Vaccine value profile for leishmaniasis

Leishmania infections are global, occurring in 98 countries and all World Health Organization (WHO) regions with 600 million to 1 billion people at risk of infection. Visceral leishmaniasis is associated with almost 20,000 reported deaths annually, with children under 5 years of age being at the greatest risk of mortality. Amongst WHO-recognised Neglected Tropical Diseases (NTDs), leishmaniasis is one of the most important in terms of mortality and morbidity. With an increasing global burden of disease and a growing threat from climate change, urbanisation and drug resistance, there remains an imperative to develop leishmaniasis vaccines. New tools to understand correlates of protection and to assess vaccine efficacy are being developed to ease the transition into larger scale efficacy trials or provide alternate routes to licensure. Early indications suggest a diverse portfolio of manufacturers exists in endemic countries with an appetite to develop leishmaniasis vaccines. This Vaccine Value Profile (VVP) provides a high-level, comprehensive assessment of the currently available data to inform the potential public health, economic, and societal value of leishmaniasis vaccines. The leishmaniasis VVP was developed by a working group of subject matter experts from academia, public health groups, policy organizations, and non-profit organizations. All contributors have extensive expertise on various elements of the leishmaniasis VVP and have collectively described the state of knowledge and identified the current gaps. The VVP was developed using only existing and publicly available information.

Review of the neglected tropical diseases programme implementation during 2012–2019 in the WHO-Eastern Mediterranean Region

Introduction

The 2012–2020 WHO NTD roadmap set targets for control, elimination, and eradication of neglected tropical diseases (NTDs). It recommends 5 strategies, out of which preventive chemotherapy (PC) and intensified disease management were key to achieve targets. WHO estimated that globally, between 2012 and 2019, the number of persons affected by NTDs decreased from nearly 2.1 to 1.7 billion people. We analysed the situation of NTDs in the WHO Eastern Mediterranean Region (EMR) in 2020 to assess the progress with the 2012–2020 roadmap and to identify gaps.

Methods

We reviewed data repositories of national data sources for 2012 to 2019 including the Global Indicator Data Platform for Sustainable Development Goals, the Global Health Observatory data repository, the WHO PC databank, and the EMR data repository. We allocated countries a Red-Amber-Green (RAG) rating based on standardized criteria, on progress and current situation of each of 11 priority NTDs.

Results

All 22 countries in EMR were affected by 1 or more autochthonous or imported NTDs. In 2019, WHO estimated that in EMR, 78 million people required interventions for NTDs, a 38% decline compared with 2012. Twelve of 22 countries needed priority public health action (i.e., red) for 1 or more NTD. Of these, Sudan needed priority public health action for 6 NTDs and Yemen for 5. Eleven countries also needed priority public health action for cutaneous leishmaniasis, and 5 countries for rabies and trachoma. Visceral leishmaniasis is on the increase in Afghanistan, Libya, Syria, and Yemen.

Conclusion

Since the first roadmap of NTDs in 2012, the EMR has made a substantial progress. Nevertheless, many challenges remain in the prevention and control of NTDs. EMR needs a regional approach to control NTDs in countries most affected and a coordinated strategy to stop the continuing increase of cutaneous leishmaniasis and a possible resurgence of visceral leishmaniasis.

Vulnerabilities to and the Socioeconomic and Psychosocial Impacts of the Leishmaniases: A Review

