during leishmaniasis chemotherapy. In this study, the genes and pathways involved in miltefosine (MIL)-resistant Leishmania were identified using microarray data and in silico approaches. GSE30685 and GSE45496 were obtained from GEO database and analyzed with GEO2R tool to identify genes involved in MIL-resistant Leishmania. 177 differentially expressed genes (DEGs) were selected from these GSEs, which about half of them were uncharacterized/hypothetical proteins. The interactions between DEGs were investigated using STRING database and protein-protein interaction (PPI) networks. Five hub nodes were found in the PPI network. The gene ontology (GO) analysis of the resulting network revealed that DNA replication (GO:0006260) and ATP hydrolysis coupled proton transport (GO:0015991) were the most enriched GO term. Iranian MIL-resistant Leishmania major (L. major) parasites were generated by exposure of wild-type isolates to the increasing concentrations of MIL over a period of 5 months. Proof of mRNA expression levels of the obtained hub genes was assessed in Iranian wild-type and acquired resistant L. major parasites by real-time PCR. A significant higher expression level of LDBPK_150170 (encoding protein phosphatase 2C, PP2C), was only observed in Iranian L. major parasites resistance to MIL. Moreover, the RT-PCR results showed that the expression of metacyclic marker (small hydrophilic endoplasmic reticulum-associated protein, SHERP) and MIL-resistant marker (Leishmania MIL-transporter, LMT) was significantly increased and decreased, respectively, in Iranian MIL-resistant L. major parasites. Taken together, these data suggested that PP2C as well as SHERP and LMT genes may be prospective targets for the treatment of MIL-resistant Leishmania.

Leishmaniasis

Leishmaniasis is a poverty-related disease with two main clinical forms: visceral leishmaniasis and cutaneous leishmaniasis. An estimated 0·7-1 million new cases of leishmaniasis per year are reported from nearly 100 endemic countries. The number of reported visceral leishmaniasis cases has decreased substantially in the past decade as a result of better access to diagnosis and treatment and more intense vector control within an elimination initiative in Asia, although natural cycles in transmission intensity might play a role. In east Africa however, the case numbers of this fatal disease continue to be sustained. Increased conflict in endemic areas of cutaneous leishmaniasis and forced displacement has resulted in a surge in these endemic areas as well as clinics across the world. WHO lists leishmaniasis as one of the neglected tropical diseases for which the development of new treatments is a priority. Major evidence gaps remain, and new tools are needed before leishmaniasis can be definitively controlled.

Does timing of antiretroviral treatment influence treatment outcomes of visceral leishmaniasis in Northwest Ethiopia?

Background

Visceral leishmaniasis (VL) patients with HIV co-infection should receive antiretroviral treatment (ART). However, the best timing for initiation of ART is not known. Among such individuals, we assessed the influence of ART timing on VL outcomes.

Methods

A retrospective cohort study was conducted in Northwest Ethiopia among VL patients starting ART between 2008 and 2015. VL outcomes were assessed by the twelfth month of starting ART, within 4 weeks of VL diagnosis or thereafter.

Results

Of 213 VL-HIV co-infected patients with ART initiation, 96 (45.1%) had moderate to severe malnutrition, 53 (24.9%) had active TB and 128 (60.1%) had hemoglobin levels under 9 g/dL. Eighty-nine (41.8%) were already on ART before VL diagnosis, 46 (21.6%) started ART within 4 weeks, and 78 (36.6%) thereafter. Definitive cure in those starting ART within 4 weeks 59% (95% CI 43–75%) and those starting thereafter 56% (95% CI 44–68%) was not significantly different. Those starting ART before primary VL had higher 12-months mortality compared to those starting later (RR 0.6; 95% CI 0.4–0.9; p=0.012).

Conclusions

VL-HIV patients are severely ill and with serious additional comorbidities. Outcomes of HIV-VL management are unsatisfactory and early ART initiation was associated with higher mortality. Further research on the optimal timing of ART initiation, and ensuring earlier diagnosis of VL patients, with improved management of comorbidities are needed.

Is Visceral Leishmaniasis the same in HIV-coinfected adults?

Introduction

Visceral Leishmaniasis is the most severe form of disease caused by the Leishmania donovani complex, with significant morbidity and mortality in developing countries. Worse outcomes occur among HIV-positive individuals coinfected with Leishmania. It is unclear, however, if there are significant differences on presentation between Visceral Leishmaniasis patients with or without HIV coinfection.

Methods

We reviewed medical records from adult patients with Visceral Leishmaniasis treated at a reference healthcare center in Fortaleza – Ceará, Brazil, from July 2010 to December 2013. Data from HIV-coinfected patients have been abstracted and compared to non-HIV controls diagnosed with Visceral Leishmaniasis in the same period.

