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Objective: To compare the efficacy and safety of sodium stibogluconate (SS) and meglumine antimoniate (MA) in the treatment of cutaneous leishmaniasis (CL) in a general hospital. Methods: Case-series of 193 patients with CL treated in three clinical trials with MA (n=69) and SS (n=124) during 2001-2010. Both study drugs were administered intravenously at a slow speed at 20 mg Sb5+/kg/day for 20 consecutive days following WHO-PAHO recommendations. Clinical and safety data were gathered from clinical files. Results: Demographic characteristics were similar between the study groups, but the size and number of lesions were higher in the MA group. Efficacy was 76.0% in the MA vs. 68.4% in the SS group (p=0.340) and 55.1% vs. 50.8% (p=0.570) in the per protocol and intention to treat analysis. respectively. Side effects more frequently reported were dysgeusia (37.0%). dizziness (32.0%). headache (36.0%). arthralgia (31.0%) and lymphangitis (21.0%). These first three symptoms as well as elevation of transaminases, leukopenia, thrombocytopenia and prolonged QTc were numerically more frequent in the SS group but without reaching statistical significance. Treatment was stopped definitively for severe toxicity in the SS group due to refractory emesis (two patients) and prolonged QTc (one patient). Conclusions: The efficacy of MA and SS is comparable. The intravenous administration of these compounds did not produce immediate reactions, but it was associated with unusual clinical and laboratory abnormalities. [ABSTRACT FROM AUTHOR]

In order to know the first-choice treatment by villagers of an endemic area of Cutaneous Leishmaniasis (CL) prior to medical attention in a health care center, a cross sectional study was realized in Pichupampa town. A census was made in order to collect demographic data and previous history of CL. 254 participants were surveyed. 41.7% (106/254) of the village had CL at least once in their lives and only half of them went to a health center to seek for primary care. 76/106 (71.7%) used some traditional treatment as their first choice and only 23.6% (25/106) subjects went to a health-care center without manipulation of their lesions. It's evident that a high percentage (71.7%) of people potentially infected by CL manipulate and treat their lesions with traditional treatments prior to professional health-care, actions that could interfere with the diagnosis and effectiveness of the program implemented by the Health Ministry. [ABSTRACT FROM AUTHOR]

Abstract: Adult patients with mucosal leishmaniasis (ML) were enrolled in a randomized, double-blind, placebo-controlled, dose-escalating clinical trial and were randomly assigned to receive three injections of either the LEISH-F1+MPL-SE vaccine (consisting of 5, 10, or 20μg recombinant Leishmania polyprotein LEISH-F1 antigen+25μg MPL®-SE adjuvant) (n =36) or saline placebo (n =12). The study injections were given subcutaneously on Days 0, 28, and 56, and the patients were followed through Day 336 for safety, immunological, and clinical evolution endpoints. All patients received standard chemotherapy with sodium stibogluconate starting on Day 0. The vaccine was safe and well tolerated, and induced both humoral and cell-mediated immune responses. Furthermore, intracellular cytokine staining showed an increase in the proportion of memory LEISH-F1-specific IL-2+ CD4 T-cells after vaccination, which was associated with clinical cure. This clinical trial shows that the LEISH-F1+MPL-SE vaccine is safe and immunogenic in patients with ML. [Copyright &y& Elsevier]

