Incidence and Disability-Adjusted Life Years (Dalys) Attributable to Leishmaniasis In Iran, 2013

Diagnostic accuracy of serological rk-39 test for visceral Leishmaniasis: Systematic review and meta-analysis

BACKGROUND

Visceral leishmaniasis (VL), or kala-azar, is a vector-borne tropical disease caused by a group of intracellular hemoflagellate protozoa belonging to the family of Trypanosomatide and the genus Leishmania. The disease is distributed around the world and transmitted via the bite of infected female Phlebotomine sandflies, and there is variation in the diagnostic accuracy. Therefore, this systematic review and meta-analysis aimed to determine the pooled global sensitivity and specificity of the rk-39 test and to evaluate if there is a difference between the different parts of the world.

METHODS

A systematic review and meta-analysis have been conducted on the diagnostic accuracy of dermoscopy. After setting eligibility criteria, literature was searched in four databases and one searching engine. Articles were screened, critically appraised, and extracted independently by two reviewers, and any disagreements were resolved with the involvement of a third person. The quality of the included studies had been assessed by the Quality Assessment of Diagnostic Accuracy Studies (QUADAS 2) tool. Pooled sensitivity and specificity were determined by bivariate random effect analysis. Heterogeneity was assessed by Higgins's I2, and when it was present, mitigation was conducted by using sensitivity analysis.

RESULT

A total of 409 studies were identified, and finally 18 articles were eligible for the review with a total sample size of 5, 253. The bivariate random effect meta-analysis of the 7 diagnostic accuracy studies showed a pooled sensitivity of 0.89 (0.76-0.95) and specificity of 0.86 (0.72-0.94). The +LR was 6.32 (95% CI: 2.85-14.02), the-LR was 0.13 (95% CI: 0.06-0.30), and the diagnostic odds ratio (DOR) was 47.8 (95% CI: 11.3-203.2). Abdel-Latif (2018) was both an outlier and influential for sensitivity, and Walter (2011) was both an outlier and influential for specificity, and removing them from sensitivity and specificity, respectively, was beneficial for reducing the heterogeneity.

CONCLUSION

Rk-39 is found to have highly accurate measures in the diagnosis of visceral leishmaniasis. Both sensitivity and specificity were found to be highly accurate in the diagnosis of leishmaniasis, with a pooled sensitivity of 0.91 (0.88-0.93) and a pooled specificity of 0.89 (0.85-0.91).

ETHICAL CONSIDERATION

As we will use secondary data for the systematic review and meta-analysis, ethical concerns are not necessary.

Cutaneous Leishmaniasis Based on Climate Regions in Iran (1998-2021): A Systematic Review and Meta-Analysis

Background

Climate change can facilitate the expansion of leishmaniasis and create the suitable habitat for vector and reservoir species. The objective of this study was to estimate the prevalence of cutaneous leishmaniasis (CL) at the climatic regions of Iran.

Materials and Methods

The literature search was conducted to identify all published studies reporting the prevalence or incidence of CL in humans in Iran. A total of 350 articles that reported leishmaniasis in Iran were retrieved, due to eligibility criteria, only 42 studies were selected to the final systematic review and meta-analysis procedure. Random effects meta-analysis was done with the estimate of heterogeneity being taken from an inverse-variance model. Subgroup analysis was conducted and it stratified the studies according to climatic regions. Between-study heterogeneity was assessed by using I ² and Cochran's Q method I ² value of heterogeneity. Meta regression was used to investigate factors potentially contributed the between-study heterogeneity.

Results

Individual studies showed that prevalence per 100,000 population estimated the range from 1.5 to 318.7 with the overall random pooled prevalence of 83.3 (95% confidence interval 74.5-92.1). Subgroup analysis by climatic regions showed that many studies were conducted in the desert areas and also, it has more prevalent than the other climatic regions.

Conclusions

Leishmaniasis was more prevalent in regions with dry and desert climates than the other climatic regions. One of the advantages of this work is that the majority of selected studies have been conducted on population-base. However, some of the studies have been designed poorly or have had a lack of internal validity.