Results

Eighty one HIV-infected patients and 365 controls were enrolled. The diagnosis in HIV patients took significantly longer, with higher recurrence and death rates. Kala-azar's classical triad (fever, constitutional symptoms and splenomegaly) was less frequently observed in Visceral Leishmaniasis-HIV patients, as well as jaundice and edema, while diarrhea was more frequent. Laboratory features included lower levels of hemoglobin, lymphocyte counts and liver enzymes, as well as higher counts of blood platelets and eosinophils. HIV-infected patients were diagnosed mainly through amastigote detection on bone marrow aspirates and treated more often with amphotericin B formulations, whereas in controls, rK39 was the main diagnostic tool and pentavalent antimony was primarily used for treatment.

Conclusions

Clinical and laboratory presentation of Visceral Leishmaniasis in HIV-coinfected patients may differ from classic kala-azar, and these differences may be, in part, responsible for the delay in diagnosing and treating leishmaniasis, which might lead to worse outcomes.

Small Myristoylated Protein-3, Identified as a Potential Virulence Factor in Leishmania amazonensis, Proves to be a Protective Antigen against Visceral Leishmaniasis

In a proteomics approach conducted with Leishmania amazonensis, parasite proteins showed either an increase or a decrease in their expression content during extensive in vitro cultivation, and were related to the survival and the infectivity of the parasites, respectively. In the current study, a computational screening was performed to predict virulence factors among these molecules. Three proteins were selected, one of which presented no homology to human proteins. This candidate, namely small myristoylated protein-3 (SMP-3), was cloned, and its recombinant version (rSMP-3) was used to stimulate peripheral blood mononuclear cells (PBMCs) from healthy subjects living in an endemic area of leishmaniasis and from visceral leishmaniasis patients. Results showed high interferon-γ (IFN-γ) production and low levels of interleukin 10 (IL-10) in the cell supernatants. An in vivo experiment was then conducted on BALB/c mice, which were immunized with rSMP-3/saponin and later challenged with Leishmania infantum promastigotes. The rSMP-3/saponin combination induced high production of protein-specific IFN-γ, IL-12, and granulocyte-macrophage colony-stimulating factor (GM-CSF) by the spleen cells of the immunized mice. This pattern was associated with protection, which was characterized by a significant reduction in the parasite load in distinct organs of the animals. Altogether, these results have revealed that this new virulence factor is immunogenic in both mice and humans, and have proven its protective efficacy against visceral leishmaniasis in a murine model.

Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies

In today's global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.

Protective Efficacy of Secondary Prophylaxis Against Visceral Leishmaniasis in Human Immunodeficiency Virus Coinfected Patients Over the Past 10 Years in Eastern India

Coinfection with visceral leishmaniasis (VL) and human immunodeficiency virus (HIV) leads to frequent treatment failure, relapse, and death. In this retrospective analysis from eastern India (2005-2015), our primary objective was to ascertain the protective efficacy of secondary prophylaxis with monthly amphotericin B (AmB) given in patients with HIV-VL coinfection toward reducing relapse and mortality rates. The secondary objective was to compare clinical features, laboratory findings, and treatment outcomes in HIV-VL patients in contrast to VL monoinfection. Overall, 53 cases of HIV-VL and 460 cases of VL monoinfection were identified after excluding incomplete records. Initial cure rate was 96.23% in HIV-VL (27 received liposomal AmB and 26 AmB deoxycholate). All patients with initial cure (N = 51) were given antiretroviral therapy. Secondary prophylaxis (N = 27) was provided with monthly 1 mg/kg AmB (15 liposomal, 12 deoxycholate). No relapse or death was noted within 6 months in the secondary prophylaxis group (relapse: none versus 18/24 [75%]; mortality: none versus 11/24 [45.8%]; P < 0.001 for both). Secondary prophylaxis remained the sole significant predictor against death in multivariate Cox regression model (hazard ratio = 0.09 [95% confidence interval = 0.03-0.31]; P < 0.001). HIV-VL patients had higher 6-month relapse rate, less relapse-free 12-month survival, and higher mortality (P < 0.001 each) than VL monoinfection. In conclusion, it appears from this study that secondary prophylaxis with monthly AmB might be effective in preventing relapse and mortality in HIV-VL.

Visceral leishmaniasis treatment outcome and its determinants in northwest Ethiopia

OBJECTIVES

Poor treatment outcomes of visceral leishmaniasis (VL) are responsible for the high mortality rate of this condition in resource-limited settings such as Ethiopia. This study aimed to identify the proportion of poor VL treatment outcomes in northwest Ethiopia and to evaluate the determinants associated with poor outcomes.

METHODS

A hospital-based retrospective study was conducted among 595 VL patients who were admitted to Kahsay Abera Hospital in northwest Ethiopia from October 2010 to April 2013. Data were entered into Epi Info version 7.0 and exported to SPSS version 20 for analysis. Bivariate and multivariate logistic regression models were fitted to identify the determinants of VL treatment outcomes. Adjusted odds ratio (aORs) with 95% confidence intervals (CIs) were used, and p-values <0.05 were considered to indicate statistical significance.