American Tegumentary Leishmaniasis (ATL) is an endemic and neglected disease of South America. Here, mucosal leishmaniasis (ML) disproportionately affects up to 20% of subjects with current or previous localised cutaneous leishmaniasis (LCL). Preclinical and clinical reports have implicated the Leishmania RNA virus-1 (LRV1) as a possible determinant of progression to ML and other severe manifestations such as extensive cutaneous and mucosal disease and treatment failure and relapse. However, these associations were not consistently found in other observational studies and are exclusively based on cross-sectional designs. In the present study, 56 subjects with confirmed ATL were assessed and followed out for 24-months post-treatment. Lesion biopsy specimens were processed for molecular detection and quantification of Leishmania parasites, species identification, and LRV1 detection. Among individuals presenting LRV1 positive lesions, 40% harboured metastatic phenotypes; comparatively 58.1% of patients with LRV1 negative lesions harboured metastatic phenotypes (p = 0.299). We found treatment failure (p = 0.575) and frequency of severe metastatic phenotypes (p = 0.667) to be similarly independent of the LRV1. Parasite loads did not differ according to the LRV1 status (p = 0.330), nor did Leishmanin skin induration size (p = 0.907) or histopathologic patterns (p = 0.780). This study did not find clinical, parasitological, or immunological evidence supporting the hypothesis that LRV1 is a significant determinant of the pathobiology of ATL. Author summary: The Leishmania RNA virus-1 (LRV1) has been implicated as a possible modulator agent in the pathogenesis of leishmaniasis. In-vivo and in-vitro studies have depicted specific mechanisms of how LRV1 could lead to metastasis. Clinical studies and epidemiological evidence have both supported and rejected the hypothesis that LRV1 is a relevant determinant of progression, treatment failure and clinical severity of American Tegumentary Leishmaniasis (ATL). This lack of consistency between preclinical and clinical reports requires further longitudinal studies to clarify the role of LRV1 in ATL. Due to the complex nature of ATL, as other frequent human diseases, these studies should tackle multiple determinants of pathogenicity, including LRV1 status, parasite features, immune status, and prevalent comorbidities affecting individuals in endemic settings. Also, critical methodological aspects allowing for the reliable identification and quantification of LRV1 should be guaranteed. [ABSTRACT FROM AUTHOR]

Cutaneous leishmaniasis (CL) is an infectious and neglected disease caused by parasites of the genus Leishmania , which produces a wide spectrum of cutaneous manifestations. CL research has shown that the innate immune activity of cells such as neutrophils, natural killers, macrophages, dendritic cells and the complement system are capable of controlling this infection. However, Leishmania can also modulate the immune activity of these cells to promote its own survival and proliferation at the intracellular level. This review discusses the role of the innate immune response in the control and spread of this infection. [ABSTRACT FROM AUTHOR]

In cutaneous leishmaniasis endemic areas it is a common practice for patients to manipulate their lesions with traditional treatments as a first therapeutic option. A case series study was conducted in order to describe the frequency and the variations of the patient manipulation of cutaneous leishmaniasis lesions at the Cayetano Heredia Hospital. The study included 124 patients with cutaneous leishmaniasis. From the patient population it was found that 54% (67/124) manipulated their lesions. Of this, 92.5% (62/67) did so with chemicals, and 43.3% (29/67) with plants. The most frequent local changes reported by patients were increased lesion size in 35.8% (24/67) and increased inflammation in 28.4% (19/67). Manipulation by patients decreased the positivity of the parasitological diagnosis in those patients with ulcerative lesions. [ABSTRACT FROM AUTHOR]

Background: Tegumentary leishmaniasis (TL) is a disease of skin and/or mucosal tissues caused by Leishmania parasites. TL patients may concurrently carry other pathogens, which may influence the clinical outcome of TL. Methodology and principal findings: This review focuses on the frequency of TL coinfections in human populations, interactions between Leishmania and other pathogens in animal models and human subjects, and implications of TL coinfections for clinical practice. For the purpose of this review, TL is defined as all forms of cutaneous (localised, disseminated, or diffuse) and mucocutaneous leishmaniasis. Human immunodeficiency virus (HIV) coinfection, superinfection with skin bacteria, and skin manifestations of visceral leishmaniasis are not included. We searched MEDLINE and other databases and included 73 records: 21 experimental studies in animals and 52 studies about human subjects (mainly cross-sectional and case studies). Several reports describe the frequency of Trypanosoma cruzi coinfection in TL patients in Argentina (about 41%) and the frequency of helminthiasis in TL patients in Brazil (15% to 88%). Different hypotheses have been explored about mechanisms of interaction between different microorganisms, but no clear answers emerge. Such interactions may involve innate immunity coupled with regulatory networks that affect quality and quantity of acquired immune responses. Diagnostic problems may occur when concurrent infections cause similar lesions (e.g., TL and leprosy), when different pathogens are present in the same lesions (e.g., Leishmania and Sporothrix schenckii), or when similarities between phylogenetically close pathogens affect accuracy of diagnostic tests (e.g., serology for leishmaniasis and Chagas disease). Some coinfections (e.g., helminthiasis) appear to reduce the effectiveness of antileishmanial treatment, and drug combinations may cause cumulative adverse effects. Conclusions and significance: In patients with TL, coinfection is frequent, it can lead to diagnostic errors and delays, and it can influence the effectiveness and safety of treatment. More research is needed to unravel how coinfections interfere with the pathogenesis of TL. [ABSTRACT FROM AUTHOR]

