Post-kala-azar dermal leishmaniasis

Persistent dermal lesions in a patient with previous history of visceral leishmaniasis

Post-kala-azar dermal leishmaniasis (PKDL) is a complication of visceral leishmaniasis (VL) that most frequently occurs after an episode of VL caused by Leishmania donovani. In this case report, we present a 21-year-old male patient with persistent skin lesions and recurrent visceral leishmaniasis (VL) due to Leishmania infantum. The patient did not respond to multiple lines of anti-leishmanial treatment (including Liposomal amphotericin B and miltefosine) and later died from cerebral lesions presumed to be secondary to persistent VL.

Xenodiagnosis to address key questions in visceral leishmaniasis control and elimination

Visceral leishmaniasis (VL) remains an important public health issue worldwide causing substantial morbidity and mortality. The Indian subcontinent accounted for up to 90% of the global VL burden in the past but made significant progress during recent years and is now moving towards elimination. However, to achieve and sustain elimination of VL, knowledge gaps on infection reservoirs and transmission need to be addressed urgently. Xenodiagnosis is the most direct way for testing the infectiousness of hosts to the vectors and can be used to investigate the dynamics and epidemiology of Leishmania donovani transmission. There are, however, several logistic and ethical issues with xenodiagnosis that need to be addressed before its application on human subjects. In the current Review, we discuss the critical knowledge gaps in VL transmission and the role of xenodiagnosis in disease transmission dynamics along with its technical challenges. Establishment of state of the art xenodiagnosis facilities is essential for the generation of much needed evidence in the VL elimination initiative.

Differential Regulation of miRNA Profiles of Human Cells Experimentally Infected by Leishmania donovani Isolated From Indian Visceral Leishmaniasis and Post-Kala-Azar Dermal Leishmaniasis

MicroRNAs are small ribonucleic acid that act as an important regulator of gene expression at the molecular level. However, there is no comparative data on the regulation of microRNAs (miRNAs) in visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). In this current study, we compared the expression miRNA profile in host cells (GTHP), with VL strain (GVL) and PKDL strain-infected host cell (GPKDL). Normalized read count comparison between different conditions revealed that the miRNAs are indeed differentially expressed. In GPKDL with respect to GVL and GTHP, a total of 798 and 879 miRNAs were identified, out of which 349 and 518 are known miRNAs, respectively. Comparative analysis of changes in miRNA expression suggested that the involvement of differentially expressed miRNAs in various biological processes like PI3K pathway activation, cell cycle regulation, immunomodulation, apoptosis inhibition, different cytokine production, T-cell phenotypic transitions calcium regulation, and so on. A pathway enrichment study using in silico predicted gene targets of differentially expressed miRNAs showed evidence of potentially universal immune signaling pathway effects. Whereas cytokine-cytokine receptor interaction, phagocytosis, and transforming growth factor beta (TGF-β) signaling pathways were more highly enriched using targets of miRNAs upregulated in GPKDL. These findings could contribute to a better understanding of PKDL pathogenesis. Furthermore, the identified miRNAs could also be used as biomarkers in diagnosis, prognosis, and therapeutics of PKDL infection control.

Quantifying the Infectiousness of Post-Kala-Azar Dermal Leishmaniasis Toward Sand Flies

Background

On the Indian subcontinent, visceral leishmaniasis (VL) incidence is on track to reach elimination goals by 2020 in nearly all endemic districts. Although not included in official targets, previous data suggest post-kala-azar dermal leishmaniasis (PKDL) patients can act as an infection reservoir.

Methods

We conducted xenodiagnosis on 47 PKDL patients and 15 VL patients using laboratory-reared Phlebotomus argentipes. In direct xenodiagnosis, flies were allowed to feed on the patient’s skin for 15 minutes. For indirect xenodiagnosis, flies were fed through a membrane on the patient’s blood. Five days later, blood-fed flies were dissected and examined by microscopy and/or polymerase chain reaction (PCR). A 3-mm skin snip biopsy (PKDL) or venous blood (VL) was processed by quantitative PCR.

Results

Twenty-seven PKDL patients (57.4%) had positive results by direct and/or indirect xenodiagnosis. Direct was significantly more sensitive than indirect xenodiagnosis (55.3% vs 6.4%, P < .0001). Those with positive xenodiagnosis had median skin parasite loads >1 log₁₀ unit higher than those with negative results (2.88 vs 1.66, P < .0001). In a multivariable model, parasite load, nodular lesions, and positive skin microscopy were significantly associated with positive xenodiagnosis. Blood parasite load was the strongest predictor for VL. Compared to VL, nodular PKDL was more likely and macular PKDL less likely to result in positive xenodiagnosis, but neither difference reached statistical significance.

Conclusions

Nodular and macular PKDL, and VL, can be infectious to sand flies. Active PKDL case detection and prompt treatment should be instituted and maintained as an integral part of VL control and elimination programs.

Mapping N- and C-terminals of Leishmania donovani tyrosine aminotransferase by gene truncation strategy: a functional study using in vitro and in silico approaches

Tyrosine aminotransferase (TAT) catalyzes the transamination of amino acids in Leishmania sp.. TAT from Leishmania donovani has been found to be extremely stable at extreme temperatures and pH conditions. This study was conceived to map the functions of the non-conserved N-terminal and conserved C-terminal domain of TAT. N-terminal (NTAT) and C-terminal (CTAT) domain of TAT was truncated and cloned into the pET28a(+) vector. The truncated proteins were expressed, purified, and biochemically characterized. The K_m of NTAT and CTAT for the tyrosine-pyruvate pair was determined to be 3.468 ± 0.796 mM and 4.581 ± 0.627 mM, repectively. Temperature and pH stability studies found NTAT to be stable like TAT but CTAT was extremely susceptible to temperature and pH changes. Upon docking and simulation for 100 ns, NTAT had lower SASA values. From UV spectroscopic study, PLP bound better to CTAT than NTAT because of the reduced SASA of NTAT. The sensitivity of CTAT was reasoned when the urea denaturation studies showed two-state denaturation which differed from NTAT’s and TAT’s biphasic folding mechanism. From this study, the authors hypothesize that the N-terminal is responsible for PLP stabilization and C-terminal protects the active site from extreme conditions.

Post kala-azar dermal leishmaniasis: A threat to elimination program

Leishmaniasis remains a public health concern around the world that primarily affects poor folks of the developing world spanning across 98 countries with mortality of 0.2 million to 0.4 million annually. Post kala-azar dermal leishmaniasis (PKDL) is the late skin manifestation of visceral leishmaniasis (VL). It has been reported that about 2.5% to 20% of patients recovered from VL develop PKDL having stilted macular or nodular lesions with parasites. In the Indian subcontinent (ISC), it manifests a few months after recovery from VL, though in Africa it can occur simultaneously with VL or a little later. New cases of PKDL are also observed without prior VL in the ISC. These individuals with PKDL represent an important but largely neglected reservoir of infection that perpetuates anthroponotic Leishmania donovani transmission in the ISC and can jeopardize the VL elimination program as these cases can infect the sand flies and spread the endemic. Therefore, it becomes imperative to eradicate PKDL as a part of the VL elimination program. With the limited treatment options besides little knowledge on PKDL, this review stands out in focusing on different aspects that should be dealt for sustained VL elimination.

