Serodiagnosis of anthroponotic cutaneous leishmaniasis (ACL) caused by Leishmania tropica in Sanliurfa Province, Turkey, where ACL Is highly endemic

The use of recombinant K39, KMP11, and crude antigen-based indirect ELISA as a serological diagnostic tool and a measure of exposure for cutaneous leishmaniasis in Sri Lanka

Cutaneous leishmaniasis (CL) in Sri Lanka is caused by Leishmania donovani, a parasite widely known to cause visceral leishmaniasis. Despite the fact that CL is not generally believed to elicit serological immune responses, recent studies show the presence of antibody responses against this atypical form of CL. This study assesses the potential of using recombinant K39 (rK39), KMP11, and crude parasite antigen-based indirect ELISAs as serological diagnostic tools and measures of exposure for CL in Sri Lanka. The study used serum samples from confirmed CL patients (n = 266) and apparently healthy individuals from endemic settings (n = 411). Serum samples from individuals residing in non-endemic areas were used as negative controls. In-house indirect ELISAs were optimized and validated for recombinant antigens. Previously validated crude parasite extract-based indirect ELISA was performed for comparison. The statistical analyses were performed using SPSS v26.0. The rK39 (sensitivity = 71.2%, specificity = 64%) and KMP11 (sensitivity = 79.2%, specificity = 71.4%) based indirect ELISA were shown to be less suitable for the diagnosis of CL, while crude parasite extract-based indirect ELISA (sensitivity = 82.4%, specificity = 85.7%) might be a better method of diagnosis. All 03 ELISAs seemed to be good methods as measures of exposure since correlations were observed between the seropositivity of all 03 ELISAs (rK39: p = 0.037, KMP11: p = 0.007, CrudeAg: p = 0.000) with provincial case incidences. The findings will be important in identifying the disease hotspots in order to design the control measures for CL induced by L. donovani in Sri Lanka.

ELISA-based evaluation of antibody response to Leishmania in a region endemic for cutaneous leishmaniasis

Leishmaniasis includes several clinical forms. While routine diagnosis of cutaneous leishmaniasis (CL) is by microscopy, an antibody response to CL has been reported in several recent studies. This study evaluated anti-leishmanial immunoglobulin G (IgG) antibody responses as a biomarker of active leishmaniasis and a measure of exposure to Leishmania. Sera from 50 untreated CL patients, 140 patients under treatment and 280 healthy individuals residing in endemic regions collected as part of an epidemiological survey, was analysed with an enzyme-linked immunosorbent assay established in-house using receiver operator characteristic curve at optimized cut-off value. The assay showed high performance as a diagnostic tool in identifying exposure in endemic individuals (sensitivity: 98%, specificity: 90.3%). All patients showed lower antibody levels over time since onset of lesion/s. Antibody levels were higher (p ˂ .01) and persisted for a longer period in untreated patients. In patients under treatment, the level of anti-IgG antibodies was negatively correlated with the total duration the patient had been on treatment. The anti-leishmanial IgG response in Leishmania donovani-induced CL is transient and is unlikely to confer protective immunity. Optimized serological assays may be useful in endemic settings for diagnosis and monitoring the treatment response in CL.

Prognostic Value of Immunoglobulin G (IgG) Patterns by Western Blotting Immunodetection in Treated Dogs Previously Infected with Leishmania infantum

Leishmaniasis is a heterogeneous group of neglected tropical diseases with various clinical syndromes, which is caused by obligate intracellular protozoa of the genus Leishmania and transmitted by the bite of a female phlebotomine sandfly. Humans and several animal species are considered as reservoirs of the disease. Among other animal species, dogs are the most important reservoirs in a domestic environment, maintaining the endemic focus of the parasite. The behavior of the disease progression and the clinical symptoms of the disease in the infected dog is mainly associated with depressed cellular immunity and strong humoral response. This study aimed to assess the role of Western blotting in the analysis of the idiotype expression of the two main immunoglobulins (IgG1 and IgG2) in dogs that are naturally infected with Leishmania infantum (L. infantum) and treated with N-methyl meglumine antimoniate. Interestingly, for the first time, our study identified several L. infantum antigen polypeptides (14, 31, 33, 49, 64, 66, 99, and 169 kDa) that more frequently stimulate an immune reaction in recovered dogs after treatment, whereas in the non-recovered group of dogs, four antigen polypeptides of L. infantum with molecular weights of 31, 49, 66, and 115 kDa with unfavorable prognosis were identified. Clearly, these interesting findings confirm the strong association between the detected immunodominant bands and the successful recovery in treated dogs that can be used for differentiating the treated dogs from the untreated dogs, as well as the markers of a favorable or unfavorable prognosis and, as a consequence, the prediction of the clinical outcome of the disease. Likewise, these data could be helpful in the implementation of novel vaccines from the detected antigens.

