Efficacy of Miltefosine for the Treatment of American Cutaneous Leishmaniasis

Miltefosine is an oral agent used for cutaneous leishmaniasis treatment. An open-label, randomized, phase III clinical trial was carried out in the Colombian army population. Miltefosine, 50 mg capsule was taken orally three times per day for 28 days (N = 145) or meglumine antimoniate, 20 mg/kg body weight per day for 20 days by intramuscular injection (N = 143). The efficacy of miltefosine by protocol was 69.8% (85/122 patients) and 58.6% (85/145 patients) by intention to treat. For meglumine antimoniate, the efficacy by protocol was 85.1% (103/121 patients) and 72% (103/143 patients) by intention to treat. No association was found between drug efficacy and L. (V.) braziliensis or L. (V.) panamensis species of Leishmania responsible for infection. Adverse gastrointestinal events were associated with the use of miltefosine, the meglumine antimoniate treatment was associated with adverse effects on the skeletal musculature, fever, cephalea, and higher toxicity in kidney, liver, pancreas, and hematological system.     

Randomized,Double-Blinded,Phase 2 Trial of WR 279,396 (Paromomycin and Gentamicin) for Cutaneous Leishmaniasis in Panama

In this randomized, double-blinded Phase 2 trial, 30 patients with Leishmania panamensis cutaneous leishmaniasis were randomly allocated (1:1) to receive once daily topical treatment with WR 279,396 (15% paromomycin + 0.5% gentamicin) or Paromomycin Alone (15% paromomycin) for 20 days. The index lesion cure rate after 6 months follow-up was 13 of 15 (87%) for WR 279,396 and 9 of 15 (60%) for Paromomycin Alone (P = 0.099). When all treated lesions were included, the final cure rate for WR 279,398-treated patients was again 87%, but the final cure rate for Paromomycin Alone-treated patients was 8 of 15 (53.3%; P = 0.046). Both creams were well tolerated with mild application site reactions being the most frequent adverse event. The increased final cure rate in the WR 279,396 group in this small Phase 2 study suggests that the combination product may provide greater clinical benefit than paromomycin monotherapy against L. panamensis cutaneous leishmaniasis.     

Transplacental Transmission of Cutaneous Leishmania mexicana Strain in BALB/c Mice

The vertical transmission of leishmaniasis has been reported in species that cause visceral leishmaniasis. However, this condition has scarcely been documented in species that cause cutaneous leishmaniasis. The aim of this study was to determine experimentally whether L. mexicana is transmitted vertically. A control group of BALB/c mice and a group infected with L. mexicana were mated, the gestation was monitored, and females were killed before delivery. Four resorptions (P = 0.023) and eight fetal deaths (P = 0.010) were observed in the infected female group; furthermore, the offspring body weight of the infected group was lower than the body weight of the healthy group (P = 0.009). DNA amplification by polymerase chain reaction (PCR) revealed that all placentas and maternal spleens as well as 39 of 110 fetal spleens obtained from the offspring of infected mothers tested positive for Leishmania. In conclusion, L. mexicana is transmitted transplacentally and causes fetal death, resorption, and reduction in offspring body weight.     

Immunopathogenic competences of Leishmania (V.) braziliensis and L. (L.) amazonensis in American cutaneous leishmaniasis

The immunopathogenic competences of Leishmania (V.) braziliensis and L. (L.) amazonensis were reviewed in the light of more recent features found in the clinical and immunopathological spectrum of American cutaneous leishmaniasis. It was shown a dichotomy in the interaction between these Leishmania species and human T-cell immune response; while L. (V.) braziliensis shows a clear tendency to lead infection from the localized cutaneous leishmaniasis (LCL), a moderate T-cell hypersensitivity form at the centre of the spectrum, toward to the mucocutaneous leishmaniasis (MCL) at the T-cell hypersensitivity pole and with a prominent Th1-type immune response, L. (L.) amazonensis shows an opposite tendency, leading infection to the anergic diffuse cutaneous leishmaniasis (ADCL) at the T-cell hyposensitivity pole and with a marked Th2-type immune response. Between the central LCL and the two polar MCL and ADCL, the infection can present an intermediary form known as borderline disseminated cutaneous leishmaniasis, characterized by an incomplete inhibition of T-cell hypersensitivity but with a evident supremacy of Th1 over Th2 immune response (Th1 ≥ Th2). These are probably the main immunopathogenic competences of L. (V.) braziliensis and L. (L.) amazonensis regarding the immune response dichotomy that modulates human infection outcome by these Leishmania parasites.     