The leishmaniases are a group of four vector-borne neglected tropical diseases (NTDs) with 1.6 billion people in some 100 countries at risk. They occur in certain eco-epidemiological foci that reflect manipulation by human activities, such as migration, urbanization and deforestation, of which poverty, conflict and climate change are key drivers. Given their synergistic impacts, risk factors and the vulnerabilities of poor populations and the launch of a new 2030 roadmap for NTDs in the context of the global sustainability agenda, it is warranted to update the state of knowledge of the leishmaniases and their effects. Using existing literature, we review socioeconomic and psychosocial impacts of leishmaniasis within a framework of risk factors and vulnerabilities to help inform policy interventions. Studies show that poverty is an overarching primary risk factor. Low-income status fosters inadequate housing, malnutrition and lack of sanitation, which create and exacerbate complexities in access to care and treatment outcomes as well as education and awareness. The co-occurrence of the leishmaniases with malnutrition and HIV infection further complicate diagnosis and treatment, leading to poor diagnostic outcomes and therapeutic response. Even with free treatment, households may suffer catastrophic health expenditure from direct and indirect medical costs, which compounds existing financial strain in low-income communities for households and healthcare systems. The dermatological presentations of the leishmaniases may result in long-term severe disfigurement, leading to stigmatization, reduced quality of life, discrimination and mental health issues. A substantial amount of recent literature points to the vulnerability pathways and burden of leishmaniasis on women, in particular, who disproportionately suffer from these impacts. These emerging foci demonstrate a need for continued international efforts to address key risk factors and population vulnerabilities if leishmaniasis control, and ultimately elimination, is to be achieved by 2030.

Prevalence of cutaneous leishmaniasis infection and clinico-epidemiological patterns among military personnel in Mullaitivu and Kilinochchi districts of the Northern Province, early war-torn areas in Sri Lanka

BACKGROUND

The 30-year-old armed conflict in Sri Lanka resulted in a general breakdown of civil administration in the Northern and Eastern provinces, leading to mobilisation of many armed forces personnel to assist with reconstruction and resettlement. This occupational group has been identified as a priority risk group for leishmaniasis.

METHODS

Individuals enlisted at all military establishments in Mullaitivu and Kilinochchi districts, Northern Province of Sri Lanka were included. Five thousand individuals were screened for skin lesions between September 2018 and August 2019. Persons with lesions suspected as cutaneous leishmaniasis (CL) were further investigated. Information on sociodemographic/other potential risk factors was obtained through an interviewer-administered structured questionnaire. The diagnosis was confirmed by microscopic visualization of parasitic stages from different samples obtained (skin scraping, lesion aspirate and tissue impression smears), histopathology and polymerase chain reaction DNA amplification.

RESULTS

Among 5000 individuals screened, 74 individuals were suspected of having CL. Of these, 67.6% (n = 50) patients were confirmed for CL by microscopy. Around two third of both males (67.6%; n = 48) and females (66.6%; n = 2) were positive for Leishmania. The soldiers belonging to 26-35-year age group reported the highest susceptibility (83.3%; OR: 4.83, 95% CI: 3.49-6.20%). Of the sociodemographic factors, age, wearing short-sleeved upper body clothing as the uniform and non-use of insect repellents were identified as significant risk factors. Most of the CL patients had a single lesion (86.0%; n = 43) of an ulcerative type (34.0%; n = 17), mostly on their upper limb (67.9%; n = 34). Lesions were mostly 5-10 mm diameter (59.9%; n = 30) in size with poorly defined margins (72.0%; n = 36). Amongst the diagnostic techniques, microscopic examination of slit skin smear and tissue impression smear were able to discriminate the majority of patients (92.1%; n = 46) for CL.

CONCLUSIONS

In order to highlight the true burden of leishmaniasis in the military personnel, cases of leishmaniasis from military institutes should be recognized as a different entity per say and be included in the national figures so as to depict the real magnitude of the disease burden amongst this high-risk group.

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.

Effect of insecticide-treated bed nets on visceral leishmaniasis incidence in Bangladesh. A retrospective cohort analysis

BACKGROUND

Visceral leishmaniasis (VL) is a parasitic disease, transmitted by the sand fly species Phlebotomus argentipes in the Indian sub-continent. Effective vector control is highly desirable to reduce vector density and human and vector contact in the endemic communities with the aim to curtail disease transmission. We evaluated the effect of long lasting insecticide treated bed nets (LLIN) and bed nets impregnated with slow-release insecticide tablet K-O TAB 1-2-3 (jointly insecticide-treated nets or ITN) on VL incidence in a highly endemic sub-district (upazila) in Bangladesh.

