Diagnosis Of Leishmaniasis Research Articles

Differential diagnosis of visceral leishmaniasis in children: a five-year retrospective study at a pediatric referral hospital.

Visceral leishmaniasis (VL) is a zoonotic disease caused by protozoa of the genus Leishmania and is transmitted by sandflies of the genus Lutzomyia. Children under 15 years are disproportionately affected. In pediatric patients, the clinical and laboratory features of VL often overlap with those of other infectious and hematology-oncology diseases, making differential diagnosis challenging. Rapid and accurate identification of VL is critical for effective treatment. This study aimed to evaluate the epidemiological, clinical, and laboratory characteristics of pediatric patients initially suspected of having VL and to compare their final diagnoses upon discharge from a referral hospital. We retrospectively analyzed medical records of children with suspected VL, admitted between July 2014 and June 2019. Infectious diseases were confirmed in 61% of cases (86 patients), with VL confirmed in 55 cases. Hematology-oncology diseases were the second most common diagnosis, affecting 22.7% of patients (32 cases). Comparisons between the VL-confirmed group and those with other diagnoses revealed no significant age difference (p = 0.690). However, female sex, spleen size, and leukopenia were identified as significant predictors of VL. Female sex, spleen size, and leukopenia were key predictors for differentiating VL from other pediatric diseases in a referral center in the Northeast Region of Brazil.

Evaluation of CD1a immunostaining in the diagnosis of cutaneous leishmaniasis caused by Leishmania donovani in Sri Lanka.

Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease, routinely diagnosed by direct light microscopy. The sensitivity of this method is dependent on the number of parasites present in the lesion. Immunoexpression of CD1a surface antigen by Leishmania amastigotes and its application as a diagnostic tool has been recently demonstrated in several species including Leishmania major, Leishmania tropica and Leishmania infantum. Leishmania donovani is the only reported species in Sri Lanka primarily causing CL and its CD1a status remains unexplored. We studied CD1a expression by amastigotes of L. donovani in skin biopsies from 116 patients with suspected CL. The biopsy sections were stained with CD1a clones O10 and MTB1 separately. Slit skin smear (SSS) results were considered the gold standard for diagnosis of CL. 103 cases were confirmed through SSS where 73 of them showed positive parasite staining for CD1a clone MTB1 with 70.9% sensitivity. Positivity was seen mostly in parasites closer to the epidermis. CD1a clone O10 failed to detect any amastigotes. Test sensitivity improved to 74.1% when the analysis was applied only to patients with low/no discernible Leishman-Donovan (LD) bodies in histology. Our findings show that CD1a clone MTB1 successfully stains amastigotes of L. donovani species and can be used as a supplementary diagnostic tool in detecting CL, especially when LD bodies are low in number. This method could be validated to detect other forms of leishmaniasis caused by L. donovani in Indian and sub-Saharan regions.

P23 A case of visceral leishmaniasis presenting as seropositive erosive rheumatoid arthritis in an immunocompromised patient