Introduction: Progress with the treatment of cutaneous leishmaniasis (CL) has been hampered by inconsistent methodologies used to assess treatment effects. A sizable number of trials conducted over the years has generated only weak evidence backing current treatment recommendations, as shown by systematic reviews on old-world and new-world CL (OWCL and NWCL). Materials and methods: Using a previously published guidance paper on CL treatment trial methodology as the reference, consensus was sought on key parameters including core eligibility and outcome measures, among OWCL (7 countries, 10 trial sites) and NWCL (7 countries, 11 trial sites) during two separate meetings. Results: Findings and level of consensus within and between OWCL and NWCL sites are presented and discussed. In addition, CL trial site characteristics and capacities are summarized. Conclusions: The consensus reached allows standardization of future clinical research across OWCL and NWCL sites. We encourage CL researchers to adopt and adapt as required the proposed parameters and outcomes in their future trials and provide feedback on their experience. The expertise afforded between the two sets of clinical sites provides the basis for a powerful consortium with potential for extensive, standardized assessment of interventions for CL and faster approval of candidate treatments. [ABSTRACT FROM AUTHOR]

Backgound: Species of the Leishmania Viannia (L. V.) subgenus harbor the double-stranded Leishmania RNA virus 1 (LRV-1), previously identified in isolates from Brazil and Peru. Higher levels of LRV-1 in metastasizing strains of L. V. guyanensis have been documented in both human and murine models, and correlated to disease severity.Methods: Expression of proinflammatory biomarkers, including interleukin (IL) 1β, tumor necrosis factor alpha (TNF-α), CXCL10, CCL5, IL-6, and superoxide dismutase, in human macrophages infected with 3 ATCC and 5 clinical isolates of L. V. braziliensis, L. V. guyanensis, and L. V. panamensis for 24 and 48 hours were measured by commercial enzyme immunoassay. Analyses were performed at 24 and 48 hours, stratified by LRV-1 status and species.Results: LRV-1-positive L. V. braziliensis demonstrated significantly lower expression levels of TNF-α (P = .01), IL-1β (P = .0015), IL-6 (P = .001), and CXCL10 (P = .0004) compared with LRV-1-negative L. V. braziliensis. No differences were observed in strains of L. V. panamensis by LRV-1 status.Conclusions: Compared to LRV-1-negative L. V. braziliensis, LRV-1-positive strains of L. V. braziliensis produced a predominant Th2-biased immune response, correlated in humans to poorer immunologic control of infection and more severe disease, including mucosal leishmaniasis. Effects of LRV-1 on the pathogenesis of American tegumentary leishmaniasis may be species specific. [ABSTRACT FROM AUTHOR]

Cutaneous and mucosal leishmaniasis, caused in South America by Leishmania braziliensis, is difficult to cure by chemotherapy (primarily pentavalent antimonials [Sb(V)]). Treatment failure does not correlate well with resistance in vitro, and the factors responsible for treatment failure in patients are not well understood. Many isolates of L. braziliensis (>25%) contain a double-stranded RNA virus named Leishmaniavirus 1 (LRV1), which has also been reported in Leishmania guyanensis, for which an association with increased pathology, metastasis, and parasite replication was found in murine models. Here we probed the relationship of LRV1 to drug treatment success and disease in 97 L. braziliensis-infected patients from Peru and Bolivia. In vitro cultures were established, parasites were typed as L. braziliensis, and the presence of LRV1 was determined by reverse transcription-polymerase chain reaction, followed by sequence analysis. LRV1 was associated significantly with an increased risk of treatment failure (odds ratio, 3.99; P = .04). There was no significant association with intrinsic Sb(V) resistance among parasites, suggesting that treatment failure arises from LRV1-mediated effects on host metabolism and/or parasite survival. The association of LRV1 with clinical drug treatment failure could serve to guide more-effective treatment of tegumentary disease caused by L. braziliensis. [ABSTRACT FROM AUTHOR]