METHODS

Several distributions of LLIN or K-O TAB 1-2-3 for self-impregnation of bed nets at home took place in Fulbaria upazila, Mymensigh district from 2004 to 2008 under three research projects, respectively funded by CDC, Atlanta, USA (2004) and WHO-TDR, Geneva, Switzerland (2006 & 2008). We included all households (n = 8142) in the 20 villages that had benefited in the past from one of these interventions (1295 donated LLIN and 11,918 local bed nets impregnated with K-O TAB 1-2-3) in the "exposed cohort". We recruited a "non-exposed cohort" in villages with contemporaneously similar incidence rates who had not received such vector control interventions (7729 HHs from nine villages). In both cohorts, we visited all families house to house and ascertained any VL cases for the 3 year period before and after the intervention. We evaluated the incidence rate (IR) of VL in both cohorts as primary endpoint, applying the difference-in-differences method.

RESULTS

The study identified 1011 VL cases (IR 140.47/10,000 per year [py]) before the intervention, of which 534 and 477 cases in the intervention and control areas respectively. The IR was 144.13/10,000 py (534/37050) and 136.59/10,000 py (477/34923) in the intervention and control areas respectively, with no significant difference (p = 0.3901) before the intervention. After the intervention, a total of 555 cases (IR 77.11/10,000 py) were identified of which 178 (IR 48.04/10,000 py) in the intervention and 377 (107.95/10,000 py) in the control area. The intervention area had a significant lower IR than the control area during follow up, rate difference = -59.91, p<0.0001. The IR during follow up was significantly reduced by 96.09/10,000 py in the intervention area (p<0.0001) and 28.63/10,000 py in control area (p<0.0001) compared to baseline. There was a strong and significant overall effect of the ITN intervention, δ = -67.45, p <0.0001. Sex (OR = 1.36, p<0.0001) and age (OR = 0.99, p<0.0001) also had a significant effect on VL incidence. Male had a higher risk of VL than female and one year increase in age decreased the likelihood of VL by about 0.92%. Two third of the VL incidence occurred in the age range 2 to 30 years (median age of VL patients was 17 years).

CONCLUSION

VL incidence rate was significantly lower in the ITN intervention cohort compared to control in Bangladesh. Some bias due to more intense screen-and-treat activities or other interventions in the intervention area cannot be ruled out. Nonetheless, given their feasibility and sustainability, ITNs should be considered for integrated vector control during the maintenance phase of the VL elimination programme.

Leishmaniasis patients' pilgrimage to access health care in rural Bolivia: a qualitative study using human rights to health approach

BACKGROUND

Leishmaniasis is a neglected tropical disease endemic in Bolivia that disproportionately affects people with little social and political capital. Although the treatment is provided free of charge by the Bolivian government, there is an under-utilization of treatments in relation to the estimated affected population. This study explores the experiences of patients with leishmaniasis and the challenges faced when searching for diagnosis and treatment in Bolivia using a human rights approach.

METHODS

We conducted open-ended interviews with 14 participants diagnosed with leishmaniasis. The qualitative data were analysed using thematic analysis and were interpreted under a human rights approach to health care.

RESULTS

Four themes emerged during data analysis: (1) the decision for seeking a cure takes time; (2) the severity of symptoms and disruption of functioning drives the search for Western medicine; (3) the therapeutic journey between Western and traditional medicine; and (4) accessibility barriers to receive adequate medical treatment. This study showed that access to health care limitations were the most important factors that prevented patients from receiving timely diagnosis and treatment. Cultural factors played a secondary role in their decision to seek medical care.

CONCLUSIONS

Accessibility barriers resulted in a large pilgrimage between public health care and traditional medicinal treatments for patients with leishmaniasis. This pilgrimage and the related costs are important factors that determine the decision to seek health care. This study contributes to the understanding of the under-utilisation problems of medical services in leishmaniasis and other similar diseases in remote and poor populations.

