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Rahim S, Sharif MM, Amin MR, Rahman MT, Karim MM. Real Time PCR-based diagnosis of human visceral leishmaniasis using urine samples. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000834. [PMID: 36962767 PMCID: PMC10022223 DOI: 10.1371/journal.pgph.0000834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 11/28/2022] [Indexed: 12/31/2022]
Abstract
Diagnosis of visceral leishmaniasis (VL) through the detection of its causative agents namely Leishmania donovani and L. infantum is traditionally based on immunochromatographic tests, microscopy of bone marrow, spleen aspirates, liver or lymph node and differential diagnosis. While the first process has low specificity, the later one carries the risk of fatal hemorrhage. Over the last decade, multiple Polymerase Chain Reaction (PCR) based diagnosis has been developed using blood and urine sample with a varying degree of sensitivity and specificity, an issue worth improving for precision diagnosis. Earlier, we reported a PCR-based diagnosis of L. donovani in peripheral blood using a novel set of PCR primers with absolute specificity. Using the same set of primers and PCR conditions, here we describe diagnosis of L. donovani from urine, for a non-invasive, rapid and safe diagnosis. Diagnosis of VL was carried out using urine samples collected from clinically diagnosed VL patients (n = 23) of Bangladesh in Real Time PCR. Test results were validated by comparing blood samples from the same set of patients. Sensitivity and specificity of this diagnosis was analyzed using retrospective bone marrow samples, collected earlier from confirmed VL patients (n = 19). The method showed 100% sensitivity in detecting L. donovani in urine and corresponding blood and retrospective bone marrow samples, as well as 100% specificity in control groups. A Real Time PCR-based molecular detection system using urine sample is hereafter presented what could be a, non-invasive approach for VL detection with precision and perfection.
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Affiliation(s)
- Samiur Rahim
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | | | - Md Robed Amin
- Department of Medicine, Dhaka Medical College, Dhaka, Bangladesh
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Hajjaran H, Saberi R, Borjian A, Fakhar M, Hosseini SA, Ghodrati S, Mohebali M. The Geographical Distribution of Human Cutaneous and Visceral Leishmania Species Identified by Molecular Methods in Iran: A Systematic Review With Meta-Analysis. Front Public Health 2021; 9:661674. [PMID: 34249836 PMCID: PMC8267797 DOI: 10.3389/fpubh.2021.661674] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/31/2021] [Indexed: 01/11/2023] Open
Abstract
Leishmaniasis is one of the most common vector-borne parasitic diseases in Iran. Leishmania species identification is necessary for epidemiological aspects, precise prognosis, control and treatment of the disease. We systematically searched all the studies, reports, and documentation related to species identification and geographical distribution of causative agents of cutaneous (CL), mucosal (ML), and visceral leishmaniasis (VL) using DNA-based molecular diagnostic techniques in Iran. International databases including PubMed, ScienceDirect, Embase, Google Scholar, Scopus, and Web of Science were systemically searched for English articles and Iran's databases including SID, IranMedex and Magiran were searched for Persian reports and articles. Searches were performed from 1999 to 2019 (20 years). The current review was conducted using the keywords: cutaneous leishmaniasis, visceral leishmaniasis, Leishmania species, Human, Molecular, PCR, and Iran. The study quality was evaluated using the NOS checklist. This meta-analysis procedure was accomplished using STATA, version 2.7.9. Of the 3,426 records identified in the initial search, 154 articles met inclusion criteria and qualified for the systematic review and meta-analysis. In subgroup analysis, the pooled frequency of causative agents of CL isolates was 67.3% (95% CI: 59.51–74.67%) for L. major and 32.1% (95% CI: 24.72–39.87%) for L. tropica. In addition, the pooled frequency of causative agents of VL isolates was 97.1% (95% CI: 94.6–98.8%) for L. infantum and 2.9% (95% CI: 1.12–5.37%) for L. tropica. The findings of this study showed that the main causative agents of CL and VL in Iran are L. major and L. infantum, respectively. Moreover, kinetoplast DNA (kDNA) and internal transcriber spacer (ITS) were the most used markers for identifying Leishmania species. The current study provides valuable data to encourage and direct researchers as well as public health managers in the comprehensive leishmaniasis control and prevention planning in Iran.
