Socio-economics of visceral leishmaniasis in Bihar (India)

Modelling spatiotemporal patterns of visceral leishmaniasis incidence in two endemic states in India using environment, bioclimatic and demographic data, 2013-2022

BACKGROUND

As of 2021, the National Kala-azar Elimination Programme (NKAEP) in India has achieved visceral leishmaniasis (VL) elimination (<1 case / 10,000 population/year per block) in 625 of the 633 endemic blocks (subdistricts) in four states. The programme needs to sustain this achievement and target interventions in the remaining blocks to achieve the WHO 2030 target of VL elimination as a public health problem. An effective tool to analyse programme data and predict/ forecast the spatial and temporal trends of VL incidence, elimination threshold, and risk of resurgence will be of use to the programme management at this juncture.

METHODOLOGY/PRINCIPAL FINDINGS

We employed spatiotemporal models incorporating environment, climatic and demographic factors as covariates to describe monthly VL cases for 8-years (2013-2020) in 491 and 27 endemic and non-endemic blocks of Bihar and Jharkhand states. We fitted 37 models of spatial, temporal, and spatiotemporal interaction random effects with covariates to monthly VL cases for 6-years (2013-2018, training data) using Bayesian inference via Integrated Nested Laplace Approximation (INLA) approach. The best-fitting model was selected based on deviance information criterion (DIC) and Watanabe-Akaike Information Criterion (WAIC) and was validated with monthly cases for 2019-2020 (test data). The model could describe observed spatial and temporal patterns of VL incidence in the two states having widely differing incidence trajectories, with >93% and 99% coverage probability (proportion of observations falling inside 95% Bayesian credible interval for the predicted number of VL cases per month) during the training and testing periods. PIT (probability integral transform) histograms confirmed consistency between prediction and observation for the test period. Forecasting for 2021-2023 showed that the annual VL incidence is likely to exceed elimination threshold in 16-18 blocks in 4 districts of Jharkhand and 33-38 blocks in 10 districts of Bihar. The risk of VL in non-endemic neighbouring blocks of both Bihar and Jharkhand are less than 0.5 during the training and test periods, and for 2021-2023, the probability that the risk greater than 1 is negligible (P<0.1). Fitted model showed that VL occurrence was positively associated with mean temperature, minimum temperature, enhanced vegetation index, precipitation, and isothermality, and negatively with maximum temperature, land surface temperature, soil moisture and population density.

CONCLUSIONS/SIGNIFICANCE

The spatiotemporal model incorporating environmental, bioclimatic, and demographic factors demonstrated that the KAMIS database of the national programmme can be used for block level predictions of long-term spatial and temporal trends in VL incidence and risk of outbreak / resurgence in endemic and non-endemic settings. The database integrated with the modelling framework and a dashboard facility can facilitate such analysis and predictions. This could aid the programme to monitor progress of VL elimination at least one-year ahead, assess risk of resurgence or outbreak in post-elimination settings, and implement timely and targeted interventions or preventive measures so that the NKAEP meet the target of achieving elimination by 2030.

Looking through the lens of social science approaches: A scoping review of leishmaniases and Chagas disease research

Scholars have called for increased attention to sociocultural, economic, historical, and political processes shaping Neglected Tropical Diseases (NTDs) ecology. We conducted a scoping review to identify major research themes and the knowledge gaps in social science literature in leishmaniases or Chagas disease (CD). Following the scoping review protocol, we first determined the focus of the review to be centered on identifying research that approaches leishmaniases and CD from social science perspective and was indexed by large, biomedically focused databases. We then searched PubMed and Web of Science using "Leishmaniasis" and "Chagas disease" with "social science" or "anthropology" as search terms. We analyzed 199 articles (123 on leishmaniases and 76 on CD), categorizing them into three main research themes. Sociocultural dimensions of the diseases (leishmaniases=60.2 %; CD=68.4 %) primarily focused on individuals' knowledge, practices, and behaviors, barriers to accessing healthcare (especially in endemic regions), psychosocial effects, stigma, and traditional treatments. Research focused on socioeconomic dimensions of the diseases (leishmaniases=29.3 %; CD=19.7 %) included topics like household characteristics, social capital, and infrastructure access. A final theme, the historical and political contexts of the diseases (Leishmaniases=10.5 %; CD=11.9 %) was less common than other themes. Here, studies consider civil war and the (re)emergence of leishmaniasis, as well as the significance of CD discovery for scientific and public health in Brazil, which is the most common country for research on both leishmaniases and CD that draws on social science approaches. Future directions for research include focusing on how social institutions and economic factors shape diseases education, control measures, healthcare access, and quality of life of people affected by NTDs. Greater attention to social sciences can help mitigate and undo the ways that structural biases have infiltrated biomedicine.