Understanding the economic impact of leishmaniasis on households in endemic countries: a systematic review

INTRODUCTION

Leishmaniasis is a poverty-related disease that causes a significant socioeconomic burden to affected households. Visceral leishmaniasis is fatal if untreated, yet illness costs may lead to delays in accessing care. Skin manifestations of leishmaniasis cause a psychological burden and even longer treatment trajectories. The objective of this review is to evaluate illness costs associated with leishmaniasis across different settings (Asia, Africa, and Latin America) and the consequences to households. Areas covered: Through a systematic review of cost-of-illness studies, we documented the distribution of costs, the health-seeking behavior, and the consequences of leishmaniasis. We discuss the value of cost-of-illness studies for leishmaniasis. Expert commentary: Despite the free provision of diagnostics and treatment in the public health care sector, out-of-pocket payments remain substantial. There has been progress in addressing the economic burden of leishmaniasis, particularly through the elimination initiative in the Indian subcontinent. Though the illness cost is decreasing due to shorter treatment regimens and better access to care, the situation remains challenging in Africa. Improvement of control tools is critical. There is a need to update cost estimates to inform policy-making and ensure sustainable solutions to reduce financial barriers to leishmaniasis care, especially in pursuing universal health coverage.

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.

The Economic Impact of Cutaneous Leishmaniasis in Sri Lanka

Cutaneous leishmaniasis (CL) is a neglected tropical disease which affects mainly the poorest communities in developing countries. Considering the limited published information on economic impact of CL in Sri Lanka, the current study was conducted with the objective of revealing the nature and magnitude of the economic impact of CL in three selected disease endemic regions in Kurunegala District, Sri Lanka. The patient records of CL notified of relevant Medical Officer of Health (MOH) office during 2013- 2016 were obtained. Patient households were visited and data collection was done using an interviewed administered questionnaire. The majority of patients (57%) were economically active at the time of infection. Of them, 65% were the only contributors to household economy. Total median costs including both direct and indirect costs were 66.85 USD (Rs. 10,831) (IQR = 57.26 - 86.78 USD), while total median economic loss to households was 61.27 USD (Rs. 9,927) (IQR= 49.61- 75.04 USD). From provider perspective, total median cost per patient was 22.83 USD (Rs. 3,696). The mean total economic loss was denoted as 65.26 USD (Rs. 10,572) which is about 5.4% of the annual household income and 20.9% of the mean annual per capita income of the study population. Although economic impact of CL infection is not catastrophic according to current interpretation, the infection may have significant economic impacts on households when considering the mean economic loss to household as a percentage of the mean annual per capita income of the population.

Socioeconomic benefit to individuals of achieving 2020 targets for four neglected tropical diseases controlled/eliminated by innovative and intensified disease management: Human African trypanosomiasis, leprosy, visceral leishmaniasis, Chagas disease

BACKGROUND

The control or elimination of neglected tropical diseases (NTDs) has targets defined by the WHO for 2020, reinforced by the 2012 London Declaration. We estimated the economic impact to individuals of meeting these targets for human African trypanosomiasis, leprosy, visceral leishmaniasis and Chagas disease, NTDs controlled or eliminated by innovative and intensified disease management (IDM).

METHODS

A systematic literature review identified information on productivity loss and out-of-pocket payments (OPPs) related to these NTDs, which were combined with projections of the number of people suffering from each NTD, country and year for 2011-2020 and 2021-2030. The ideal scenario in which the WHO's 2020 targets are met was compared with a counterfactual scenario that assumed the situation of 1990 stayed unaltered. Economic benefit equaled the difference between the two scenarios. Values are reported in 2005 US$, purchasing power parity-adjusted, discounted at 3% per annum from 2010. Probabilistic sensitivity analyses were used to quantify the degree of uncertainty around the base-case impact estimate.

RESULTS

The total global productivity gained for the four IDM-NTDs was I$ 23.1 (I$ 15.9 -I$ 34.0) billion in 2011-2020 and I$ 35.9 (I$ 25.0 -I$ 51.9) billion in 2021-2030 (2.5th and 97.5th percentiles in brackets), corresponding to US$ 10.7 billion (US$ 7.4 -US$ 15.7) and US$ 16.6 billion (US$ 11.6 -US$ 24.0). Reduction in OPPs was I$ 14 billion (US$ 6.7 billion) and I$ 18 billion (US$ 10.4 billion) for the same periods.