Thermotherapy is an accepted alternative therapy for new-world cutaneous leishmaniasis, but current heat-delivery modalities are too costly to be made widely available to endemic populations. We adapted a low-cost heat pack named the HECT-CL device that delivers safe, reliable, and renewable conduction heat. 25 patients with cutaneous leishmaniasis completed treatment with the device at an initial temperature of 52°C±2°C for 3 minutes to each lesion, repeated daily for 7 days, and were followed up for 6 months by direct observation. The overall definitive clinical cure rate was 60%. Concurrently, 13 patients meeting minimally significant exclusion criteria received identical compassionate use treatment with a cumulative definitive cure rate of 68.4%, 75% for those who had experienced CL relapse after prior antimonial treatment. Therapy was well tolerated. Reversible second-degree burns occurred in two patients and no bacterial super-infections were observed. HECT-CL is a promising treatment and deserves further study to verify its safety and efficacy as adjuvant and mono- therapy. [ABSTRACT FROM AUTHOR]

In South America, various species of Leishmania are endemic and cause New World tegumentary leishmaniasis (NWTL). The correct identification of these species is critical for adequate clinical management and surveillance activities. We developed a real-time polymerase chain reaction (PCR) assay and evaluated its diagnostic performance using 64 archived parasite isolates and 192 prospectively identified samples collected from individuals with suspected leishmaniasis enrolled at two reference clinics in Lima, Peru. The real-time PCR assay was able to detect a single parasite and provided unambiguous melting peaks for five Leishmania species of the Viannia subgenus that are highly prevalent in South America: L. (V.) braziliensis, L. (V.) panamensis, L. (V.) guyanensis, L. (V.) peruviana and L. (V.) lainsoni. Using kinetoplastid DNA-based PCR as a gold standard, the real-time PCR had sensitivity and specificity values of 92% and 77%, respectively, which were significantly higher than those of conventional tests such as microscopy, culture and the leishmanin skin test (LST). In addition, the real-time PCR identified 147 different clinical samples at the species level, providing an overall agreement of 100% when compared to multilocus sequence typing (MLST) data performed on a subset of these samples. Furthermore, the real-time PCR was three times faster and five times less expensive when compared to PCR - MLST for species identification from clinical specimens. In summary, this new assay represents a cost-effective and reliable alternative for the identification of the main species causing NWTL in South America. Author Summary: Leishmaniasis is a neglected disease with more than two million new human infections annually worldwide. Tegumentary leishmaniasis, cutaneous and mucocutaneous, is mainly caused by five Leishmania species of the Viannia complex in South America. Different species can cause disease with similar symptoms but have dissimilar prognoses and may need different therapeutic regimens. Identification of Leishmania species traditionally relies on the multilocus enzyme electrophoresis (MLEE) assay, but it can only be applied to culture-positive samples and takes at least six weeks of intense laboratory work. A reliable and rapid assay for species identification can be a valuable tool. Molecular assays are the fastest and most accurate way to identify the etiological agents causing leishmaniasis. This paper describes a novel real-time PCR assay for identification of the five main species that cause tegumentary leishmaniasis in the New World. The assay correctly identified each of these five species of Leishmania directly from clinical samples. Because of its reliability, speed and simplicity, this assay could be used for species identification in routine laboratory diagnosis of leishmaniasis in endemic regions. [ABSTRACT FROM AUTHOR]

In South America, various species of Leishmania are endemic and cause New World tegumentary leishmaniasis (NWTL). The correct identification of these species is critical for adequate clinical management and surveillance activities. We developed a real-time polymerase chain reaction (PCR) assay and evaluated its diagnostic performance using 64 archived parasite isolates and 192 prospectively identified samples collected from individuals with suspected leishmaniasis enrolled at two reference clinics in Lima, Peru. The real-time PCR assay was able to detect a single parasite and provided unambiguous melting peaks for five Leishmania species of the Viannia subgenus that are highly prevalent in South America: L. (V.) braziliensis, L. (V.) panamensis, L. (V.) guyanensis, L. (V.) peruviana and L. (V.) lainsoni. Using kinetoplastid DNA-based PCR as a gold standard, the real-time PCR had sensitivity and specificity values of 92% and 77%, respectively, which were significantly higher than those of conventional tests such as microscopy, culture and the leishmanin skin test (LST). In addition, the realtime PCR identified 147 different clinical samples at the species level, providing an overall agreement of 100% when compared to multilocus sequence typing (MLST) data performed on a subset of these samples. Furthermore, the real-time PCR was three times faster and five times less expensive when compared to PCR - MLST for species identification from clinical specimens. In summary, this new assay represents a cost-effective and reliable alternative for the identification of the main species causing NWTL in South America. [ABSTRACT FROM AUTHOR]

