Post Kala-azar Dermal Leishmaniasis Cases Research Articles

Leptomonas seymouri Co-infection in Cutaneous Leishmaniasis Cases Caused by Leishmania donovani From Himachal Pradesh, India.

Himachal Pradesh in India is a newer endemic state with co-existence of cutaneous and visceral leishmaniasis. The cutaneous leishmaniasis cases are on an increase in the region and reported to be unusually caused by Leishmania donovani with limited molecular validation. In order to molecularly characterize the causative parasite of the cutaneous disease, parasite specific Internal-Transcribed Spacer 1 (ITS1) PCR RFLP and sequence analysis was performed on skin lesional biopsies from cutaneous leishmaniasis patients. Interestingly, we found the presence of Leptomonas seymouri in 38.5% (22/57) of the patients along with L. donovani detected in all the samples. L. seymouri is a monoxenous insect trypanosomatid, generally incapable of infecting humans. In recent years, the parasite is also reported to co-infect humans with L. donovani in visceral and post kala-azar dermal leishmaniasis (PKDL) cases prevalent in northeastern India. The finding of L. seymouri-L. donovani co-infection in unusual cutaneous cases from Himachal Pradesh is the first ever to our knowledge and imply a newer disease paradigm. There is an urgent need to understand the biology of Leptomonas co-infection with L. donovani and its possible role in visceral and/or dermotropic disease outcome. Importantly, L. seymouri co-infection in cutaneous cases and previously reported visceral and PKDL cases needs to be recognized as a newer phenomenon by the leishmaniasis surveillance program in India.

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.

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.

Iron trafficking in patients with Indian Post kala-azar dermal leishmaniasis.

During infections involving intracellular pathogens, iron performs a double-edged function by providing the pathogen with nutrients, but also boosts the host's antimicrobial arsenal. Although the role of iron has been described in visceral leishmaniasis, information regarding its status in the dermal sequel, Post Kala-azar Dermal Leishmaniasis (PKDL) remains limited. Accordingly, this study aimed to establish the status of iron within monocytes/macrophages of PKDL cases. The intramonocytic labile iron pool (LIP), status of CD163 (hemoglobin-haptoglobin scavenging receptor) and CD71 (transferrin receptor, Tfr) were evaluated within CD14+ monocytes by flow cytometry, and soluble CD163 by ELISA. At the lesional sites, Fe3+ status was evaluated by Prussian blue staining, parasite load by qPCR, while the mRNA expression of Tfr (TfR1/CD71), CD163, divalent metal transporter-1 (DMT-1), Lipocalin-2 (Lcn-2), Heme-oxygenase-1 (HO-1), Ferritin, Natural resistance-associated macrophage protein (NRAMP-1) and Ferroportin (Fpn-1) was evaluated by droplet digital PCR. Circulating monocytes demonstrated elevated levels of CD71, CD163 and soluble CD163, which corroborated with an enhanced lesional mRNA expression of TfR, CD163, DMT1 and Lcn-2. Additionally, the LIP was raised along with an elevated mRNA expression of ferritin and HO-1, as also iron exporters NRAMP-1 and Fpn-1. In monocytes/macrophages of PKDL cases, enhancement of the iron influx gateways (TfR, CD163, DMT-1 and Lcn-2) possibly accounted for the enhanced LIP. However, enhancement of the iron exporters (NRAMP-1 and Fpn-1) defied the classical Ferritinlow/Ferroportinhigh phenotype of alternatively activated macrophages. The creation of such a pro-parasitic environment suggests incorporation of chemotherapeutic strategies wherein the availability of iron to the parasite can be restricted.

Treatment of post kala-azar dermal leishmaniasis with fungisome – A novel Indian liposomal amphotericin B

Post kala-azar dermal leishmaniasis (PKDL) is a late cutaneous manifestation of visceral leishmaniasis (VL), though it can occur without a history of visceral disease. The diagnosis and treatment of PKDL is important as cases of PKDL have been known to cause outbreaks of VL. We report a case of PKDL from an area with low endemicity of VL and has presented with PKDL without VL. Due to poor tolerance to conventional amphotericin B (CAmB), he was successfully treated with Fungisome™ – Indian liposomal amphotericin B (LAmB). We want to emphasize on the successful treatment of PKDL with Fungisome™ – an Indian LAmB. This is a first such case of PKDL being treated with LAmB (Fungisome™), developed jointly by the Department of Clinical Pharmacology, Seth Gordhandas Sunderdas Medical College and King Edward Memorial Hospital, Mumbai, and the Department of Biochemistry, Delhi University with funding from the Department of Biotechnology. Translational research and commercialization was done by Lifecare Innovations, India.

