Biomarkers of disease severity in patients with visceral leishmaniasis co-infected with HIV.

Visceral leishmaniasis (VL) is caused by the protozoan Leishmania spp, transmitted by sand fly bites. VL is one of the deadliest tropical infection diseases, yet the coinfection with HIV virus drastically increases relapses, treatment failure and mortality. The concomitant action of these two pathogens leads to high cellular activation independently of the progression to AIDS. In addition, microbial translocation and bacterial infections are thought to contribute worsening the clinical picture. Identifying biomarkers associated with disease severity is of interest for clinical management of patients with VL-HIV/AIDS. Thus, we analyzed in the sera several markers including interleukins (IL-1ß, IL-6, IL-8, and IL-17), interferon-γ (IFN- γ), tumor necrosis factor (TNF), lipopolysaccharide (LPS), soluble CD14 (sCD14), macrophage migration inhibitory factor (MIF) and intestinal fatty acid-binding protein (IFABP). These markers were compared with disease severity in 24 patients with VL/HIV presenting different clinical outcomes. Disease severity was defined by the probability of death calculated using a score set system derived by the Kala-Cal® software. Probability of death ranged from 3.7% to 97.9%, with median of 28.8%. Five patients died (20%). At the univariate analysis, disease severity was correlated with TNF, IFN-γ and sCD14. LPS was positively correlated with sCD14 specifically in patients with low CD4+ count (CD4+ T-cell <200 cells/mL). Most importantly, the multivariate analysis including LPS, CD4+count and sCD14 showed that sCD14 was the only independent predictor for disease severity and death. Altogether, our results indicated that sCD14 is a powerful marker of pathogenicity and death for patients with VL-HIV/AIDS.

Evidence map of diagnosis, treatment, prognosis, prevention, and control in visceral leishmaniasis.

Objective: To develop an evidence map on visceral leishmaniasis prevention, control, diagnosis, treatment, and prognosis. Methods: Systematic reviews on visceral leishmaniasis were searched using MEDLINE/PubMed and Virtual Health Library. After selection, each included systematic review was assessed, characterized, and categorized by intervention type and by outcomes, according to the methodology offered by the PAHO/WHO Latin American and Caribbean Center on Health Sciences Information (BIREME). The methodological quality was assessed using the AMSTAR2 tool to determine the confidence level of the evidence obtained. Results: Among the prevention and control interventions, insecticide spraying, bednets, dog collars, and dog culling were the most assessed, emphasizing that insecticidal dog collars can reduce visceral leishmaniasis incidence in dogs. Regarding diagnosis, polymerase chain reaction (PCR), rK39 immunochromatographic test (rK39 ICT), and direct agglutination test (DAT) presented high sensitivity and specificity. As for treatment, pentavalent antimonials and amphotericin B were the most analyzed drugs and showed therapeutic success; however, serious adverse events can occur due to their use. The prognostic factors identified were anemia, edema, bleeding, jaundice, age, and HIV coinfection. Conclusions: The evidence map developed shows rK39 ICT and DAT as promising diagnostic alternatives and reinforces the efficacy of liposomal amphotericin B and pentavalent antimonials. Insecticide-impregnated dog collars appear as a promising measure for the control of visceral leishmaniasis, but there is also a need for future studies and reviews with higher methodological quality, especially on prevention and control interventions.

A Novel Antigen, Otubain Cysteine Peptidase of Leishmania donovani, for the Serodiagnosis of Visceral Leishmaniasis and for Monitoring Treatment Response.

Tests for visceral leishmaniasis (VL) are not uniformly effective for all endemic regions. In a serological assay, a novel antigen, otubain cysteine peptidase, compared with rK39, showed comparable sensitivity with Indian VL serum samples and prominently increased sensitivity with Brazilian samples, as well as improved monitoring of the treatment response.

Influence of sex hormones on the immune response to leishmaniasis.