Abstract: The heat-shock protein 70 gene (hsp70) has been exploited for Leishmania species identification in the Old and New World, using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism analysis. Three new Leishmania-specific hsp70 PCRs were recently described, and we applied 2 of these on 89 clinical samples from a total of 73 Peruvian patients with either cutaneous or mucocutaneous leishmaniasis. The new PCRs on average showed a 2- to 3-fold improved sensitivity in the tested sample types (lesion biopsies, aspirates, and scrapings), for both genus detection and species typing, and were most successful in biopsies. Leishmania braziliensis, L. peruviana, and L. guyanensis were encountered. About one third of the L. braziliensis parasites contained 2 hsp70 alleles. This study is a paradigm for the implementation of a globally applicable upgraded tool for the identification of Leishmania directly on human specimens from cutaneous and mucocutaneous lesions in the New World. [Copyright &y& Elsevier]

Background: Increased rates for failure in leishmaniasis antimony treatment have been recently recognized worldwide. Although several risk factors have been identified there is no clinical score to predict antimony therapy failure of cutaneous leishmaniasis. Methods: A case control study was conducted in Peru from 2001 to 2004. 171 patients were treated with pentavalent antimony and followed up to at least 6 months to determine cure or failure. Only patients with ulcerative cutaneous leishmaniasis (N = 87) were considered for data analysis. Epidemiological, demographical, clinical and laboratory data were analyzed to identify risk factors for treatment failure. Two prognostic scores for antimonial treatment failure were tested for sensitivity and specificity to predict antimony therapy failure by comparison with treatment outcome. Results: Among 87 antimony-treated patients, 18 (21%) failed the treatment and 69 (79%) were cured. A novel risk factor for treatment failure was identified: presence of concomitant distant lesions. Patients presenting concomitant-distant lesions showed a 30.5-fold increase in the risk of treatment failure compared to other patients. The best prognostic score for antimonial treatment failure showed a sensitivity of 77.78% and specificity of 95.52% to predict antimony therapy failure. Conclusions: A prognostic score including a novel risk factor was able to predict antimonial treatment failure in cutaneous leishmaniasis with high specificity and sensitivity. This prognostic score presents practical advantages as it relies on clinical and epidemiological characteristics, easily obtained by physicians or health workers, and makes it a promising clinical tool that needs to be validated before their use for developing countries. Author Summary: The manuscript is relevant because of the finding of a new risk factor for chemotherapy failure and the development of a prognosis score for cutaneous leishmaniasis. The proportion of patients that have multiple lesions in American Tegumentary Leishmaniasis (ATL) is considerable. Publications and our experience permit to estimate that they represent around 20% of the affected population from the Amazon basin with cutaneous lesions. In addition, about 1/3 of them would correspond to the concomitant distant lesions category, the novel risk factor identified with a very high odds ratio (20–30) associated. Such numbers merit study of concomitant distant ulcers category on its own, not only because of clinical management implications, but also to search for factors that are contributing to chemotherapy failure. Finally, the simple equation proposed in the manuscript can be easily adapted to smart phone technologies. Similar prognosis equations are scarce for other pathologies and do not exist for Cutaneous Leishmaniasis at all. The simplicity of this tool should be followed by subsequent epidemiologic studies in other ATL endemic regions. [ABSTRACT FROM AUTHOR]

Background: Increased rates for failure in leishmaniasis antimony treatment have been recently recognized worldwide. Although several risk factors have been identified there is no clinical score to predict antimony therapy failure of cutaneous leishmaniasis. Methods: A case control study was conducted in Peru from 2001 to 2004. 171 patients were treated with pentavalent antimony and followed up to at least 6 months to determine cure or failure. Only patients with ulcerative cutaneous leishmaniasis (N = 87) were considered for data analysis. Epidemiological, demographical, clinical and laboratory data were analyzed to identify risk factors for treatment failure. Two prognostic scores for antimonial treatment failure were tested for sensitivity and specificity to predict antimony therapy failure by comparison with treatment outcome. Results: Among 87 antimony-treated patients, 18 (21%) failed the treatment and 69 (79%) were cured. A novel risk factor for treatment failure was identified: presence of concomitant distant lesions. Patients presenting concomitant-distant lesions showed a 30.5-fold increase in the risk of treatment failure compared to other patients. The best prognostic score for antimonial treatment failure showed a sensitivity of 77.78% and specificity of 95.52% to predict antimony therapy failure. Conclusions: A prognostic score including a novel risk factor was able to predict antimonial treatment failure in cutaneous leishmaniasis with high specificity and sensitivity. This prognostic score presents practical advantages as it relies on clinical and epidemiological characteristics, easily obtained by physicians or health workers, and makes it a promising clinical tool that needs to be validated before their use for developing countries. [ABSTRACT FROM AUTHOR]