Estimating the global demand curve for a leishmaniasis vaccine: A generalisable approach based on global burden of disease estimates

Background

A pressing need exists to develop vaccines for neglected diseases, including leishmaniasis. However, the development of new vaccines is dependent on their value to two key players–vaccine developers and manufacturers who need to have confidence in the global demand in order to commit to research and production; and governments (or other international funders) who need to signal demand based on the potential public health benefits of the vaccine in their local context, as well as its affordability. A detailed global epidemiological analysis is rarely available before a vaccine enters a market due to lack of resources as well as insufficient global data necessary for such an analysis. Our study seeks to bridge this information gap by providing a generalisable approach to estimating the commercial and public health value of a vaccine in development relying primarily on publicly available Global Burden of Disease (GBD) data. This simplified approach is easily replicable and can be used to guide discussions and investments into vaccines and other health technologies where evidence constraints exist. The approach is demonstrated through the estimation of the demand curve for a future leishmaniasis vaccine.

Methodology/Principal findings

We project the ability to pay over the period 2030–2040 for a vaccine preventing cutaneous and visceral leishmaniasis (CL / VL), using an illustrative set of countries which account for most of the global disease burden. First, based on previous work on vaccine demand projections in these countries and CL / VL GBD-reported incidence rates, we project the potential long-term impact of the vaccine on disability-adjusted life years (DALYs) averted as a result of reduced incidence. Then, we apply an economic framework to our estimates to determine vaccine affordability based on the abilities to pay of governments and global funders, leading to estimates of the demand and market size. Based on our estimates, the maximum ability-to-pay of a leishmaniasis vaccine (per course, including delivery costs), given the current estimates of incidence and population at risk, is higher than $5 for 25–30% of the countries considered, with the average value-based maximum price, weighted by quantity demanded, being $5.7–6 [$0.3 - $34.5], and total demand of over 560 million courses.

Conclusion/Significance

Our results demonstrate that both the quantity of vaccines estimated to be required by the countries considered as well as their ability-to-pay could make a vaccine for leishmaniasis commercially attractive to potential manufacturers. The methodology used can be equally applied to other technology developments targeting health in developing countries.

Three different mutations in the DNA topoisomerase 1B in Leishmania infantum contribute to resistance to antitumor drug topotecan

Background

The evolution of drug resistance is one of the biggest challenges in leishmaniasis and has prompted the need for new antileishmanial drugs. Repurposing of approved drugs is a faster and very attractive strategy that is gaining supporters worldwide. Different anticancer topoisomerase 1B (TOP1B) inhibitors have shown strong antileishmanial activity and promising selective indices, supporting the potential repurposing of these drugs. However, cancer cells and Leishmania share the ability to become rapidly resistant. The aim of this study was to complete a whole-genome exploration of the effects caused by exposure to topotecan in order to highlight the potential mechanisms deployed by Leishmania to favor its survival in the presence of a TOP1B inhibitor.

Methods

We used a combination of stepwise drug resistance selection, whole-genome sequencing, functional validation, and theoretical approaches to explore the propensity of and potential mechanisms deployed by three independent clones of L. infantum to resist the action of TOP1B inhibitor topotecan.

Results

We demonstrated that L. infantum is capable of becoming resistant to high concentrations of topotecan without impaired growth ability. No gene deletions or amplifications were identified from the next-generation sequencing data in any of the three resistant lines, ruling out the overexpression of efflux pumps as the preferred mechanism of topotecan resistance. We identified three different mutations in the large subunit of the leishmanial TOP1B (Top1B^F187Y, Top1B^G191A, and Top1B^W232R). Overexpression of these mutated alleles in the wild-type background led to high levels of resistance to topotecan. Computational molecular dynamics simulations, in both covalent and non-covalent complexes, showed that these mutations have an effect on the arrangement of the catalytic pentad and on the interaction of these residues with surrounding amino acids and DNA. This altered architecture of the binding pocket results in decreased persistence of topotecan in the ternary complex.