RESULTS

The proportion of poor treatment outcomes was 23.7%. Late diagnosis (≥29 days) (aOR, 4.34; 95% CI, 2.22 to 8.46), severe illness at admission (inability to walk) (aOR, 1.63; 95% CI, 1.06 to 2.40) and coinfection with VL and human immunodeficiency virus (HIV) (aOR, 2.72; 95% CI, 1.40 to 5.20) were found to be determinants of poor VL treatment outcomes.

CONCLUSIONS

Poor treatment outcomes, such as death, treatment failure, and non-adherence, were found to be common. Special attention must be paid to severely ill and VL/HIV-coinfected patients. To improve VL treatment outcomes, the early diagnosis and treatment of VL patients is recommended.

Clinical and Microbiological Characteristics of Visceral Leishmaniasis Outbreak in a Northern Italian Nonendemic Area: A Retrospective Observational Study

Background. Visceral leishmaniasis (VL) caused by Leishmania infantum is endemic in the Mediterranean area. In the last decades a northward spread of the parasite has been observed in Italy. This paper describes a VL outbreak in Modena province (Emilia-Romagna, Northern Italy) between 2012 and 2015. Methods. Retrospective, observational study to evaluate epidemiological, microbiological characteristics, and clinical management of VL in patients referring to Policlinico Modena Hospital. Results. Sixteen cases of VL occurred in the study period. An immunosuppressive condition was present in 81.3%. Clinical presentation included anemia, fever, leukopenia, thrombocytopenia, and hepatosplenomegaly. Serology was positive in 73.3% of cases, peripheral blood PCR in 92.3%, and bone marrow blood PCR in 100%. Culture was positive in 3/6 cases (50%) and all the isolates were identified as L. infantum by ITS1/ITS2 sequencing. The median time between symptom onset and diagnosis was 22 days (range 6–131 days). All patients were treated with liposomal amphotericin b. 18.8% had a VL recurrence and were treated with miltefosine. Attributable mortality was 6.3%. Conclusions. VL due to L. infantum could determine periodical outbreaks, as the one described; thus it is important to include VL in the differential diagnosis of fever of unknown origin, even in low-endemic areas.

Evaluating drug resistance in visceral leishmaniasis: the challenges

For decades antimonials were the drugs of choice for the treatment of visceral leishmaniasis (VL), but the recent emergence of resistance has made them redundant as first-line therapy in the endemic VL region in the Indian subcontinent. The application of other drugs has been limited due to adverse effects, perceived high cost, need for parenteral administration and increasing rate of treatment failures. Liposomal amphotericin B (AmB) and miltefosine (MIL) have been positioned as the effective first-line treatments; however, the number of monotherapy MIL-failures has increased after a decade of use. Since no validated molecular resistance markers are yet available, monitoring and surveillance of changes in drug sensitivity and resistance still depends on standard phenotypic in vitro promastigote or amastigote susceptibility assays. Clinical isolates displaying defined MIL- or AmB-resistance are still fairly scarce and fundamental and applied research on resistance mechanisms and dynamics remains largely dependent on laboratory-generated drug resistant strains. This review addresses the various challenges associated with drug susceptibility and -resistance monitoring in VL, with particular emphasis on the choice of strains, susceptibility model selection and standardization of procedures with specific read-out parameters and well-defined threshold criteria. The latter are essential to support surveillance systems and safeguard the limited number of currently available antileishmanial drugs.

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.

Magnesium-Dependent Ecto-ATP Diphosphohydrolase Activity in Leishmania donovani

In this work, we have described the expression of ecto-ATPDase on the external surface of Leishmania donovani. This enzyme has the ability to hydrolyze extracellular ATP. There is a low level of ATP hydrolysis in the absence of divalent cation 2.5 ± 0.51 nM Pi 10⁷ cells/h which shows the divalent cation-dependent activity of this enzyme in the intact parasite. However, MgCl₂ stimulated the ATP hydrolysis to a greater extent compared with CaCl₂ and ZnCl₂. This activity was also observed when replaced by MnCl₂. The Mg-dependent ecto-ATPase activity was 46.58 ± 6.248 nM Pi 10⁷ cells/h. The apparent K _m for ATP was 5.76 mM. Since Leishmania also possesses acid phosphatase activity and to discard the possibility that the observed ATP hydrolysis was due to acid phosphatase, the effect of pH was examined. In the pH range 6.0-9.0, in which the cells were viable, the phosphatase activity decreased while ATPase activity increased. To show that the observed ATP hydrolysis was not due to phosphatase or nucleotidase activity, certain inhibitors for these enzymes were tested. Vandate and NaF inhibited the phosphatase activity; Ammonium molybdate inhibited 5'-nucleotidase activity, but these inhibitors did not inhibit the observed ATP hydrolysis. However, when ADP was used as a substrate, there was no inhibition of ATP hydrolysis showing the possibility of ATP diphosphohydrolase activity. To confirm that this Mg-dependent ATPase activity is an ecto-ATPase activity, we used an impermeable inhibitor, 4,4'-diisothiocyanostilbene 2,-2'-disulfonic acid, as well as suramin, an antagonist of P2-purinoceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg²⁺-dependent ATPase activity in a dose-dependent manner. The presence of L. donovani E-NTPDase activity was demonstrated using antibodies against NTPDase by Western blotting and flow cytometry. The presence of Mg²⁺-dependent ATP diphosphohydrolase activity on the surface of L. donovani modulates the nucleotide concentration and protects the parasite from the lytic effects of the nucleotides mainly ATP. Ecto-ATPDase from L. donovani may be further characterized as a good antigen and as a target for immunodiagnosis and drug development, respectively.