Susceptibility of Cebus apella monkey (Primates: Cebidae) to experimental Leishmania (L.) infantum chagasi-infection

In Amazonian Brazil, the Cebus apella monkey (Primates: Cebidae) has been associated with the enzootic cycle of Leishmania (V.) shawi, a dermotropic parasite causing American cutaneous leishmaniasis (ACL). It has also been successfully used as animal model for studying cutaneous leishmaniasis. In this work, there has been investigated its susceptibility to experimental Leishmania (L.) infantum chagasi-infection, the etiologic agent of American visceral leishmaniasis (AVL). There were used ten C. apella specimens, eight adult and two young, four males and six females, all born and raised in captivity. Two experimental infection protocols were performed: i) six monkeys were inoculated, intra-dermal via (ID), into the base of the tail with 2 x 10(6) promastigotes forms from the stationary phase culture medium; ii) other four monkeys were inoculated with 3 x 10(7) amastigotes forms from the visceral infection of infected hamsters by two different via: a) two by intravenous via (IV) and, b) other two by intra-peritoneal via (IP). The parameters of infection evaluation included: a) clinical: physical exam of abdomen, weigh and body temperature; b) parasitological: needle aspiration of the bone-marrow for searching of amastigotes (Giemsa-stained smears) and promastigotes forms (culture medium); c) immunological: Indirect fluorescence antibody test (IFAT) and, Delayed-type hypersensitivity (DTH). In the six monkeys ID inoculated (promastigotes forms) all parameters of infection evaluation were negative during the 12 months period of follow-up. Among the four monkeys inoculated with amastigotes forms, two IV inoculated showed the parasite in the bone-marrow from the first toward to the sixth month p.i. and following that they cleared the infection, whereas the other two IP inoculated were totally negative. These four monkeys showed specific IgG-antibody response since the third month p.i. (IP: 1/80 and IV: 1/320 IgG) toward to the 12th month (IP: 1/160 and IV: 1/5120). The DTH-conversion occurred in only one IV inoculated monkey with a strong (30 mm) skin reaction. Considering these results, we do not encourage the use of C. apella monkey as animal model for studying the AVL.     

An evaluation of indices for quantifying tuberculosis transmission using genotypes of pathogen isolates

Background

Determinants of the clinical presentation of the leishmaniases are poorly understood but Leishmania species and strain differences are important. To examine the relationship between clinical presentation, species and isoenzyme polymorphisms, 56 Leishmania isolates from distinct presentations of American tegumentary leishmaniasis (ATL) from Ecuador were analyzed.

Methods

Isolates were characterized by multilocus enzyme electrophoresis for polymorphisms of 11 isoenzymes. Patients were infected in four different ecologic regions: highland and lowland jungle of the Pacific coast, Amazonian lowlands and Andean highlands.

Results

Six Leishmania species constituting 21 zymodemes were identified: L. (Viannia) panamensis (21 isolates, 7 zymodemes), L. (V.) guyanensis (7 isolates, 4 zymodemes), L. (V.) braziliensis (5 isolates, 3 zymodemes), L. (Leishmania) mexicana (11 isolates, 4 zymodemes), L. (L.) amazonensis (10 isolates, 2 zymodemes) and L. (L.) major (2 isolates, 1 zymodeme). L. panamensis was the species most frequently identified in the Pacific region and was associated with several clinical variants of cutaneous disease (CL); eight cases of leishmaniasis recidiva cutis (LRC) found in the Pacific highlands were associated with 3 zymodemes of this species. Mucocutaneous leishmaniasis found only in the Amazonian focus was associated with 3 zymodemes of L. braziliensis. The papular variant of CL, Uta, found in the Andean highlands was related predominantly with a single zymodeme of L. mexicana.

Conclusion

Our data show a high degree of phenotypic variation within species, and some evidence for associations between specific variants of ATL (i.e. Uta and LRC) and specific Leishmania zymodemes. This study further defines the geographic distribution of Leishmania species and clinical variants of ATL in Ecuador.     