The differences in morbidity and mortality patterns and life expectancy between the sexes are well established in different infectious and parasitic conditions, such as in leishmaniases, in which biological, genetic, sexual and hormonal variations can modulate the immune response indicating greater infectivity, prevalence and clinical severity in men. In this regard, in seeking the understanding of factors related to protection and susceptibility to infection, this review aimed to discuss the influence of sex hormones on the immune response to leishmaniases. In the literature, sex hormone variations promote differences in the innate, humoral and cell-mediated immune response, leading to greater susceptibility, mortality and complications in males. Epidemiological estimates confirm these results, showing a predominance of the disease, in its different clinical forms, in men and suggesting that sexual variations influence immunomodulatory mechanisms since the prevalence of cases comprises the post-puberty and adulthood period. In this perspective, the action of sex hormones has been investigated in different clinical models, highlighting the potential of testosterone in immunosuppression, given its association with greater susceptibility and poor control of parasite load and the induction of cell apoptosis and attenuation of pro-inflammatory signalling pathways. Therefore, hormonal variations influence the immune response among males and females against leishmaniases, in which androgens may present immunosuppressive potential, while steroids present immunomodulatory characteristics.

Biomarkers of the early response to treatment of visceral leishmaniasis: A prospective cohort study.

BACKGROUND: Early biomarkers of the response to treatment are lacking and may help to reduce mortality by the vector-borne disease visceral leishmaniasis (VL). METHODS: A prospective cohort study was conducted to investigate plasma cytokines and clinical laboratory data as biomarkers of the early response to specific treatment for VL in 36 patients. RESULTS: The mean interleukin 6 (IL-6) concentration on the 7th day was 2.3% of the pre-treatment concentration, interleukin 10 (IL-10) was 8.0%, and interleukin 8 (IL-8) was 8.2%. On the 7th day, IL-10 was below half of the pre-treatment concentration in 100.0%, IL-8 in 95.5% and IL-6 in 90.9%. The spleen and liver sizes, haemoglobin, interleukin 1 beta (IL-1ß) and tumour necrosis factor alpha (TNF-α) showed a slower recovery. Fever disappeared in 91% on the 7th day, 69.4% had a normal white cell count, and 77.8% had a normal platelet value by this time. CONCLUSIONS: The plasma cytokines IL-6, IL-10 and IL-8 were demonstrated to be excellent markers of the early response to VL treatment and if tested before the 7th day, will likely prove to be better than fever measurement.

Performance of two immunochromatographic tests for diagnosis of visceral leishmaniasis in patients coinfected with HIV.

Because of visceral leishmaniasis (VL) urbanization and spreading of the human immunodeficiency virus (HIV) infection to rural areas, coinfection has become more common. Here, we compared the accuracy of Kalazar Detect® (KD), an rK39-based immunochromatographic (IC) test, and OrangeLife® (OL), an rK39 + rK28 IC test, for diagnosing VL in patients coinfected with HIV in an endemic area in Brazil. Seventy-six VL patients and 40 patients with other diseases, of which 31 and 21 patients, respectively, were infected with HIV, were examined. The sensitivity of OL and KD tests was 88.89 and 95.45%, respectively, in patients without HIV. The sensitivity dropped to 67.74 and 61.29%, respectively, in coinfected patients. The decrease in sensitivity was not related to a decrease in the production of Leishmania-specific IgG. Because of the low sensitivity of rk39 test in HIV-infected patients, we suggest that patients with negative rK39 results should undergo further investigation with additional serological tests that are not based only on the rK39 antigen and examination of bone marrow aspirates.

Lipoprotein lipase and PPAR alpha gene polymorphisms, increased very-low-density lipoprotein levels, and decreased high-density lipoprotein levels as risk markers for the development of visceral leishmaniasis by Leishmania infantum.