Background: Traditional methods of diagnosing mucosal leishmaniasis (ML), such as biopsy with histopathology, are insensitive and require collection of an invasive diagnostic specimen. Methods: We compared standard invasive procedures including biopsy histopathology, biopsy PCR, and leishmanin skin test (LST) to a novel, non-invasive, cytology-brush based PCR for the diagnosis of ML in Lima, Peru. Consensus reference standard was 2/4 tests positive, and outcome measures were sensitivity and specificity. Leishmania species identification was performed by PCR-based assays of positive specimens. Results: Twenty-eight patients were enrolled, 23 of whom fulfilled criteria for a diagnosis of ML. Sensitivity and specificity of biopsy with histopathology were 21.7% [95% CI 4.9-38.5%] and 100%; 69.6% [95% CI 50.8-88.4%] and 100% for LST; 95.7% [95% CI 87.4-100%] and 100% for biopsy PCR; and 95.7% [95% CI 87.4-100%] and 90% [95% CI 71.4-100%] for cytology brush PCR using both CervisoftH and HistobrushH cervical cytology brushes. Represented species identified by PCR-RFLP included: L. (V). braziliensis (n = 4), and L. (V). peruviana (n = 3). Conclusions: Use of commercial grade cytology brush PCR for diagnosis of ML is sensitive, rapid, well tolerated, and carries none of the risks of invasive diagnostic procedures such as biopsy. Further optimization is required for adequate species identification. Further evaluation of this method in field and other settings is warranted. [ABSTRACT FROM AUTHOR]

Background. Traditional detection of Leishmania from ulcers involves collection of invasive specimens that cause discomfort, require technical expertise, and carry risks of invasive procedures. We compared traditional diagnostic methods with a molecular noninvasive filter paper-based method for the diagnosis of cutaneous leishmaniasis. Methods. Consecutive patients presenting to the Leishmania Clinic at Hospital Nacional Cayetano Heredia were enrolled. Polymerase chain reaction (PCR) was performed on lesion scrapings, aspirates, and filter paper impressions. The reference standard was any 2 of 5 tests positive: smear, aspirate culture, invasive-specimen PCR (scrapings and aspirates), filter paper PCR, and leishmanin skin test. Outcome measures were sensitivity and specificity. Leishmania speciation was performed by PCR--restriction fragment length polymorphism (RFLP) of positive specimens. Results. Forty-five patients with 66 lesions were enrolled. Of 52 lesions diagnosed as cutaneous leishmaniasis, 50 were positive by PCR of invasive specimens versus 48 by PCR of filter papers (P = .930). Sensitivity and specificity of PCR on invasively obtained specimens were 94.2% (95% confidence interval [CI], 87.9%-100%) and 92.9% (95% CI, 79.4%-100%). Sensitivity and specificity of filter paper PCR were 92.3% (95% CI, 85.1%-99.5%) and 100%. Culture, smear, and leishmanin skin test all had inferior sensitivities, compared with PCR of invasive or noninvasive specimens (P < .001). Of 50 specimens positive by PCR, 19 had sufficient DNA for PCR-RFLP analysis. Conclusions. Filter paper PCR constitutes a sensitive and specific alternative to traditional diagnostic assays. This novel, rapid, well-tolerated method has the potential for widespread use in the field and in pediatric populations where traditional specimen collection is most difficult to perform, and can potentially be used for rapid species identification. [ABSTRACT FROM AUTHOR]