Disseminated cutaneous leishmaniasis due to Leishmania(Leishmania) amazonensis in human immunodeficiency virus(HIV)-infected patients: A report of two cases

Rationale: Co-infection of human immunodeficiency virus(HIV) and Leishmania spp. has impact on clinical and therapeutic outcomes of leishmaniases. Most studies do not present the identification of Leishmania species causing American tegumentary leishmaniasis in co-infections. In the Americas, Leishmania(L.) Viannia(V.) braziliensis and L.(V.) guyanensis have been identified. Patient concerns: In this study, two cases of American tegumentary leishmaniasis in patients infected with HIV are described. Patients presented several lesions with rapid dissemination and mucosal involvement. Diagnosis: Disseminated cutaneous leishmaniasis caused by L. amazonensis was identified by molecular test. Interventions: The patients were treated with conventional therapies for HIV infection and American tegumentary leishmaniasis. Outcomes: In co-infection, the clinical manifestations are atypical and the treatment response can be impaired. Lessons: These cases show that HIV infection impacts L. amazonensis infection and point to the relevance of identifying Leishmania species, which can lead to a better patient management.     

First human cases of Leishmania (Viannia) naiffi infection in Ecuador and identification of its suspected vector species

Epidemiological surveillance of leishmaniasis was conducted in a northern Amazonian region of Ecuador, in which cutaneous leishmaniasis cases were recently reported. Sand flies were captured in the military training camp, and the natural infection of sand flies by Leishmania species was examined. Out of 334 female sand flies dissected, the natural infection by flagellates was microscopically detected in 3.9% of Lutzomyia yuilli yuilli and 3.7% of Lutzomyia tortura, and the parasite species were identified as Endotrypanum and Leishmania (Viannia) naiffi, respectively. After the sand fly surveillance, specimens from cutaneous leishmaniasis (CL) patients considered to have acquired the infection in the training camp area were obtained, and the infected parasite species were identified as L. (V.) naiffi. The present study reported first cases of CL caused by L. (V.) naiffi infection in Ecuador. In addition, a high ratio of infection of Lu. tortura by L. (V.) naiffi in the same area strongly suggested that Lu. tortura is responsible for the transmission of L. (V.) naiffi in this area.     

Case Report: Simultaneous Infection with Leishmania (Viannia) braziliensis and L. (V.) lainsoni in a Peruvian Patient with Cutaneous Leishmaniasis

Conventional understanding suggests that simultaneous infection with more than one species of Leishmania is unlikely. In Peru, co-infections are clinically relevant because causative species dictates prognosis, treatment response, and follow-up. We describe a case of Leishmania (Viannia) braziliensis and L. (V.) lainsoni co-infection in a Peruvian patient with cutaneous leishmaniasis.     

The rarity of infection with Leishmania (Viannia) braziliensis among patients from the Manaus region of Amazonas state,Brazil, who have cutaneous leishmaniasis

The frequency of Leishmania ( Viannia) braziliensis infection was assessed in 79 of the 138 patients with cutaneous leishmaniasis who attended a reference outpatient unit in Manaus, Amazonas state, between the August and December of 1997. The disease was characterized by one or more cutaneous ulcers, the skin lesions being frequently associated with satellite lymph-node enlargement. All parasite isolates were identified using monoclonal antibodies and enzyme electrophoresis. Only two (2.8%) of the 71 patients from whom parasites were successfully isolated were found to be infected with L. ( V.) braziliensis, the other 69 isolates being identified, from their isoenzyme profiles, as L. ( V.) guyanensis. In the Manaus region, therefore, almost all human cutaneous leishmaniasis is the result of infection with L. (V.) guyanensis, and L. ( V.) braziliensis is a relatively rare cause of the disease.     

Cross-immunity experiments between different species or strains of Leishmania in rhesus macaques (Macaca mulatta)

This study evaluates cross-immunity in rhesus monkeys (Macaca mulatta) previously infected with one species of Leishmania and have had self-cured disease or were cured by antimony-based therapy upon development of full-blown disease. We found that a self-healing cutaneous leishmaniasis (CL) following experimental infection with Leishmania (Leishmania) major induces significant protection for L. (L.) amazonensis and L. (Viannia) guyanensis, and was dependent on time of re-challenge by L (L.) amazonensis after animals had recovered from primary lesions, but lacked protection against L. (V.) braziliensis. In contrast, monkeys that recovered from L. (V.) braziliensis CL or L. (L.) chagasi visceral leishmaniasis following chemotherapeutic intervention were protected by challenge with L. (V.) braziliensis and L (L.) amazonensis. These findings indicate the relative variability in protection after self-cure or drug-cured experimental leishmaniasis to challenge by heterologous leishmanial parasites. Further studying the immune response may provide information regarding relevant factors influencing cross-protective immunity.     