Parasitic Infections in Hematopoietic Stem Cell Transplantation

Parasitic infections are rarely documented in hematopoietic stem cell transplant recipients. However they may be responsible for fatal complications that are only diagnosed at autopsy. Increased awareness of the possibility of parasitic diseases both in autologous and allogeneic stem cell transplant patients is relevant not only for implementing preventive measures but also for performing an early diagnosis and starting appropriate therapy for these unrecognized but fatal infectious complications in hematopoietic transplant recipients. In this review, we will focus on parasitic diseases occurring in this population especially those with major clinical relevance including toxoplasmosis, American trypanosomiasis, leishmaniasis, malaria, and strongyloidiasis, among others, highlighting the diagnosis and management in hematopoietic transplant recipients.

An unusual presentation of leishmaniasis in a human immunodeficiency virus-positive individual

Introduction:

Leishmaniasis is a neglected tropical disease caused by vector-borne protozoa of the genus Leishmania. Cutaneous and mucocutaneous forms result in disfiguration or mutilation, whilst visceral leishmaniasis (VL) affects multiple organs and is fatal if untreated. Notably, Leishmania are capable of establishing a chronic infection, which may reactivate years after initial infection when the host becomes immune-suppressed.

Case Presentation:

A 24-year-old human immunodeficiency virus (HIV)-positive male presented for excision of anal condylomas. At the time of his current condyloma excision, the patient had no additional symptoms or cutaneous findings, but was noted to have been only intermittently compliant with his antiretroviral therapy. Microscopic examination of the haematoxylin and eosin-stained anal condyloma tissue revealed koilocytic change, ulceration and brisk histiocytic inflammation containing numerous small intracellular bodies suggestive of Leishmania amastigotes. A bone marrow biopsy was performed and demonstrated similar intracellular forms. Anal condyloma tissue and bone marrow aspirate were sent to the Centers for Disease Control and Prevention's Parasitic Diseases Branch for confirmation of Leishmania and speciation. Specific immunohistochemical staining for Leishmania in the tissue section was positive and the species was confirmed as Leishmania donovani by PCR. Subsequently, the patient resumed highly active antiretroviral therapy and received anti-Leishmania therapy.

Conclusion:

Whilst the presentation of VL in HIV-positive patients is often similar to those without HIV, here we describe an unusual initial presentation of leishmaniasis in an HIV-positive patient where the parasite was found in an anal condyloma. VL is a critical diagnosis that should be considered and pursued when leishmaniasis is encountered in seemingly illogical clinical settings.

Feasibility of eliminating visceral leishmaniasis from the Indian subcontinent: explorations with a set of deterministic age-structured transmission models

Background

Visceral leishmaniasis (VL) is a neglected tropical disease transmitted by sandflies. On the Indian subcontinent (ISC), VL is targeted for elimination as a public health problem by 2017. In the context of VL, the elimination target is defined as an annual VL incidence of <1 per 10,000 capita at (sub-)district level. Interventions focus on vector control, surveillance and on diagnosing and treating VL cases. Many endemic areas have not yet achieved optimal control due to logistical, biological as well as technical challenges. We used mathematical modelling to quantify VL transmission dynamics and predict the feasibility of achieving the VL elimination target with current control strategies under varying assumptions about the reservoir of infection in humans.

Methods

We developed three deterministic age-structured transmission models with different main reservoirs of infection in humans: asymptomatic infections (model 1), reactivation of infection after initial infection (model 2), and post kala-azar dermal leishmaniasis (PKDL; model 3). For each model, we defined four sub-variants based on different assumptions about the duration of immunity and age-patterns in exposure to sandflies. All 12 model sub-variants were fitted to data from the KalaNet study in Bihar (India) and Nepal, and the best sub-variant was selected per model. Predictions were made for optimal and sub-optimal indoor residual spraying (IRS) effectiveness for three different levels of VL endemicity.