Modeling post-kala-azar dermal leishmaniasis as an infection reservoir for visceral leishmaniasis

Visceral Leishmaniasis (VL) is a potentially fatal disease caused by the protozoan parasite Leishmania donovani. This disease is a health problem for the very poor because it results in thousands of deaths and illnesses every year. Some countries, such as India and Bangladesh, have started programs to reduce the occurrences of VL by focusing on early diagnosis and complete treatment of VL. Post-Kala-azar Dermal Leishmaniasis (PKDL) is a cutaneous manifestation of Leishmaniasis that can occur following the incomplete treatment of VL. Diagnosis and treatment of PKDL are limited in affected regions, and PKDL has been identified as a possible reservoir for infection. This study develops a mathematical model of the relationship between the level of PKDL treatment and the incidences of VL during a given period. The results indicate a nearly linear relationship between PKDL treatment rates and the percent reduction of VL incidences. With the current treatments available and considering achievable levels of treatment, the model predicts that up to 20% of VL cases could be prevented by treating new PKDL cases. Hypothetical combined treatment initiatives including bed nets and insecticide spraying are also considered. Results suggest that the population of individuals with PKDL is certainly a significant factor in the transmission of L. donovani infection, with treatment of new cases particularly important.

Insights from mathematical modelling and quantitative analysis on the proposed WHO 2030 targets for visceral leishmaniasis on the Indian subcontinent.

Visceral leishmaniasis (VL) is a neglected tropical disease (NTD) caused by Leishmania protozoa that are transmitted by female sand flies. On the Indian subcontinent (ISC), VL is targeted by the World Health Organization (WHO) for elimination as a public health problem by 2020, which is defined as <1 VL case (new and relapse) per 10,000 population at district level in Nepal and sub-district level in Bangladesh and India. WHO is currently in the process of formulating 2030 targets, asking whether to maintain the 2020 target or to modify it, while adding a target of zero mortality among detected cases. The NTD Modelling Consortium has developed various mathematical VL transmission models to gain insight into the transmission dynamics of VL, identify the main knowledge gaps, and predict the feasibility of achieving and sustaining the targets by simulating the impact of varying intervention strategies. According to the models, the current target is feasible at the appropriate district/sub-district level in settings with medium VL endemicities (up to 5 reported VL cases per 10,000 population per year) prior to the start of the interventions. However, in settings with higher pre-control endemicities, additional efforts may be required. We also highlight the risk that those with post-kala-azar dermal leishmaniasis (PKDL) may pose to reaching and sustaining the VL targets, and therefore advocate adding control of PKDL cases to the new 2030 targets. Spatial analyses revealed that local hotspots with high VL incidence remain. We warn that the current target provides a perverse incentive to not detect/report cases as the target is approached, posing a risk for truly achieving elimination as a public health problem although this is taken into consideration by the WHO procedures for validation. Ongoing modelling work focuses on the risk of recrudescence when interventions are relaxed after the elimination target has been achieved.

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

ABSTRACTVisceral 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.

Post-Kala-Azar Dermal Leishmaniasis as a Reservoir for Visceral Leishmaniasis Transmission

Post-kala-azar dermal leishmaniasis (PKDL) is a parasitic skin infection which can occur after visceral leishmaniasis (VL). Recent xenodiagnosis studies (Mondal et al., Clin. Infect. Dis., 2018) have uncovered the infectiousness of PKDL. When including this in a transmission model, PKDL cases appear as an important reservoir of infection, likely frustrating the VL elimination efforts on the Indian subcontinent.

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.

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. 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. 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). 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.

Histopathological study of post kala-azar dermal leishmaniasis and its importance for diagnosis in a peripheral tertiary institution

Histopathological study of post kala-azar dermal leishmaniasis and its importance for diagnosis in a peripheral tertiary institution - IJCED- Print ISSN No: - 2581-4710 Online ISSN No:- 2581-4729 Article DOI No:- 10.18231/2581-4729.2019.0003, IP Indian Journal of Clinical and Experimental Dermatology-IP Indian J Clin E

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

BackgroundPost 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 findingsPatients 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/SignificanceActive 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.

Noninvasive Sweat-Based Diagnosis of Visceral Leishmaniasis and Post Kala-Azar Dermal Leishmaniasis.