Species diversity of Leishmania (Viannia) parasites circulating in an endemic area for cutaneous leishmaniasis located in the Atlantic rainforest region of northeastern Brazil

Objectives  To identify the aetiological agents of cutaneous leishmaniasis and to investigate the genetic polymorphism of Leishmania (Viannia) parasites circulating in an area with endemic cutaneous leishmaniasis (CL) in the Atlantic rainforest region of northeastern Brazil.
Methods  Leishmania spp. isolates came from three sources: (i) patients diagnosed clinically and parasitologically with CL based on primary lesions, secondary lesions, clinical recidiva, mucocutaneous leishmaniasis and scars; (ii) sentinel hamsters, sylvatic or synanthropic small rodents; and (iii) the sand fly species Lutzomyia whitmani . Isolates were characterised using monoclonal antibodies, multilocus enzyme electrophoresis (MLEE) and polymerase chain reaction-restriction fragment length polymorphism of the internal transcribed spacer region rDNA locus.
Results  Seventy-seven isolates were obtained and characterised. All isolates were identified as Leishmania (Viannia) braziliensis serodeme 1 based on reactivity to monoclonal antibodies. MLEE identified 10 zymodemes circulating in the study region. Most isolates were classified as zymodemes closely related to L. (V.) braziliensis, but five isolates were classified as Leishmania (Viannia) shawi . All but three of the identified zymodemes have so far been observed only in the study region. Enzootic transmission and multiclonal infection were observed.
Conclusions  Our results confirm that transmission cycle complexity and the co-existence of two or more species in the same area can affect the level of genetic polymorphism in a natural Leishmania population. Although it is not possible to make inferences as to the modes of genetic exchange, one can speculate that some of the zymodemes specific to the region are hybrids of L. (V.) braziliensis and L. (V.) shawi .     

Experimental acquisition,development, and transmission of Leishmania tropica by Phlebotomus duboscqi

We report experimental infection and transmission of Leishmania tropica (Wright), by the blood-feeding sand fly Phlebotomus duboscqi (Neveu-Lemaire). Groups of laboratory-reared female sand flies that fed “naturally” on L. tropica-infected hamsters, or artificially, via membrane feeding device, on a suspension of L. tropica amastigotes, were dissected at progressive time points post-feeding. Acquisition, retention and development of L. tropica through procyclic, nectomonad, and leptomonad stages to the infective metacyclic promastigote stage, and anterior progression of the parasites from abdominal midgut bloodmeal to the thoracic midgut were demonstrated in both groups. Membrane feeding on the concentrated amastigote suspension led to metacyclic promastigote infections in 60% of sand flies, whereas only 3% of P. duboscqi that fed naturally on an infected hamster developed metacyclics. Sand flies from both groups re-fed on naïve hamsters, but despite infections in 25–50% of membrane-fed and 2–3.5% of naturally fed flies, no skin lesions developed in the hamsters. After four months of observation these animals were euthanized and necropsied. Screening of the organs and tissue by polymerase chain reaction (PCR) that targeted the small subunit RNA gene, amplified generic Leishmania DNA from liver, spleen, bone marrow, and blood, but only from hamsters bitten by membrane-infected P. duboscqi. These results are notable in demonstrating the ability of P. duboscqi, originating from Kenya, to acquire, retain, develop, and transmit a Turkish strain of L. tropica originally isolated from a human case of cutaneous leishmaniasis. This marks the first demonstration of complete development and transmission of L. tropica by a member of the Phlebotomus subgenus of sand flies.     