CONCLUSIONS

We faced important limitations to our work, such as finding no OPPs for leprosy. We had to combine limited data from various sources, heterogeneous background, and of variable quality. Nevertheless, based on conservative assumptions and subsequent uncertainty analyses, we estimate that the benefits of achieving the targets are considerable. Under plausible scenarios, the economic benefits far exceed the necessary investments by endemic country governments and their development partners. Given the higher frequency of NTDs among the poorest households, these investments represent good value for money in the effort to improve well-being, distribute the world's prosperity more equitably and reduce inequity.

The direct costs of treating human visceral leishmaniasis in Brazil

INTRODUCTION:

The drugs available for visceral leishmaniasis (VL) treatment in Brazil have specific characteristics in terms of operability, effectiveness, toxicity, and cost. The aim of this study was to estimate the direct costs of therapies recommended by the Ministry of Health (MH) for VL treatment in Brazil.

METHODS:

The analytical perspective used was that adopted by the Brazilian Public Health System. Three drugs and four regimens were included: 1) N-methyl glucamine antimoniate intramuscularly at 20mg per kg per day for 30 days; 2) N-methyl glucamine antimoniate intravenously at 20mg per kg per day for 30 days; 3) amphotericin B deoxycholate at 1mg per kg per day for 21 days; and 4) liposomal amphotericin B at 3mg per kg per day for a 7 days treatment.

RESULTS:

The estimated direct costs of treatment for an adult patient using N-methylglucamine antimoniate administered via the intramuscular and intravenous routes were USD 418.52 and USD 669.40, respectively. The estimated cost of treatment with amphotericin B deoxycholate was USD 1,522.70. Finally, the estimated costs of treatment with liposomal amphotericin B were USD 659.79, and USD 11,559.15 using the price adopted by the WHO and the Drug Regulation Board, respectively.

CONCLUSIONS:

This analysis indicates the economic feasibility of replacing N-methyl glucamine antimoniate with liposomal amphotericin B, which allows a shorter treatment period with less toxicity compared with other treatments, provided that the purchase value used by the WHO and transferred to the MH is maintained.

A new approach for development of vaccine against visceral leishmaniasis: Lipophosphoglycan and polyacrylic acid conjugates

OBJECTIVE

To determine the antileishmanial vaccine effectiveness of lipophosphoglycan (LPG) and polyacrylic acids (PAA) conjugates on in vivo mice models.

METHODS

LPG molecule was isolated and purified from large-scale Leishmania donovani parasite culture. Protection efficacies of LPG alone, in combination with Freund's adjuvant, in a physical mixture and in conjugate (consisting of various LPG concentrations) with PAA, were comparatively determined by various techniques, such as cultivation with the micro-culture method, assessment of in vitro infection rates of peritoneal macrophages, determination of parasite load in liver with Leishman-Donovan Units, and detection of cytokine responses.

RESULTS

Obtained results demonstrated that the highest vaccine-mediated immune protection was provided by LPG-PAA conjugate due to all parameters investigated. According to the Leishman-Donovan Units results, the sharpest decline in parasite load was seen with a ratio of 81.17% when 35 μg LPG containing conjugate was applied. This value was 44.93% for the control group immunized only with LPG. Moreover, decreases in parasite load were 53.37%, 55.2% and 65.8% for the groups immunized with 10 μg LPG containing LPG-PAA conjugate, a physical mixture of the LPG-PAA, and a mixture of LPG + Freund's adjuvant, respectively. Furthermore, cytokine results supported that Th1 mediated protection occurred when mice were immunized with LPG-PAA conjugate.

CONCLUSIONS

It has been demonstrated in this study that conjugate of LPG and PAA has an antileishmanial vaccine effect against visceral leishmaniasis. In this respect, the present study may lead to new vaccine approaches based on high immunogenic LPG molecule and adjuvant polymers in fighting against Leishmania infection.

Snowball Vs. House-to-House Technique for Measuring Annual Incidence of Kala-azar in the Higher Endemic Blocks of Bihar, India: A Comparison

Background

Visceral Leishmaniasis, commonly known as kala-azar, is widely prevalent in Bihar. The National Kala-azar Control Program has applied house-to-house survey approach several times for estimating Kala-azar incidence in the past. However, this approach includes huge logistics and operational cost, as occurrence of kala-azar is clustered in nature. The present study aims to compare efficiency, cost and feasibility of snowball sampling approach to house-to-house survey approach in capturing kala-azar cases in two endemic districts of Bihar, India.