The usefulness of trained field workers in diagnosis of post-kala-azar dermal leishmaniasis (PKDL) and clinico-epidemiological profile in highly endemic areas of Bihar

BACKGROUND

Surveillance of post-kala-azar dermal leishmaniasis (PKDL) is critical to the elimination of visceral leishmaniasis (VL). In this study we assessed the feasibility of using trained field workers for detecting suspected PKDL cases.

METHODS

A cross-sectional study using a multistage sampling technique was conducted in the Araria district of Bihar. Trained field workers were utilized for identification of suspected PKDL case.

RESULTS

We investigated 57 099 individuals from 11 300 households. The trained field workers were useful in identifying 107 (18%) probable PKDL cases. The calculated PKDL prevalences were 18.7/10 000 and 9.7/10 000 for probable and confirmed PKDL cases, respectively. The median duration of onset of PKDL was 23 months (interquartile range 16.5-56.5). The younger age group developed PKDL significantly more often compared with the older age group (p=0.007). Of the 107 patients, 25 (55.5%) were positive by microscopy of slit skin smear and 42 (93.3%) by polymerase chain reaction. Of 45 patients, 33 (73%) PKDL cases were cured after full treatment. The risk of not being cured with incomplete treatment was three times higher than with complete treatment (relative risk 3.12 [95% confidence interval 1.23 to 8.67], p=0.004).

CONCLUSIONS

We conclude that the prevalence of PKDL is high and the use of trained field workers may be feasible to actively detect PKDL cases in VL-endemic areas of Bihar, India.

Conversion of asymptomatic infection to symptomatic visceral leishmaniasis: A study of possible immunological markers

Introduction

Presence of asymptomatic individuals in endemic areas is common. The possible biomarkers in asymptomatic individuals once they get exposed to infection as well as following conversion to symptomatic disease are yet to be identified.We identified asymptomatic Visceral leishmaniasis (VL) infection amongst rK39⁺sorted direct agglutination test positive (DAT⁺) endemic healthy population and confirmed it by quantitative PCR(qPCR).The immunological determinants such as Adenosine deaminase (ADA), Interferon gamma (IFN-γ), Tumour Necrosis Factor alpha (TNF-α) and Interleukin 10 (IL-10)were examined to predict probable biomarkers for conversion to symptomatic VL.

Methods

Sample size was 5794 healthy individuals from VL endemic region. Antibody tests(DAT &rK39) were performed and later a qPCR assay was employed using kDNA specific primers and probes. Immunological biomarkers examined were ADA level by ADA–MTP kit and quantitative cytokines(IFN-γ, IL-10 and TNF-α) by ELISA.

Results

120 asymptomatic individuals of 308 rK39 sero-positives were DAT positive comprising of 56 with previous history and 64 with no history of VL. RT-PCR confirmed asymptomatic VL in 42 sero-positives. These were followed up through repeated qPCR and evaluation of immunological determinants. We observed10 symptomatic cases converted from a total of 42 asymptomatic individuals identified at base-line. The level of ADA, IL-10 and IFN-γ remained consistently high in asymptomatic cases and amongst these, ADA and IL-10 but not IFN-γ remained higher at the development of clinical symptoms into active VL. On the contrary, there was no significant change in the mean concentration of TNF-α at both stages of the disease.

Discussion

We surmise from our data that considerable proportion of asymptomatic cases can be a reservoir and may play a crucial role in transmission of visceral leishmaniasis in endemic areas.

The data also suggests that ADA and IL-10 can serve as a potential biomarker during the conversion of asymptomatic into symptomatic VL.

The most threatening form of leishmaniasis is human visceral leishmaniasis, which is caused by L. donovani in Indian subcontinent. The disease accounts for huge annual burden of infectious disease in India. Efforts towards disease elimination programme are far beyond satisfaction and there is need to re-strengthen health monitoring, surveillance programme in endemic areas. There is a greater need to identify asymptomatic individuals amongst endemic healthy control by active surveillance programme. Further, except a few, many asymptomatic subjects become sero-negative without developing VL due to strong inherent cellular immunity possessed by them. This study enumerates use of rK39, DAT and quantitative PCR(qPCR) in asymptomatic detection and then evaluate immunological biomarkers(Adenosine deaminase, IFN-γ, TNF-α and IL-10) which help in disease conversion to symptomatic VL, at 6 month follow- up. Follow–up analysis revealed that antibody testing with rK39 (3.24%), DAT (8.33%) had poor agreement with disease conversion. By qPCR, we could identify the level of parasitemia, and collectively with serology, the test detected 23.80% of asymptomatic cases converted into disease. The level of ADA and IL-10 remained consistently high during conversion. IFN-γ became high in asymptomatic infection but became low on conversion, whereas, no significant change in level of TNF-α was observed at both stages of disease. Thus by use of qPCR, concomitantly with DAT over rK39⁺ sorted endemic healthy control may be employed for early case detection. Adenosine is produced by ecto-nucleotide during L.donovaniinfection, has been previously reported and in parallel to this study we conclude that determination of adenosine deaminase level (ADA) might help identify early cases with more tendency to convert into disease. This will help to boost health monitoring programme to eradicate Kala-azar in Bihar, India.

Clinical Proteomics Profiling for Biomarker Identification Among Patients Suffering With Indian Post Kala Azar Dermal Leishmaniasis

Background: Post Kala Azar Dermal Leishmaniasis (PKDL) is a non-fatal dermal sequel of Visceral Leishmaniasis (VL), affecting individuals worldwide. Available diagnostic tools lack sensitivity and specificity toward identifying macular (MAC) PKDL patients, due to low parasite load in patients' sample. Confirmatory test like punch biopsy are invasive and painful. Considering the rural nature of this disease and the prevailing situation of diagnostic scenario, PKDL patients mostly remains unattended from receiving proper medical care. They in turn act as “mobile parasite reservoir,” responsible for VL transmission among healthy individuals (HI). This study aims to identify PKDL disease specific glycated protein biomarkers, utilizing the powerful LC-MS/MS technology, which is the tool of choice to efficiently identify and quantify disease specific protein biomarkers. These identified PKDL disease specific novel glycoproteins could be developed in future as immunochromatographic based assay for efficient case detection.

Methodology: Previously our lab had identified importance of glycated (Circulating Immune Complexes) CICs, among PKDL patients. This study aims to further characterize disease specific glycated protein biomarkers, among MAC PKDL patients for both diagnostic and prognostic evaluation of the disease. LC-MS/MS based comparative spectral count analysis of MAC PKDL to polymorphic (POLY) PKDL, HI, and Cured (CR) individuals were performed. Proteins level alterations among all study groups were confirmed by Western blot and enzyme-linked immunosorbant Assay (ELISA).

Results: Among MAC PKDL patients 43, 60, 90 proteins were altered compared to POLY PKDL, HI, and CR groups, respectively. Filtering for the most significant proteins, Plasminogen (PLG) and Vitronectin (VTN) were identified which promisingly identified MAC PKDL cases. Active surveillance results from endemic districts of West Bengal revealed drastic rise of MAC PKDL cases, alarming the urgency for field adaptive efficient biomarker.

Conclusion: This current study aims to establish PLG and VTN as novel diagnostic and prognostic protein biomarker for MAC and POLY PKDL cases management.