Comparative Testing of Susceptibility Levels of Phlebotomus sergenti, the Main Vector of Anthroponotic Cutaneous Leishmaniasis, to Conventional Insecticides Using Two Capture Methods in Kerman City, Southeastern Iran

Background:

Collecting live sand flies from indoor sites is a major challenge for researchers in large cities due to the reluctance of families to survey their homes. This study was conducted to assess the efficacy of two methods for collecting sand flies for use in susceptibility tests in the urban area of Kerman, southeastern Iran.

Methods:

Sandflies were mainly collected using both baited traps and hand catch methods from outdoor and indoor sites. Susceptibility tests were separately done according to the standard World Health Organization testing protocol on Phlebotomus sergenti, including 60-minute exposure to DDT 4.0%, propoxur 0.1%, deltamethrin 0.05%, and malathion 5.0%.

Results:

During this research, the natural habitats and suitable indoor sites were selected to predict the density of live sand fly with perfect accuracy. The number of live Ph. sergenti caught by hand catch and baited traps methods was 42 and 361 in indoor and outdoor sites, respectively. The mortality rate of Ph. sergenti exposed to DDT 4%, deltamethrin 0.05, malathion 5%, and propoxur was 100%.

Conclusion

The baited traps showed a significant efficiency compared to hand catch for collecting live Ph. sergenti for use in susceptibility tests in urban areas. The Ph. sergenti collected from both indoor and outdoor sites were susceptible to all insecticides.

The Effects of Silver Nanoparticles Biosynthesized Using Fig and Olive Extracts on Cutaneous leishmaniasis Induced Inflammation in Female Balb/c Mice

Leishmaniasis is a group of infectious and non-contagious severe parasitic diseases, caused by protozoans of the Leishmania genus. Natural products characterize a rich source of prospective chemical entities for the development of new effective drugs for neglected diseases. Scientific evaluation of medicinal plants has made it possible to use some metabolites from flavonoids and polyphenols compounds for the treatment of parasitic diseases. Therefore, we aimed in this study to evaluate the protective effect of Silver nanoparticles (Ag-NPs) biosynthesized using Fig and Olive extracts (NFO) against Cutaneous leishmaniasis in female Balb/c mice. A total of 70 mice were used and divided into seven groups. Treatment was initiated when local lesions were apparent, we found Fig and Olive extracts were found to be a good source for the synthesis of (Ag-NPs), their formation was confirmed by color change and stability in solution. Nanoparticles biosynthesized using Fig and Olive extracts induced a reduction in the average size of cutaneous leishmaniasis lesions compared with the untreated mice. Moreover, nanoparticles treatment decreased oxidative stress (LPO, NO), down regulation gene expression levels (TNF-α, IL-1β and BAX) and this antileishmanial activity of nanoparticles was associated with enhanced antioxidant enzyme activities. In addition, histopathological evaluation proved the antileishmanial activity of nanoparticles compared to the positive control. Therefore, we aimed in this study to evaluate the protective effect of silver nanoparticles biosynthesized using Fig and Olive extracts against cutaneous lesions induced by Leishmania major infection through their anti-inflammatory, antioxidant activities and faster clinical efficacy than standard pentavalent antimonial treatment.