The diagnosis of visceral leishmaniasis (VL) is one of the foremost barriers in the control of this disease, as demonstration of the parasite by splenic/bone marrow aspiration is relatively difficult and requires expertise and laboratory support. The aim of the present study was to find a noninvasive diagnostic approach using the existing recombinant kinesine-39 (rK-39) immunochromatographic nitrocellulose strips test (ICT) with a human sweat specimen for the diagnosis of VL. The investigation was carried out on specimens (blood, sweat, and urine) collected from 58 confirmed VL, 50 confirmed post kala-azar dermal leishmaniasis (PKDL), 36 healthy control, and 35 patients from other diseases. The data obtained from this study reveal that 96.6% clinically confirmed active VL participants were found to be positive when tested against a sweat specimen. Interestingly, the scenario was similar when tested against a blood specimen (96.6% positive by rK-39). Moreover, a test of both sweats and blood specimens from 50 PKDL participants resulted in 100% positivity, whereas no healthy control participants were found to be rK-39 positive. The sensitivity of the rK-39 ICT in sweat specimen was 94.7%, whereas the specificity was 100% in healthy controls from endemic, nonendemic, and other infectious diseases, respectively. No difference was observed in sweat specimen of VL and PKDL cases which signifies its reliability. However, further evaluation of this method on a larger scale could enhance the reliability of the proposed model so that it could be used efficiently in VL management and eradication.

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

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. 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. 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. 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.

Using focused pharmacovigilance for ensuring patient safety against antileishmanial drugs in Bangladesh\u2019s National Kala-azar Elimination Programme

BackgroundAdverse effects of antileishmanial drugs can affect patients’ quality of life and adherence to therapy for visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). In Bangladesh, there are 26 treatment centers that manage leishmaniasis cases coming from 100 endemic upazilas (subdistricts) of 26 districts (these include VL, PKDL, treatment failure, and relapse VL and cutaneous leishmaniasis cases). This study aimed to investigate the feasibility of using focused pharmacovigilance for VL (VLPV) in Bangladesh’s National Kala-azar Elimination Programme for the early detection and prevention of expected and unexpected adverse drug reactions (ADRs).MethodsThis activity has been going on since December 2014. Activity area includes secondary public hospital or Upazila health complex (UHC) in hundred sub districts and Surya Kanta Kala-azar Research Center (SKKRC) in Mymensingh District, a specialized center for management of complicated VL and PKDL cases. Communicable Disease Control (CDC) of the Directorate General of Health Services (DGHS) assigned twenty five of hundred UHCs and SKKRC (total 26) as treatment centers depending on their suitable geographical location. This was implemented for better management of VL cases with Liposomal Amphotericin B (AmBisome®) to ensure patient convenience and proper utilization of this expensive donated drug. A VLPV expert committee and a UHC VLPV team were established, an operational manual and pharmacovigilance report forms were developed, training and refresher training of health personnel took place at UHCs and at the central level, collected information such as patient data including demographics, treatment history and response, adverse events were analyzed. This report includes information for the period from December 2014 to December 2016.ResultsFrom December 2014 to December 2016, 1327 leishmaniasis patients were treated and 1066 (80%) were available for VLPV. Out of these, 57, 33, 9, and 1% were new VL, PKDL, VL relapse, and other cases, respectively. Liposomal amphotericin B was mostly used (82%) for case management, followed by miltefosine (20%) and paromomycin (3%). Out of the 1066 patients, 26% experienced ADRs. The most frequent ADR was fever (17%, 176/1066), followed by vomiting (5%, 51/1066). Thirteen serious adverse events (SAEs) (eight deaths and five unexpected SAEs) were observed. The expert committee assessed that three of the deaths and all unexpected SAEs were possibly related to treatment. Out of the five unexpected SAEs, four were miltefosine-induced ophthalmic complications and the other was an AmBisome®-induced avascular necrosis of the nasal alae. The Directorate General of the Drug Administration entered the ADRs into the World Health Organization Uppsala Monitoring Centre (WHO-UMC) VigiFlow database.ConclusionsThis study found that VLPV through NKEP is feasible and should be continued as a routine activity into the public health system of Bangladesh to ensure patient safety against anti-leishmanial drugs.