Abstract Introduction Visceral leishmaniasis (VL) is a potentially fatal parasitic infection occurring primarily in the tropics, subtropics, and southern Europe. A strong humoral response can be observed in VL due to polyclonal activation of B-lymphocytes, and it can also result in the production of rheumatoid factor (RF), anti-CCP and anti-nuclear antibodies. We present this case here of visceral leishmaniasis presenting as seropositive RA on the background of HIV and hepatitis B infection. Case description We present a case of a 46-year-old Caucasian male with a two-year history of skin nodules, symmetrical arthralgia and weight loss. He was diagnosed with HIV a decade ago which was well controlled with bictegravir, emtricitabine and tenofovir alafenamide. He received pulmonary tuberculosis (TB) treatment in 2012 and had chronic e-antigen-positive hepatitis B. He previously resided in Ukraine and travelled frequently to Crimea and the Middle East. There was no history of Raynaud’s, chest pain, shortness of breath, sicca symptoms, mouth ulcers, genital ulcers, hair loss or photosensitivity. On examination, he was cachectic with generalised lymphadenopathy and multiple subcutaneous (1-2cm, firm, mildly tender, non-ulcerating) forearm nodules. There was synovitis on two joints but no tenosynovitis or joint deformity. Initial investigations revealed pancytopenia, hyperuricemia, proteinuria, positive RF (>200 IU/ml) and anti-CCP, positive ANA and anti-Ro antibody and erosion of proximal phalanx of the big toe bilaterally. His CD4 count was 166 (33%) with undetectable HIV viral load. Imaging showed lymphadenopathy and splenomegaly (17.5cm). A diagnosis of rheumatoid arthritis with possible connective tissue disease overlap was made and he was initiated on hydroxychloroquine. Because of systemic symptoms and atypical skin nodules, further investigation was undertaken including lymph node, bone marrow and skin biopsies, all of which confirmed a diagnosis of leishmaniasis. Blood PCR was positive for L. donovani complex, and serological analysis showed direct agglutination test and k39 Ag positivity. Treatment was initiated by the infectious diseases team initially with amphotericin B 40 mg/kg monotherapy, later on further amphotericin B 30 mg/kg and miltefisone. He responded well as evidenced by reduced splenomegaly, resolution of skin nodules and improvement in cytopenia. His joint symptoms also improved except for the recurrence of ankle pain for which he received intra-articular steroids. Discussion It has been widely reported in literature that leishmaniasis can trigger autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosis. There have also been multiple studies confirming the presence of rheumatoid factor, anti-CCP and ANA in patients with leishmaniasis without any presence of symptomatic autoimmune disease. The mechanisms involved in the pathophysiology of autoantibody productions are not yet fully understood. There is some evidence that these are related to activation of polyclonal B cells due to a decreased regulatory T cell activity. Another possible mechanism would be production of autoantigen in response to cross reaction between the parasite and the hoarse tissue antigens. There have been multiple case reports of leishmaniasis in patients with rheumatoid arthritis who were taking anti-TNF biologics. This represents the reactivation of leishmaniasis due to immunosuppression. There has been a long-known link between HIV infection and leishmaniasis. Our patient was a known case of HIV. Interestingly, not only did he have significantly positive rheumatoid factor, anti-CCP, ANA and anti-Ro antibodies, but he also had active synovitis on his joints and even erosions were seen on the X-ray. He fulfilled the criteria for rheumatoid arthritis. Our case was unique in the sense that this is a case of visceral leishmaniasis in an HIV patient who presented with rheumatoid arthritis. Skin nodules in this patient were appearing similar to rheumatoid nodules. Later on, the biopsy confirmed that these were due to leishmaniasis. It is also a challenge to manage RA in patients with HIV especially when have already an opportunistic infection like leishmaniasis. A high prevalence of hyperuricemia in HIV infection has been reported in multiple studies. Our case did have raised urate but his disease was not consistent with gout clinically. Key learning points • This is a rare case showing seropositive erosive RA coexisting with VL in an HIV patient, underscoring the link between autoimmune diseases and chronic infections. Chronic infections are always considered an important differential in inflammatory arthritis or connective tissue disease especially when they present with systemic features of fever, weight loss and organomegaly. • Although this disease is considered rare in the Western hemisphere, in the diverse, multiethnic and immigrant UK population this should be considered an important differential diagnosis. Another key element in clenching these diagnoses is detailed travel history. Multidisciplinary approach is key in managing such difficult cases. Our case was managed jointly by the rheumatology, dermatology and infectious disease teams, and the national leishmaniasis multidisciplinary team from University College London Hospitals. • It is important to do a holistic assessment for these patients and get help from other specialities especially in such challenging cases.