Evaluation of Rapid Extraction Methods Coupled with a Recombinase Polymerase Amplification Assay for Point-of-Need Diagnosis of Post-Kala-Azar Dermal Leishmaniasis

To detect Post-kala-azar leishmaniasis (PKDL) cases, several molecular methods with promising diagnostic efficacy have been developed that involve complicated and expensive DNA extraction methods, thus limiting their application in resource-poor settings. As an alternative, we evaluated two rapid DNA extraction methods and determined their impact on the detection of the parasite DNA using our newly developed recombinase polymerase amplification (RPA) assay. Skin samples were collected from suspected PKDL cases following their diagnosis through national guidelines. The extracted DNA from three skin biopsy samples using three different extraction methods was subjected to RPA and qPCR. The qPCR and RPA assays exhibited highest sensitivities when reference DNA extraction method using Qiagen (Q) kit was followed. In contrast, the sensitivity of the RPA assay dropped to 76.7% and 63.3%, respectively, when the boil & spin (B&S) and SpeedXtract (SE) rapid extraction methods were performed. Despite this compromised sensitivity, the B&S-RPA technique yielded an excellent agreement with both Q-qPCR (k = 0.828) and Q-RPA (k = 0.831) techniques. As expected, the reference DNA extraction method was found to be superior in terms of diagnostic efficacy. Finally, to apply the rapid DNA extraction methods in resource-constrained settings, further methodological refinement is warranted to improve DNA yield and purity through rigorous experiments.

Impact of sequelae of visceral leishmaniasis and their contribution to ongoing transmission of Leishmania donovani

Visceral leishmaniasis (VL) in the Old World is caused by infection with Leishmania donovani. Although the numbers of new reported cases of VL in Africa have been relatively stable for several years, the low numbers currently reported on the Indian subcontinent suggest a positive impact of new treatments and intervention strategies. In both regions, however, VL relapse and post-kala-azar dermal leishmaniasis (PKDL) maintain infectious reservoirs and therefore present a threat to control programs. In this review, we outline the evolving appreciation of PKDL as an impactful disease in its own right and discuss the various diagnostic methods that can be applied for the detection and characterization of PKDL cases. We also highlight the data that indicate the potential, and likely contribution, of PKDL cases to ongoing transmission of L. donovani.

Screening Marine Natural Products for New Drug Leads against Trypanosomatids and Malaria

Neglected Tropical Diseases (NTD) represent a serious threat to humans, especially for those living in poor or developing countries. Almost one-sixth of the world population is at risk of suffering from these diseases and many thousands die because of NTDs, to which we should add the sanitary, labor and social issues that hinder the economic development of these countries. Protozoan-borne diseases are responsible for more than one million deaths every year. Visceral leishmaniasis, Chagas disease or sleeping sickness are among the most lethal NTDs. Despite not being considered an NTD by the World Health Organization (WHO), malaria must be added to this sinister group. Malaria, caused by the apicomplexan parasite Plasmodium falciparum, is responsible for thousands of deaths each year. The treatment of this disease has been losing effectiveness year after year. Many of the medicines currently in use are obsolete due to their gradual loss of efficacy, their intrinsic toxicity and the emergence of drug resistance or a lack of adherence to treatment. Therefore, there is an urgent and global need for new drugs. Despite this, the scant interest shown by most of the stakeholders involved in the pharmaceutical industry makes our present therapeutic arsenal scarce, and until recently, the search for new drugs has not been seriously addressed. The sources of new drugs for these and other pathologies include natural products, synthetic molecules or repurposing drugs. The most frequent sources of natural products are microorganisms, e.g., bacteria, fungi, yeasts, algae and plants, which are able to synthesize many drugs that are currently in use (e.g. antimicrobials, antitumor, immunosuppressants, etc.). The marine environment is another well-established source of bioactive natural products, with recent applications against parasites, bacteria and other pathogens which affect humans and animals. Drug discovery techniques have rapidly advanced since the beginning of the millennium. The combination of novel techniques that include the genetic modification of pathogens, bioimaging and robotics has given rise to the standardization of High-Performance Screening platforms in the discovery of drugs. These advancements have accelerated the discovery of new chemical entities with antiparasitic effects. This review presents critical updates regarding the use of High-Throughput Screening (HTS) in the discovery of drugs for NTDs transmitted by protozoa, including malaria, and its application in the discovery of new drugs of marine origin.

Report of the Fifth Post-Kala-Azar Dermal Leishmaniasis Consortium Meeting, Colombo, Sri Lanka, 14-16 May 2018

The 5th Post-Kala-Azar Dermal Leishmaniasis (PKDL) Consortium meeting brought together PKDL experts from all endemic areas to review and discuss existing and new data on PKDL. This report summarizes the presentations and discussions and provides the overall conclusions and recommendations.

Global genome diversity of the Leishmania donovani complex

Protozoan parasites of the Leishmania donovani complex - L. donovani and L. infantum - cause the fatal disease visceral leishmaniasis. We present the first comprehensive genome-wide global study, with 151 cultured field isolates representing most of the geographical distribution. L. donovani isolates separated into five groups that largely coincide with geographical origin but vary greatly in diversity. In contrast, the majority of L. infantum samples fell into one globally-distributed group with little diversity. This picture is complicated by several hybrid lineages. Identified genetic groups vary in heterozygosity and levels of linkage, suggesting different recombination histories. We characterise chromosome-specific patterns of aneuploidy and identified extensive structural variation, including known and suspected drug resistance loci. This study reveals greater genetic diversity than suggested by geographically-focused studies, provides a resource of genomic variation for future work and sets the scene for a new understanding of the evolution and genetics of the Leishmania donovani complex.

Immune Responses in Post Kala-azar Dermal Leishmaniasis

Kala-azar, commonly known as visceral leishmaniasis (VL), is a neglected tropical disease that has been targeted in South Asia for elimination by 2020. Presently, the Kala-azar Elimination Programme is aimed at identifying new low-endemic foci by active case detection, consolidating vector control measures, and decreasing potential reservoirs, of which Post Kala-azar Dermal Leishmaniasis (PKDL) is considered as the most important. PKDL is a skin condition that occurs after apparently successful treatment of VL and is characterized by hypopigmented patches (macular) or a mixture of papules, nodules, and/or macules (polymorphic). To achieve this goal of elimination, it is important to delineate the pathophysiology so that informed decisions can be made regarding the most appropriate and cost-effective approach. We reviewed the literature with regard to PKDL in Asia and Africa and interpreted the findings in establishing a potential correlation between the immune responses and pathophysiology. The overall histopathology indicated the presence of a dense, inflammatory cellular infiltrate, characterized by increased expression of alternatively activated CD68+ macrophages, CD8+ T cells showing features of exhaustion, CD20+ B cells, along with decreased CD1a+ dendritic cells. Accordingly, this review is an update on the overall immunopathology of PKDL, so as to provide a better understanding of host-parasite interactions and the immune responses generated which could translate into availability of markers that can be harnessed for assessment of disease progression and improvement of existing treatment modalities.

Protein glycosylation inLeishmaniaspp

Protein glycosylation is a co- and post-translational modification that, inLeishmaniaparasites, plays key roles in vector–parasite–vertebrate host interaction.