In visceral leishmaniasis (VL) endemic areas, a minority of infected individuals progress to disease since most of them develop protective immunity. Therefore, we investigated the risk markers of VL within nonimmune sector. Analyzing infected symptomatic and, asymptomatic, and noninfected individuals, VL patients presented with reduced high-density lipoprotein cholesterol (HDL-C), elevated triacylglycerol (TAG), and elevated very-low-density lipoprotein cholesterol (VLDL-C) levels. A polymorphism analysis of the lipoprotein lipase (LPL) gene using HindIII restriction digestion (N = 156 samples) (H+ = the presence and H- = the absence of mutation) revealed an increased adjusted odds ratio (OR) of VL versus noninfected individuals when the H+/H+ was compared with the H-/H- genotype (OR = 21.3; 95% CI = 2.32-3335.3; P = 0.003). The H+/H+ genotype and the H+ allele were associated with elevated VLDL-C and TAG levels (P < 0.05) and reduced HDL-C levels (P < 0.05). An analysis of the L162V polymorphism in the peroxisome proliferator-activated receptor alpha (PPARα) gene (n = 248) revealed an increased adjusted OR when the Leu/Val was compared with the Leu/Leu genotype (OR = 8.77; 95% CI = 1.41-78.70; P = 0.014). High TAG (P = 0.021) and VLDL-C (P = 0.023) levels were associated with susceptibility to VL, whereas low HDL (P = 0.006) levels with resistance to infection. The mutated LPL and the PPARα Leu/Val genotypes may be considered risk markers for the development of VL.

Identification of blood meal sources of Lutzomyia longipalpis using polymerase chain reaction-restriction fragment length polymorphism analysis of the cytochrome B gene.

An analysis of the dietary content of haematophagous insects can provide important information about the transmission networks of certain zoonoses. The present study evaluated the potential of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial cytochrome B (cytb) gene to differentiate between vertebrate species that were identified as possible sources of sandfly meals. The complete cytb gene sequences of 11 vertebrate species available in the National Center for Biotechnology Information database were digested with Aci I, Alu I, Hae III and Rsa I restriction enzymes in silico using Restriction Mapper software. The cytb gene fragment (358 bp) was amplified from tissue samples of vertebrate species and the dietary contents of sandflies and digested with restriction enzymes. Vertebrate species presented a restriction fragment profile that differed from that of other species, with the exception of Canis familiaris and Cerdocyon thous. The 358 bp fragment was identified in 76 sandflies. Of these, 10 were evaluated using the restriction enzymes and the food sources were predicted for four: Homo sapiens (1), Bos taurus (1) and Equus caballus (2). Thus, the PCR-RFLP technique could be a potential method for identifying the food sources of arthropods. However, some points must be clarified regarding the applicability of the method, such as the extent of DNA degradation through intestinal digestion, the potential for multiple sources of blood meals and the need for greater knowledge regarding intraspecific variations in mtDNA.

Association between clinical outcomes, peripheral blood and cytomorphologic features of bone marrow in visceral leishmaniasis.

INTRODUCTION: An intracellular parasite of mononuclear phagocytes, mainly distributed in the bone marrow and the spleen, causes visceral leishmaniasis. Complete blood count (CBC) reveals the poorly understood pathogenesis of anemia, leukopenia and thrombocytopenia. Our study aimed to compare the CBC with bone marrow cytomorphological features and their association with clinical outcomes to clarify this relevant issue. METHODS: The CBC and bone marrow of 118 patients were described by two hematologists and compared to check their association with each other and mortality. RESULTS: Peripheral cytopenias were common findings, particularly anemia, as seen in almost all patients. No relationship was found between values of hemoglobin, neutrophils and platelet count with fatal outcomes. The bone marrow was normocellular in 61.9% of the cases. Dysplasia figures were frequent and 49.1% of the samples had dysgranulopoiesis. Additionally, erythroid hyperplasia was found in 72% of the patients with severe anemia. Patients with reduced bone marrow cellularity, erythroid hypercellularity and dyserythropoiesis seem to have a riskier disease. CONCLUSION: The study results suggest that the bone marrow of patients with visceral leishmaniasis manifests a reactional pattern to the inflammatory event, thereby modulating cytokines and other colony growth factors. This compensatory response may be dysplastic and ineffective and generate peripheral cytopenias of varying intensity. Further studies are needed to clarify the signaling pathways involved, which may be used as therapeutic tools in the future.