Results

Structurally different models explained the KalaNet data equally well. However, the predicted impact of IRS varied substantially between models, such that a conclusion about reaching the VL elimination targets for the ISC heavily depends on assumptions about the main reservoir of infection in humans: asymptomatic cases, recovered (immune) individuals that reactivate, or PKDL cases.

Conclusions

Available data on the impact of IRS so far suggest one model is probably closest to reality (model 1). According to this model, elimination of VL (incidence of <1 per 10,000) by 2017 is only feasible in low and medium endemic settings with optimal IRS. In highly endemic settings and settings with sub-optimal IRS, additional interventions will be required.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1292-0) contains supplementary material, which is available to authorized users.

Post-kala-azar dermal Leishmaniasis in two different clinical contexts

In Brazil, visceral Leishmaniasis is caused by Leishmania chagasi. The development of cutaneous lesions in visceral leishmaniasis patients has been described in two different clinical contexts. Patients with compromised immunity can develop skin lesions as a direct consequence of a current visceral disease. Equally, patients with a history of kala-azar and progressive, immune improvement occasionally develop skin lesions as a consequence of immune reconstitution infl ammatory syndrome. These cases manifest in similar fashion to the classic form of post-kala-azar dermal Leishmaniasis. We describe different cases that exemplify these two clinical presentations.

Relapse of visceral leishmaniasis in an HIV-infected patient successfully treated with a combination of miltefosine and amphotericin B

The present report documents a 49-year-old HIV-infected man receiving antiretroviral therapy with a suboptimal immune response and a CD4 count of 95 cells/mm(3), despite virological suppression. Investigation of bone marrow was conducted and yielded a diagnosis of visceral leishmaniasis. The clinical course was complicated by gastrointestinal involvment and relapse occurred after amphotericin B therapy. With the addition of miltefosine, the patient no longer presented with bone marrow amastigotes, and displayed an increased CD4 count and negative Leishmania polymerase chain reaction results. The present case highlights atypical presentation of visceral leishmaniasis, including poor immune reconstitution and gastrointestinal involvement. The high likelihood of relapse and response to combination therapy are illustrated.

Antimony to Cure Visceral Leishmaniasis Unresponsive to Liposomal Amphotericin B

We report on 4 patients (1 immunocompetent, 3 immunosuppressed) in whom visceral leishmaniasis had become unresponsive to (or had relapsed after) treatment with appropriate doses of liposomal amphotericin B. Under close follow-up, full courses of pentavalent antimony were administered without life-threatening adverse events and resulted in rapid and sustained clinical and parasitological cure.

Visceral leishmaniasis causes fever, enlargement of internal organs like the liver and the spleen, and leads to death if no treatment is given. It is caused by a microbe called Leishmania and affects children and adults in warm and temperate regions of the world. Antimony in different forms has been used to treat Visceral Leishmaniasis for almost one century and is still in use in several countries despite the fact that it sometimes displays toxic effects, especially in patients with underlying health problems. Because it is better tolerated and at least as effective as antimony, liposomal amphotericin B is now used as the first treatment for Visceral Leishmaniasis in Southern Europe. We observed that a small proportion of patients—especially those with an impaired immune system—do not cure even after several courses of liposomal amphotericin B. In 4 such patients with “unresponsiveness” to liposomal amphotericin B, antimony provided a sustained cure without major side effects. We conclude that when multiple failures or relapses occur after treatment with liposomal amphotericin B, antimony is a reasonable, potentially life-saving treatment option. These observations also suggest that “unresponsiveness” to amphotericin B results from unusual resistance mechanisms.

A Novel Sterol Isolated from a Plant Used by Mayan Traditional Healers Is Effective in Treatment of Visceral Leishmaniasis Caused by Leishmania donovani

Visceral leishmaniasis (VL), caused by the protozoan parasite Leishmania donovani, is a global health problem affecting millions of people worldwide. Treatment of VL largely depends on therapeutic drugs such as pentavalent antimonials, amphotericin B, and others, which have major drawbacks due to drug resistance, toxicity, and high cost. In this study, for the first time, we have successfully demonstrated the synthesis and antileishmanial activity of the novel sterol pentalinonsterol (PEN), which occurs naturally in the root of a Mexican medicinal plant, Pentalinon andrieuxii. In the experimental BALB/c mouse model of VL induced by infection with L. donovani, intravenous treatment with liposome-encapsulated PEN (2.5 mg/kg) led to a significant reduction in parasite burden in the liver and spleen. Furthermore, infected mice treated with liposomal PEN showed a strong host-protective TH1 immune response characterized by IFN-γ production and formation of matured hepatic granulomas. These results indicate that PEN could be developed as a novel drug against VL.