Evaluation of Loopamp Leishmania detection kit for the diagnosis of cutaneous leishmaniasis in Ethiopia

BackgroundCutaneous leishmaniasis (CL) in Ethiopia and some parts of Kenya is predominantly caused by Leishmania aethiopica. While skin-slit (SS) microscopy is routinely used for CL diagnosis, more sensitive molecular tests are available. The Loopamp™ Leishmania detection kit (Loopamp) is a robust loop-mediated isothermal amplification (LAMP) assay with the potential for implementation in primary healthcare facilities. In this study, we comparatively assessed the diagnostic accuracy of four methods currently used to diagnose CL: Loopamp, kinetoplast DNA (kDNA) PCR, spliced leader RNA (SL-RNA) PCR and SS microscopy.MethodsA study on 122 stored tape disc samples of suspected CL patients was conducted in Gondar, northwestern Ethiopia. Routine SS microscopy results were obtained from all patients. Total nucleic acids were extracted from the tapes and subjected to PCR testing targeting kDNA and SL-RNA, and Loopamp. Diagnostic accuracy was calculated with SS microscopy as a reference test. The limit of detection (LoD) of Loopamp and kDNA PCR were determined for cultured L. aethiopica and Leishmania donovani.ResultsOf the 122 patients, 64 (52.5%) were identified as CL cases based on SS microscopy. Although the PCR tests showed a sensitivity of 95.3% (95% confidence interval [CI] 91.6–99.1), Loopamp only had 48.4% (95% CI 39.6–57.3) sensitivity and 87.9% (95% CI 82.1–93.7) specificity. The LoD of Loopamp for L. donovani was 100-fold lower (20 fg/µl) than that for L. aethiopica (2 pg/µl).ConclusionsThe Loopamp™ Leishmania detection kit is not suitable for the diagnosis of CL in Ethiopia, presumably due to a primer mismatch with the L. aethiopica 18S rRNA target. Further research is needed to develop a simple and sensitive point-of-care test that allows the decentralization of CL diagnosis in Ethiopia.Graphical

Otimização do conjugado Anti-IGG canino no kit diagnóstico da Leishmaniose Visceral Canina (LVC)

Introduction: The diagnosis of canine visceral leishmaniasis (CVL) is of great importance in the control of visceral leishmaniasis, a disease that is neglected worldwide and represents a significant public health problem. Enzyme-linked immunosorbent assay (ELISA) test is widely used because of the possibility of large-scale diagnosis and low cost. Objective: The objective of this study was to optimize the stoichiometry of the conjugate used in the EIE/CVL kit; for this purpose, some conjugation and monitoring parameters were modified through molecular exclusion chromatography to improve the final product. Method: The conjugate produced by Bio-Manguinhos was optimized by purification using SEC gel filtration chromatography and evaluated using the EIE-leishmaniasis-visceral-canine-Bio-Manguinhos kit (EIE-LVC). The conjugates were produced with different stoichiometries (IgG X peroxidase): current conjugate, optimized conjugate and optimized and purified conjugate. Results: The results obtained were validated using the manual Canine Visceral Leishmaniasis test. The homogeneity of the conjugate means in the ELISA test was evaluated using the chi-square test, thereby demonstrating the normality and reliability of the data. Based on statistical data, positive samples obtained by the ELISA test showed homogeneity at a significance level of 0.05, i.e. a data reliability level of 95%. The optimization of the production of the canine anti-IgG conjugate, an extremely important component used in the composition of the Bio-Manguinhos EIE LVC KIT, contributed to ensuring the quality of the kit and improving the diagnosis of canine visceral leishmaniasis disease, making it more sensitive and inexpensive for public health. Conclusions: This work demonstrates that it is possible to optimize the anti-IgG canine peroxidase (HRP) conjugate used in the EIE CVL kit to make it more specific and ultimately more economical.