Domestic mammals as reservoirs for Leishmania donovani on the Indian subcontinent: Possibility and consequences on elimination

Leishmania donovani is the causative agent of historically anthroponotic visceral leishmaniasis (VL) on the Indian subcontinent (ISC). L. donovani is transmitted by the sand fly species Phlebotomus argentipes. Our collaborative group and others have shown that sand flies trapped outside in endemic villages have fed on cattle and dogs in addition to people. Domestic animals are reservoirs for L. donovani complex spp., particularly L. infantum, in other endemic areas. Multiple studies using quantitative PCR or serological detection methods have demonstrated that goats, cattle, rats and dogs were diagnostically positive for L. donovani infection or exposure in eastern Africa, Bangladesh, Nepal and India. There is a limited understanding of the extent to which L. donovani infection of domestic animals drives transmission to other animals or humans on the ISC. Evidence from other vector-borne disease elimination strategies indicated that emerging infections in domestic species hindered eradication. The predominant lesson learned from these other situations is that non-human reservoirs must be identified, controlled and/or prevented. Massive efforts are underway for VL elimination on the Indian subcontinent. Despite these herculean efforts, residual VL incidence persists. The spectre of an animal reservoir complicating elimination efforts haunts the final push towards full VL control. Better understanding of L. donovani transmission on the Indian subcontinent and rigorous consideration of how non-human reservoirs alter VL ecology are critical to sustain elimination goals.

Gender disparity in cases enrolled in clinical trials of visceral leishmaniasis: A systematic review and meta-analysis

BACKGROUND

A higher caseload of visceral leishmaniasis (VL) has been observed among males in community-based surveys. We carried out this review to investigate how the observed disparity in gender distribution is reflected in clinical trials of antileishmanial therapies.

METHODS

We identified relevant studies by searching a database of all published clinical trials in VL from 1980 through 2019 indexed in the Infectious Diseases Data Observatory (IDDO) VL clinical trials library. The proportion of male participants enrolled in studies eligible for inclusion in this review were extracted and combined using random effects meta-analysis of proportion. Results were expressed as percentages and presented with respective 95% confidence intervals (95% CIs). Heterogeneity was quantified using I2 statistics and sub-group meta-analyses were carried out to explore the sources of heterogeneity.

RESULTS

We identified 135 published studies (1980-2019; 32,177 patients) with 68.0% [95% CI: 65.9%-70.0%; I2 = 92.6%] of the enrolled participants being males. The corresponding estimates were 67.6% [95% CI: 65.5%-69.7%; n = 91 trials; I2 = 90.5%; 24,218 patients] in studies conducted in the Indian sub-continent and 74.1% [95% CI: 68.4%-79.1%; n = 24 trials; I2 = 94.4%; 6,716 patients] in studies from Eastern Africa. The proportion of male participants was 57.9% [95% CI: 54.2%-61.5%] in studies enrolling children aged <15 years, 78.2% [95% CI: 66.0%-86.9%] in studies that enrolled adults (≥15 years), and 68.1% [95% CI: 65.9%-70.0%] in studies that enrolled patients of all ages. There was a trend for decreased proportions of males enrolled over time: 77.1% [95% CI: 70.2%-82.8%; 1356 patients] in studies published prior to the 1990s whereas 64.3% [95% CI: 60.3%-68.2%; 15,611 patients] in studies published on or after 2010. In studies that allowed the inclusion of patients with HIV co-infections, 76.5% [95% CI: 63.8%-85.9%; 5,123 patients] were males and the corresponding estimate was 64.0% [95% CI: 61.4%-66.5% 17,500 patients] in studies which excluded patients with HIV co-infections.

CONCLUSIONS

Two-thirds of the participants enrolled in clinical studies in VL conducted in the past 40 years were males, though the imbalance was less in children and in more recent trials. VL treatment guidelines are informed by the knowledge of treatment outcomes from a population that is heavily skewed towards adult males. Investigators planning future studies should consider this fact and ensure approaches for more gender-balanced inclusion.

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.