Parasitic Infections of the Stem Cell Transplant Recipient and the Hematologic Malignancy Patient, Including Toxoplasmosis and Strongyloidiasis

Hematopoietic stem cell transplantation (HSCT) recipients may infrequently develop parasitic infections at the time of the procedure via contamination from allograft tissue or blood products, and in the post-transplantation period through the traditional route of infection or as a reactivation caused by immunosuppression related to the transplant. To reduce risk, efforts should be directed at performing a comprehensive history, maintaining a high index of suspicion, and adhering to preventive measures. Additional strategies for the prevention, screening and careful follow-up, identification, and pre-emptive treatment of parasitic infections are required to reduce morbidity and mortality in HSCT patients.

Policy Recommendations From Transmission Modeling for the Elimination of Visceral Leishmaniasis in the Indian Subcontinent

Background

Visceral leishmaniasis (VL) has been targeted by the World Health Organization (WHO) and 5 countries in the Indian subcontinent for elimination as a public health problem. To achieve this target, the WHO has developed guidelines consisting of 4 phases of different levels of interventions, based on vector control through indoor residual spraying of insecticide (IRS) and active case detection (ACD). Mathematical transmission models of VL are increasingly used for planning and assessing the efficacy of interventions and evaluating the intensity and timescale required to achieve the elimination target.

Methods

This paper draws together the key policy-relevant conclusions from recent transmission modeling of VL, and presents new predictions for VL incidence under the interventions recommended by the WHO using the latest transmission models.

Results

The model predictions suggest that the current WHO guidelines should be sufficient to reach the elimination target in areas that had medium VL endemicities (up to 5 VL cases per 10000 population per year) prior to the start of interventions. However, additional interventions, such as extending the WHO attack phase (intensive IRS and ACD), may be required to bring forward elimination in regions with high precontrol endemicities, depending on the relative infectiousness of different disease stages.

Conclusions

The potential hurdle that asymptomatic and, in particular, post-kala-azar dermal leishmaniasis cases may pose to reaching and sustaining the target needs to be addressed. As VL incidence decreases, the pool of immunologically naive individuals will grow, creating the potential for new outbreaks.

Visceral Leishmaniasis: Recent Advances in Diagnostics and Treatment Regimens

Diagnostic advances in visceral leishmaniasis include the development of the rK39 and rK28 rapid diagnostic test. The direct agglutination test is also increasingly used, as well as conventional and real-time polymerase chain reaction, which also performs well on peripheral blood. The choice of treatment for visceral leishmaniasis depends on the geographic region where the infection is acquired. Liposomal amphotericin B is generally found to be safe and effective in most endemic regions of the world; antimonials still remain to be the most effective in eastern Africa despite its high toxicity. Combination therapy is increasingly explored. Immunosuppressed patients require adapted diagnostic and therapeutic strategies.

Cutaneous leishmaniasis: A great imitator

Cutaneous leishmaniasis (CL) is called "the great imitator," because it can mimic almost all types of dermatoses. This similarity may sometimes lead to misdiagnosis, resulting in inappropriate treatment and morbidities. Atypical forms occur due to the interaction between parasitic factors and the host immune response. Secondary infection or mistreatment of CL can also alter the natural course, resulting in bizarre and misdiagnosed cases. Atypical leishmaniasis should be considered in longstanding and painless lesions that may simulate erysipelas, dermatitis, verruca, herpes zoster, paronychia, and sporotrichosis. Less commonly, sarcoidosis, deep mycosis, basal and squamous cell carcinoma, cutaneous lymphoma, or pseudolymphomalike lesions may need to be considered in the differential diagnosis. A high index of suspicion is required to consider a diagnosis of CL, especially in nonendemic or newly endemic regions. Smear, histopathologic examination, culture, and polymerase chain reaction serve as important tools to differentiate CL from its clinical and histologic look-alikes. CL is discussed from various perspectives, with emphasis on CL and its broad differential diagnosis.

The impact of leishmaniasis on mental health and psychosocial well-being: A systematic review

BACKGROUND

Leishmaniasis is a neglected tropical parasitic disease endemic in South Asia, East Africa, Latin America and the Middle East. It is associated with low socioeconomic status (SES) and responsible for considerable mortality and morbidity. Reports suggest that patients with leishmaniasis may have a higher risk of mental illness (MI), psychosocial morbidity (PM) and reduced quality of life (QoL), but this is not well characterised. The aim of this study was to conduct a systematic review to assess the reported impact of leishmaniasis on mental health and psychosocial wellbeing.

METHODS

A systematic review of the literature was carried out. Pre-specified criteria were applied to identify publications including observational quantitative studies or systematic reviews. Two reviewers screened all of the titles, abstracts and full-studies and a third reviewer was consulted for disagreements. Data was extracted from papers meeting the criteria and quality appraisal of the methods was performed using the Newcastle-Ottawa Scale or the Risk of Bias in Systematic Review tool.

RESULTS

A total of 14 studies were identified from 12,517 records. Nine cross-sectional, three case-control, one cohort study and one systematic review were included. Eleven assessed MI outcomes and were measured with tools specifically designed for this; nine measured PM and 12 measured QoL using validated measurement tools. Quality appraisal of the studies showed that six were of good quality. Cutaneous leishmaniasis and post kala-azar dermal leishmaniasis showed evidence of associated MI and PM including depression, anxiety and stigma, while all forms of disease showed decreased QoL. The findings were used to inform a proposed model and conceptual framework to show the possible links between leishmaniasis and mental health outcomes.

CONCLUSION

There is evidence that leishmaniasis has an impact on MI, PM or QoL of patients and their families and this occurs in all the main subtypes of the disease. There are however large gaps in the evidence. Further research is required to understand the full extent of this problem and its mechanistic basis.

Adverse ocular events on miltefosine treatment for post-kala-azar dermal leishmaniasis in India

A 12-week course of miltefosine (MF) is recommended in India for the treatment of post-kala-azar dermal leishmaniasis (PKDL). We report a case series of four patients with PKDL, across three districts of Bihar state, who developed eye complications during treatment. They presented with acute scleritis and corneal infiltration with or without corneal ulceration. One patient solely with corneal infiltration recovered completely. The three others with corneal ulceration healed with corneal opacificity. One patient with bilateral eye involvement underwent corneal transplantation to prevent blindness. All adverse events were graded as certain using the World Health Organization-Uppsala Monitoring Centre causality assessment scale. There is need to counsel patients regarding possible adverse ocular events during MF treatment, to expand pharmacovigilance to all primary health centres in kala-azar endemic areas, and to update drug safety information considering the emerging evidence.

Relationship of Serum Antileishmanial Antibody With Development of Visceral Leishmaniasis, Post-kala-azar Dermal Leishmaniasis and Visceral Leishmaniasis Relapse

Introduction

To sustain the achievement of kala-azar elimination program (KEP), early detection and treatment of the visceral leishmaniasis (VL) cases and associated modalities such as treatment failure (TF), relapse VL (RVL), and Post-kala-azar dermal leishmaniasis (PKDL) is the cornerstone. A predictive biomarker for VL development and related complications could also play a crucial role in curtailing disease incidence and transmission. Investigations to find a biomarker with prospective capabilities are, however, scarce. Using samples and known clinical outcomes generated within two previous longitudinal cohort studies, we aimed to determine if fluctuations in serum anti-rK39 antibody levels could provide such predictive value.