Methodology/Principal findings

A community based cross-sectional study was conducted in two highly endemic Primary Health Centre (PHC) areas, each from two endemic districts of Bihar, India. Snowball technique (used to locate potential subjects with help of key informants where subjects are hard to locate) and house-to-house survey technique were applied to detect all the new cases of Kala-azar during a defined reference period of one year i.e. June, 2010 to May, 2011. The study covered a total of 105,035 households with 537,153 populations. Out of total 561 cases and 17 deaths probably due to kala-azar, identified by the study, snowball sampling approach captured only 221 cases and 13 deaths, whereas 489 cases and 17 deaths were detected by house-to-house survey approach. Higher value of McNemar’s χ² statistics (64; p<0.0001) for house-to-house survey approach than snowball sampling and relative difference (>1) indicates that most of the kala-azar cases missed by snowball sampling were captured by house-to-house approach with 13% of omission.

Conclusion/Significance

Snowball sampling was not found sensitive enough as it captured only about 50% of VL cases. However, it captured about 77% of the deaths probably due to kala-azar and was found more cost-effective than house-to-house approach. Standardization of snowball approach with improved procedure, training and logistics may enhance the sensitivity of snowball sampling and its application in national Kala-azar elimination programme as cost-effective approach for estimation of kala-azar burden.

Visceral Leishmaniasis, commonly known as kala-azar, is one of the major health concerns for Bihar state in India. Time to time estimation of kala-azar incidence plays a pivotal role in defining and evaluating control strategies under National Kala-azar Elimination programme. The house-to-house survey approach, adopted several times for estimation of kala-azar incidence, requires huge logistics and operational cost as occurrence of kala-azar is clustered in nature. Snowball sampling approach is used to locate potential subjects with help of key informants where subjects are hard to locate. This is the first ever comparative study to assess efficacy, cost and feasibility of snowball sampling approach to house-to-house survey in capturing kala-azar cases. Snowball sampling was found cost-effective, but not sensitive enough as it captured about 50% of kala-azar cases. It captured deaths possibly due to kala-azar more efficiently (77%). However, standardization of snowball approach with improved procedure, training, logistics, etc. may enhance the sensitivity of snowball sampling and its application in national Kala-azar elimination programme as cost-effective approach for estimation of kala-azar burden.

Study of implementation and direct cost estimates for diagnostic tests for human visceral leishmaniasis in an urban area in Brazil

This work reports the process and costs of comprehensively implementing two tests to decentralize the diagnosis of visceral leishmaniasis (VL) in an endemic city in Brazil: a rapid test (IT LEISH) and a direct agglutination test (DAT-LPC). The implementation began by training health professionals to perform the tests. Estimation of the training costs considered the proportional remuneration of all professionals involved and the direct costs of the tests used for training. The study was conducted between November 2011 and November 2013. During that time, 17 training sessions were held, and 175 professionals were trained. The training cost for each professional was US$ 7.13 for the IT LEISH and US$ 9.93 for the DAT-LPC. The direct costs of the IT LEISH and DAT-LPC were estimated to be US$ 6.62 and US$ 5.44, respectively. This first evaluation of the implementation of these diagnostic tests indicates the feasibility of decentralizing both methods to extend access to VL diagnosis in Brazil.

Social and Economic Burden of Human Leishmaniasis

Leishmaniasis continues to pose a major public health problem worldwide. With new epidemics occurring in endemic areas and the spread of the disease to previously free areas because of migration, tourism, and military activities, there is a great need for the development of an effective vaccine. Leishmaniasis is a disease of the poor, occurring mostly in remote rural villages with poor housing and little or no access to modern health-care facilities. In endemic areas, diagnosis of any form of leishmaniasis puts a huge financial strain on an already meagre financial resource at both the individual and community levels. Most often families need to sell their assets (land and livestock) or take loans from informal financial outfits with heavy interest rates to pay for the diagnosis and treatment of leishmaniasis. Here, we discuss the disease with special emphasis on its socioeconomic impact on the affected individual and community. In addition, we highlight the reasons why continued research aimed at developing an effective Leishmania vaccine is necessary.