The spleen is the graveyard of CD4+ cells in patients with immunological failure of visceral leishmaniasis and AIDS.

BACKGROUND: Visceral leishmaniasis (VL), or kala-azar, is a common comorbidity in patients with AIDS in endemic areas. Many patients continue to experiences relapses of VL despite virological control, but with immunological failure. These patients remain chronically symptomatic with hypersplenism, for example with anemia, leukopenia, and thrombocytopenia, and are at risk of severe co-infection due to low CD4+ count. Therefore, in this study, splenectomized patients with VL and HIV infection were investigated to understand why the CD4+ count fails to recover in these patients, evaluating the importance of spleen mass for hypersplenism and immunological failure. METHODS: From a retrospective open cohort of 13 patients who had previously undergone splenectomy as salvage therapy for relapsing VL, 11 patients with HIV infection were investigated. This study compared the patients' complete blood cell count (CBC) and CD4+ and CD8+ cell counts before and after splenectomy with respect to spleen weight. RESULTS: CBC was substantially improved after splenectomy, indicating hypersplenism. However, to the best of our knowledge, this is the first study to show that spleen mass is strongly and negatively correlated with CD4+ cell count (ρ = -0.71, P = 0.015). CONCLUSIONS: This finding was unexpected, as the spleen is the most extensive lymphoid tissue and T-lymphocyte source. After reviewing the literature and reasoning, we hypothesized that the immunological failure was secondary to CD4+ loss initially by apoptosis in the spleen induced by productive HIV infection and, subsequently, by pyroptosis sustained by parasitic infection in spleen macrophages.

Systematic review of visual illusions in schizophrenia.

Visual illusions have long been used as tools to investigate sensory-perceptual deficits in schizophrenia. Recent conflicting accounts have called into question the assumption of abnormal illusion perception in patients and, therefore, the validity of this approach. Here, we present a systematic review of the current evidence regarding visual illusion perception abnormalities in patients with schizophrenia. Relevant publications were identified by a systematic search of PubMed, Literatura LILACS, PsycINFO, Embase, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), IBECS, BIOSIS, and Web of Science. Forty-five studies were selected which included illusions classified as 'Motion illusions', 'Geometric-optical illusions', 'Illusory contours', 'Depth inversion illusion', and 'Non-specific'. There is concordant evidence of abnormal processing of illusions in patients for most categories, especially in facial Depth Inversion and Müller-Lyer illusions. There were significant methodological disparities and shortcomings, but risk of bias was overall low for individual studies. The usefulness of visual illusions as tools in clinical settings as well as in basic research may be contingent on significant methodological refinements.

Neck circumference as a predictor of cardiometabolic risk and truncal obesity in people living with HIV.

Introduction: Introduction: recent studies have suggested the use of neck circumference as a parameter capable of identifying risks of cardiometabolic complications and the accumulation of truncal fat caused by both antiretroviral therapy and the lifestyle of people with the human immunodeficiency virus (HIV). Objective: to investigate the relationship between neck circumference and anthropometric indicators and to assess cardiometabolic risk and truncal obesity through proposed cut-off points. Methods: cross-sectional study including 233 people with HIV. Demographic, socioeconomic, lifestyle and clinical data were collected using a structured questionnaire. The anthropometric evaluation included: weight, height, body mass index (BMI) measurements; waist (WC), neck (NC), arm and arm muscle circumferences; triceps and subscapular skinfolds and their sum. ROC curves were constructed to determine the accuracy of NC in predicting cardiometabolic risk in people living with HIV. Results: the sample was 57.5 % male, with a mean age of 38.4 years (95 %CI: 37.2-39.7 years). NC showed a positive and significant correlation with all anthropometric variables analyzed (p < 0.05), and a higher correlation strength with WC and BMI. The NC cut-off point selected as a predictor of risk of cardiac metabolic complications and truncal obesity in women was ≥ 32.4 cm, considering both WC and BMI. For men, the NC cut-off points were different when considering WC (≥ 39.6 cm) and BMI (≥ 38.1 cm) as a reference. It is worth noting that NC performed well in ROC curve analysis for men, while in women it was a poor performance. Conclusion: NC proved to be a promising indicator in the assessment of nutrition and health of people living with HIV, especially in men.