Leishmania species of the subgenus Viannia and especially Leishmania braziliensis are responsible for a large proportion of New World leishmaniasis cases. The reproductive mode of Leishmania species has often been assumed to be predominantly clonal, but remains unsettled. We have investigated the genetic polymorphism at 12 microsatellite loci on 124 human strains of Leishmania braziliensis from 2 countries, Peru and Bolivia. There is substantial genetic diversity, with an average of 12.4 ± 4.4 alleles per locus. There is linkage disequilibrium at a genome-wide scale, as well as a substantial heterozygote deficit (more than 50% the expected value from Hardy-Weinberg equilibrium), which indicates high levels of inbreeding. These observations are inconsistent with a strictly clonal model of reproduction, which implies excess heterozygosity. Moreover, there is large genetic heterogeneity between populations within countries (Wahlund effect), which evinces a strong population structure at a microgeographic scale. Our findings are compatible with the existence of population foci at a microgeographic scale, where clonality alternates with sexuality of an endogamic nature, with possible occasional recombination events between individuals of different genotypes. These findings provide key clues on the ecology and transmission patterns of Leishmania parasites. [ABSTRACT FROM AUTHOR]

Background. Tegumentary leishmaniasis in Latin America is caused mainly by Leish mania viannia braziliensis complex parasites. L. braziliensis and Leish mania viannia peruviana are the 2 predominant Leish mania species in Pern. L. braziliensis is more virulent, because it can cause mucocutaneous leishmaniasis, known as espundia, that results in severe facial destruction. Early identification of the species that causes the initial cutaneous infection would greatly help to prevent mucocutaneous leishmaniasis, because it would allow more aggressive treatment and follow-up. However, because of the close genetic similarity of L. braziliensis and L. peruviana, there currently exists no simple assay to distinguish between these species. Methods. We cloned the mannose phosphate isomerase gene from both L. braziliensis and L. peruviana. It is the only known isoenzyme capable of differentiating between L. braziliensis and L. peruviana in multilocus enzyme electrophoresis. Interestingly, only a single nucleotide polymorphism was found between the mannose phosphate isomerase genes from L. braziliensis and L. peruviana, resulting in an amino acid change from threonine to arginine at amino acid 361. A polymerase chain reaction assay was developed to distinguish the single nucleotide polymorphism of the mannose phosphate isomerase gene to allow for the specific identification of L. braziliensis or L. peruviana. Results. This assay was validated with 31 reference strains that were previously typed by multilocus enzyme electrophoresis, successfully applied to patient biopsy samples, and adapted to a real-time polymerase chain reaction assay. Conclusions. This innovative approach combines new genetic knowledge with traditional biochemical fundamentals of multilocus enzyme electrophoresis to better manage leishmaniasis in Latin America. [ABSTRACT FROM AUTHOR]

Objective: To determine the efficacy and toxicity of the World Health Organization's (WHO) recommended treatment for mucosal leishmaniasis: antimony, 20 mg/kg body weight per day for 28 days.Design: Open trial with 12-month follow-up.Setting: Inpatient unit of a regional referral hospital in a developing country.Patients: Twenty-nine consecutive eligible patients with culture-confirmed infection of the mucosa with Leishmania species who were otherwise healthy. Eight patients (28%) had mild to moderate disease (confined to the nasal mucosa). Twenty-one patients (72%) had severe disease (including the oropharynx as well as the nasal mucosa).Intervention: Antimony, 20 mg/kg body weight intravenously every day for 28 days. Patients received antimony in the form of sodium stibogluconate.Measurements and Main Results: Initial results of therapy were as follows: 63 of 72 lesions (88%) healed or markedly improved; all lesions were culture-negative for parasites; and 18 of 29 patients (62%) showed complete clinical and parasitologic cure of all lesions. By the 12-month follow-up examinations, however, 37 lesions had recurred, 8 new lesions had appeared, and only 8 patients (30%) showed clinical cure of all lesions. Of the 8 patients with mild to moderate disease, 6 were cured compared with only 2 of the 21 patients with severe disease. Side effects of this treatment regimen included T-wave inversion on electrocardiogram (4 patients), abnormal liver function tests (10 patients), and musculoskeletal pain (24 patients). No side effects occurred during week 1 of therapy.Conclusions: The only recommended treatment for mucosal leishmaniasis is ineffective in patients with severe disease. The acceptable toxicity of the regimen suggests that longer courses of therapy with antimony, or that trials with other antileishmanial agents alone or combined with antimony be evaluated as initial therapy for this disease. [ABSTRACT FROM AUTHOR]