Conclusions

This work helps elucidate the previously unclear potential mechanisms of topotecan resistance in Leishmania by mutations in the large subunit of TOP1B and provides a valuable clue for the design of improved inhibitors to combat resistance in both leishmaniasis and cancer. Our data highlights the importance of including drug resistance evaluation in drug discovery cascades.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04947-4.

Human Cutaneous Leishmaniosis in Iran, Up to Date-2019

Cutaneous leishmaniasis is a neglected and parasitic vector borne diseases that is endemic in tropical and subtropical countries, including Iran. The aim of this study was to explain the present status of CL in Iran. This report is based on data that recorded by cutaneous leishmaniasis surveillance system in 2019, and evaluated in Center for Communicable Diseases Management in Ministry of Health in Iran. Iran has been considered an endemic area for cutaneous leishmaniasis in the world. Dependent to activities for cutaneous leishmaniasis control the number of cases decreased from 23202 in 2008 (Incidence rate 32 per 100000) to 13124 in 2019 (Incidence rate 15.8 per 100000), more cases reported from September to December, in 2019, 46% of cases had one lesion and 21% had 2 lesions, 85% of cases diagnosed when the diameter of lesions had 3 centimeters and bellows. Although the Leishmania control program began in 1977, the incidence of the disease has dropped dramatically since 2008 when the new cutaneous leishmaniasis control program have been implemented. Although in some areas the incidence of the disease increased, but the implementation of the new program has reduced the number of cases, in order to continue reducing the disease, permanent support for the control programs is needed.

Designing of a Novel Fusion Protein Vaccine Candidate Against Human Visceral Leishmaniasis (VL) Using Immunoinformatics and Structural Approaches

Leishmaniasis is caused by an obligate intracellular protozoan parasite. The clinical forms of leishmaniasis differ from cutaneous leishmaniasis, mucocutaneous leishmaniasis and visceral leishmaniasis (VL) which depend on the parasite species and the host’s immune responses. There are significant challenges to the available anti-leishmanial drug therapy, particularly in severe forms of disease, and the rise of drug resistance has made it more difficult. Currently, no licensed vaccines have been introduced to the market for the control and elimination of VL. A potential target for use in candidate vaccines against leishmaniasis has been shown to be leishmania Kinetoplastid membrane protein-11 (KMP-11) antigen. In this study, we chose KMP-11 antigen as target antigen in our vaccine construct. In addition, B-type flagellin (fliC) was used as an adjuvant for enhancing vaccine immunogenicity. The GSGSGSGSGSG linker was applied to link the KMP-11 antigen and fliC (KMP-11-fliC) to construct our fusion protein. Bioinformatics approaches such as; 3D homology modeling, CTL, B-cell, MHC class I and II epitopes prediction, allergenicity, antigenicity evaluations, molecular docking, fast simulations of flexibility of docked complex and in silico cloning were employed to analysis and evaluation of various properties of the designed fusion construct. Computational results showed that our engineered structure has the potential for proper stimulation of cellular and humoral immune responses against VL. Consequently, it could be proposed as a candidate vaccine against VL according to these data and after verifying the efficacy of the candidate vaccine through in vivo and in vitro immunological tests.