REASONS OF ABANDONMENT TREATMENT IN PATIENTS WITH LEISHMANIASIS

The goals of this study that examined patients with Cutaneous Leishmaniasis (CL) who were diagnosed and treated at the Sanliurfa Cutaneous Leishmaniasis Diagnosis and Treatment Center (SCLDTC), were to determine the frequency of treatment discontinuation and the reasons for discontinuation. This was a descriptive study that included individuals who visited the SCLDTC for diagnosis and treatment in 2020 and were diagnosed with CL. The study’s data collection phase took place between July 1, 2020 and December 31, 2020. The study comprised 370 patients who were diagnosed with CL and under treatment as of January 1, 2020. It was found that 187 of these patients discontinued treatment. The frequency of treatment discontinuation was 50.5%. Of those who discontinued treatment, 50.8% were women. It was determined that 3.7% of those who discontinued treatment did not speak Turkish, and 41.1% had not received formal education. Among the patients who discontinued treatment, 21.4% had no job, and 83.9% belonged to the lower socioeconomic status and unemployed group. Of those who discontinued treatment, 54.6% stopped before completing the first course, while 39,0% did not attend the follow-up examination after completing the first course. In cases of cutaneous leishmaniasis, the most common reasons for discontinuing treatment were believing that they do not require treatment (28.9%), disregarding the disease (27.3%), and a lack of medication in SCLDTC (26.7%). In the present study, the most common reasons for discontinuing treatment were a lack of belief in the necessity for treatment, disregarding the disease, and a shortage of medication. Patients’ and society’s knowledge and awareness of CL should be increased, public education programs should be organized, patients admitted to SCLDTC and their relatives should be informed, and the importance of completing the treatment should be explained, especially in neighborhoods where CL cases are densely distributed.

Rapid antigen detection test for diagnosis of post kala-azar dermal leishmaniasis: application of CL Detect™ rapid test for active case detection in the endemic area.

Post-kala-azar dermal leishmaniasis (PKDL) is a skin condition that occurs in a small percentage of people who have been cured of visceral leishmaniasis (VL), and contributes to transmission of VL. The rK39 rapid test cannot decisively diagnose PKDL due to presence of antileishmanial antibodies from past VL episodes. CL Detect™ Rapid Test, an in-vitro diagnostic test that detects Leishmania antigen peroxidoxin, was assessed for diagnosing PKDL. The CL Detect RDT had 73.3% sensitivity and 100% specificity in the study. The test can be used as a primary screening tool to monitor PKDL in endemic regions and identify active Leishmania infection.

Antigenic reactivity of Leishmania (Viannia) lainsoni axenic amastigote proved to be a suitable alternative for optimizing Montenegro skin test

BackgroundLaboratory diagnosis of American cutaneous leishmaniasis (ACL) requires a tool amenable to the epidemiological status of ACL in Brazil. Montenegro skin test (MST), an efficient immunological tool used for laboratory diagnosis of ACL, induces delayed-type hypersensitivity (DTH) response to the promastigote antigens of Leishmania; however, human immune responses against infection are modulated by the amastigote of the parasite. Leishmania (V.) lainsoni induces strong cellular immunity in humans; therefore, the antigenic reactivity of its axenic amastigote (AMA antigen) to MST was evaluated for the laboratory diagnosis of ACL.MethodsAmong 70 individuals examined, 60 had a laboratory-confirmed diagnosis of ACL; 53 had localized cutaneous leishmaniasis (LCL), and 7 had mucosal leishmaniasis (ML). Patients were treated at the Evandro Chagas Institute’s leishmaniasis clinic, Pará State, Brazil. Ten healthy individuals with no history of ACL (control group) were also examined. Leishmania (V.) braziliensis promastigote antigen (PRO) was used to compare the reactivity with that of AMA antigen. Paired Student’s t-test, kappa agreement, and Spearman test were used to evaluate the reactivity of AMA and PRO.ResultsThe mean reactivity of AMA in ACL patients was 19.4 mm ± 13.3, which was higher (P < 0.001) than that of PRO: 12.1 mm ± 8.1. MST reactivity according to the clinical forms revealed that AMA reactivity in LCL and ML, 18.8 mm ± 13.3 and 24.3 mm ± 13.7, was higher (P < 0.001) than that of PRO, 11.8 mm ± 8.2 and 14.6 mm ± 8.4, respectively.ConclusionAMA reactivity was higher than that of PRO, indicating that AMA is a promising alternative for optimizing MST in the laboratory diagnosis of ACL.Graphical abstract

The Epidemiology of PCR-Confirmed Cutaneous Leishmaniasis in Israel: A Nationwide Study.