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

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

First Serological Study Revealing High Humoral Response and Evidence for Antigenic Heterogeneity in Leishmania donovani Induced CL in Sri Lanka

Posing a threat to the ongoing leishmaniasis elimination efforts in the Indian subcontinent, L. donovani-induced cutaneous leishmaniasis (CL) has been recently reported in many countries. Sri Lanka reports a large focus of human cutaneous leishmaniasis (CL) caused by Leishmania donovani, a usually visceralizing parasite. Enhanced case detection, early treatment, and in-depth understanding of sequalae are required to contain the spread of disease. Visceralizing potential of dermotropic strains has not been fully ruled out. Sri Lankan strains have shown a poor response to established serological assays. The present concern was to develop an in-house serological assay and to determine the seroprevalence of CL for identifying visceralizing potential and its usefulness in enhancing case detection. Crude cell lysate of dermotropic L. donovani promastigotes-based indirect enzyme-linked immunosorbent assay (ELISA) was previously optimized. Assay was evaluated using sera from 200 CL patients, 50 endemic and 50 nonendemic healthy controls, 50 patients with other skin diseases, and 50 patients with other systemic diseases. Seroprevalence and clinicoepidemiological associations were analyzed. Assay was compared with light microscopy (LM) and in vitro culturing (IVC). Cost comparison was carried out. Seroprevalence of CL was 82.0%. The assay had 99.5% specificity, and all healthy controls were negative at 0.189 cut-off. Positive and negative predictive values were 99.4% and 84.7%, respectively. Positivity obtained in ELISA was comparable to LM and higher than that of IVC. Cost per patient was 3.0 USD for both ELISA and LM and 6.0 USD for IVC. Infections occurring in all age groups and both genders demonstrated >75.0% of seropositivity. Patients had lesions with different durations/types/sizes showed >70.0% of seropositivity. Study identified a high seroprevalence of L. donovani-induced CL for the first time, indicating potential for visceralization or transient serological response. This can be used as a second line test in LM-negative CL cases to enhance clinical case detection. Further studies are warranted to examine in-depth correlations, antigen profiles, comparison with other established serological tools, and usefulness in the detection of asymptomatic cases. (National patent LK/P/1/19697).

Cloning and molecular characterization of thiol-specific antioxidant gene of Leishmania tropica Turkey isolate

Background/aim

Thiol-specific antioxidant (TSA) protein is one of the most promising molecules among candidates for vaccine against cutaneous leishmaniasis. It was found to be significantly protective against different Leishmania species. In this study, cloning and molecular characterization of thiol-specific antioxidant gene of L. tropica Turkey isolate (LtTSA) were aimed.

Materials and methods

LtTSA was amplified by PCR using the specific primers of TSA gene and cloned into the pcDNA3.1 vector. The cloning was confirmed by PCR screening, restriction enzyme reactions, and DNA sequence analysis. Finally, three-dimensional structure and antigenic properties of the protein encoded by the LtTSA were determined

Results

Six hundred base pair bands belonging to LtTSA were shown with electrophoresis. It was found that LtTSA and its encoded protein have high similarity with different Leishmania species. LtTSA protein consisting of 199 amino acids was found to have 7 different antigenic regions.

Conclusion

LtTSA and its encoded TSA protein were found to be highly immunogenic and similar to TSA proteins previously tested as a vaccine candidate.

Immunodetection and molecular determination of visceral and cutaneous Leishmania infection using patients' urine