Fever of unknown origin: a clinical approach

Fevers of unknown origin remain one of the most difficult diagnostic challenges in medicine. Because fever of unknown origin may be caused by over 200 malignant/neoplastic, infectious, rheumatic/inflammatory, and miscellaneous disorders, clinicians often order non-clue-based imaging and specific testing early in the fever of unknown origin work-up, which may be inefficient/misleading. Unlike most other fever-of-unknown-origin reviews, this article presents a clinical approach. Characteristic history and physical examination findings together with key nonspecific test abnormalities are the basis for a focused clue-directed fever of unknown origin work-up.

Case Report: No Response to Liposomal Daunorubicin in a Patient with Drug-Resistant HIV-Associated Visceral Leishmaniasis

Visceral leishmaniasis (VL) in patients with HIV co-infection presents a significant therapeutic challenge due to the lessened chance of achieving long-term cure. We report a case of VL in a 60-year-old man with HIV infection who became refractory to anti-leishmania treatment due to multi-drug resistance. In the face of a worsening clinical situation, and with no other options available, he was treated with an experimental regimen of liposomal daunorubicin, which has previously been shown to have in vitro activity against Leishmania donovani and to be effective treatment of VL in animal studies. To our knowledge, he was the first patient with VL and HIV co-infection to have this treatment evaluated. We report on the lack of response to this treatment and possible causes for its failure.

In areas where leishmaniasis is endemic, visceral leishmaniasis (VL) is a potentially incurable AIDS illness in HIV infected people. Co-infection with HIV and any of the Leishmania species that cause VL can result in failure of the CD4 lymphocyte count to rise above 200 cells/mm³ despite sustained, effective suppression of HIV infection, and this failure of CD4 recovery then commonly prevents immune mediated eradication of VL despite aggressive, prolonged anti-Leishmania treatment. The situation is made more challenging by the limited number of agents active against VL and their high rate of adverse effects. We report the first evaluation of liposomal daunorubicin used to treat VL in a patient with HIV and L. infantum co-infection. We selected this drug on the basis of the proven activity of anthracyclines against Leishmania species both in vitro and in animal models and the well tolerated use of daunorubicin in HIV infected patients with Kaposi’s sarcoma. This treatment proved unsuccessful in our patient, probably because resistance of L. infantum to liposomal daunorubicin had been induced by previous treatment with another anti-leishmania drug, miltefosine.

Combination Treatment for Visceral Leishmaniasis Patients Coinfected with Human Immunodeficiency Virus in India

We describe the safety and efficacy of treating visceral leishmaniasis (VL) in patients with human immunodeficiency virus-VL coinfection with concurrent intravenous liposomal amphotericin B (AmBisome) and oral miltefosine (Impavido) in India. The regimen was safe, well tolerated, with lower relapse rates than monotherapy.

Background. There are considerable numbers of patients coinfected with human immunodeficiency virus (HIV) and visceral leishmaniasis (VL) in the VL-endemic areas of Bihar, India. These patients are at higher risk of relapse and death, but there are still no evidence-based guidelines on how to treat them. In this study, we report on treatment outcomes of coinfected patients up to 18 months following treatment with a combination regimen.

Methods. This retrospective analysis included all patients with confirmed HIV-VL coinfection receiving combination treatment for VL at a Médecins Sans Frontières treatment center between July 2012 and September 2014. Patients were treated with 30 mg/kg body weight intravenous liposomal amphotericin B (AmBisome) divided as 6 equal dose infusions combined with 14 days of 100 mg/day oral miltefosine (Impavido). All patients were encouraged to start or continue on antiretroviral therapy (ART).

Results. 102 patients (76% males, 57% with known HIV infection, 54% with a prior episode of VL) were followed-up for a median of 11 months (interquartile range: 4–18). Cumulative incidence of all-cause mortality and VL relapse at 6, 12, and 18 months was 11.7%, 14.5%, 16.6% and 2.5%, 6.0%,13.9%, respectively. Cumulative incidence of poor outcome at 6, 12, and 18 months was 13.9%, 18.4%, and 27.2%, respectively. Not initiating ART and concurrent tuberculosis were independent risk factors for mortality, whereas no factors were associated with relapse.

Conclusions. In this Bihar-based study, combination therapy appeared to be well tolerated, safe, and effective and may be considered as an option for treatment of VL in HIV coinfected patients.