Introducción: Introducción: estudios recientes han sugerido el uso de la circunferencia del cuello como parámetro capaz de identificar los riesgos de complicaciones cardiometabólicas y la acumulación de grasa troncal causados tanto por la terapia antirretroviral como por el estilo de vida de las personas con el virus de la inmunodeficiencia humana (VIH). Objetivo: investigar la relación entre la circunferencia del cuello y los indicadores antropométricos y evaluar el riesgo cardiometabólico y la obesidad troncal a través de los puntos de corte propuestos. Métodos: estudio transversal que incluyó a 233 personas con VIH. Se recogieron datos demográficos, socioeconómicos, de estilo de vida y clínicos mediante un cuestionario estructurado. La evaluación antropométrica incluyó: medidas de peso, altura, índice de masa corporal (IMC); circunferencias de cintura (CC), cuello (CN), brazo (CA) y músculo del brazo (MCB); pliegues cutáneos del tríceps y subescapular y su suma. Se construyeron curvas ROC para determinar la precisión de la CN en la predicción del riesgo cardiometabólico en personas que viven con el VIH. Resultados: el 57,5 % de la muestra eran varones, con una edad media de 38,4 años (IC 95 %: 37,2-39,7 años). La CN mostró una correlación positiva y significativa (p < 0,05) con todas las variables antropométricas analizadas, y una mayor fuerza de correlación con la CC y el IMC. El punto de corte de la CN seleccionado como predictor de riesgo de complicaciones metabólicas cardiacas y obesidad troncular en mujeres fue ≥ 32,4 cm, considerando tanto la CC como el IMC. En el caso de los hombres, los puntos de corte de la CN fueron diferentes al considerar como referencia la CC (≥ 39,6 cm) y el IMC (≥ 38,1 cm). Cabe destacar que la CN obtuvo buenos resultados en el análisis de la curva ROC en el caso de los hombres, mientras que en el de las mujeres fue deficiente. Conclusión: la CN demostró ser un indicador prometedor en la evaluación de la nutrición y la salud de las personas que viven con el VIH, especialmente en los hombres.

Parasite Detection in Visceral Leishmaniasis Samples by Dye-Based qPCR Using New Gene Targets of Leishmania infantum and Crithidia.

Visceral leishmaniasis (VL) is a neglected disease considered a serious public health problem, especially in endemic countries. Several studies have discovered monoxenous trypanosomatids (Leptomonas and Crithidia) in patients with VL. In different situations of leishmaniasis, investigations have examined cases of co-infection between Leishmania spp. and Crithidia spp. These coinfections have been observed in a wide range of vertebrate hosts, indicating that they are not rare. Diagnostic techniques require improvements and more robust tools to accurately detect the causative agent of VL. This study aimed to develop a real-time quantitative dye-based PCR (qPCR) assay capable of distinguishing Leishmania infantum from Crithidia-related species and to estimate the parasite load in samples of VL from humans and animals. The primer LinJ31_2420 targets an exclusive phosphatase of L. infantum; the primer Catalase_LVH60-12060_1F targets the catalase gene of Crithidia. Therefore, primers were designed to detect L. infantum and Crithidia sp. LVH60A (a novel trypanosomatid isolated from VL patients in Brazil), in samples related to VL. These primers were considered species-specific, based on sequence analysis using genome data retrieved from the TriTryp database and the genome assembling of Crithidia sp. LVH60A strain, in addition to experimental and clinical data presented herein. This novel qPCR assay was highly accurate in identifying and quantifying L. infantum and Crithidia sp. LVH60A in samples obtained experimentally (in vitro and in vivo) or collected from hosts (humans, dogs, cats, and vectors). Importantly, the screening of 62 cultured isolates from VL patients using these primers surprisingly revealed that 51 parasite cultures were PCR+ for Crithidia sp. In addition, qPCR assays identified the co-infection of L. infantum with Crithidia sp. LVH60A in two new VL cases in Brazil, confirming the suspicion of co-infection in a previously reported case of fatal VL. We believe that the species-specific genes targeted in this study can be helpful for the molecular diagnosis of VL, as well as for elucidating suspected co-infections with monoxenous-like trypanosomatids, which is a neglected fact of a neglected disease.