Human visceral leishmaniasis: epidemiological, temporal and spacial aspects in Northeast Brazil, 2003-2017

Visceral leishmaniasis is a highly lethal zoonosis transmitted by a sandfly. It is caused by a Leishmania protozoan parasite and dogs are the main reservoir. Ceara State is endemic to visceral leishmaniasis and it is considered a high risk transmission area. Temporal and spatial epidemiological studies have been used as tools to analyze the distribution and frequency of human visceral leishmaniasis (HVL). This study aimed to characterize HVL in its epidemiological andtemporal aspects in Ceara State, from 2003 to 2017, as this is a neglected disease and a public health problem. This is an ecological study carried out with HVL confirmed cases in Ceara, using three blocks of years (2003 to 2007, 2008 to 2012 and 2013 to 2017). The disease presented an endemic behavior, affecting mainly male residents in the urban area, especially children under five and young adults between 30 and 49 years old. HVL is recorded in all the municipalities, for more than 10 years, with a growing trend and territorial expansion to the Central and Eastern regions of the State. The results of this study indicated the increase in the incidence and lethality, as well as the expansion of leishmaniasis in Ceara State.

Housing Characteristics and Leishmaniasis: A Systematic Review

Leishmaniasis is a major neglected tropical disease associated with high rates of disability and death. This disease is associated with poverty, which can be reflected in housing quality, especially in rural areas. This systematic review found that mud walls with cracks and holes, damp, and dark houses were risk factors for transmission of leishmaniasis. These characteristics create favorable conditions for sand fly breeding and resting as sand flies prefer humidity, warmth, and protection from sunlight during the day. Housing interventions might be a promising research area with a special focus on education as individual and collective protection for the effective control of leishmaniasis.

Variations in macrophage migration inhibitory factor gene are not associated with visceral leishmaniasis in India

BACKGROUND

The host genetic factors play important role in determining the outcome of visceral leishmaniasis (VL). Macrophage migration inhibitory factor (MIF) is an important host cytokine, which is a key regulator of innate immune system. Genetic variants in MIF gene have been found to be associated with several inflammatory and infectious diseases. Role of MIF is well documented in leishmaniasis diseases, including Indian visceral leishmaniasis, where elevated level of serum MIF has been associated with VL phenotypes. However, there was no genetic study to correlate MIF variants in VL, therefore, we aimed to study the possible association of three reported MIF gene variants -794 CATT, -173G > C and non-coding RNA gene LOC284889 in Indian VL phenotype.

METHODS

Study subjects comprised of 214 VL patients along with ethnically and demographically matched 220 controls from VL endemic regions of Bihar state in India.

RESULTS

We found no significant difference between cases and controls in allelic, genotypic and haplotype frequency of the markers analysed [-794 CATT repeats (χ2=0.86; p=0.35; OR=0.85; 95% CI=0.61-1.19); -173 G>C polymorphism (χ2=1.11; p=0.29; OR=0.83; 95% CI=0.59-1.16); and LOC284889 (χ2=0.78; p=0.37; OR=0.86; 95% CI=0.61-1.20)].

CONCLUSION

Since we did not find any significant differences between case and control groups, we conclude that sequencing of complete MIF gene and extensive study on innate and adaptive immunity genes may help in identifying genetic variations that are associated with VL susceptibility/resistance among Indians.

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.

Dynamics of American tegumentary leishmaniasis in a highly endemic region for Leishmania (Viannia) braziliensis infection in northeast Brazil

Background

American Tegumentary Leishmaniasis (ATL) caused by Leishmania braziliensis is endemic in Corte de Pedra, Northeast Brazil. Most L. braziliensis infections manifest as localized cutaneous leishmaniasis (CL). Disseminated manifestations include mucosal leishmaniasis (ML), present at a low constant level for several decades, and newly emerging disseminated leishmaniasis (DL). Surprisingly, DL has recently surpassed ML in its spatial distribution. This led us to hypothesize that distinct forms of ATL might spread in different patterns through affected regions.

Methodology/Principal findings

We explored the incidence and geographic dispersion of the three clinical types of ATL over a span of nearly two decades in Corte de Pedra. We obtained the geographic coordinates of the homes of patients with ATL during 1992–1996, 1999–2003 and 2008–2011. The progressive dispersion of ML or DL in each time period was compared to that of CL in 2008–2011 with the Cusick and Edward’s geostatistical test. To evaluate whether ATL occurred as clusters, we compared each new case in 2008–2011 with the frequency of and distance from cases in the previous 3 to 12 months. The study revealed that DL, ML and CL actively spread within that region, but in distinct patterns. Whereas CL and DL propagated in clusters, ML occurred as sporadic cases. DL had a wider distribution than ML until 2003, but by 2011 both forms were distributed equally in Corte de Pedra. The incidence of ML fluctuated over time at a rate that was distinct from those of CL and DL.