Leishmaniasis revisited: Current aspects on epidemiology, diagnosis and treatment

Leishmaniasis is a vector-borne disease caused by protozoan parasites of the genus Leishmania. It is transmitted by phlebotomine female sand flies of the genera Phlebotomus and Lutzomyia in the old and new world, respectively. More than 20 well-recognized Leishmania species are known to infect humans and cause visceral (VL), cutaneous (CL) and mucocutaneous (ML) forms of the disease. Approximately 350 million people are at risk of contracting the disease and an estimated 1.6 million new cases occur annually. The disease mainly affects poor people in Africa, Asia and Latin America, and is associated with malnutrition, population migration, poor residency conditions, frail immune system and lack of resources. Previously, diagnosis of leishmaniasis relied mainly on invasive techniques of detecting parasites in splenic and bone marrow aspirates. Nevertheless, serological tests using the recombinant kinesin antigen (rK39) and molecular methods (polymerase chain reaction) are considered the best options for diagnosis today, despite problems related to varying sensitivities and specificities and field adaptability. Therapy of leishmaniasis ranges from local treatment of cutaneous lesions to systemic often toxic, therapy for disseminated CL, ML and VL. Agents with efficacy against leishmaniasis include amphotericin B, pentavalent antimonial drugs, paromomycin and miltefosine. No single therapy of VL currently offers satisfactory efficacy along with safety. This article provides a brief and updated systematic review on the epidemiology, diagnosis and treatment of this neglected disease.

Multilocus microsatellite typing of Leishmania and clinical applications: a review

Microsatellite markers have been used for Leishmania genetic studies worldwide, giving useful insight into leishmaniasis epidemiology. Understanding the geographic distribution, dynamics of Leishmania populations, and disease epidemiology improved markedly with this tool. In endemic foci, the origins of antimony-resistant strains and multidrug treatment failures were explored with multilocus microsatellite typing (MLMT). High genetic variability was detected but no association between parasite genotypes and drug resistance was established. An association between MLMT profiles and clinical disease manifestations was highlighted in only three studies and this data needs further confirmation. At the individual level, MLMT provided information on relapse and reinfection when multiple leishmaniasis episodes occurred. This information could improve knowledge of epidemiology and guide therapeutic choices for active chronic visceral leishmaniasis, the disease form in some HIV-positive patients.

Current clinical, laboratory, and treatment outcome characteristics of visceral leishmaniasis: results from a seven-year retrospective study in Greece

OBJECTIVES

Visceral leishmaniasis (VL) is re-emerging in endemic areas. The epidemiological, clinical, laboratory, and treatment outcome characteristics in a large cohort of VL patients is described herein.

METHODS

The cases of 67 VL patients (57% male, mean age 56 years) treated in two Greek hospitals over the last 7 years were identified and evaluated retrospectively.

RESULTS

Forty-six percent of patients reported contact with animals. Seventeen patients (25%) were immunocompromised, and 22% were co-infected with another pathogen. Sixty-four percent of patients had fever, 57% had weakness, 37% had sweats, 21% had weight loss, and 13% had a dry cough, while 6% developed haemophagocytic syndrome. The median duration of symptoms was 28 days. Fifty-eight percent of patients had splenomegaly, 49% had hepatomegaly, and 36% had lymphadenopathy. The diagnosis was established by positive PCR in peripheral blood (73%) and/or bone marrow specimens (34%). Sixty-one patients (91%) received liposomal amphotericin (L-AMB). Six patients (10%) did not respond or relapsed but were eventually cured after a second cycle of L-AMB. During a 6-month follow-up, the overall mortality was 9%, although none of these deaths was attributed to VL.

CONCLUSIONS

VL is still a common disease in endemic areas, affecting immunocompetent and immunocompromised patients. Its diagnosis is challenging, and molecular techniques are valuable and helpful tools to achieve this. Treatment with L-AMB is safe and very effective.

Travel advice for the immunocompromised traveler: prophylaxis, vaccination, and other preventive measures

Immunocompromised patients are traveling at increasing rates. Physicians caring for these complex patients must be knowledgeable in pretravel consultation and recognize when referral to an infectious disease specialist is warranted. This article outlines disease prevention associated with international travel for adults with human immunodeficiency virus, asplenia, solid organ and hematopoietic transplantation, and other immunosuppressed states. While rates of infection may not differ significantly between healthy and immunocompromised travelers, the latter are at greater risk for severe disease. A thorough assessment of these risks can ensure safe and healthy travel. The travel practitioners' goal should be to provide comprehensive risk information and recommend appropriate vaccinations or prevention measures tailored to each patient's condition. In some instances, live vaccines and prophylactic medications may be contraindicated.

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.

Leishmania infantum ecto-nucleoside triphosphate diphosphohydrolase-2 is an apyrase involved in macrophage infection and expressed in infected dogs

Background

Visceral leishmaniasis is an important tropical disease, and Leishmania infantum chagasi (synonym of Leishmania infantum) is the main pathogenic agent of visceral leishmaniasis in the New World. Recently, ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases) were identified as enablers of infection and virulence factors in many pathogens. Two putative E-NTPDases (∼70 kDa and ∼45 kDa) have been found in the L. infantum genome. Here, we studied the ∼45 kDa E-NTPDase from L. infantum chagasi to describe its natural occurrence, biochemical characteristics and influence on macrophage infection.