The diagnosis of leishmaniasis relies mainly on the use of invasive processes, to collect the biological material for detecting Leishmania parasites. Body fluids, which can be collected by non-invasive process, would greatly facilitate the leishmaniasis diagnosis. In the present study, we investigated the potency of urine immunoblotting to diagnose cutaneous and visceral leishmaniasis and we compared with routine molecular methods. A total of 80 samples, including 40 sera and their 40 corresponding urine samples were collected from 37 suspected patients with cutaneous and visceral leishmaniasis, and 3 healthy individuals (as control), in Ilam and Ardabil provinces of Iran. All sera and urine samples were analyzed, using immunoblotting. The confirmation of leishmaniasis infection was performed, using conventional and quantitative PCRs as well as by sequencing the amplicons. Among 37 suspected patients, 23 patients presented cutaneous lesions (CL) and 14 exhibited clinical symptoms reminiscent of visceral leishmaniasis (L. infantum). Among cutaneous patients, 15 were positive for zoonotic cutaneous leishmaniasis (L. major), and eight for anthroponotic cutaneous leishmaniasis (L. tropica). Molecular quantification of Leishmania parasites was performed on sera, urines and cutaneous biopsies of CL and VL patients, demonstrating that parasite load is lower in urines, compared to sera or biopsy. DNA can be detected in 20 out of 23 (86.9%) CL urine samples and in 13 out of 14 (92.8%) VL urine samples. Immunodetection analysis demonstrates that 22 out of 23 (95.6%) sera from CL patients and all patients suspected with VL are positive. For urine samples, 18 out of 23 (78.2%) urine of CL patients and 13 out of 14 (92.8%) urine of VL patients were positive, using Western blot. Therefore, immunodetection and molecular analysis using urine samples can be used as a diagnostic tool for surveying cutaneous and visceral leishmaniasis.

Concomitant visceral and localized cutaneous leishmaniasis in two Moroccan infants

Background

Leishmaniases are vector-borne diseases caused by the protozoa of the Leishmania genus. The clinical spectrum of these diseases extends from benign dermal lesions to visceral forms. In the Mediterranean region, zoonotic visceral leishmaniasis (ZVL) is caused by L. infantum. If untreated within two years, the disease usually leads to death. In Morocco, ZVL is endemic in the north, with a hundred cases notified each year, mostly in children aged below five years. Here, we report on two clinical observations in infants presenting unusual concomitant VL and cutaneous leishmaniasis (CL) in Morocco.

Case presentation

In this case study, we report on two infants aged nine and 12 months old. They both have a history of febrile splenomegaly, anemia, and pallor of mucous membranes. Visceral leishmaniasis was confirmed by parasitological diagnosis (positive bone marrow smear and screening of anti-L. infantum antibodies). However, the clinical examination also showed cutaneous lesions that suggested the presence of CL. This was reinforced by the patients having a history of living or traveling to endemic foci. Thus, direct examination, culture, and PCR-RFLP (ITS1-Hae 3) were carried out on the patients’ dermal exudates. In one of the infants, CL was associated with L. infantum, while in the other it was associated with L. tropica. The infants were treated as according to the recommendations of the Ministry of Health. Both patients were cured in two months; defervescence, reduction of splenomegaly, and healing of cutaneous lesions were all observed.

Conclusions

These singular patients illustrate the clinical polymorphism of CL and the necessity of updating the differential diagnosis of leukemia-like syndromes, including VL, in children living in or travelling to known endemic areas. These observations suggest a change in the Mediterranean VL phenotype that may be associated with CL.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0413-8) contains supplementary material, which is available to authorized users.

Evidence for Seroprevalence in Human Localized Cutaneous Leishmaniasis Caused by Leishmania donovani in Sri Lanka

Visceral leishmaniasis (VL) is considered as a major health threat in the Indian subcontinent. Leishmania donovani, a usually visceralizing species, causes cutaneous leishmaniasis (CL) in Sri Lanka. However, visceralizing potential of the local L. donovani is not yet fully understood. This project studied the seroprevalence of local CL by using an in-house ELISA. An IgG-based ELISA using crude Leishmania antigen (Ag) was developed and validated. A total of 50 laboratory confirmed cases of locally acquired CL were examined using the newly developed ELISA. According to the optimized ELISA, seroprevalence of anti-Leishmania IgG antibodies in the study group was 34.0% (n = 17/50). Majority of seropositive individuals were males (n = 13/17), representing 76%. Nearly half of the seropositive individuals were young adults (20–40 years, n = 9/17, 53%). Higher proportions of single lesions, large lesions, and nodular lesions were associated with a seroconversion. A proportion of local L. donovani infections leading to CL have the ability to raise an antibody response in the host. This may indicate early systemic involvement as one possibility. Study of a large number of patients with adequate follow-up would be useful.