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Affiliation(s)
- Homa Hajjaran
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Saberi
- Toxoplasmosis Research Center, Communicable Diseases Institute, Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.,Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Alireza Borjian
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahdi Fakhar
- Toxoplasmosis Research Center, Communicable Diseases Institute, Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Abdollah Hosseini
- Toxoplasmosis Research Center, Communicable Diseases Institute, Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Sajjad Ghodrati
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mohebali
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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Aksulu A, Bilgiç HB, Karagenç T, Bakırcı S. Seroprevalence and molecular detection of Leishmania spp. in cats of West Aegean Region, Turkey. Vet Parasitol Reg Stud Reports 2021; 24:100573. [PMID: 34024389 DOI: 10.1016/j.vprsr.2021.100573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 04/05/2021] [Accepted: 04/05/2021] [Indexed: 10/21/2022]
Abstract
Zoonotic visceral leishmaniasis is caused by protozoa of the genus Leishmania. Although dogs are considered to be primary reservoir hosts of Leishmania spp., several mammals, such as foxes, jackals and small rodents may also be hosts of different Leishmania spp. Previously, cats were considered as asymptomatic hosts of the parasite without acting as a reservoir. In recent years, there has been an increasing number of leishmaniasis cases in cats, especially in regions where the infection endemically occurs. This data indicate that cats are more likely to be one of the main reservoirs of Leishmania spp. rather than being a non-reservoir host. The aim of this study is to determine the prevalence of Leishmania spp. by molecular and serological techniques among owned and stray cats in four different cities located in western part of Turkey. A total of 386 blood and 301 serum samples were collected from cats in Western Turkey where leishmaniasis is endemic. Feline serum samples were tested by IFAT to detect IgG antibodies against Leishmania spp. antigens. Blood samples collected from 386 cats were examined by PCR for the presence of Leishmania spp. According to PCR results using RV1/RV2 primers, nine (2.3%) out of 386 samples were positive for Leishmania spp. Further PCR analysis using MC1/MC2 primers showed that one cat in Izmir was found to be infected with L. infantum/donovani complex. Sequence analysis revealed the presence of L. infantum, L. major and L. tropica among sampled cats in western part of Turkey. On the other hand, IFAT results indicated that an overall of 47 out of 301 (15.6%) cats that examined by PCR were found to have anti-Leishmania antibodies. Also, six of the seropositive cats were owned animals. The present study demonstrated that both owned and stray cats can be infected with Leishmania spp. and might be potential reservoirs for other animals and humans. Therefore, all communities living in or nearby endemic regions should be made aware of the role of cats as potential reservoirs of infection. In endemic regions, all animals should be protected against infection with insecticides and monitored routinely to control the spread of zoonotic visceral leishmaniasis.
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Affiliation(s)
- Ayça Aksulu
- Aydın Adnan Menderes University, Faculty of Veterinary Medicine, Department of Parasitology, Isıklı-Efeler, Aydın, Turkey
| | - Hüseyin Bilgin Bilgiç
- Aydın Adnan Menderes University, Faculty of Veterinary Medicine, Department of Parasitology, Isıklı-Efeler, Aydın, Turkey
| | - Tülin Karagenç
- Aydın Adnan Menderes University, Faculty of Veterinary Medicine, Department of Parasitology, Isıklı-Efeler, Aydın, Turkey
| | - Serkan Bakırcı
- Aydın Adnan Menderes University, Faculty of Veterinary Medicine, Department of Parasitology, Isıklı-Efeler, Aydın, Turkey.