Materials and Methods

Serum samples collected at four different time points (Baseline, 12, 18, and 24 months) from 16 patients who had developed VL within the monitoring period and 15 of their asymptomatic healthy controls counterparts were investigated. To investigate potential prediction of VL related complications, serum samples of 32 PKDL, 10 RVL, 07 TF, and 38 cured VL from a single dose AmBisome trial were analyzed. Of this second panel, all patients were monitored for 5 years and sera were collected at four time points (Baseline then 1, 6, and 12 months after treatment). The level of anti-rK39 antibodies in archived samples was measured by a semi-quantitative ELISA.

Results

The mean antibody level was significantly higher in VL patients compared to their asymptomatic healthy counterparts at each time point. Likewise, we observed a trend toward elevations in antibody levels for PKDL, RVL, TF relative to the reducing levels observed in cured VL. Receiver operating characteristic (ROC) analysis found a promising predictive power of rK39 antibody levels to reveal progression from asymptomatic Leishmania donovani infection stage to VL, defined as 87.5% sensitive and 95% specific. Following treatment, rk39 antibody notably showed 100% sensitivity and 95% specificity in predicting TF.

Conclusion

Our data indicate that the relative quantity of serum anti-rK39 antibody has promise within either a predictive or prognostic algorithm for VL and VL-related modalities. These could enable VL control programs to implement more effective measures to eliminate the disease. Further research is, however, imperative to standardize the rK39 antibody ELISA between sites prior to broader use.

An unusual case of post-kala-azar dermal leishmaniasis in a patient with HIV and visceral leishmaniasis co-infection

Visceral leishmaniasis (VL) is a vector-borne disease caused by Leishmania donovani complex. Post-kala-azar dermal leishmaniasis (PKDL) is a rash that can occur following treatment for VL due to L. donovani species. We describe an unusual case of PKDL occurring during treatment for Leishmania infantum VL in a patient with human immunodeficiency virus-co infection.

In-situ immune profile of polymorphic vs. macular Indian Post Kala-azar dermal leishmaniasis

Post Kala-azar Dermal Leishmaniasis (PKDL), a sequel of apparently cured Visceral Leishmaniasis presents in South Asia with papulonodular (polymorphic) or hypomelanotic lesions (macular). Till date, the polymorphic variant was considered predominant, constituting 85–90%. However, following active-case surveillance, the proportion of macular PKDL has increased substantially to nearly 50%, necessitating an in-depth analysis of this variant. Accordingly, this study aimed to delineate the cellular infiltrate in macular vis-à-vis polymorphic PKDL. To study the overall histopathology, hematoxylin and eosin staining was performed on lesional sections and phenotyping by immunohistochemistry done in terms of dendritic cells (CD1a), macrophages (CD68), HLA-DR, T-cells (CD8, CD4), B-cells (CD20) and Ki67 along with assessment of the status of circulating homing markers CCL2, CCL7 and CXCL13. In polymorphic cases (n = 20), the cellular infiltration was substantial, whereas in macular lesions (n = 20) it was mild and patchy with relative sparing of the reticular dermis. Although parasite DNA was identified in both variants by ITS-1 PCR, the parasite load was significantly higher in the polymorphic variant and Leishman-Donovan bodies were notably minimally present in macular cases. Both variants demonstrated a decrease in CD1a⁺ dendritic cells, HLA-DR expression and CD4⁺ T-cells. In macular cases, the proportion of CD68⁺ macrophages, CD8⁺ T-cells and CD20⁺ B-cells was 4.6 fold, 17.0 fold and 1.6 fold lower than polymorphic cases. The absence of Ki67 positivity and increased levels of chemoattractants suggested dermal homing of these cellular subsets. Taken together, as compared to the polymorphic variant, patients with macular PKDL demonstrated a lower parasite load along with a lesser degree of cellular infiltration, suggesting differences in host-pathogen interactions, which in turn can impact on their disease transmitting potential and responses to chemotherapy.

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Comparative analysis of immunopathology of polymorphic vs. macular PKDL.

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Dense lymphohistiocytic infiltrate in polymorphic PKDL.

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Mild and patchy cellular infiltration in macular PKDL with minimal Leishman Donovan bodies.

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Decreased presence of CD1a, HLA-DR and CD4⁺ T-cells in both variants.

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The presence of CD8⁺, CD68⁺and CD20⁺ cells in polymorphic>>>macular PKDL.

Relationship between treatment regimens for visceral leishmaniasis and development of post-kala-azar dermal leishmaniasis and visceral leishmaniasis relapse: A cohort study from Bangladesh

Background

We investigated the relationship of treatment regimens for visceral leishmaniasis (VL) with post-kala-azar dermal leishmaniasis (PKDL) and visceral leishmaniasis relapse (VLR) development.

Methods

Study subjects included cohorts of patients cured of VL since treatment with monotherapy by sodium stibogluconate (SSG), miltefosine (MF), paromomycin intramuscular injection (PMIM), liposomal amphotericin B [AmBisome (AMB)] in a single dose (SDAMB) and in multidose (MDAMB), and combination therapies by AMB+PMIM, AMB+MF, and PMIM+MF. Follow up period was 4 years after treatment. Cohorts were prospective except SSG (retrospective) and MF (partially retrospective). We compared incidence proportion and rate in 100-person-4year of PKDL and VLR by treatment regimens using univariate and multivariate analysis.

Findings

974 of 984 enrolled participants completed the study. Overall incidence proportion for PKDL and VLR was 12.3% (95% CI, 10.4%–14.5%) and 7.0% (95% CI, 5.6%–8.8%) respectively. The incidence rate (95% CI) of PKDL and VLR was 14.0 (8.6–22.7) and 7.6 (4.1–14.7) accordingly. SSG cohort had the lowest incidence rate of PKDL at 3.0 (1.3–7.3) and VLR at 1.8 (0.6–5.6), followed by MDAMB at 8.2 (4.3–15.7) for PKDL and at 2.7 (0.9–8.4) for VLR.

Interpretation

Development of PKDL and VLR is related with treatment regimens for VL. SSG and MDAMB resulted in less incidence of PKDL and VLR compared to other treatment regimens. MDAMB should be considered for VL as a first step for prevention of PKDL and VLR since SSG is highly toxic and not recommended for VL.

Post-kala-azar Dermal Leishmaniasis (PKDL), a sequale of visceral leishmaniasis (VL), and reappearance VL (visceral leishmaniasis relapse, VLR) are intra-epidemic reservoirs of VL and threats control of VL in long run. Currently there is no strategy for prevention of PKDL and VLR. If a relationship between treatment for VL and development of PKDL and VLR is there, and then selection of proper treatment regimen for VL should prevent PKDL and VLR. So far no study has been carried out to investigate the relationship between treatment regimens for VL and development of PKDL and VLR. The study demonstrated that multi-dose liposomal amphotericin B (AmBisome) defined as MDAMB herein for VL results in least PKDL and VLR among all existing and recommended by WHO treatment regimens for VL. We recommend adaptation of MDAMB in the national visceral leishmaniasis elimination program for VL cases management during subsequent phases of the national program when VL burden is low and hospitalization of VL patients for 3-5-days is now feasible.