High seroprevalence of Leishmania infantum is linked to immune activation in people with HIV: a two-stage cross-sectional study in Bahia, Brazil.

Visceral leishmaniasis is an opportunistic disease in HIV-1 infected individuals, unrecognized as a determining factor for AIDS diagnosis. The growing geographical overlap of HIV-1 and Leishmania infections is an emerging challenge worldwide, as co-infection increases morbidity and mortality for both infections. Here, we determined the prevalence of people living with HIV (PWH) with a previous or ongoing infection by Leishmania infantum and investigated the virological and immunological factors associated with co-infection. We adopted a two-stage cross-sectional cohort (CSC) design (CSC-I, n = 5,346 and CSC-II, n = 317) of treatment-naïve HIV-1-infected individuals in Bahia, Brazil. In CSC-I, samples collected between 1998 and 2013 were used for serological screening for leishmaniasis by an in-house Enzyme-Linked Immunosorbent Assay (ELISA) with SLA (Soluble Leishmania infantum Antigen), resulting in a prevalence of previous or ongoing infection of 16.27%. Next, 317 PWH were prospectively recruited from July 2014 to December 2015 with the collection of sociodemographic and clinical data. Serological validation by two different immunoassays confirmed a prevalence of 15.46 and 8.20% by anti-SLA, and anti-HSP70 serology, respectively, whereas 4.73% were double-positive (DP). Stratification of these 317 individuals in DP and double-negative (DN) revealed a significant reduction of CD4+ counts and CD4+/CD8+ ratios and a tendency of increased viral load in the DP group, as compared to DN. No statistical differences in HIV-1 subtype distribution were observed between the two groups. However, we found a significant increase of CXCL10 (p = 0.0076) and a tendency of increased CXCL9 (p = 0.061) in individuals with DP serology, demonstrating intensified immune activation in this group. These findings were corroborated at the transcriptome level in independent Leishmania- and HIV-1-infected cohorts (Swiss HIV Cohort and Piaui Northeast Brazil Cohort), indicating that CXCL10 transcripts are shared by the IFN-dominated immune activation gene signatures of both pathogens and positively correlated to viral load in untreated PWH. This study demonstrated a high prevalence of PWH with L. infantum seropositivity in Bahia, Brazil, linked to IFN-mediated immune activation and a significant decrease in CD4+ levels. Our results highlight the urgent need to increase awareness and define public health strategies for the management and prevention of HIV-1 and L. infantum co-infection.

Genetic diversity of Leishmania infantum field populations from Brazil.

Leishmania infantum (syn. Leishmania chagasi) is the etiological agent of visceral leishmaniasis (VL) in Brazil. The epidemiology of VL is poorly understood. Therefore, a more detailed molecular characterization at an intraspecific level is certainly needed. Herein, three independent molecular methods, multilocus microsatellite typing (MLMT), random amplification of polymorphic DNA (RAPD) and simple sequence repeats-polymerase chain reaction (SSR-PCR), were used to evaluate the genetic diversity of 53 L. infantum isolates from five different endemic areas in Brazil. Population structures were inferred by distance-based and Bayesian-based approaches. Eighteen very similar genotypes were detected by MLMT, most of them differed in only one locus and no correlation was found between MLMT profiles, geographical origin or the estimated population structure. However, complex profiles composed of 182 bands obtained by both RAPD and SSR-PCR assays gave different results. Unweighted pair group method with arithmetic mean trees built from these data revealed a high degree of homogeneity within isolates of L. infantum. Interestingly, despite this genetic homogeneity, most of the isolates clustered according to their geographical origin.