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Fayaz S, Fard-Esfahani P, Bahrami F, Parvizi P, Ajdary S. High resolution melting assay in discrimination of the main etiologic agents of leishmaniasis in Iran. IRANIAN JOURNAL OF MICROBIOLOGY 2021; 13:137-144. [PMID: 33889373 PMCID: PMC8043822 DOI: 10.18502/ijm.v13i1.5505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background and Objectives: The three old world Leishmania species i.e., L. major, L. tropica, and L. infantum are considered as potential etiological agents of the various clinical forms of leishmaniasis in Iran. Different species co-exist in some areas. Accurate differentiation between the species is essential for choosing an appropriate therapy. Conventional and gold standard methods for the detection and characterization of parasites are time-consuming, laborious, and have low sensitivity. A polymerase chain reaction followed by high resolution melting (PCR-HRM) analysis has been employed for detection and species identification. Most of the studies suffer from the use of multiple targets and/or requiring more than one reaction to identify a single sample. The present study aimed to design a PCR method based on the amplification of kinetoplast DNA minicircles (kDNA) and HRM analysis of the amplicons for rapid discrimination of the three mentioned species. Materials and Methods: DNA from reference strains including L. major, L. tropica, and L. infantum and fifty-eight strains subjected to PCR-HRM analysis targeting kDNA. All the samples were also analyzed by conventional kDNA-PCR. Results: The PCR-HRM analysis allowed discrimination between the three Old World species. The normalized HRM curves for the amplicons of kDNA indicated a unique and repeatable melting plot for each species, even in combination with human and mouse genomic DNA. Conventional kDNA-PCR could not properly discriminate L. tropica from L. infantum. Conclusion: PCR-HRM analysis of kDNA proved to be fast and accurate for discrimination of L. major, L. tropica, and L. infantum.
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Affiliation(s)
- Shima Fayaz
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran.,Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
| | | | - Fariborz Bahrami
- Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
| | - Parviz Parvizi
- Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Soheila Ajdary
- Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
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Eberhardt E, Hendrickx R, Van den Kerkhof M, Monnerat S, Alves F, Hendrickx S, Maes L, Caljon G. Comparative evaluation of nucleic acid stabilizing reagents for RNA- and DNA-based Leishmania detection in blood as proxy for visceral burdens. J Microbiol Methods 2020; 173:105935. [PMID: 32376283 DOI: 10.1016/j.mimet.2020.105935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Molecular detection techniques using peripheral blood are preferred over invasive tissue aspiration for the diagnosis and post-treatment follow-up of visceral leishmaniasis (VL) patients. This study aims to identify suitable stabilizing reagents to prevent DNA and RNA degradation during storage and transport to specialized laboratories where molecular diagnosis is performed. METHODOLOGY The stabilizing capacities of different commercially available reagents were compared using promastigote-spiked human blood and peripheral blood of Syrian golden hamsters subjected to experimental infection, treatment (miltefosine or aminopyrazole DNDi-1044) and immunosuppression. The impact of various storage temperature conditions was tested in combination with an established kinetoplast DNA (kDNA) qPCR and a recently developed spliced leader RNA (SL-RNA) assay for Leishmania detection. PRINCIPAL FINDINGS Irrespective of the blood type and stabilizer used, threshold (cT) values obtained with the SL-RNA qPCR were systematically lower than those obtained with the kDNA assay, confirming the advantage of the SL-RNA assay over the widely used kDNA assay for low-level Leishmania detection. Peripheral blood parasite levels correlated relatively well with hepatic burdens. RNA protect cell reagent provided the most optimal simultaneous DNA and RNA stabilization in both human and hamster blood. However, this stabilizer requires an erythrocyte lysis step, which can be challenging under field conditions. DNA/RNA shield provides a good alternative for downstream kDNA and SL-RNA assays, especially if sample storage capacity at 4 °C can be guaranteed. CONCLUSIONS/SIGNIFICANCE The recommended stabilizing reagents are compatible with RNA- and DNA-based Leishmania detection in peripheral blood in the VL hamster model and spiked human blood. Since molecular detection techniques using peripheral blood are less invasive than microscopic assessment of tissue aspirates, the findings of this study may be applied to human VL clinical studies.
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Affiliation(s)
- Eline Eberhardt
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium
| | - Rik Hendrickx
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium
| | - Magali Van den Kerkhof
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium
| | | | - Fabiana Alves
- Drugs for Neglected Disease initiative (DNDi), Geneva, Switzerland
| | - Sarah Hendrickx
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium.