The site of cutaneous infection influences the immunological response and clinical outcome of hamsters infected with Leishmania panamensis

We determined that the site of inoculation (foot or snout) influences the clinical evolution and immune responses of hamsters infected with Leishmania (Viannia) panamensis. Hamsters infected in the snout showed (i) a more rapid and severe lesion evolution at multiple time points (P < 0.05), (ii) a more extensive inflammatory infiltrate and tissue necrosis, (iii) a higher tissue parasite burden, (iv) a higher antibody titre (P < 0.01), but lower antigen-specific spleen cell proliferative response (P = 0.02), and (v) a slower response to anti-leishmanial drug treatment (P < 0.002). In both inoculation groups there was co-expression of type 1 (IFN-gamma and IL-12) and some type 2 (IL-10 and TGF-beta, but not IL-4) cytokines in the cutaneous lesions and spleen. Early in the course of infection, hamsters infected in the snout showed higher expression of splenic IL-10 (P = 0.04) and intra-lesional IFN-gamma (P = 0.02) than foot infections. No expression of IL-12p40 or IL-4 was detected. During the chronic phase, snout lesions expressed more IFN-gamma (P = 0.001), IL-12p40 (P = 0.01), IL-10 (P = 0.009) and TGF-beta (P = 0.001), and the level of expression of each of these cytokines correlated with lesion size (P < or = 0.01). These results suggest that the site of infection influences the clinical outcome in experimental cutaneous leishmaniasis, and that the expression of macrophage-deactivating type 2 cytokines and/or an exaggerated type 1 proinflammatory cytokine response may contribute to lesion severity.     

Systemic therapy of New World cutaneous leishmaniasis: A case report and review article

Cutaneous leishmaniasis is a disease endemic to Central and South America, Mexico and the Caribbean, and affects millions of people. As travel to these regions becomes more common, cutaneous leishmaniasis is becoming a disease of increasing importance in the developed world. However, disease recognition and access to appropriate therapy for cutaneous leishmaniasis remains a challenge in North America. The present article reports a case of cutaneous leishmaniasis in a Canadian man following a trip to Costa Rica. Species-specific diagnosis was confirmed by polymerase chain reaction analysis of a skin biopsy, which was positive for Leishmania panamensis. After failing a course of itraconazole, the patient was successfully treated with sodium stibogluconate, despite significant barriers to administering this therapy, and the paucity of data regarding its efficacy and tolerability. The pathophysiology, diagnosis and systemic treatment of cutaneous leishmaniasis, as well as its emerging presence in the developed world, are reviewed.     

Kidney involvement in leishmaniasis—a review

Leishmaniasis is an infectious disease caused by protozoa of the genus Leishmania transmitted by insects of the genus Lutzomyia sp. or Phlebotomus sp. The main syndromes are cutaneous leishmaniasis, mucocutaneous leishmaniasis, visceral leishmaniasis (kala-azar) and post-kala-azar dermal leishmaniasis. This article reviews kidney involvement in cutaneous and visceral leishmaniasis, highlighting the aspects of their pathophysiology, clinical manifestations, histopathological findings, outcome and treatment.     

Age Modifies the Immunologic Response and Clinical Presentation of American Tegumentary Leishmaniasis

Leishmania (Viannia) braziliensis is the main causal agent of American tegumentary leishmaniasis (ATL) that may present as cutaneous, mucosal, or disseminated cutaneous leishmaniasis. The disease is highly prevalent in young males and there is a lack of studies of ATL in the elderly. Herein, we compared clinical manifestations, immunologic response, and response to antimony therapy between patients > 60 years of age (N = 58) and patients who were 21–30 years of age (N = 187). The study was performed in Corte de Pedra, Bahia, Brazil, a well-known area of L. braziliensis transmission. Cytokine production by cultured peripheral blood mononuclear cells stimulated with soluble Leishmania antigen was performed. Elderly subjects more frequently had a previous history of cutaneous leishmaniasis, large lesions, or mucosal leishmaniasis, and they were less likely to have lymphadenopathy. There was no difference regarding gender and response to therapy. Peripheral blood mononuclear cells from elderly subjects produced a similar amount of tumor necrosis factor than young patients but they produced less interferon-gamma and more interleukin-10 than young subjects. We concluded that elderly patients with cutaneous leishmaniasis should be searched for mucosal or disseminated leishmaniasis. The decreased interferon-gamma production and increase in interleukin-10 observed in elderly patients may contribute to parasite persistence and L. braziliensis infection dissemination.     