Molecular identification of Leishmania spp. isolates causes cutaneous leishmaniasis (CL) in Sanliurfa Province, Turkey, where CL is highly endemic

Cutaneous leishmaniasis (CL) is an important public health problem in Turkey. CL has been most frequently seen in Sanliurfa. There is an expectation of increase in the population of leishmaniasis cases with the influence of Syrian refugees arriving in Turkey. In this study we aimed to diagnosis of CL and identifying of parasite from Leishmania isolates by using ITS 1 PCR RFLP. Samples were collected from 135 CL patients in Sanliurfa. After the specimens were inoculated in medium NNN, the ones which were cultures positive were cultivated in RPMI 1640 followed by PCR-RFLP. Genomic DNA was extracted phenol-chloroform procedure. Samples were examined by using ITS 1 PCR followed by RFLP analysis. Our results indicated that two species, L. tropica (132 samples) and L. major (3 samples), are responsible for cutaneous leishmaniasis in Sanlıurfa. Our study is the first scientific study in which it is reported molecular analyses of cutaneous leishmaniasis cases caused by L. major in Sanliurfa in Southestern Anatolia Region. Because CL cases caused by L.major are detected in our study, it is considered that genotyping is important for diagnosis of Leishmania and following change of epidemiology.

Epidemiological Trends of Cutaneous Leishmaniasis in Al-Madinah Al-Munawarah Province, Western Region of Saudi Arabia

Objective:

To investigate the epidemiological trends of cutaneous leishmaniasis (CL) in Al-Madinah Al-Munawarah, western region of KSA.

Materials and Methods:

Four hundred and sixty-seven parasitologically confirmed CL cases attending Al-Meeqat Hospital, Al-Madinah, during 2012–2015, were included in this study.

Results:

Both Saudi and non-Saudi nationals were infected, with the highest infection rate being among Saudis (68.7%). Males were more affected than females as 86.9% of the total CL cases were males. Moreover, CL was prevalent in all age groups with higher frequency among young adults and adolescents (23.1% and 22.7%, respectively). Interestingly, almost all the patients in the adolescent and child age groups were Saudis (96.2% and 93.5%, respectively). Considering geographical distribution, the highest percentage of the cases (40.5%) were from the northern parts of Al-Madinah province while the eastern parts reported the least infection rate (7.3%). Few cases (2.5%) were supposed to encounter the infection abroad. Additionally, the frequency of infection was found to follow a seasonal distribution. Regarding treatment, pentostam, ketoconazole, or cryotherapy were the treatment options usually used.

Conclusion:

CL is prevalent in Al-Madinah Al-Munawarah area and new foci are being introduced. Thus, detailed studies with large surveillances regarding vector and reservoir hosts in and around the area are needed.

Detection of Potentially Diagnostic Leishmania Antigens with Western Blot Analysis of Sera from Patients with Cutaneous and Visceral Leishmaniases

BACKGROUND

Visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) are important public health problems in Iran. We aimed to evaluate the diagnostic potential of Western blot (WB) compared with indirect immunofluorescence test (IFAT) to serodiagnosis of leishmaniasis.

METHODS

This study was performed from 2010-2014 and participants were different parts of Iran. Serum samples were obtained from 43 patients with proven CL, 33 patients with proven VL, 39 patients with other parasitic diseases and 23 healthy individuals.

RESULTS

WB sensitivity for CL and VL was 100% and 91%, compared to IFA 4.6% and 87.8%, respectively. Sera from patients with CL and VL recognized numerous antigens with molecular weights ranging from 14 to 68 kDa and 12 to 94 kDa, respectively. The most sensitive antigens were 14 and 16 kDa for CL recognized by 100% of the sera from patients with proven CL and 12, 14 and 16 kDa for VL, recognized by 63.6%, 100% and 63.6% of the sera from patients with proven VL respectively. WB analysis is more sensitive than IFAT for the diagnosis of leishmaniasis particularly in cases of cutaneous leishmaniasis. The 12, 14 and 16 kDa can be valuable diagnostic molecules for serodiagnosis of leishmaniasis because at least two immunogenic molecules were simultaneously detected by all patient sera, as well as produced antibodies against these antigens have no cross-reactivity with other control groups.