Leishmaniasis, mainly cutaneous leishmaniasis (CL), is endemic in Israel. In recent years, the diagnosis of leishmaniasis has transitioned to a molecular diagnosis. To summarize all cases of leishmaniasis and the identified species seen in Israel based on molecular diagnosis. A retrospective study was performed of patients diagnosed with leishmaniasis between January 2017 and December 2022. All five medical centers in Israel in which Leishmania diagnosis is performed were included: Soroka, HaEmek, Hadassah, Rambam, and Sheba, all utilized molecular diagnostic methods. Data on the annual number of cases, species, age, and gender were retrieved. During the years 2017-2022, a total of 4168 cases of leishmaniasis were diagnosed, which corresponds with ~7/100,000 inhabitants. L. (L.) major and L. (L.) tropica accounted for 84% and 14%, respectively. During the years 2020-2021, L. (L.) infantum emerged as a new form of cutaneous disease [2.7% of cases during this period]. Visceral L. (L.) infantum was found in five cases. Imported New World leishmaniasis accounted for 1% of the cases. L. (L.) major affected more males (67%) while L. (L.) tropica commonly affected more children and caused more facial lesions. The mean annual number of cases during these years is ~700. The dominant species is L. (L.) major. Since 2020, cutaneous L. (L.) infantum is an emerging infection in Israel.

Comparison of urine and serum IgG detection ELISA for tegumentary leishmaniasis diagnosis and prognosis

Laboratorial diagnosis of tegumentary leishmaniasis (TL) is hampered by variable sensitivity and/or specificity of the tests, which are still hampered by blood́ invasive collection. In this context, in the present study, we develop a serum- and urine-based ELISA to TL diagnoses. A recombinant protein (rLiHyA), which was previously showed to be antigenic for the disease, as well as a B-cell epitope produced as synthetic peptide and a Leishmania antigenic extract (SLA), were used as antigens. A total of paired 205 urine and serum samples were used, which were comprised by samples from cutaneous (n = 30) and mucosal (n = 30) leishmaniasis patients, as well as from healthy individuals living in endemic region of disease (n = 45), of patients with Chagas disease (n = 30), leprosy (n = 35), malaria (n = 15) or HIV-infected (n = 20). Results showed that serum-based ELISA presented sensitivity of 24.0 %, 100 % and 41.0 %, when SLA, rLiHyA and synthetic peptide were used as antigens, and specificity of 98.4 %, 98.4 % and 98.4 %, respectively. The area under the curve (AUC) was calculated and results were 0.74, 1.0, and 0.71, respectively, when SLA, rLiHyA and synthetic peptide were used as antigens. Performing an urine-based ELISA, sensitivity was 28.0 %, 100 % and 75.0 %, respectively, when SLA, rLiHyA, and synthetic peptide were used, while specificity values were of 98.4 %, 98.4 % and 98.4 %, respectively. In addition, the AUC values were 0.82, 1.0, and 0.94, respectively. A significant drop in specific antibodies levels in both patientś serum and urine samples was found six months after treatment, suggesting a prognostic role of rLiHyA for TL. In conclusion, preliminary data suggest the potential of use patient urine to TL diagnoses.

Identificación de &lt;i&gt;Leishmania &lt;/i&gt;spp en caninos de tres departamentos del centro de Colombia y su correlación clínica

The species Leishmania infantum and L. chagasi are considered causal agents of visceral leishmaniasis, a relevant disease due to its zoonosis and severity in humans. Canines are the main reservoirs, hence the need to implement precise diagnoses to identify the Leishmania species involved. The aim of the study was to perform a molecular diagnosis of leishmaniasis (conventional PCR and Sanger sequencing) in 29 tissue samples from canines clinically suspected of leishmaniasis, previously diagnosed by non-molecular methods. The presence of the parasite could be identified by PCR in 9/29 samples (L. infantum, n=4; L. chagasi, n=4; L. braziliensis, n=1), evidencing a predominance of L. infantum and L. chagasi in canines with cutaneous and mucocutaneous leishmaniasis. The PCR allowed to clarify previously negative diagnoses; however, limitations were found, such as the absence of Leishmania DNA in some samples and the inability to obtain additional samples due to inaccessibility to patients. Despite these limitations, the study highlights the importance of molecular diagnosis to identify the species causing leishmaniasis.