Conclusions/Significance

These findings suggest that CL and DL maintain endemic levels through successive outbreaks of cases. The sporadic pattern of ML cases may reflect the long and variable latency before infected patients develop clinically detectable mucosal involvement. Intimate knowledge of the geographic distribution of leishmaniasis and how it propagates within foci of active transmission may guide approaches to disease control.

American tegumentary leishmaniasis (ATL) caused by Leishmania braziliensis is characterized by lesions to the skin and/or mucosal surfaces of the oropharynx. It is widely distributed in endemic regions of northeast Brazil and has been difficult to control. Three common clinical forms of L. braziliensis infections are localized skin ulcers called cutaneous leishmaniasis (CL), mucosal leishmaniasis (ML) affecting mucosal surfaces, and disseminated leishmaniasis (DL), a recently described form with widespread skin lesions. Using GPS and epidemiologic data we explored the incidence and pattern of spread of ATL in the highly endemic region of Corte de Pedra, Brazil between 1992 and 2011. Geographic clusters of CL and DL cases were observed. In contrast, there was a sporadic non-clustered pattern of ML cases in the study area. The numbers of new cases of CL and DL presented similar fluctuation during the study period, but ML incidences were never correlated to those of CL and DL. We conclude that all forms of ATL actively spread within affected foci, but in different patterns. CL and DL cases occur in clusters suggesting active spread of causative parasite strains, whereas ML cases occurred in a sporadic pattern suggesting it may emerge due to factors such as host immunity or environmental conditions.

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.

Worldwide risk factors in leishmaniasis

Recently, vector-borne parasitic diseases such as leishmaniasis have been emerged or re-emerged in many geographical areas and resulted in global health and economic concerns that involve humans, domestic animals and wild life. The ecology and epidemiology of leishmaniasis are affected by the between host, reservoir and vector (human, animal and sandfly) and the environment. Important drivers for the emergence and spread of leishmaniasis include environmental factors such as alterations in temperature and water storage, irrigation habits, deforestation, climate changes, immunosuppression by HIV or organ transplant, development of drug resistance, increase traveling to endemic regions and dog importation. War, poor socio-economic status and low level household are also major contributors to the spread of this disease. Health education via the public media and training should be implemented by international organizations and governmental agencies in collaboration with research institutions. Fully protection during transmission season, using bednets and insecticides and reservoirs' control should be also mentioned in the planning. Based on the findings of the recent studies and high prevalence of leishmaniasis, it is concluded that serious public health monitoring should be considered.

Particle induced X-ray emission study of blood samples of Indian Kala-azar patients

Visceral leishmaniasis (VL) or Kala-azar (KA) is a neglected tropical disease caused by protozoan parasite, Leishmania sp. and is fatal, if left untreated. In this study, we measured trace elements (K, Fe, Cu, Zn, Br, Cl, S, Ca, Mn, Cr, Ni, As, Se, Rb and Sr) in the blood of Indian VL patients (32) by particle-induced X-ray emission (PIXE) study. Blood was collected from 36 subjects including healthy controls from Rambagh Kala-azar Hospital, Muzaffarpur, Bihar, India. PIXE experiment was carried out at the Institute of Physics, Bhubaneswar, India and data were analyzed by GUPIXWIN software. We observed first time the association of bromine with the disease. The results showed 48.47 % decrease in Br, 35.16 % decrease in Zn and 29.05 % decrease in Fe in untreated state of the KA patients. In the same group, Cu has been increased by 16.73 %. Cu/Zn ratio has been altered in diseased state. The association of bromine with the disease is reported for the first time and altered levels of trace elements (Br, Cu, Fe and Zn) may come back to normal after completion of the treatment regimen with Amphotericin B.

Developments in Diagnosis of Visceral Leishmaniasis in the Elimination Era

Visceral leishmaniasis (VL) is the most devastating parasitic infection worldwide causing high morbidity and mortality. Clinical presentation of VL ranges from asymptomatic or subclinical infection to severe and complicated symptomatic disease. A major challenge in the clinical management of VL is the weakness of health systems in disease endemic regions. People affected by VL mostly present to primary health care centers (PHCs), often late in their therapeutic itinerary. PHC physicians face a major challenge: they do not deal with a single disease issue but with patients presenting with complaints pointing to several diagnostic possibilities. Risk exists when some patients having less clinical manifestations are misdiagnosed. Therefore, field based accurate, sensitive, and cost effective rapid diagnostic tools that can detect disease in its mildest form are essential for effective control and reaching the goal of VL elimination. In this review, we discuss the current status and challenges of various diagnostic tools for the diagnosis of VL and assess their application in resource poor settings.