Parasite Genotype Is a Major Predictor of Mortality from Visceral Leishmaniasis.

Visceral leishmaniasis (VL) is a potentially fatal disease caused mainly by Leishmania infantum in South America and Leishmania donovani in Asia and Africa. Disease outcomes have been associated with patient genotype, nutrition, age, sex, comorbidities, and coinfections. In this study, we examine the effects of parasite genetic variation on VL disease severity in Brazil. We collected and sequenced the genomes of 109 L. infantum isolates from patients in northeastern Brazil and retrieved matching patient clinical data from medical records, including mortality, sex, HIV coinfection, and laboratory data (creatinine, hemoglobin, and leukocyte and platelet counts). We identified genetic differences between parasite isolates, including single nucleotide polymorphisms (SNPs), small insertions/deletions (indels), and variations in genic, intergenic, and chromosome copy numbers (copy number variants [CNVs]). To describe associations between the parasite genotypes and clinical outcomes, we applied quantitative genetics methods of heritability and genome-wide association studies (GWAS), treating clinical outcomes as traits that may be influenced by parasite genotype. Multiple aspects of the genetic analysis indicate that parasite genotype affects clinical outcomes. We estimate that parasite genotype explains 83% chance of mortality (narrow-sense heritability [h2] = 0.83 ± 0.17) and has a significant relationship with patient sex (h2 = 0.60 ± 0.27). Impacts of parasite genotype on other clinical traits are lower (h2 ≤ 0.34). GWAS analysis identified multiple parasite genetic loci that were significantly associated with clinical outcomes; 17 CNVs were significantly associated with mortality, two with creatinine, and one with bacterial coinfection, jaundice, and HIV coinfection, and two SNPs/indels and six CNVs were associated with age, jaundice, HIV and bacterial coinfections, creatinine, and/or bleeding sites. Parasite genotype is an important factor in VL disease severity in Brazil. Our analysis indicates that specific genetic differences between parasites act as virulence factors, enhancing risks of severe disease and mortality. More detailed understanding of these virulence factors could be exploited for novel therapies. IMPORTANCE Multiple factors contribute to the risk of mortality from visceral leishmaniasis (VL), including, patient genotype, comorbidities, and nutrition. Many of these factors are influenced by socioeconomic biases. Our work suggests that the virulence of the infecting parasite is an important risk factor for mortality. We pinpoint some specific genomic markers that are associated with mortality, which can lead to a greater understanding of the molecular mechanisms that cause severe VL disease, to the identification of genetic markers for virulent parasites, and to the development of drug and vaccine therapies.

Development and Clinical Evaluation of Serum and Urine-Based Lateral Flow Tests for Diagnosis of Human Visceral Leishmaniasis.

Visceral leishmaniasis (VL), a fatal parasitic infection, is categorized as being neglected among tropical diseases. The use of conventional tissue aspiration for diagnosis is not possible in every setting. The immunochromatography-based lateral flow assay (LFA) has attracted attention for a long time due to its ability to give results within a few minutes, mainly in resource-poor settings. In the present study, we optimized and developed the LFA to detect anti-Leishmania antibodies for VL diagnosis. The performance of the developed test was evaluated with serum and urine samples of Indian VL patients and Brazilian sera. The new test exploits well-studied and highly-sensitive purified antigens, LAg isolated from Leishmania donovani promastigotes and protein G conjugated colloidal-gold as a signal reporter. The intensity of the bands depicting the antigen-antibody complex was optimized under different experimental conditions and quantitatively analyzed by the ImageJ software. For the diagnosis of human VL in India, LFA was found to be 96.49% sensitive and 95% specific with serum, and 95.12% sensitive and 96.36% specific with urine samples, respectively. The sensitivity and specificity of LFA were 88.57% and 94.73%, respectively, for the diagnosis of Brazilian VL using patients' sera infected with Leishmania infantum. LFA is rapid and simple to apply, suitable for field usage where results can be interpreted visually and particularly sensitive and specific in the diagnosis of human VL. Serum and urine LFA may improve diagnostic outcomes and could be an alternative for VL diagnosis in settings where tissue aspiration is difficult to perform.