Oral Leishmaniasis in HIV-Positive and HIV-Negative Patients: A Comparative Analysis with Two New Case Reports.

This case report examines the clinical presentation, diagnosis, treatment, and outcomes of mucocutaneous leishmaniasis with primary oral involvement in HIV-positive and HIV-negative patients diagnosed in Brazil. We discuss the clinical manifestations, diagnostic methods, and therapeutic strategies, highlighting the clinical and histopathologic diagnostic features and distinct progression patterns based on HIV status. Our findings are compared with patterns observed in other countries, emphasizing the differences between the Americas and Europe, Asia, and Africa. In the Americas, particularly in Brazil, mucocutaneous leishmaniasis often presents with localized oral lesions, even in the presence of systemic immunosuppression, whereas in the Europe, Asia, and Africa, oral involvement is typically associated with visceral leishmaniasis in immunocompromised patients. These differences were due to variations in the parasite species involved. This comparison underscores the importance of regional and immunological factors in diagnosing and managing this neglected infectious disease.

Clinical manifestations and diagnostic approaches in cases of canine leishmaniasis in Bulgaria.

Leishmaniasis, a parasitic disease found in many parts of southern Europe, is transmitted in both humans and canines through the bite of phlebotomine sandflies, and can present in a variety of ways, such as cutaneous, mucocutaneous, diffuse, and visceral. In Bulgaria there are endemic areas of canine leishmaniasis, with sporadic cases in humans. However, no detailed studies of the animal population and vectors have been performed. Here we describe a few clinical cases of canine visceral leishmaniasis in two districts in western Bulgaria: one endemic and one without previously detected cases in humans or dogs. Diagnosis was confirmed serologically and molecularly using both real time and conventional PCR. Specific anti-leishmanial antibodies were confirmed in three of the cases via ELISA, with 50% of them returning extremely high values. In the majority of the cases DNA fragments were detected in the skin or lymph node aspirate but not in the blood. This paper highlights the need for further studies updating the current knowledge on the epidemiology, diagnosis, and control of visceral leishmaniasis in the reservoir host population.

A Diagnostic Algorithm for Detection of Leishmania spp. in Human Fresh and Fixed Tissue Samples.

Leishmaniasis is an important travel-related parasitic infection in the United States. Treatment regimens vary by Leishmania species and require an accurate diagnosis. The sensitivity and specificity of diagnostic methods depend on the type and condition of specimen analyzed. To identify the best algorithm for detection of parasites in fresh and fixed tissue samples, we evaluated parasite cultures, two PCR methods, and Leishmania immunohistochemistry (IHC) in samples received by the CDC from 2012 through 2019. The sensitivity and specificity of IHC assays were evaluated in fresh specimens tested. Diagnostic accuracy for formalin-fixed tissue was evaluated by using PCR-based methods and IHC. Of 100 suspected cases with fresh tissue available, Leishmania spp. infection was identified by PCR in 56% (56/100) of specimens; from these, 80% (45/56) were positive by parasite culture and 59% (33/56) by IHC. Of 420 possible cases where only fixed specimens were available, 58% (244/420) were positive by IHC and/or PCR. Of these, 96% (235/420) were positive by IHC and 84% (204/420) by PCR-based methods. Overall parasite detection using all methodologies was similar for fresh and formalin-fixed tissue specimens (56% versus 58%, respectively). Although PCR-based methods were superior for diagnosis of leishmaniasis and species identification in fresh samples, IHC in combination with PCR increased the accuracy for Leishmania spp. detection in fixed samples. In conclusion, PCR is the most effective method for detecting Leishmania infection in fresh tissue samples, whereas for formalin-fixed samples, IHC and PCR-based methods should be used in combination.