Economic and financial evaluation of neglected tropical diseases

Economic and financing studies are particularly important for decision-making when resources are scarce or considerably limited. This is the case for neglected tropical diseases (NTDs). In fact, the definition of NTDs is an economic one. The shortage of resources for NTD control may be due in large part to the fact that the burden of NTDs and economic value of control measures have not been fully characterized. A number of economic study methodologies are available: cost of illness can quantify the extent, magnitude, and change of a problem; cost of intervention studies can outline the feasibility and guide the design of a policy or intervention; and cost-benefit, cost-effectiveness, and return-on-investment studies can determine the potential value of different interventions and policies. NTDs have unique characteristics that require special consideration in such analyses. Hence, approaches used for other diseases may need modifications to capture the full impact of NTDs. While the existing literature has made important findings, there is a need for substantially more work, as many NTDs and their associated interventions and policies require more evaluation. With increasing work in this area, NTDs may not be as 'neglected' in the future as they are now.

Health economic evaluations of visceral leishmaniasis treatments: a systematic review

Visceral leishmaniasis (VL) is a severe form of the leishmaniasis-disease complex. Its importance to public health relies on its high fatality rate in non-treated cases, the socio-economic impact related to its morbidity, and its endemicity on different continents. The estimated burden of disease of VL varies from 1,969,000 to 2,357,000 Disability Adjusted Life Years (DALYs). VL is classified as a Neglected Tropical Disease (NTD), and is strongly related to poverty and its consequences. Visceral leishmaniasis calls for the development of cost-effective technologies for diagnosis and treatment.

Visceral leishmaniasis (VL), also known as kala azar, is a neglected tropical disease caused by parasitic protozoa of the genus Leishmania. VL is related to poverty and its consequences, which leads to its status of neglected disease. For that reason, cost-effective forms of diagnoses and treatment are very important and still needed. This research aimed at a better understanding of the publications about the technologies currently available, from the standpoint of their economic value. For that purpose, we conducted a systematic review of the literature in order to identify the papers that conducted economic evaluations of technologies used in VL. We initially retrieved 107 articles, which were inspected according to specific guidelines for systematic reviews. After that process, 14 articles matched the inclusion criteria in our review. We classified those studies according to the type of economic evaluation they made, and the methodology used in each one. We found evaluations about a variety of technologies, but the studies were geographically concentrated in Asia, more specifically in India. This concentration is not good because the disease also affects other continents and it is not possible to transfer the economic evaluation from one country or epidemiologic scenario to another.

The economic burden of visceral leishmaniasis in Sudan: an assessment of provider and household costs

Visceral leishmaniasis (VL) is a neglected parasitic disease that is fatal if left untreated and is endemic in eastern Sudan. We estimated the direct and indirect costs of treatment of VL from the perspective of the provider and the household at three public hospitals in Gedaref State. The median total cost for one VL episode was estimated to be US$450. Despite the free provision of VL drugs at public hospitals, households bore 53% of the total cost of VL with one episode of VL representing 40% of the annual household income. More than 75% of households incurred catastrophic out-of-pocket expenditures. The length of treatment of 30 days led to important costs for both health providers and households. Alternative treatment regimens that reduce the duration of treatment are urgently needed.

Disease control priorities for neglected tropical diseases: lessons from priority ranking based on the quality of evidence, cost effectiveness, severity of disease, catastrophic health expenditures, and loss of productivity

BACKGROUND

In the context of limited health care budgets in countries where Neglected Tropical Diseases (NTDs) are endemic, scaling up disease control interventions entails the setting of priorities. However, solutions based solely on cost-effectiveness analyses may lead to biased and insufficiently justified priorities.

OBJECTIVES

The objectives of this paper are to 1) demonstrate how a range of equity concerns can be used to identify feasible priority setting criteria, 2) show how these criteria can be fed into a multi-criteria decision-making matrix, and 3) discuss the conditions under which this decision-making procedure should be carried out in a real-world decision-making context.