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Caldas S, Marcelino AP, Faria G, de Oliveira Silva F, Ataide ACZ, Cunha LM, Bahia MT, Paz GF, Gontijo CMF. Visceral leishmaniasis: a practical strategy for quantitative molecular diagnosis in naturally infected dogs. Parasitol Res 2020; 119:1683-1690. [PMID: 32285265 DOI: 10.1007/s00436-020-06654-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 03/09/2020] [Indexed: 11/29/2022]
Abstract
The diagnosis of canine visceral leishmaniasis (CVL) has been a problem for public health services due to the variety of clinical signs similar to other diseases and low sensitivity and specificity of available tests. In this sense, our main objective was to develop a simple, rapid, and accurate quantitative real-time PCR (qPCR) diagnosis for CVL. Thus, low-invasive samples from bone marrow (BM), popliteal lymph nodes (PLN), and conjunctival swabs (CS) were selected from negative and VL-positive dogs, using as gold standard, immunological and parasitological tests performed with different tissues. Oligonucleotides for Leishmania infantum kDNA were designed and the limit of quantification and amplification efficiency of the qPCR were determined using tissue-specific standards produced with DNA from those different tissues, mixed with DNA from a known amount of L. infantum promastigotes. Endogenous control was used to validate a comparative Ct method, and tissue parasite concentrations were estimated by comparison with tissue-specific reference standard samples. The overall analysis of the qPCR data suggests the following ranking for tissue choice: PLN > BM > CS. Finally, we have concluded that this molecular approach simplifies and accelerates the quantitative diagnostic process because it is easy to perform, requiring no DNA dosing or standard curve application, and it shows good diagnostic parameters, especially when using popliteal lymph node samples.
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Affiliation(s)
- Sérgio Caldas
- Serviço de Biotecnologia e Saúde, Diretoria de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias, Belo Horizonte, MG, Brazil.
| | - Andreza P Marcelino
- Instituto Nacional de Infectologia Evandro Chagas, Fiocruz-RJ, Rio de Janeiro, RJ, Brazil
| | - Gilson Faria
- Serviço de Biotecnologia e Saúde, Diretoria de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias, Belo Horizonte, MG, Brazil
| | - Fernanda de Oliveira Silva
- Serviço de Biotecnologia e Saúde, Diretoria de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias, Belo Horizonte, MG, Brazil
| | - Ana Caroline Zampiroli Ataide
- Serviço de Biotecnologia e Saúde, Diretoria de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias, Belo Horizonte, MG, Brazil
| | - Lucas Maciel Cunha
- Serviço de Biotecnologia e Saúde, Diretoria de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias, Belo Horizonte, MG, Brazil
| | - Maria Terezinha Bahia
- Laboratório de Doenças Parasitárias, Escola de Medicina & Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
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Eberhardt E, Van den Kerkhof M, Bulté D, Mabille D, Van Bockstal L, Monnerat S, Alves F, Mbui J, Delputte P, Cos P, Hendrickx S, Maes L, Caljon G. Evaluation of a Pan-Leishmania Spliced-Leader RNA Detection Method in Human Blood and Experimentally Infected Syrian Golden Hamsters. J Mol Diagn 2018; 20:253-263. [PMID: 29355825 DOI: 10.1016/j.jmoldx.2017.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 11/24/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022] Open
Abstract
Several methods have been developed for the detection of Leishmania, mostly targeting the minicircle kinetoplast DNA (kDNA). A new RNA real-time quantitative PCR (qPCR) assay was developed targeting the conserved and highly expressed spliced-leader (SL) mini-exon sequence. This study compared the limits of detection of various real-time PCR assays in hamsters infected with Leishmania infantum, in spiked human blood, and in clinical blood samples from visceral leishmaniasis patients. The SL-RNA assay showed an excellent analytical sensitivity in tissues (0.005 and 0.002 parasites per mg liver and spleen, respectively) and was not prone to false-positive reactions. Evaluation of the SL-RNA assay on clinical samples demonstrated lower threshold cycle values than the kDNA qPCR, an excellent interrun stability of 97%, a 93% agreement with the kDNA assay, and an estimated sensitivity, specificity, and accuracy of 93.2%, 94.3%, and 93.8%, respectively. The SL-RNA qPCR assay was equally efficient for detecting Leishmania major, Leishmania tropica, Leishmania mexicana, Leishmania guayensis, Leishmania panamensis, Leishmania braziliensis, L. infantum, and Leishmania donovani and revealed similar SL-RNA levels in the different species and the occurrence of polycistronic SL-containing transcripts in Viannia species. Collectively, this single SL-RNA qPCR assay enables universal Leishmania detection and represents a particularly useful addition to the widely used kDNA assay in clinical studies in which the detection of viable parasites is pivotal to assess parasitological cure.