Biomarkers in Post-kala-azar Dermal Leishmaniasis

Post-kala-azar dermal leishmaniasis (PKDL) follows visceral leishmaniasis (VL, kala-azar) in 10–60% of cases. It is characterized by an asymptomatic skin rash, usually starting in the face and consisting of macules, papules, or nodules. Diagnosis is difficult in the field and is often made clinically. There is an extensive differential diagnosis, and parasitological confirmation is preferred particularly when drug treatment is considered. The response to treatment is difficult to assess as this may be slow and lesions take long to heal, thus possibly exposing patients unnecessarily to prolonged drug treatment. Biomarkers are needed; these may be parasitological (from microscopy, PCR), serological (from blood, or from the lesion), immunological (from blood, tissue), pathological (from cytology in a smear, histology in a biopsy), repeated clinical assessment (grading, photography), or combinations. In this paper, we will review evidence for currently used biomarkers and discuss promising developments.

Application of kDNA Minicircle PCR-RFLP to CharacterizeLeishmania donovaniClinical Isolates Obtained from Post-Kala-Azar Dermal Leishmaniasis in Eastern Nepal

Post-kala-azar dermal leishmaniasis (PKDL) is a skin manifestation of visceral leishmaniasis (VL) which develops after apparent cure in some patients. PKDL is considered as the potential reservoir for the VL infection. Molecular epidemiological characterization of L. donovani isolates obtained from VL and PKDL isolates is essentially required in order to understand the transmission dynamics of the VL infection. To date, genetic variation among the VL and PKDL L. donovani isolates was not fully elucidated. Therefore, 14 clinical isolates from VL and 4 clinical isolates from PKDL were speciated by hsp70 and rDNA genes. Further characterization of L. donovani by haspB PCR demonstrates two different genotypes. All PKDL isolates have the same genetic structure. kDNA PCR-RFLP assay revealed 18 different genotypes; however, structural analysis showed the two distinct kDNA genotype population (k = 2). The kDNA fingerprint patterns of parasites from hilly districts were clustered separately from low-land districts. Therefore, further study with a large number of samples is urgently required for systematic characterization of the clinical isolates to track the molecular epidemiology of the Leishmania donovani causing VL and the role of PKDL as a reservoir.

Cutaneous leishmaniasis: A neglected disfiguring disease for women

Leishmaniasis is one of eight neglected tropical diseases currently endemic in 102 countries/areas around the world. In recent years, cutaneous leishmaniasis (CL) has been increasingly observed among migrants, travelers, ecotourists, and military personnel. Because of its great capacity to mimic other dermatoses, CL is one of the great imitators and can mislead practitioners, which can result in untreated lesions that cause scars. CL is a disfiguring disease, especially for women, and often leaves scars on visible body sites, causing psychological, social, and economic problems. CS is a challenge, especially in nonendemic regions, such as Australia, because experience with diagnosis and management of the disease is limited.

Arab world's growing contribution to global leishmaniasis research (1998-2017): a bibliometric study

BACKGROUND

Leishmaniasis is a parasitic disease caused by a protozoan of the Leishmania genus, and is considered a neglected tropical disease. It still remains a main public health concern at global level and in Arab world mainly in low-income countries. Therefore, this study was designed to evaluate the Arab world's growing contribution to global leishmaniasis research.

METHODS

This study describes a bibliometric review of all leishmaniasis research publications published between January 1998 and December 2017 indexed on the Scopus database.

RESULTS

The total number of publications published at global level was 17,570 papers, which achieves an average annual productivity of 878.50 papers publications. Brazil was responsible for the greatest output with the total number of publications of 3865 followed by the Unites States (n = 2729), India (n = 2119), the United Kingdom (n = 1363), and Spain (n = 1274). By limiting the analysis to the publications that have been published by Arab world, the research productivity was 993 papers, which represents 5.65% of total research output at global level in research regarding leishmaniasis. Tunisia was responsible for the greatest output from Arab world with the total number of publications of 297 followed by Sudan (n = 192), Saudi Arabia (n = 131), Morocco (n = 119) and Egypt (n = 67). Since 1998, the growth of publications on leishmaniasis fluctuates, overall showing a rising trend in both global and Arab world. There is a highly significant correlation between publication productivity related to leishmaniasis at global level and the Arab world (r = 0.936; p-value< 0.001). Leishmaniasis treatment, intracellular mechanism of infection, and lifecycle of leishmania are the major current hot topics for the research in this subject at global level and the Arab world.

CONCLUSIONS

The current study presents a novel review of the current Arab leishmaniasis-related research, and how these results are related to worldwide output. In comparison to the global research output, the Arab world produced less leishmaniasis research. The data presented in the current study by this innovative approach may serve relevant researchers to direct the global leishmaniasis research to Arab counties in which leishmaniasis is endemic.

How to master the host immune system? Leishmania parasites have the solutions!

Infection by protozoan parasites of the genus Leishmania results in the development of leishmaniasis, an increasingly prevalent group of diseases affecting over 12 million people worldwide. Leishmaniasis can have very different outcomes ranging from cutaneous lesions, mucosal lesions to visceralization depending on the species of the infecting parasite and on the immune response developed by the host. As an obligate intracellular parasite, residing within macrophages, Leishmania evolved in strict contact with the host immune system, developing different mechanisms to evade or modulate the immune response. Various types of immune responses are observed during different Leishmania spp. infections, resulting in parasite clearance but also contributing to the pathogenesis, thus increasing the complexity of the course of the disease. Interestingly, depending on the type of leishmaniasis developed, opposite treatment strategies, which either boost or inhibit the inflammatory response, have shown efficacy. In this review, we summarize the contribution of different immune cell types to the development of the anti-leishmanial immune response and the parasite strategies to evade and modulate host immunity. Further, we discuss the involvement of co-infecting pathogens in the determination of the outcome of leishmaniasis and on the effectiveness of treatment and the implication of the immune response for treatment and vaccine development.

[Cutaneous leishmaniasis]

Cutaneous leishmaniasis is a parasitic infection caused by a flagellated parasite belonging to the genus Leishmania. In most cases, it is a zoonotic disease transmitted via a bite by bloodsucking sand-flies of the genus Phlebotomus. The disease reservoirs consist of wild or semi-domesticated animals, generally rodents or dogs. The disease itself is distributed extensively worldwide in the Americas, Asia, Europe and Africa. Epidemiology is affected by environmental, migratory and climatic factors. Identification of the different types of leishmaniasis is based chiefly on the biochemical characteristics (isoenzymes) on which their classification is based. The offending parasites are dimorphic intracellular organisms within the phagosome of the host's immune cells, and a single-cell flagellated protozoan with a kinetoplast contained in the gut of the vector and in culture. Three major clinical forms are seen: cutaneous leishmaniasis, mucosal leishmaniasis and visceral leishmaniasis. The clinical presentation depends on factors associated with the virulence of the parasite, with individual immune response and with the site of lesions. Although each type of leishmaniasis may have its own specific cutaneous signs and endemic regions, the most common presentations are crusted, ulcerated nodules and plaques. The natural history of leishmaniasis must also be considered when formulating therapeutic strategies. Cutaneous leishmaniasis resolves spontaneously within between one month and six years. While numerous therapeutic options have been considered in recent decades, very few have shown proven efficacy and safety. Antimony compounds administered either directly to the lesion or parenterally remain the standard treatment and their toxicity calls for vigilance and monitoring of therapy.