Treatment of widespread nodular post kala-azar dermal leishmaniasis with extended- dose liposomal amphotericin B in Bangladesh: A series of four cases

Background: Post Kala-azar Dermal Leishmaniasis (PKDL) is a sequela of Visceral Leishmaniasis (VL) and suggested as reservoirs of parasite. Currently, Miltefosine (MF), Amphotericin B Deoxycholate (ABD) and Liposomal Amphotericin B (LAmB) are recommended by World health organization (WHO) as treatment options for PKDL. But single MF or LAmB often causes incomplete cure specially cases with extensive lesion. To overcome this problem here we describe four cases of PKDL who had widespread nodular and macular lesions and were treated with two cycles of LAmB doses with 20 mg/kg body weight divided into 4 equal doses and administered every alternate day. Methods & Materials: Patients admitted to the Surya kanta kala-azar research centre (SKKRC) with extensive nodular or mixed lesion were considered to treat with LAmB. Hospital physician collected patients’ history and performed physical examination. Suspected cases were confirmed by microscopic examination of slit skin smear. At first, LAmB treatment was initiated at the dose of 20 mg/kg into four divided doses every alternate day. Before starting treatment all haematological and biochemical markers were checked. Second cycle was initiated for those who displayed marked improvement but not complete recovery. Finally, a follow up physical and microscopic examination was also done to evaluate the treatment outcome. Results: Of them, two had previous VL history and two had no previous VL history at all. The lesions started from chin with macular type, later distributed to other parts of the body with both macular and nodular type. The lesions were non-itching, touch sensitive and rk 39 strip test was positive. All of them were confirmed through microscopic examination of slit skin smear. Their haematological and biochemical markers were within normal limit. After first cycle, all of them showed initial progress and after second cycle all of them attained complete cure. Fever with shivering was the only documented adverse event during treatment and was managed by paracetamol. Conclusion: The cases highlighted in this report explore the success of utilising extended LAmB dose schedule for treating a patient with widespread lesions.The triumph of this alternate treatment schedule for PKDL needs to be supported with clinical trials that evaluate its efficacy and safety.

Cytokines and chemokines differentially regulate innate immune cell trafficking during post kala-azar dermal leishmaniasis.

Post kala-azar dermal leishmaniasis (PKDL) is often considered to be the anthroponotic reservoir of visceral leishmaniasis (VL) in India. A better understanding of the host immune-response in dermal lesions of PKDL patients is therefore of utmost significance to minimize such patients and to restrict VL transmission. Although the innate immune response is known to play an important role in parasite clearance from dermal lesions, the actual contribution of innate cells to the pathogenicity of PKDL is poorly understood. The present study explored the immune-pathogenesis of PKDL patients to understand the expression of CD62L, CD11b, CXCL8/IL-8, and MIP1-α and their contribution in signaling during innate cell trafficking. Twenty-five individuals were enrolled, who comprised eight active and untreated macular cases, seven active and untreated cases with papulo-nodular PKDL manifestations, five successfully treated post PKDL cases and five healthy individuals from a non-endemic region of Bihar, India. The immunological investigation was performed on biopsy specimens prepared with a disaggregation technique and blood samples. We observed that the PMNs in nodular patients displayed decreased L-selectin (CD62L) levels and increased integrin (CD11b) expression compared with those in macular patients. Further analysis showed that lower PMN extravasation in macular patients occurred because of inadequate CXCL8/ IL-8 release. In summary, Leishmania donovani (L. donovani) infection in macular PKDL patients decreased leucocyte rolling (L-selectin shedding) and induced up-regulation of the cellular signaling factors involved in pathogenesis (ERK1/2) as well as down regulated the signaling elements (p38 MAPK) involved in the Th1 response, especially in PMNs.

Deciphering the Role of Post-Kala-Azar Dermal Leishmaniasis Patients in the Transmission of Leishmania Donovani: Implications for the Kala-Azar Elimination Program

Background: In 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 of 47 PKDL and 15 kala-azar patients using laboratory-reared Phlebotomus argentipes. In direct xenodiagnosis, flies were given access to the the patient's skin to feed 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 PCR. A 3-mm skin snip biopsy (PKDL) or venous blood (kala-azar) was processed by quantitative PCR. Findings: 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 1 log10 unit higher than those with negative results (2.88 vs 1.66, p<0.0001). 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 kala-azar. Compared to kala-azar, nodular PKDL was more likely and macular PKDL less likely to result in positive xenodiagnosis, but neither difference reached statistical significance. Interpretation: Both nodular and macular PKDL 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. Funding: This work was supported by the World Health Organization Special Programme for Research and Training in Tropical Diseases, Switzerland; Spanish Foundation for lnternational Cooperation, Health and Social Affairs; and icddr,b core donors. The funding sources had no role in the study design, collection, analysis and interpretation of the data, preparation of the manuscript, or the decision to submit for publication. Conflict of Interest: Dr. Bern reports personal fees from DNDi, outside the submitted work. All other authors: No reported conflicts of interest. Ethical Approval Statement: The protocol was approved by the Ethical Review Committee of ICDDR,B (#PR-14010). All patients provided written informed consent.