Herbal extract targets in Leishmania tropica

The present study aims to investigate the effect of some herbal extract such as phenolic compounds on the viability of Leishmania tropica promastigotes in vitro. Four tested chemical agents (caffeic acid (CA), ferulic acid (FA), syringic acid (SA) and 4-hydroxybenzoic acid (4-HBA)) were used in this study. The viability of Leishmania tropica promastigotes was investigated under five different concentrations (10, 15, 20, 25 and 30 mg/ml) of each agent after (72 h). CA was the most active agent on the promastigotes viability after 72 h exposure to 30 mg/ml concentration so that the parasiticidal effect reach (53 × 10(4)) promastigote/ml. FA is the second agent in parasiticidal effect that parasiticidal effect reach to (50 × 10(4) promastigote/ml) at a concentration (30 mg/ml), 4-HBA is the third agent in parasiticidal effect that reach to (48 × 10(4) promastigote/ml) at a concentration (30 mg/ml), SA is the weakest agent in parasiticidal activity that reach to (44 × 10(4) promastigote/ml) at a concentration (30 mg/ml). It can be concluded that (CA, FA, SA and 4-HBA) possess acidal effect on the Leishmania tropica promastigotes in vitro.

IL10 Variant g.5311A Is Associated with Visceral Leishmaniasis in Indian Population

Background

Visceral leishmaniasis (VL) is a multifactorial disease, where the host genetics play a significant role in determining the disease outcome. The immunological role of anti-inflammatory cytokine, Interleukin 10 (IL10), has been well-documented in parasite infections and considered as a key regulatory cytokine for VL. Although VL patients in India display high level of IL10 in blood serum, no genetic study has been conducted to assess the VL susceptibility / resistance. Therefore, the aim of this study is to investigate the role of IL10 variations in Indian VL; and to estimate the distribution of disease associated allele in diverse Indian populations.

Methodology

All the exons and exon-intron boundaries of IL10 were sequenced in 184 VL patients along with 172 ethnically matched controls from VL endemic region of India.

Result and Discussion

Our analysis revealed four variations; rs1518111 (2195 A>G, intron), rs1554286 (2607 C>T, intron), rs3024496 (4976 T>C, 3’ UTR) and rs3024498 (5311 A>G, 3’ UTR). Of these, a variant g.5311A is significantly associated with VL (χ²=18.87; p =0.00001). In silico approaches have shown that a putative micro RNA binding site (miR-4321) is lost in rs3024498 mRNA. Further, analysis of the above four variations in 1138 individuals from 34 ethnic populations, representing different social and linguistic groups who are inhabited in different geographical regions of India, showed variable frequency. Interestingly, we have found, majority of the tribal populations have low frequency of VL (‘A’ of rs3024498); and high frequency of leprosy (‘T’ of rs1554286), and Behcet’s (‘A’ of rs1518111) associated alleles, whereas these were vice versa in castes. Our findings suggest that majority of tribal populations of India carry the protected / less severe allele against VL, while risk / more severe allele for leprosy and Behcet’s disease. This study has potential implications in counseling and management of VL and other infectious diseases.

Correlation between Socioeconomic Status and Clinical Course in Patients with Cutaneous Leishmaniasis

OBJECTIVE

Leishmaniasis has long been known as a poverty-associated disease, which is particularly prevalent in developing and less developed countries. The role of socioeconomic status in the clinical course of the disease is less clearly defined. In this study, we investigated the potential relationship between the clinical course of cutaneous leishmaniasis in terms of its evolution into chronic forms and the socioeconomic status of the patients.

METHODS

A total of 140 patients attending the dermatology clinic in Imam Reza Hospital, Mashhad, Iran, were enrolled. The patients were grouped into high, medium, and low socioeconomic classes according to a comprehensive questionnaire. They received routine treatment protocols for leishmaniasis and were followed up for 1 year.

RESULTS

We found a statistically significant relationship between the clinical course of the disease and socioeconomic status.

CONCLUSION

Poverty might prolong the course of cutaneous leishmaniasis for many different reasons.

Asymptomatic Leishmania infections in northern India: a threat for the elimination programme?