Active surveillance identified a neglected burden of macular cases of Post Kala-azar Dermal Leishmaniasis in West Bengal

BACKGROUND

Post Kala-azar Dermal Leishmaniasis (PKDL) develops in patients apparently cured of Visceral Leishmaniasis (VL), and is the strongest contender for being the disease reservoir. Therefore, existence of a few cases is sufficient to trigger an epidemic of VL in a given community, emphasizing the need for its active detection and in turn ensuring success of the current elimination program. This study explored the impact of active surveillance on the demographic profile of PKDL patients in West Bengal.

METHODOLOGY/PRINCIPAL FINDINGS

Patients with PKDL were recruited through passive (2003-date, n = 100) and active surveillance (2015-date, n = 202), the former from outpatient departments of dermatology in medical colleges in West Bengal and the latter through an active door-to-door survey in four VL hyper-endemic districts of West Bengal. Passive surveillance indicated a male preponderance and a predominance of polymorphic lesions, whereas active surveillance indicated absence of any gender bias and more importantly, macular PKDL constituted almost 50% of the population burden. In terms of polymorphic vs. macular PKDL, the former appeared at a later age, their disease duration was longer and had a higher parasite burden. In the polymorphic variant, the lesional distribution was asymmetrical, comprised of papules/nodules/macules that were present mainly in sun-exposed areas whereas in macular cases, the hypopigmented patches were diffusely present all over the body.

CONCLUSIONS/SIGNIFICANCE

Active surveillance unraveled a disease component whose demographic profile showed important differences with PKDL cases who sought treatment in government hospitals. Detection of a higher proportion of macular cases indicates that this variant is not an uncommon presentation as conventionally stated in text books, and should be studied in greater detail to ensure success of the ongoing Leishmaniasis elimination programme.

Prevalence of Cutaneous Leishmaniasis in Western Highlands in Yemen

Leishmaniasis in Yemen is still not fully investigated nor well studied. Recently, outbreaks of cutaneous leishmaniasis (CL) in western highland were declared. However, there are no reports concerning the disease and the circulating species in the region. The aim of this study was to determine the prevalence of cutaneous leishmaniasis in Utmah district located in Western Highlands in Yemen. A cross-sectional survey was carried out at those highlands. For the survey, 1165 participants were subjected to Leishmanin Skin Test (LST) accompanied with direct interviews and physical examination. The overall prevalence of cutaneous leishmaniasis in the district was 18.5% and the cutaneous leishmaniasis (CL) was more frequent in the escarpments with a prevalence of 37%, including 5.5% for active lesion and 31.5% for scar of healed lesions. Children under the age of 16 years old comprised most of the CL cases (76.3%). The escarpments of western highlands in Yemen were hyperendemic areas for CL and the infection was more prevalent in children.

Severe post-kala-azar dermal leishmaniasis successfully treated with miltefosine in an Ethiopian HIV patient

Post-kala-azar dermal leishmaniasis (PKDL) is a neglected tropical disease characterized by a dermatosis which often appears after successful treatment of visceral leishmaniasis caused by Leishmania donovani. PKDL treatment options are few and have severe limitations. In East-Africa, the standard treatment of PKDL is with daily painful potentially toxic sodium stibogluconate injections, administered for a prolonged duration of 30-60 days. In the Indian subcontinent, PKDL is mainly treated with miltefosine, a safer orally administered drug. However, in East-Africa, there is very limited experience in the use of miltefosine for treatment of severe PKDL, with only one published case report. Here we report a severe PKDL case in an Ethiopian HIV patient successfully treated with oral miltefosine (100mg/day for 28 days). Miltefosine was efficacious, safe and well tolerated, suggesting that it can play an important role in the treatment of severe PKDL also in East-African patients. Further research is warranted.

Impaired activation of lesional CD8+ T-cells is associated with enhanced expression of Programmed Death-1 in Indian Post Kala-azar Dermal Leishmaniasis

Post Kala-azar dermal leishmaniasis (PKDL), caused by Leishmania donovani is the dermal sequel of Visceral Leishmaniasis and importantly, is the proposed disease reservoir. The survival of Leishmania parasites within monocytes/macrophages hinges on its ability to effectively nullify immune activation mechanisms. Thus, delineating the disease-promoting immune mechanisms can facilitate development of immunotherapeutic strategies. Accordingly, in the absence of an animal model, this study aimed to delineate the status of CD8⁺ T-cells in patients with PKDL. At disease presentation, the absence of CD4⁺ T-cells at lesional sites was concomitant with an overwhelming infiltration of CD8⁺ T-cells that demonstrated an absence of Perforin, Granzyme and Zap-70, along with an enhanced expression of Programmed Death-1 (PD-1) and the skin-homing CCL17. Additionally, the lesional CCR4⁺CD8⁺ population was associated with an enhanced expression of IL-10 and IL-5. In circulation, the enhanced CD8⁺CCR4⁺ T-cell population and raised levels of CCL17/22 was associated with an increased frequency of PD-1, while CD127 was decreased. Taken together, in PKDL, the enhanced plasma and lesional CCL17 accounted for the dermal homing of CD8⁺CCR4⁺ T-cells, that along with a concomitant upregulation of PD-1 and IL-10 mediated immune inactivation, emphasizing the need for designing immunotherapies capable of reinvigorating T-cell potency.

Visceral Leishmaniasis IgG1 Rapid Monitoring of Cure vs. Relapse, and Potential for Diagnosis of Post Kala-Azar Dermal Leishmaniasis

Background: There is a recognized need for an improved diagnostic test to assess post-chemotherapeutic treatment outcome in visceral leishmaniasis (VL) and to diagnose post kala-azar dermal leishmaniasis (PKDL). We previously demonstrated by ELISA and a prototype novel rapid diagnostic test (RDT), that high anti-Leishmania IgG1 is associated with post-treatment relapse versus cure in VL.

Methodology: Here, we further evaluate this novel, low-cost RDT, named VL Sero K-SeT, and ELISA for monitoring IgG1 levels in VL patients after treatment. IgG1 levels against L. donovani lysate were determined. We applied these assays to Indian sera from cured VL at 6 months post treatment as well as to relapse and PKDL patients. Sudanese sera from pre- and post-treatment and relapse were also tested.

Results: Of 104 paired Indian sera taken before and after treatment for VL, when deemed clinically cured, 81 (77.9%) were positive by VL Sero K-SeT before treatment; by 6 months, 68 of these 81 (84.0%) had a negative or reduced RDT test line intensity. ELISAs differed in positivity rate between pre- and post-treatment (p = 0.0162). Twenty eight of 33 (84.8%) Indian samples taken at diagnosis of relapse were RDT positive. A comparison of Indian VL Sero K-SeT data from patients deemed cured and relapsed confirmed that there was a significant difference (p < 0.0001) in positivity rate for the two groups using this RDT. Ten of 17 (58.8%) Sudanese sera went from positive to negative or decreased VL Sero K-SeT at the end of 11–30 days of treatment. Forty nine of 63 (77.8%) PKDL samples from India were positive by VL Sero K-SeT.