Nutritional status and vitamin A and zinc levels in patients with kala-azar in Piauí, Brazil.

INTRODUCTION: Malnutrition and kala-azar (or visceral leishmaniasis) are significant public health problems in different parts of the world. Immunity and susceptibility to infectious and parasitic diseases are directly linked to the host's nutritional state, but little is known about the interaction between nutrition and kala-azar. This study aimed to evaluate nutritional status with kala-azar and correlate these findings with the clinical and laboratory manifestations of the disease, and zinc and retinol levels. METHODS: This was a cross-sectional study of 139 patients with kala-azar. Nutritional status classification was performed according to international recommendations. Parametric or nonparametric tests were applied whenever indicated in a two-sided test with a 5% significance level. RESULTS: Weight loss and malnutrition were more frequent in adults. Body mass index-for-age, fat area of the arm, and upper arm muscle area were significantly associated with probability of death. The presence of human immunodeficiency virus, hepatomegaly, and splenomegaly was correlated with nutritional assessment. Blood leukocyte and lymphocyte, serum creatine, and vitamin A levels were significantly higher in adult men. Vitamin A levels were highly associated with the level of hemoglobin and C-reactive protein (CRP) in multivariate analysis. All patients had reduced plasma zinc levels, but this finding had no association with the outcome variables. CONCLUSIONS: Malnutrition was correlated with severe disease and was more prevalent in older people with kala-azar. Vitamin A deficiency was associated with hemoglobin and CRP. Zinc levels were reduced in patients with kala-azar.

Application of next generation sequencing (NGS) for descriptive analysis of 30 genomes of Leishmania infantum isolates in Middle-North Brazil.

Visceral leishmaniasis (VL) is a life-threatening disease caused by the protozoa Leishmania donovani and L. infantum. Likely, L. infantum was introduced in the New World by the Iberic colonizers. Due to recent introduction, the genetic diversity is low. Access to genomic information through the sequencing of Leishmania isolates allows the characterization of populations through the identification and analysis of variations. Population structure information may reveal important data on disease dynamics. Aiming to describe the genetic diversity of L. infantum from the Middle-North, Brazil, next generation sequencing of 30 Leishmania isolates obtained in the city of Teresina, from where the disease dispersed, was performed. The variations were categorized accordingly to the genome region and impact and provided the basis for chromosomal ploidy and population structure analysis. The results showed low diversity between the isolates and the Iberic reference genome JPCM5. Most variations were seen in non-coding regions, with modifying impact. The ploidy number analysis showed aneuploid profile. The population structure analysis revealed the presence of two L. infantum populations identified in Teresina. Further population genetics studies with a larger number of isolates should be performed in order to identify the genetic background associated with virulence and parasite ecology.

Recurrent kala-azar: report of two cured cases after total splenectomy.

In Latin America, the causative agent of kala-azar is the intracellular protozoan Leishmania infantum. Most cases in South America are reported in Brazil. Worldwide, it mainly affects Bangladesh, Ethiopia, India, South Sudan and Sudan. Despite the high morbidity and lethality of kala-azar, most infections are asymptomatic. However, a small portion of patients evolves with recurrence of kala-azar becoming symptomatic even after all available drug treatments. Kala-azar is not a formal indication for splenectomy in adults. Splenectomy is recommended as a saving measure, when kala-azar is associated with symptomatic hypersplenism and for drug-resistant cases. In the study, we report two cases of kala-azar with splenomegaly that presented several hospitalizations due to the recurrence of the kala-azar, in addition to hospitalizations for normalizing the blood count. After splenectomy, kala-azar cases and the effects of hypersplenism are cured. Thus, splenectomy should be seen as a surgical treatment option with a curative purpose in patients with recurrent kala-azar, in whom the possibilities of drug therapy have been exhausted and even so they progressed with hypersplenism and clinical repercussions.