CONCLUSION

WB could be useful for screening and serodiagnosis of CL and VL in epidemiologic studies in endemic areas.

Leishmaniasis: diagnostic issues in Europe

Leishmaniasis is a parasitic disease with clinical presentations that vary from asymptomatic infection to cutaneous, mucocutaneous or visceral disease. Recent epidemiological studies have shown an increased prevalence in Europe largely caused by an increase in international travel, difficulty eradicating leishmanial infection in AIDS patients, and the use of immunosuppressive medications. Clinical diagnosis may be challenging, and parasitological diagnosis entails the use of invasive procedures which may be unrevealing in the immunosuppressed. A number of less invasive tests for the detection of anti-leishmanial antibodies or leishmanial antigen are available but their sensitivity and specificity may vary with the infective species and results have to be interpreted in light of the clinical presentation. The availability of polymerase chain reaction assays amplifying leishmanial genetic material has been a major step forward in improving the diagnosis of leishmanial disease and the response to treatment.

Resurgence of cutaneous leishmaniasis in Israel, 2001-2012

Cutaneous leishmaniasis has long been endemic in Israel. After a 15-year period of moderate illness rates, reported incidence increased from 0.4 cases per 100,000 population in 2001 to 4.4 cases per 100,000 population in 2012, and the disease emerged in areas where its presence had previously been minimal. We analyzed all cases reported to the national surveillance system and found that outbreak patterns revealed an expansion of Leishmania major infections over large areas in the southern part of the country and the occurrence of spatially focused L. tropica outbreaks in the northern part of the country. Outbreaks often followed new construction in populated areas. Further study of factors affecting the transmission of cutaneous leishmaniasis is needed in Israel, as well as the development of effective methods to control the disease, an increase in awareness among health care professionals, and intensive public education regarding control measures in areas of known leishmaniasis foci.

Complementary exams in the diagnosis of American tegumentary leishmaniasis

The diagnosis of American Tegumentary Leishmaniasis is a difficult but essential task when considering the high toxicity profile of the drugs available. Since the discovery of its etiologic agent, numerous diagnostic tests have been developed. None of the tests available today can be considered as the gold standard, since they do not add enough accuracy for the disease detection. Good epidemiological and clinical knowledge of the disease are fundamental precepts of the dermatology practice and precede the rational use of existing diagnostic tests. In this article we aim, through extensive literature review, to recall fundamental concepts of any diagnostic test. Subsequently, based on this information, we will weave important comments about the characteristics of existing diagnostic tests, including immunological tests such as Montenegro's skin test, serology and detection of parasites by direct examination, culture or histopathology. Finally we will discuss the new technologies and options for the diagnosis of Cutaneous Leishmaniasis. The molecular biology technique is considered a promising tool, promoting the rapid identification of the species involved. We also aim to educate dermatologists about a disease with high morbidity and assist in its difficult recognition.

Utility of Western Blot Analysis for the Diagnosis of Cutaneous Leishmaniasis

BACKGROUND

Cutaneous leishmaniasis (CL) is a parasitic disease with a relatively wide distribution in different areas of the world, including Iran. The parasite is mainly diagnosed microscopically, but serological approaches might be useful for diagnosis as well. This study aimed to assess the efficacy of an immunoblotting system for serodiagnosis of cutaneous leishmaniasis in Iran.

METHODS

Sixty-one sera samples from parasitologically confirmed CL patients and 50 sera samples from healthy controls along with 50 sera sample from non-CL patients were collected. Native strain of Leishmania major was cultured in Schneider medium and soluble Leishmania antigens were prepared from amastigotes-like parasites. All of sera samples were evaluated by an immunoblotting system.

RESULTS

Components of 14 to 135 kDa were detectable by the sera of CL patients. From 61 sera of CL patients, 59 cases (96.7%) detected a 63 kDa subunit and 51 cases (83.6%) recognized a 32-35 kDa component. Among all subunits, the 63 kDa band showed the highest sensitivity (96.7%) and a 75 kDa band had the highest (98%) specificity.

CONCLUSION

Immunoblotting has a satisfactory performance in diagnosis of CL and this test can be used, as an aid, for proper diagnosis of CL.