Conclusion: We have further shown the relevance of IgG1 in determining clinical status in VL patients. A positive VL Sero K-SeT may also be helpful in supporting diagnosis of PKDL. With further refinement, such as the use of specific antigens, the VL Sero K-SeT and/or IgG1 ELISA may be adjuncts to current VL control programmes.

CYP51 as drug targets for fungi and protozoan parasites: past, present and future

The efficiency of treatment of human infections with the unicellular eukaryotic pathogens such as fungi and protozoa remains deeply unsatisfactory. For example, the mortality rates from nosocomial fungemia in critically ill, immunosuppressed or post-cancer patients often exceed 50%. A set of six systemic clinical azoles [sterol 14α-demethylase (CYP51) inhibitors] represents the first-line antifungal treatment. All these drugs were discovered empirically, by monitoring their effects on fungal cell growth, though it had been proven that they kill fungal cells by blocking the biosynthesis of ergosterol in fungi at the stage of 14α-demethylation of the sterol nucleus. This review briefs the history of antifungal azoles, outlines the situation with the current clinical azole-based drugs, describes the attempts of their repurposing for treatment of human infections with the protozoan parasites that, similar to fungi, also produce endogenous sterols, and discusses the most recently acquired knowledge on the CYP51 structure/function and inhibition. It is our belief that this information should be helpful in shifting from the traditional phenotypic screening to the actual target-driven drug discovery paradigm, which will rationalize and substantially accelerate the development of new, more efficient and pathogen-oriented CYP51 inhibitors.

Histopathological features of skin lesions in patients affected by non-ulcerated or atypical cutaneous leishmaniasis in Honduras, Central America

In Honduras visceral leishmaniasis and non-ulcerated or atypical cutaneous leishmaniasis (NUCL) are caused by the species Leishmania (L.) infantum chagasi. NUCL is the most common clinical form in the southern regions of the country, mainly affecting the young. In view of the lack of knowledge about the pathogenesis of the disease pattern caused by L. (L) infantum chagasi in individuals affected by NUCL, the aim of the present study was to describe in detail the histopathological features of the skin lesion caused by the parasite. Biopsies from human NUCL lesions with a positive parasitological diagnosis were collected and processed using standard histological techniques. Paraffin sections stained by haematoxylin and eosin were used to examine the histopathological alterations seen in the skin. The lesions varied between 3 and 5 mm, and the majority of the patients (60%) had a single lesion. Lesions were more frequently seen in females (65%), with an average age of 33.4 years. Microscopically, the skin lesions were characterized by mononuclear inflammatory infiltrate in the dermis composed of lymphocytes, macrophages and a few plasma cells. The intensity of the infiltration varied from discrete to intense. In both cases, the parasitic infection was discrete. Granulomas were present in 60% of cases and were associated with intense inflammation. The data revealed by the histopathological alterations in the skin of individuals affected by NUCL suggest activation of a cellular immune response that potentially controls parasite spreading.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Leishmaniasis

Leishmaniasis is a poverty-related disease with two main clinical forms: visceral leishmaniasis and cutaneous leishmaniasis. An estimated 0·7-1 million new cases of leishmaniasis per year are reported from nearly 100 endemic countries. The number of reported visceral leishmaniasis cases has decreased substantially in the past decade as a result of better access to diagnosis and treatment and more intense vector control within an elimination initiative in Asia, although natural cycles in transmission intensity might play a role. In east Africa however, the case numbers of this fatal disease continue to be sustained. Increased conflict in endemic areas of cutaneous leishmaniasis and forced displacement has resulted in a surge in these endemic areas as well as clinics across the world. WHO lists leishmaniasis as one of the neglected tropical diseases for which the development of new treatments is a priority. Major evidence gaps remain, and new tools are needed before leishmaniasis can be definitively controlled.

Evaluation of Real-time PCR for Diagnosis of Post-Kala-azar Dermal Leishmaniasis in Endemic Foci of Bangladesh

Background

Post-kala-azar dermal leishmaniasis (PKDL) is a sequel to visceral leishmaniasis (VL), which is found in VL-endemic countries including Bangladesh. Because of these enigmatic cases, the success of the National Kala-azar Elimination Program is under threat. To date, diagnostic methods for PKDL cases in endemic regions have been limited to clinical examination and rK39 test or microscopy, and a suitable and accurate alternative method is needed. In this study, we investigated the application of real-time polymerase chain reaction (PCR) as a potential method for diagnosis of PKDL in comparison with microscopy.

Methods

Ninety-one suspected macular PKDL cases from Mymensingh district, Bangladesh, were enrolled in the study after diagnosis by clinical examination and an rK39 strip test. All of them responded after completion of the treatment with miltefosine. During enrollment, a skin biopsy was done for each patient, and both microscopy and real-time PCR were performed for detection and quantification of Leishmania donovan body (LDB) and LD DNA, respectively.

Results

Real-time PCR detected 83 cases among all suspected PKDL patients, with an encouraging sensitivity of 91.2% (83.4%–96.1%), whereas microscopy showed 50.6% (39.9%–61.2%) sensitivity. Among all suspected PKDL cases, 42 cases were positive in both microscopy and qPCR, whereas 41 cases were detected as positive through qPCR only.

Conclusions

This study provides evidence that real-time PCR is a promising tool for diagnosis of PKDL in endemic regions. In addition to diagnosis, the quantitative ability of this method could be further exploited for after-treatment prognosis and cure assessment of PKDL cases.

Knowledge, stigma, health seeking behaviour and its determinants among patients with post kalaazar dermal leishmaniasis, Bihar, India

Background

Lesishmaniasis is a neglected tropical disease endemic in Bihar, India. Inappropriate health seeking behaviour of post kala-azar dermal leishmaniasis (PKDL) patients may increase the disease duration, severity and transmissibility. Simultaneously, lack of knowledge and perceived stigma may also increase the length of delay in receiving treatment. This ultimately effects the kala-azar elimination program.

Methods

A cross sectional study was conducted in 120 confirmed PKDL patients, aged 18 years and older. Data related to knowledge and health seeking behaviour was collected by a pre-tested questionnaire. EMIC stigma scale was used for assessing the perceived stigma. Patients were personally interviewed after taking informed consent. Data analysis was done by using SPSS 16 software.

Results

The time between appearance of symptoms and first medical consultation (patient delay) ranged from 15 days to 5475 days (15 years) with a median of 285 days. The time between first medical consultations to onset of specific treatment (system delay) ranged from 2 to 5475 days with a median of 365 days. Many patients approached first to quacks (8.4%), homeopathic and ayurvedic practitioners (25.8%) upon recognition of symptoms. Majority of the patients (68.3%) had poor knowledge about PKDL and its vector. Type of skin lesions and gender had significant association with patient delay and system delay respectively (p<0.05). Distance to primary health centre (PHC) had significant association with patients delay as well as system delay (p<0.05). Patients with younger age, unmarried and polymorphic lesions had higher stigma (p<0.05). Patients with PKDL feel stigmatized in different areas.

Conclusion

PKDL treatment delays were unacceptably high and patients had poor knowledge compounded with feelings of stigmatization. To reduce the delay, a system may be evolved to establish some sort of public-private collaboration, besides awareness programs should be tailored, and implemented for improving the patient education regarding the disease and its linkage with VL.