Cutaneous leishmaniasis in Iran: A systematic review and meta-analysis

Cutaneous leishmaniasis as a public health concern that attracts many attentions in endemic area. There is no exact estimation of cutaneous leishmaniasis in Iran. This study aimed to assess the exact prevalence of disease and carried out in databases including: Pub Med, Google Scholar, Science Direct, Scopus, Web of Science, Magiran, Iran doc, Barakatkns and Scientific Information Database (SID) from 2000 to 2019. Totally 84 studies were eligible to be included in this systematic review and Meta-analysis study. Based on a random effect model the pooled prevalence of leishmaniasis was estimated 45% (95% CI: 39%-51%; I^2 = 99.8%P < 0.001). The highest prevalence of CL was related to Isfahan 66% (53%-78%), Golestan 64% (62%-65%) and Fars province 63% (38%-84%) and the lowest prevalence was estimated in Kermanshah province 4% (4%-5%), Hormozgan 10% (8%-11%), Bushehr 12% (1%-35%) and Kerman 15% (9%-22%) provinces respectively. The lowest prevalence was associated with L. trapica spices 23% (11%-38%) and the highest was associated with L. major spices 32% (21%-45%). The prevalence with both L. trapica and L. major spices was achieved 60% (48%-71%). It is essential for health authorities to take steps to control and prevent the epidemic by rapid treatment of patients, destroying gerbils and promotion of general and health education for the local population.

Leishmaniasis and Autoimmunity in Patient with LPS-Responsive Beige-Like Anchor Protein (LRBA) Deficiency

BACKGROUND/OBJECTIVE

LPS-responsive beige-like anchor protein (LRBA) deficiency is a combined immunodeficiency and immune dysregulation. The authors present a case report of LPSresponsive beige-like anchor protein (LRBA) deficiency with the history of autoimmunity, enteropathy and visceral leishmaniasis. Sirolimus therapy was started for autoimmunity and enteropathy but was discontinued due to recurrent leishmaniasis. Therefore, a common side-effect of many immunosuppressive drugs in patients with LRBA deficiency is increased susceptibility to infections.

METHODS

Whole exome sequencing was performed to detect the underlying genetic mutation and Leishmania DNA was detected by the PCR technique in this patient.

RESULTS

Whole exome sequencing of the patient reported a homozygous frameshift deletion mutation in the LRBA gene (NM_006726: exon29: c.4638delC, p. S1546fs). Leishmania DNA PCR was positive in this case.

CONCLUSION

Parasite infections manifestations report in LRBA deficiency. Leishmania infections in patients with chronic diarrhea and autoimmunity should be considered for immunodeficiency.

Trypanothione Reductase Gene Mutations in Meglumine Antimoniate Resistant Isolates from Cutaneous Leishmaniasis Patients Using Molecular Dynamics Method

Background:

In this study, mutations in the tripanothion reductase of Leishmania tropica isolated from Iran was investigated using sequencing and simulation of the enzyme by the molecular dynamic method.

Methods:

Fifteen susceptible and 15 clinical resistant L. tropica specimens were collected from skin lesions from different regions of Iran in 2017. After DNA extraction, trypanothione reductase (TRYR or TPR), gene fragment was amplified using PCR and sequencing methods. In the case of structural mutations, the components were simulated by molecular dynamics using the GROMACS software.

Results:

Some structural mutations were observed in 9 amino acids surrounding the active site of the TRYR gene of L. tropica with three-dimensional trypanothione reductase alteration.

Conclusion:

Change in the active site of TRYR of L. tropica, could probably contribute to the development of resistant L. tropica to glucantime. Because of the likely occurrence of mutations in glucantime as well as the ease of development of L. tropica resistant populations, more samples are needed to demonstrate the relationship between mutations in this enzyme and clinical resistance to glucantime. On the other hand, it is recommended that enzymatic studies be performed to confirm the role of mutation in the function and expression of trypanothione reductase in glucantime resistant and susceptible populations.

Lived Experiences of Patients Suffering from Acute Old World Cutaneous Leishmaniasis: A Qualitative Content Analysis Study from Iran

BACKGROUND

The aim of this study was to explore the experiences of patients who suffer from acute cutaneous leishmaniasis in Iran, focusing on quality of life.

METHODS

The study was conducted at two different sites in Iran in 2010-2011. Individual in-depth interviews were conducted with six men and six women parasitologically confirmed acute cutaneous leishmaniasis. Interviews were recorded, transcribed verbatim, and translated into English. Qualitative content analysis was used for data analysis.