Performance of an ELISA and indirect immunofluorescence assay in serological diagnosis of zoonotic cutaneous leishmaniasis in iran

Serological assays have been extensively evaluated for diagnosis of visceral leishmaniasis (VL) and considered as a routine method for diagnosis of VL while these methods are not properly evaluated for diagnosis of cutaneous leishmaniasis (CL). This study aimed to assess the performance of indirect immunofluorescent-antibody test (IFA) and enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of cutaneous leishmaniasis in Iran. Sixty-one sera samples from parasitologically confirmed CL patients and 50 sera from healthy controls along with 50 sera from non-CL patients were collected. Antigen was prepared from promastigotes and amastigotes of Leishmania major. IFA was used to detect anti-Leishmania IgG while ELISA was used to detect anti-Leishmania IgM, total IgG, or IgG subclasses (IgG1 and 4). ELISA, for detection of total IgG and IgM, showed sensitivity of 83.6% and 84.7% and specificity of 62.7% and 54.6%, respectively. Sensitivity and specificity of ELISA for detecting IgG1 and IgG4 were 64%, 75% and 85%, 49%, respectively. Sensitivity and specificity of IFA were 91.6% and 81%. Conclusion. Findings of this study demonstrated that serological test, especially IFA, can be used for proper diagnosis of CL.

Recombinant Leishmania infantum heat shock protein 83 for the serodiagnosis of cutaneous, mucosal, and visceral leishmaniases

Routine serological diagnoses for leishmaniases, except in visceral cases, are performed using whole-parasite antigens. We used enzyme-linked immunosorbent assay (ELISA) to evaluate the performance of Leishmania infantum rHsp83 compared with L. major-like total promastigote antigen in the diagnosis of cutaneous (CL), mucosal (ML), and visceral leishmaniases (VL). ELISA-rHsp83 was significantly more sensitive than ELISA–L. major-like when considering either CL/ML (P = 0.041) or all leishmaniasis patients (P = 0.013). When samples from other infectious disease patients were evaluated for cross-reactivity, ELISA-rHsp83 was more specific than ELISA–L. major-like, specifically for Chagas disease samples (P < 0.001). We also evaluated the anti-rHsp83 antibody titers months after treatment and observed no significant difference in ML (P = 0.607) or CL (P = 0.205). We recommend ELISA–L. infantum-rHsp83 as a routine confirmatory serological assay for the diagnosis of Leishmania infection because of the high sensitivity, the specificity, and the insignificant cross-reactivity with other infectious diseases.

Western blot analysis as an aid for the diagnosis of cutaneous leishmaniasis due to Leishmania major

Cutaneous leishmaniasis (CL) due to Leishmania major is endemic in the Old World. To evaluate the diagnostic value of Western blot (WB) compared with IFAT, we tested serum samples from 45 patients with proven CL. Twenty-one (47%) patients were positive by IFAT and all patients were positive by WB with specific bands against 14kDa and/or 18kDa Leishmania antigens. Our results suggest that WB could be a useful non-invasive tool for the diagnosis of CL caused by L. major.

Leishmania tropica in rock hyraxes (Procavia capensis) in a focus of human cutaneous leishmaniasis

Cutaneous leishmaniasis, caused by Leishmania tropica, has recently emerged in urban and rural foci of central and northern Israel, and constitutes a major public health concern. Rock hyraxes (Procavia capensis), the suspected natural reservoir, were trapped in the cutaneous leishmaniasis urban focus of Maale Adumim in central Israel and evaluated for L. tropica infection by real-time kinetoplast DNA (kDNA) polymerase chain reaction (PCR) and serology. Real-time PCR on blood and computerized western blot serology analysis was positive for L. tropica in 58% and 80%, respectively, of the hyraxes tested. Phylogenetic analysis of the ribosomal internal transcribed spacer 1 region indicated that similar genotypes were present in humans and hyraxes from the same habitat. The high rates of infection and exposure to L. tropica among hyraxes supports their involvement in the transmission cycle of this parasite, and their potential role as a reservoir for human disease.