Influence of Leishmania (Viannia) species on the response to antimonial treatment in patients with American tegumentary leishmaniasis

BACKGROUND: Pentavalent antimonials (SbV) are the first-line chemotherapy for American tegumentary leishmaniasis (ATL). There are, however, reports of the occurrence of treatment failure with these drugs. Few studies in Latin America have compared the response to SbV treatment in ATL caused by different Leishmania species. METHODS: Clinical parameters and response to SbV chemotherapy were studied in 103 patients with cutaneous leishmaniasis (CL) in Peru. Leishmania isolates were collected before treatment and typed by multilocus polymerase-chain-reaction restriction fragment-length polymorphism analysis. RESULTS: The 103 isolates were identified as L. (Viannia) peruviana (47.6%), L. (V.) guyanensis (23.3%), L. (V.) braziliensis (22.3%), L. (V.) lainsoni (4.9%), L. (Leishmania) mexicana (1%), and a putative hybrid, L. (V.) braziliensis/L. (V.) peruviana (1%). L. (V.) guyanensis was most abundant in central Peru. Of patients infected with the 3 former species, 21 (21.9%) did not respond to SbV chemotherapy. The proportions of treatment failure (after 12 months of follow-up) were 30.4%, 24.5%, and 8.3% in patients infected with L. (V.) braziliensis, L. (V.) peruviana, and L. (V.) guyanensis, respectively. Infection with L. (V.) guyanensis was associated with significantly less treatment failure than L. (V.) braziliensis, as determined by multiple logistic regression analysis (odds ratio, 0.07 [95% confidence interval, 0.007-0.8]; P=.03). CONCLUSIONS: Leishmania species can influence SbV treatment outcome in patients with CL. Therefore, parasite identification is of utmost clinical importance, because it should lead to a species-oriented treatment.     

A Controlled,Randomized-Blinded Clinical Trial to Assess the Efficacy of a Nitric Oxide Releasing Patch in the Treatment of Cutaneous Leishmaniasis by Leishmania (V.) panamensis

A topical nanofiber nitric oxide (NO) releasing patch (≈3.5 μmol NO/cm²/day for 20 days, NOP) was compared with intramuscular meglumine antimoniate (Glucantime, 20 mg/kg/day for 20 days) for the treatment of cutaneous leishmaniasis (CL) caused by Leishmania (V.) panamensis in Santander and Tolima, Colombia. A double-blind, randomized, placebo-controlled, clinical trial was conducted to determine whether the NOP is as effective as Glucantime for the treatment of CL. Patients were randomly assigned to Glucantime and placebo patches or NOP and placebo of Glucantime. The cure rates after a 3-month follow-up were 94.8% for the group that received Glucantime compared with 37.1% in the NOP group. Despite the lower efficacy of the NOP versus Glucantime, a significantly lower frequency of non-serious adverse events and a reduced variation in serum markers were observed in patients treated with NOP. Treatment of CL with NOP resulted in a lower effectiveness compared with Glucantime; however, the low frequency of adverse events and the facility of topic administration justify the development of new generations of NOP systems for the treatment of CL.     

Sensitivity of the polymerase chain reaction for the diagnosis of cutaneous leishmaniasis due to Leishmania (Viannia) guyanensis.

The sensitivity of the polymerase chain reaction (PCR) in 35 consecutive outpatients with cutaneous leishmaniasis caused by Leishmania (Viannia) guyanensis was evaluated using, as gold standard, the in vitro isolation of the parasite through culture of aspirates of the cutaneous ulcers. All isolates were identified using electrophoretic enzyme analysis. Patients were mainly young males with recent onset disease without prior specific treatment. PCR was performed using DNA extracted from fresh frozen biopsies of cutaneous ulcers. The reaction used a pair of oligonucleotides that amplify the conserved region of the minicircle molecule. PCR showed 100% sensitivity (95% CI from 90.0 to 100.0). These results were similar to the visualization of amastigotes in imprint preparations of cutaneous biopsy tissue and the inoculation of biopsy material in golden hamsters. Despite the high sensitivity of the PCR, in this particular clinical setting of cutaneous leishmaniasis caused by L. (V.) guyanensis in the Brazilian Amazon, it appears that the method of choice for diagnosis should be the direct visualization of amastigotes using imprint preparations and the PCR reserved for those patients with negative imprint results.