Post-kala-azar dermal leishmaniasis in the Indian subcontinent: A threat to the South-East Asia Region Kala-azar Elimination Programme.

BackgroundThe South-East Asia Region Kala-azar Elimination Programme (KAEP) is expected to enter the consolidation phase in 2017, which focuses on case detection, vector control, and identifying potential sources of infection. Post-kala-azar dermal leishmaniasis (PKDL) is thought to play a role in the recurrence of visceral leishmaniasis (VL)/kala-azar outbreaks, and control of PKDL is among the priorities of the KAEP.Methodology and principal findingWe reviewed the literature with regard to PKDL in Asia and interpreted the findings in relation to current intervention methods in the KAEP in order to make recommendations. There is a considerable knowledge gap regarding the pathophysiology of VL and PKDL, especially the underlying immune responses. Risk factors (of which previous VL treatments may be most important) are poorly understood and need to be better defined. The role of PKDL patients in transmission is largely unknown, and there is insufficient information about the importance of duration, distribution and severity of the rash, time of onset, and self-healing. Current intervention methods focus on active case detection and treatment of all PKDL cases with miltefosine while there is increasing drug resistance. The prevention of PKDL by improved VL treatment currently receives insufficient attention.Conclusion and significancePKDL is a heterogeneous and dynamic condition, and patients differ with regard to time of onset after VL, chronicity, and distribution and appearance of the rash, as well as immune responses (including tendency to self-heal), all of which may vary over time. It is essential to fully describe the pathophysiology in order to make informed decisions on the most cost-effective approach. Emphasis should be on early detection of those who contribute to transmission and those who are in need of treatment, for whom short-course, effective, and safe drug regimens should be available. The prevention of PKDL should be emphasised by innovative and improved treatment for VL, which may include immunomodulation.

Real-time PCR in detection and quantitation of Leishmania donovani for the diagnosis of Visceral Leishmaniasis patients and the monitoring of their response to treatment.

Sustained elimination of Visceral Leishmaniasis (VL) requires the reduction and control of parasite reservoirs to minimize the transmission of Leishmania donovani infection. A simple, reproducible and definitive diagnostic procedure is therefore indispensable for the early and accurate detection of parasites in VL, Relapsed VL (RVL) and Post Kala-azar Dermal Leishmaniasis (PKDL) patients, all of whom are potential reservoirs of Leishmania parasites. To overcome the limitations of current diagnostic approaches, a novel quantitative real-time polymerase chain reaction (qPCR) method based on Taqman chemistry was devised for the detection and quantification of L. donovani in blood and skin. The diagnostic efficacy was evaluated using archived peripheral blood buffy coat DNA from 40 VL, 40 PKDL, 10 RVL, 20 cured VL, and 40 cured PKDL along with 10 tuberculosis (TB) cases and 80 healthy endemic controls. Results were compared to those obtained using a Leishmania-specific nested PCR (Ln-PCR). The real time PCR assay was 100% (95% CI, 91.19–100%) sensitive in detecting parasite genomes in VL and RVL samples and 85.0% (95% CI, 70.16–94.29%) sensitive for PKDL samples. In contrast, the sensitivity of Ln-PCR was 77.5% (95% CI, 61.55–89.16%) for VL samples, 100% (95%CI, 69.15–100%) for RVL samples, and 52.5% (95% CI, 36.13–68.49%) for PKDL samples. There was significant discordance between the two methods with the overall sensitivity of the qPCR assay being considerably higher than Ln-PCR. None of the assay detected L. donovani DNA in buffy coats from cured VL cases, and reduced infectious burdens were demonstrated in cured PKDL cases who remained positive in 7.5% (3/40) and 2.5% (1/40) cases by real-time PCR and Ln-PCR, respectively. Both assays were 100% (95% CI, 95.98–100) specific with no positive signals in either endemic healthy control or TB samples. The real time PCR assay we developed offers a molecular tool for accurate detection of circulating L. donovani parasites in VL, PKDL and RVL patients, as well as being capable of assessing response to treatment. As such, this real time PCR assay represents an important contribution in efforts to eliminate VL.