Non-invasive urine-based ELISA using a recombinant Leishmania protein to diagnose tegumentary leishmaniasis

The diagnosis of tegumentary leishmaniasis (TL) is hampered by variable sensitivity and/or specificity of the tests. Serological assays are suitable to diagnose visceral leishmaniasis (VL); however, they present low performance for the detection of TL cases. Additionally, blood collection to obtain patient serum represents a challenge, as it is an invasive and uncomfortable procedure, requiring laboratorial infrastructure and trained professionals. In this context, the present study proposed to evaluate patient urine to detect TL, given that this analyte has proven to be effective in ELISA experiments for the detection of VL cases. For this, a Leishmania protein called LiHyV, two specific B-cell epitopes derived from protein amino acid sequence, and a Leishmania antigenic extract (SLA) were used as antigens. A total of 215 paired urine and serum samples were evaluated, and results showed that, when serum was employed as an analyte, rLiHyV, Peptide1, Peptide2, and SLA presented a sensitivity of 85 %, 29 %, 58 %, and 31 %, respectively, and a specificity of 97.5 %, 98 %, 100 %, and 97.5 %, respectively, in the diagnosis of TL. When urine was used, rLiHyV, Peptide1, Peptide2, and SLA presented a sensitivity of 95 %, 74 %, 67 %, and 52 %, respectively, and a specificity of 100 %, 99 %, 98 %, and 86 %, respectively. In conclusion, preliminary data suggest that urine could be considered as an alternative biological sample for the detection of TL cases.

Molecular Diagnosis of Human Cutaneous Leishmaniasis and Identification of the Causative Leishmania Species in Iran: A Narrative Review

Cutaneous leishmaniasis (CL) is a common form of leishmaniasis in underdeveloped countries. Although CL tends to be self-limiting, it can cause significant scars and may progress to more severe manifestations. Additionally, Leishmania species vary in susceptibility to the available treatments. The selection of treatment and clinical outcome of CL depend on the accurate determination of the Leishmania species. This mini-review aims to provide an overview of the molecular diagnosis techniques such as PCR-based assays, nucleic acid sequence-based amplification, and loop-mediated isothermal amplification utilized in the identification of Leishmania species in Iran.

Histopathological findings and diagnosis of cutaneous leishmaniasis, confirmed by PCR, in an endemic region of Brazil.

Diagnosis of cutaneous leishmaniasis (CL) is difficult, and the correct use of histopathological criteria can be useful in clinical practice. The present study evaluates the association between histopathological findings and the results of polymerase chain reaction (PCR) in clinically suspected cases of CL. Skin samples were received in a laboratory from an endemic region of Brazil for over nine years. Associations were analyzed by means of the Chi square test with a 5% level of significance. Of the 222 examined samples, 190 (85.6%) tested positive by PCR. All 25 cases identified by microscopic examination also tested positive by PCR. Except for the more intense inflammatory infiltrate, all other evaluated histological variables (ulceration, epidermal hyperplasia, hyperkeratosis, presence of granuloma, neutrophils, histiocytes, lymphocytes, plasmocytes, and necrosis) were not significantly associated with PCR positivity. The intensity of the inflammatory infiltrate is a good indicator of the occurrence of CL. Histopathological aspects are useful to increase the predictive values of CL diagnoses, but PCR is still necessary to confirm or exclude the disease.

ELISA with recombinant antigen Lb6H validated for the diagnosis of American tegumentary leishmaniasis.