METHODS

This paper draws on elements from theories of decision analysis and ethical theories of fair resource allocation. We explore six typical NTD interventions by employing a modified multi-criteria decision analysis model with predefined criteria, drawn from a priority setting guide under development by the WHO. To identify relevant evidence for the six chosen interventions, we searched the PubMed and Cochrane databases.

DISCUSSION

Our in vitro multi-criteria decision analysis suggested that case management for visceral leishmaniasis should be given a higher priority than mass campaigns to prevent soil-transmitted helminthic infections. This seems to contradict current health care priorities and recommendations in the literature. We also consider procedural conditions that should be met in a contextualised decision-making process and we stress the limitations of this study exercise.

CONCLUSION

By exploring how several criteria relevant to the multi-facetted characteristics of NTDs can be taken into account simultaneously, we are able to suggest how improved priority settings among NTDs can be realised.

The economic value of a visceral leishmaniasis vaccine in Bihar state, India

Visceral leishmaniasis (VL) is responsible for substantial morbidity and mortality and current available treatments have many limitations. The ability of VL infection to generate life-long immunity offers promise for the development of a VL vaccine. A VL vaccine candidate has recently completed phase I clinical trials. We constructed a computer simulation model to determine the potential economic value of a VL vaccine in the endemic region of Bihar state, India. Results found a potential vaccine to be cost-effective (and in many cases economically dominant, i.e., saving costs and providing health benefits) throughout a wide range of vaccination costs and vaccine efficacies, and VL risks. Overall, our study strongly supports the continued development of a VL vaccine.

Nonprofit drugs as the salvation of the world's healthcare systems: the case of Antabuse (disulfiram)

The effort to repurpose old drugs for new uses is not sufficient; even drugs that have been used clinically for decades must undergo expensive clinical trials. This process requires the pharmaceutical industry to fund the repatenting of old drugs. Because inexpensive drugs are necessary for people around the world, attempts should be made to develop nonprofit drugs through clinical trials of generic drugs that are funded by governments and charities. Evidence supports the use the old anti-alcoholic drug Antabuse as a new nonprofit drug for cancer.

Visceral leishmaniasis: immunology and prospects for a vaccine

Human visceral leishmaniasis (HVL) is the most severe clinical form of a spectrum of neglected tropical diseases caused by protozoan parasites of the genus Leishmania. Caused mainly by L. donovani and L. infantum/chagasi, HVL accounts for more than 50 000 deaths every year. Drug therapy is available but costly, and resistance against several drug classes has evolved. Here, we review our current understanding of the immunology of HVL and approaches to and the status of vaccine development against this disease.

A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1+MPL-SE vaccine for use in the prevention of visceral leishmaniasis

Healthy Indian adult volunteers, with or without a history of leishmaniasis, were evaluated for evidence of previous infection with Leishmania donovani based on the direct agglutination test (DAT). Three cohorts of 6 DAT-negative and 6 DAT-positive subjects were enrolled in an open-label, dose-escalating, uncontrolled clinical trial and received three injections of the LEISH-F1+MPL-SE vaccine (consisting of 5μg, 10μg, or 20μg recombinant Leishmania polyprotein LEISH-F1 antigen+25μg MPL®-SE adjuvant). The study injections were given subcutaneously on days 0, 28, and 56, and the subjects were followed through day 168 for safety and immunological endpoints. The vaccine was safe and well-tolerated in DAT-negative and DAT-positive subjects and induced T-cell production of IFN-γ and other cytokines in response to stimulation with the LEISH-F1 antigen. This clinical trial shows that the LEISH-F1+MPL-SE vaccine is safe and immunogenic in healthy subjects with and without history of previous infection with Leishmania donovani.

Socio-economic aspects of neglected diseases: sleeping sickness and visceral leishmaniasis

Several tropical diseases that are essentially poverty-related have recently gained more attention under the label of 'neglected tropical diseases' or NTD. It is estimated that over 1000 million people currently suffer from one or more NTD. Here, the socio-economic aspects of two NTD - human African trypanosomiasis and human visceral leishmaniasis - are reviewed. Both of these diseases affect the poorest of the poor in endemic countries, cause considerable direct and indirect costs (even though the national control programmes tend to provide free care) and push affected households deeper into poverty.