Visceral leishmaniasis (VL) continues to embody as a mammoth public health problem and hurdle to the socioeconomic development of Bihar, India. Interestingly, all leishmanial infections do not lead to overt clinical disease and may stay asymptomatic for a period of time. Asymptomatic cases of VL are considered as probable potential reservoirs of VL, and thus can play a major role in transmission of the disease in highly endemic areas of Bihar, India. They outnumber the exact disease burden in endemic areas of this region, thus jeopardizing the goal of the elimination program that is due by 2015. This article discusses the potential risk factors, epidemiological markers of transmission and requirement of highly sensitive diagnostic tools for efficient recognition of the high risk groups of conversion to symptomatic for proper designing of strategies for implementation of the control programs.

Leishmaniasis in Uganda: historical account and a review of the literature

Visceral leishmaniasis (VL) or kala azar is a fatal and neglected disease caused by protozoan parasites. It occurs worldwide including north-eastern Uganda. This review gives a historical account of and reviews available literature on VL in Uganda to raise more awareness about the disease. Information was collected from: MEDLINE searches; records of Ministry of Health (Uganda), Amudat hospital records; records of NGOs and multilateral institutions; dissertations and personal communication. Results show that VL in Uganda was first reported in the 1950's, followed by almost four decades of neglect. Earlier records from the ministry of health and Amudat hospital on VL are also incomplete. From early 2000, reports mainly on the disease management and risk factors, started to appear in the literature. Management of VL has mainly been by NGOs and multilateral institutions including MSF Swiss. Currently DNDi is funding its management and clinical trials in Amudat hospital through LEAP. New cases of VL were reported recently from Moroto and Kotido districts and more patients continue to be received from these areas. In conclusion, management of VL is well established in Amudat hospital. However its sustainability and wider coverage remains a challenge. First-line drugs have now been registered in the country. Visceral leishmaniasis is apparently more widespread in north-eastern Uganda than originally thought. Research and surveillance on leishmaniasis is still weak. Strengthening the capacity of local institutions to; conduct surveillance and research, combined with effective management should mitigate VL in Uganda.

Visceral leishmaniasis prevalence and associated risk factors in the saran district of Bihar, India, from 2009 to July of 2011

India is one of three countries that account for an estimated 300,000 of 500,000 cases of visceral leishmaniasis (VL) occurring annually. Bihar State is the most affected area of India, with more than 90% of the cases. Surveys were conducted in two villages within the Saran district of Bihar, India, from 2009 to July of 2011 to assess risk factors associated with VL. Forty-five cases were identified, and individuals were given an oral survey. The results indicated that men contracted the disease more than women (58%), and cases over the age of 21 years accounted for 42% of the total VL cases. April to June showed the highest number of new cases. Of 135 households surveyed for sleeping conditions, 95% reported sleeping outside, and 98% slept in beds. Proximity to VL cases was the greatest risk factor (cluster 1 relative risk = 11.89 and cluster 2 relative risk = 138.34). The VL case clustering observed in this study can be incorporated in disease prevention strategies to more efficiently and effectively target VL control efforts.

Visceral Leishmaniasis Eradication is a Reality: Data from a Community-based Active Surveillance in Bangladesh

More than 20 million people in Bangladesh are considered at risk of developing visceral leishmaniasis (VL). A community-based active surveillance was conducted in eight randomly selected villages in a highly endemic area of Bangladesh from 2006 to 2008. A total of 6,761 individuals living in 1,550 mud-walled houses were included in the active surveillance. Rapid rK39 dipstick tests were conducted throughout the study period to facilitate the case diagnosis. Individuals with previous or current clinical leishmaniasis were identified on the basis of the case definition of the VL elimination program. Untreated cases of suspected VL were referred to the hospital for treatment. Socioeconomic and environmental information including bed net use was also collected. In 2006, the annual incidence of clinical leishmaniasis in the study area was 141.9 cases per 10,000 population, which was significantly increased by the following year owing to community-based active surveillance for case detection and reporting. However, early case detection and early referral for treatment led to a significant decrease in incidence in 2008. This study suggests that community-based active surveillance using a simple diagnostic tool might play a role in achieving the goal of the VL elimination program.