American tegumentary leishmaniasis (ATL) diagnosis is an open question, and the search for a solution is urgent. The available tests that detect the etiological agent of the infection are specific for ATL diagnosis. However, they present disadvantages, such as low sensitivity and the need for invasive procedures to obtain the samples. Immunological methods (leishmanin skin test and search for anti-Leishmania antibodies) are good alternatives to the etiological diagnosis of ATL. Presently, we face problems with disease confirmation due to the discontinuity in the production of leishmanin skin test antigen, particularly in resource-poor settings. Aiming to diagnose ATL, we validated rLb6H-ELISA for IgG antibodies using 1,091 samples from leishmaniasis patients and healthy controls, divided into four panels, living in 19 Brazilian endemic and non-endemic states. The rLb6H-ELISA showed a sensitivity of 98.6% and a specificity of 100.0%, with the reference panel comprising 70 ATL patient samples and 70 healthy controls. The reproducibility evaluation showed a coefficient of variation of positive samples ≤ 8.20% for repeatability, ≤ 17,97% for reproducibility, and ≤ 8.12% for homogeneity. The plates sensitized with rLb6H were stable at 4°C and -20°C for 180 days and 37°C for seven days, indicating 12 months of validity. In samples of ATL patients from five research and healthcare centers in endemic and non-endemic areas, rLb6H-ELISA showed a sensitivity of 84.0%; no significant statistical difference was observed among the five centers (chi-square test, p = 0.13). In samples of healthy controls from four areas with different endemicity, a specificity of 92.4% was obtained; lower specificity was obtained in a visceral leishmaniasis high endemicity locality (chi-square test, p<0.001). Cross-reactivity was assessed in 166 other disease samples with a positivity of 13.9%. Based on the good diagnostic performance and the reproducibility and stability of the antigen, we suggest using ELISA-rLb6H to diagnose ATL.

Comparison of SensPERT® Leishmania rapid test with two other immunochromatographic tests for the diagnosis of canine visceral leishmaniasis in Brazil.

In urban environments, dogs serve as the primary reservoir for visceral leishmaniasis (VL). Rapidly diagnosing canine VL through tests enables early treatment and a favorable prognosis. This study aimed to assess the diagnostic performance of the SensPERT® Leishmania test kit (Dechra®), Alere® Leishmaniasis Ac test kit, and the rapid test dual path platform (TR-DPP®) Bio-Manguinhos in detecting VL. 30 serum samples from reactive VL dogs and 30 serum samples from healthy dogs were employed for assessing the sensitivity and specificity variation between SensPERT® Leishmania test kit, Alere® Leishmaniasis Ac test kit, and rapid test dual platform - TR-DPP®. The SensPERT® Leishmania test outperformed Alere® and TR-DPP® in terms of sensitivity, specificity, positive and negative predictive values and demonstrated near-perfect concordance with Alere® and substantial concurrence with TR-DPP®. The SensPERT® Leishmania rapid test proved to be a promising test in the detection of VL in dogs.

Feline Leishmaniasis: Evidence-based Treatments and Challenges to be Solved.

Leishmaniasis is a neglected tropical disease caused by protozoa parasites from the Leishmania genus. Vertebrate hosts acquire the infection through the bite of a female sandfly, initiating a complex parasite development cycle. Contrary to previous beliefs regarding cats' resistance, these animals have recently been identified as potential reservoirs for leishmaniasis. Clinical symptoms in cats can manifest in diverse forms, including cutaneous, mucocutaneous, and visceral manifestations. The diagnosis of feline leishmaniasis is complicated by nonspecific symptoms and the relatively lower specificity of serological tests. The recommended treatment for feline leishmaniasis involves the administration of medications; however, success varies in each cat. This review aims to present cases of feline leishmaniasis, highlighting clinical symptoms, diagnostic methods, therapy schedules, and outcomes. Among the 24 cases documented in the available literature, 12 achieved successful treatment without relapses, resulting in a reduced parasite load and improved symptoms. Three cases responded well but presented persistent sequelae. Two feline leishmaniasis cases initially had treatment success but later experienced recurrences. Finally, no response was observed in seven cases, leading to the euthanasia of cats due to ineffectiveness or irregularities along the therapy. Conventional treatments, despite potential hepatotoxicity and nephrotoxicity, exhibit a high efficacy in reducing parasitic load, thereby improving clinical symptoms and increasing the life expectancy of affected cats. Nevertheless, consistent adherence is crucial, as interruptions may render the therapy ineffective and contribute to parasite resistance. Therefore, addressing the challenges associated with feline leishmaniasis treatment necessitates the development of new strategies to ensure a more effective and sustained approach.