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Affiliation(s)
- Eline Eberhardt
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Magali Van den Kerkhof
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Dimitri Bulté
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Dorien Mabille
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Lieselotte Van Bockstal
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | | | - Fabiana Alves
- Drugs for Neglected Disease Initiative, Geneva, Switzerland
| | - Jane Mbui
- Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Peter Delputte
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Paul Cos
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Sarah Hendrickx
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium.
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Hossain F, Ghosh P, Khan MAA, Duthie MS, Vallur AC, Picone A, Howard RF, Reed SG, Mondal D. Real-time PCR in detection and quantitation of Leishmania donovani for the diagnosis of Visceral Leishmaniasis patients and the monitoring of their response to treatment. PLoS One 2017; 12:e0185606. [PMID: 28957391 PMCID: PMC5619796 DOI: 10.1371/journal.pone.0185606] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 09/17/2017] [Indexed: 11/19/2022] Open
Abstract
Sustained elimination of Visceral Leishmaniasis (VL) requires the reduction and control of parasite reservoirs to minimize the transmission of Leishmania donovani infection. A simple, reproducible and definitive diagnostic procedure is therefore indispensable for the early and accurate detection of parasites in VL, Relapsed VL (RVL) and Post Kala-azar Dermal Leishmaniasis (PKDL) patients, all of whom are potential reservoirs of Leishmania parasites. To overcome the limitations of current diagnostic approaches, a novel quantitative real-time polymerase chain reaction (qPCR) method based on Taqman chemistry was devised for the detection and quantification of L. donovani in blood and skin. The diagnostic efficacy was evaluated using archived peripheral blood buffy coat DNA from 40 VL, 40 PKDL, 10 RVL, 20 cured VL, and 40 cured PKDL along with 10 tuberculosis (TB) cases and 80 healthy endemic controls. Results were compared to those obtained using a Leishmania-specific nested PCR (Ln-PCR). The real time PCR assay was 100% (95% CI, 91.19-100%) sensitive in detecting parasite genomes in VL and RVL samples and 85.0% (95% CI, 70.16-94.29%) sensitive for PKDL samples. In contrast, the sensitivity of Ln-PCR was 77.5% (95% CI, 61.55-89.16%) for VL samples, 100% (95%CI, 69.15-100%) for RVL samples, and 52.5% (95% CI, 36.13-68.49%) for PKDL samples. There was significant discordance between the two methods with the overall sensitivity of the qPCR assay being considerably higher than Ln-PCR. None of the assay detected L. donovani DNA in buffy coats from cured VL cases, and reduced infectious burdens were demonstrated in cured PKDL cases who remained positive in 7.5% (3/40) and 2.5% (1/40) cases by real-time PCR and Ln-PCR, respectively. Both assays were 100% (95% CI, 95.98-100) specific with no positive signals in either endemic healthy control or TB samples. The real time PCR assay we developed offers a molecular tool for accurate detection of circulating L. donovani parasites in VL, PKDL and RVL patients, as well as being capable of assessing response to treatment. As such, this real time PCR assay represents an important contribution in efforts to eliminate VL.
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Affiliation(s)
- Faria Hossain
- Laboratory of Emerging Infections and Parasitology, Nutrition and Clinical science division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Prakash Ghosh
- Laboratory of Emerging Infections and Parasitology, Nutrition and Clinical science division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Md. Anik Ashfaq Khan
- Laboratory of Emerging Infections and Parasitology, Nutrition and Clinical science division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Malcolm S. Duthie
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Aarthy C. Vallur
- InBios International Inc, Seattle, Washington, United States of America
| | - Alessandro Picone
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Randall F. Howard
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Steven G. Reed
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Dinesh Mondal
- Laboratory of Emerging Infections and Parasitology, Nutrition and Clinical science division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
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