Identification of bloodmeals in wild caught blood fed Phlebotomus argentipes (Diptera: Psychodidae) using cytochrome b PCR and reverse line blotting in Bihar, India

Identification of the source of bloodmeals in vectors plays an important role in epidemiological studies by determining the host preferences of wild sand flies in natural habitat. The anthropophilic index is a crucial component in human leishmaniasis. Bloodmeal analysis can identify the reservoir hosts of vector borne diseases. The amplification of the mitochondrial cytochrome b gene, followed by reverse line blot analysis, helps to identify the bloodmeal ingested by the wild caught sand flies. In the current study, blood fed sand flies were collected from three different villages in Bihar, India, by using Centers for Disease Control mini traps with incandescent light. Traps were placed in five different sites in the villages. Whole genome DNA was extracted from the blood fed sand flies and was amplified for the cytochrome b region, followed by reverse line blot analysis. In total, 442 blood fed sand flies were analyzed out of which 288 (65%) were positive to cytochrome b polymerase chain reaction. Humans, cattle, buffalo, and goats were the major bloodmeals identified, followed by chickens. In some of the blood fed sand flies, multiple bloodmeals were identified. In the current study, sand flies mostly fed on humans, followed by cattle, buffalo, and goats. In this regard, it is necessary to also consider cattle, buffalo, and goats when addressing vector control in Bihar, India.

Low castes have poor access to visceral leishmaniasis treatment in Bihar, India

OBJECTIVES

Bihar, the poorest state in India, concentrates most of the visceral leishmaniasis (VL) cases in the country. A large proportion of the poor rural communities where VL is endemic are marginalized by their socio-economic status, intrinsically related to the caste system. In this study, we evaluated whether people from low socio-economic strata had difficulties accessing VL treatment in Bihar. As a secondary outcome, we evaluated whether people delaying their VL treatment had poorer clinical indicators at admission.

METHODS

Data on 2187 patients with VL treated by Médecins Sans Frontières (MSF) in Vaishali district from July 2007 to December 2008 were analysed. Patients who reported having onset of symptoms ≥8 weeks before admission were defined as 'late presenters'. Logistic regression models were used to evaluate whether low castes had higher risk to be 'late presenters' compared to the rest of castes and whether 'late presenters' had poorer indicators at admission (i.e. haemoglobin level, spleen size).

RESULTS

After adjusting for age, gender and distance to VL treatment facility, Mushars (the lowest caste in Bihar) had twice the odds to be 'late presenters' compared to the rest of castes (OR 2.05, 95% CI: 1.24-2.38). Subjects that had VL symptoms for ≥8 weeks had a larger spleen and lower haemoglobin level than those that were treated earlier.

CONCLUSION

Low castes have poor access to VL treatment in Bihar, and late presenters have poorer clinical indicators at admission. These findings have implications at individual and community levels and should stimulate targeted VL control programmes to ensure that marginalized communities in Bihar are properly treated.

Economic consequences of post-kala-azar dermal leishmaniasis in a rural Bangladeshi community

Post-kala-azar dermal leishmaniasis (PKDL) is a complication of visceral leishmaniasis. Bangladesh national treatment guidelines during the study period called for 120 intramuscular injections of sodium antimony gluconate (SAG). We assessed care-seeking behavior, diagnosis and treatment costs, and coping strategies among 134 PKDL patients; 56 (42%) patients had been treated with SAG, and 78 (58%) remained untreated. The median direct cost per patient treated was US$367 (interquartile range [IQR] = 90-284), more than two times the estimated per capita annual income for the study population. The most common coping strategy was to take a loan; the median amount borrowed was US$98 (IQR = 71-150), with a median interest of US$32 (IQR = 16-95). Households lost a median of 123 work-days per patient treated. The current regimen for PKDL imposes a significant financial burden, reinforcing the link between poverty and visceral leishmaniasis. More practical shorter-course regimens for PKDL are urgently needed to achieve national and regional visceral leishmaniasis elimination goals.

Bionomics of phlebotomine sand flies from three villages in Bihar, India

This study examined the spatial distribution and seasonal fluctuations of population densities of phlebotomine sand flies and was designed to obtain baseline data on the population trends of Phlebotomus argentipes, P. papatasi, and Sergentomyia spp. in a visceral leishmaniasis endemic area of Bihar, India. Beginning on 28 October 2009 and through 20 October 2010, 63 CDC light traps were evenly distributed in human homes, cattle sheds, combined dwellings, chicken coops, and adjacent vegetation areas in three villages in the Saran District of Bihar State. Sand fly collections were made on a weekly basis, sorted, and identified according to species, sex, and feeding status of the two genera. The daily temperatures and relative humidity ranges were collected in a representative human home, cattle shed, and combined dwelling in each of the three study villages. Village census surveys were conducted in the three study villages in February 2010, acquiring human population data, structural composition data, and livestock census information, and documenting the history of visceral leishmaniasis within each household. A total of 52,653 sand flies was trapped and identified over 3,276 trap-nights. Peaks in abundance were observed in November 2009, March and April, June through August. Of the sand flies trapped, 72.1% were P. argentipes, 27.1%Sergentomyia spp., and 0.8%P. papatasi. Distribution of the sand fly captures included 30.6%, 26.7%, 18.6%, 12.1%, and 12.0% from vegetation, combined dwellings, cattle sheds, housing, and poultry houses, respectively.