RESULTS

The participants, aged 23 to 63yr, had mild to severe disease. Based on the analysis four main themes were developed. "Fearing an agonizing disease" reflects patients' experiences of disease development resulting in sadness and depression, "struggling to cope" and "taking on the blame" both illustrate how patients experience living with the disease, which included both felt and enacted stigma as major social concerns. "Longing for being seen and heard" refers to patients' experiences with healthcare as well as their expectations and demands from communities and healthcare to be involved in closing the knowledge and awareness gap.

CONCLUSION

Mental and social dimensions of cutaneous leishmaniasis were complex and adversely affected patients' lives by causing psychological burden and limiting their social interactions. Health authorities have to plan programs to increase the disease awareness to prevent the existing stigma to improve patients' social condition and medical care.

Apoptotic Effect of Morphine, Imiquimod and Nalmefene on Promastigote, Infected and Uninfected Macrophages with Amastigote of Leishmania Major by Flow Cytometry

The parasites of genus Leishmania are the causative agents of one of the most widespread and devastating diseases. According to follow-up data, these medications may provoke adverse drug reactions, drug resistance, relapse, as well as financial burden. The mechanism of action of opioid drugs is primarily exerted via transmembrane G-protein coupled receptors. One of the potent synthetic immunomodulator agents is imiquimod with low molecular weight and unknown mechanism of action. Monocyte and macrophage are the primary site of action for imiquimod. Nalmefene is a well-known opioid antagonist agent which simultaneously inhibits these receptors and augments intracellular pathogenicity, hence providing opportunities to investigate their function. The aim of present work was evaluating the effect of morphine, imiquimod and nalmephen on the Leishmania major and investigating cytotoxic effect this drug on the uninfected macrophage and infected macrophage for detected early apoptosis, necrosis and secondry apoptosis by flowcytometry method. In this study we used morphine, imiquimod, nalmefene, and Glucantime. We treated promastigotes, macrophages, and infected macrophages with above drugs, and the apoptosis evaluated by flow cytometry. The results showed that in all concentration of morphine more than 98% of promastigotes remained alive that it is deduced that morphine lacks any lethal effect on L. major after 24 h, whereas in groups treated with Glucantime alone or in combination with Nalmephene and Imiquimod, 84.13%, 88.96% and 86.72% of promastigotes were alive, respectively. The results of macrophage treatment with morphine, imiquimod, and nalmefene demonstrated that most necrosis has occurred in nalmefene group (6.54%).

Immunodiagnosis of Visceral Leishmaniasis: Current Status and Challenges: A Review Article

BACKGROUND

Diagnosis of Visceral Leishmaniasis (VL) is still challenging. This review highlighted current status and challenges in the serological diagnosis of VL. Furthermore, the drawback of currently available serological tests and the most recent advancement in the designing and application of these assays for the diagnosis of VL are addressed.

METHODS

All the published literature cited within PubMed, ISI Web of Science, Google Scholar, Scopus, and IranMedex, regarding the immunodiagnosis of VL in human were sought from 2000 till Mar 2017. The search terms were "visceral leishmaniasis", or "kala-azar" subsequently combined with the search terms "diagnosis", "serodiagnosis", "human", "serological", "antigen detection" or "antibody detection". Data were extracted from literature which fulfilled our eligibility criteria.

RESULTS

Direct agglutination test (DAT) and rk39 dipstick have made a great improvement in the serological diagnosis of VL. Besides, other kinesin-related protein including K26, K28, and KE16 provided promisingly diagnostic accuracy in the diagnosis of VL. The Latex Agglutination Test for the diagnosis of VL (KAtex), with moderate sensitivity but high specificity, made a substantial contribution to the field. Moreover, a range of protein antigens has recently been detected in the urine of VL patients with encouraging diagnostic value.

CONCLUSION

The suboptimal diagnostic accuracy of the currently available serological assays for the diagnosis of human VL necessitates further research and development in this field. Outcomes of immunodiagnostic tests based on recombinant antigens are favorable. These proteins might be the most appropriate antigens to be further evaluated and utilized for the diagnosis of human VL.