Methodology/Principal Findings

We used live L. infantum chagasi to demonstrate its natural ecto-nucleotidase activity. We then isolated, cloned and expressed recombinant rLicNTPDase-2 in bacterial system. The recombinant rLicNTPDase-2 hydrolyzed a wide variety of triphosphate and diphosphate nucleotides (GTP> GDP  =  UDP> ADP> UTP  =  ATP) in the presence of calcium or magnesium. In addition, rLicNTPDase-2 showed stable activity over a pH range of 6.0 to 9.0 and was partially inhibited by ARL67156 and suramin. Microscopic analyses revealed the presence of this protein on cell surfaces, vesicles, flagellae, flagellar pockets, kinetoplasts, mitochondria and nuclei. The blockade of E-NTPDases using antibodies and competition led to lower levels of parasite adhesion and infection of macrophages. Furthermore, immunohistochemistry showed the expression of E-NTPDases in amastigotes in the lymph nodes of naturally infected dogs from an area of endemic visceral leishmaniasis.

Conclusions/Significance

In this work, we cloned, expressed and characterized the NTPDase-2 from L. infantum chagasi and demonstrated that it functions as a genuine enzyme from the E-NTPDase/CD39 family. We showed that E-NTPDases are present on the surface of promastigotes and in other intracellular locations. We showed, for the first time, the broad expression of LicNTPDases in naturally infected dogs. Additionally, the blockade of NTPDases led to lower levels of in vitro adhesion and infection, suggesting that these proteins are possible targets for rational drug design.

Visceral leishmaniasis is a dangerous and important, but neglected, tropical disease that affects millions of people, mainly in underdeveloped and developing countries. Presently, there are no vaccines against Leishmaniasis, and the few drugs with which the disease is treated have low efficacy and high side effects. The pathogenic agent of this disease in the New World is Leishmania infantum chagasi. In this work, we studied a protein from this parasite named ENTPDase-2. We expressed it in a bacterial system, purified it and characterized it as a genuine nucleotidase of the ENTPDase family. This protein seems to be localized at the surface of the parasite and in other intracellular locations. ENTPDase seems to facilitate in vitro infection because its blockade leads to lower levels of infection of macrophages. In addition, the protein is found in naturally infected dogs. A previous study demonstrated that ENTPDase-2 from L. infantum chagasi is a good antigen for immunodiagnosis of canine visceral leishmaniasis. We have now studied this protein in greater depth and suggest that it may be a good target for drug development.

Visceral leishmaniasis due to Leishmania infantum with renal involvement in HIV-infected patients

Background

We describe histological, clinical findings and outcomes of renal involvement during Leishmania infantum infection in four HIV-infected patients in South France and North Italy hospital settings.

Cases presentation

Four HIV-infected Caucasian patients (age 24-49) performed renal biopsy during episodes of visceral leishmaniasis. They presented severe immunosuppression, frequent relapses of visceral leishmaniasis during a follow-up period of several years and partial or complete recovery of renal function after anti-parasitic treatment. Main clinical presentations were nephrotic or nephritic syndrome and/or acute renal failure secondary to membranoproliferative type III glomerulonephritis or acute interstitial nephritis. Clinical outcome was poor, probably as a consequence of insufficient immuno-virological control of the HIV infection.

Conclusions

Our findings suggest that the main histological findings in case of renal involvement due to Leishmania infantum infection in HIV-infected patients are type III MPGN and acute interstitial nephritis, with a histological specificity similar to that observed in canine leishmaniasis. Poor immune status in HIV-infected patients, altering the capacity for parasite clearance, and prolonged course of chronic active VL in this population may lead to the development of specific renal lesions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0561-9) contains supplementary material, which is available to authorized users.

A case of panuveitis with hypopyon due to presumed ocular leishmaniasis in a HIV patient

Background

Post-kala-azar dermal leishmaniasis is a well-known immunologic cutaneous reaction. There are few case reports of ocular leishmaniasis. It is a sight-threatening condition that needs to be rapidly recognized and treated to avoid permanent visual loss. Ocular leishmaniasis panuveitis can present with severe inflammation in patients with highly active anti-retroviral therapy (HAART)-induced immune reconstitution syndrome.

Findings

A case of a 40-year-old man, human immunodeficiency virus (HIV) positive on HAART, with a presumed diagnosis of ocular leishmaniasis, is presented. He had a past history of visceral leishmaniasis and was referred to the uveitis service with rapidly worsening panuveitis and counting fingers vision in both eyes. On empirical anti-leishmania therapy and systemic steroids, the visual acuity of the left eye improved to 6/9 but remained poor in the right eye. Based on the medical history, improvement with therapy and the exclusion of other common infections, a presumed diagnosis of ocular leishmaniasis-related panuveitis was made.

Conclusions

A major immune reaction against lingering parasites may play a key role in the pathogenesis of this sight-threatening and rapidly progressive condition. Both the infection and the immune reaction should be treated.

Electronic supplementary material

The online version of this article (doi:10.1186/s12348-014-0021-0) contains supplementary material, which is available to authorized users.