Brain Parenchyma (pons) Involvement by Visceral Leishmaniasis: A Case Report

Leishmaniasis, as a vector-borne disease, is transmitted by sandfly and caused by Leishmania protozoa. Brain involvement rarely occurs in visceral leishmaniasis. In this paper, a rare case of pons involvement by visceral leishmaniasis (VL) is reported. A 54 yr old man from Southwest of Iran (Yasuj) presented to the Emergency Ward with a 3-wk history of headache (continuous, throbbing, and general), fever, chills, weakness, anorexia, and weight loss.

Spatio-temporal analysis of cutaneous leishmaniasis using geographic information system among Iranian Army Units and its comparison with the general population of Iran during 2005-2014

To investigate the time trend and distribution of cutaneous leishmaniasis in Iranian Army Units (IAUs) and general population (GP). with using census, Data on CL incidence in IAUs (from AJA University of Medical Sciences) and GP (from Ministry of Health) during 2005-2014 were extracted and entered into the GIS software. Cochran-Armitage test, choropleth map, hot-spot analysis and high/low clustering analysis were used to determine time trend, distribution of disease, hot-spots, and possible abnormal clustering, respectively. The number of infected individuals in IAUs and GP were 6533 and 153,499 respectively (with incidence rates of 143.68 per 100,000 and 25.86 per 100,000, respectively). Time trend analysis revealed the departure from linear trend for the incidence in IAUs (p < 0.001), but no such time trend was found in GP. According to choropleth maps; in IAUs, Khozestan from southwest, Esfahan from central and Kermanshah from west parts of Iran and among GP; Fars, Yazd, and Kerman in southern-east of Iran showed a high incidence rates. In IAUs, Esfahan and Khuzestan provinces was hot-spots of CL (p < 0.05), but in GP, provinces like Fars and Khorasan-shomali was hot-spots (p < 0.05). No clustering pattern of disease was observed in either study populations. Observed spatiotemporal variability in CL among IAUs and GP warrants proper health programs particularly to Khozestan and Esfahan in IAUs and Fars and Khorasan-shomali in GP are highly recommended.

Diagnostic Accuracy of Loop-mediated Isothermal Amplification Assay as a Field Molecular Tool for Rapid Mass Screening of Old World Leishmania Infections in Sand Flies and In Vitro Culture

BACKGROUND

We employed a highly sensitive loop-mediated isothermal amplification (LAMP) by targeting 18S rRNA gene to identify the rapid mass screening of Leishmania infections in captured sand flies of southwest Iran and In vitro culture.

METHODS

One hundred fifty sand flies were collected from 11 sites adjacent to Iraqi's borders in southern parts of Khuzestan Province by using sticky sheets of paper and CDC miniature light traps during late May 2014 to Nov 2015. Following morphological identification of sand flies species, the DNA of infected samples was extracted and amplified by PCR and LAMP assays by targeting ITS-rDNA and 18S rRNA genes. The PCR amplicons were directly sequenced to conduct the phylogenetic analysis.

RESULTS

Ten (6.6%) Leishmania infections were identified by LAMP assay (detection limit 0.01 parasites DNA) among infected Sergentomyia baghdadis, S. sintoni and Phlebotomus papatasi sand flies that was more sensitive than PCR (n=6.4%; (detection limit 10¹ parasites DNA). LAMP can identify 10¹-10⁶ promastigotes/100 μl RPMI 1640 while PCR recognized 10⁴-10⁶ promastigotes. The majority infection rate of sand flies was confirmed to L. major inferred by phylogenetic analysis.

CONCLUSION

This is the first exploration characterized the Old World Leishmania infections by LAMP technique in both infected sand flies and In vitro conditions. The LAMP method because of its shorter reaction time, robustness, more sensitivity, lack of requirement of complicated equipment and visual discriminatory of positivity can be appeared a promising tool instead of PCR to identify low Leishmania loads and entomological monitoring of leishmaniasis in resource-limited endemic of the world.