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.

Classification and regression tree and spatial analyses reveal geographic heterogeneity in genome wide linkage study of Indian visceral leishmaniasis

Background

Genome wide linkage studies (GWLS) have provided evidence for loci controlling visceral leishmaniasis on Chromosomes 1p22, 6q27, 22q12 in Sudan and 6q27, 9p21, 17q11-q21 in Brazil. Genome wide studies from the major focus of disease in India have not previously been reported.

Methods and Findings

We undertook a GWLS in India in which a primary ∼10 cM (515 microsatellites) scan was carried out in 58 multicase pedigrees (74 nuclear families; 176 affected, 353 total individuals) and replication sought in 79 pedigrees (102 nuclear families; 218 affected, 473 total individuals). The primary scan provided evidence (≥2 adjacent markers allele-sharing LOD≥0.59; nominal P≤0.05) for linkage on Chromosomes 2, 5, 6, 7, 8, 10, 11, 20 and X, with peaks at 6p25.3-p24.3 and 8p23.1-p21.3 contributed to largely by 31 Hindu families and at Xq21.1-q26.1 by 27 Muslim families. Refined mapping confirmed linkage across all primary scan families at 2q12.2-q14.1 and 11q13.2-q23.3, but only 11q13.2-q23.3 replicated (combined LOD = 1.59; P = 0.0034). Linkage at 6p25.3-p24.3 and 8p23.1-p21.3, and at Xq21.1-q26.1, was confirmed by refined mapping for primary Hindu and Muslim families, respectively, but only Xq21.1-q26.1 replicated across all Muslim families (combined LOD 1.49; P = 0.0045). STRUCTURE and SMARTPCA did not identify population genetic substructure related to religious group. Classification and regression tree, and spatial interpolation, analyses confirm geographical heterogeneity for linkages at 6p25.3-p24.3, 8p23.1-p21.3 and Xq21.1-q26.1, with specific clusters of families contributing LOD scores of 2.13 (P = 0.0009), 1.75 (P = 0.002) and 1.84 (P = 0.001), respectively.

Conclusions

GWLS has identified novel loci that show geographical heterogeneity in their influence on susceptibility to VL in India.

Impact of socio-economic conditions on the incidence of visceral leishmaniasis in Bihar, India

Visceral leishmaniasis (VL) is one of the world's worst parasitic killers, second only to Malaria, claiming thousands of lives every year. More than three fifths of the world's VL cases occur in the Indian state of Bihar alone. While some research has been conducted with emphasis on the effects of climatic variables on the VL incidence rate, rigorous analysis of the effects of socio-economic variables is still lacking. In this paper a regression model is developed that describes the relationship between VL incidence rate and a variety of socio-economic factors. It uses data from 2005 and explains 92% of the observed variance. In addition, a stepwise regression model is also used to identify the most important factors that facilitate the prevalence of the VL disease. A discussion on how to most effectively distribute Bihar's limited resources on various control measures to decrease the incidence of VL is also presented.

Study of house-level risk factors associated in the transmission of Indian Kala-azar

BACKGROUND

In visceral leishmaniasis (VL), phlebotomine vectors are the main target to reduce for control measures. An attempt has been taken to delineate the association between Phlebotomous argentipes and housing characteristics between two districts e.g. endemic and non-endemic.

METHODS

A cross-sectional survey was conducted on 240 households for both the endemic (Vaishali district) and non-endemic (Lohardaga district) site. Logistic regression analysis was used to identify factors related to housing characteristics influencing suitable habitats for P. argentipes. Vector density estimated using a CDC light trap.

RESULTS

The proportion of P. argentipes in both endemic and non-endemic areas was significantly much higher (P < 0.001) when compared with the proportion of Sergentomiya and P. papatasi. The results of multilevel logistic regression analysis showed that mud plastered wall (P value = 0.001), mixed dwelling (P value = 0.002) and area (P value = 0.001) were strongly associated with the presence of vectors.

CONCLUSION

Result of the studied household characteristics provides an accurate, rapid assessment of house-level variation in risk. The results also have implications for maximizing surveillance efficacy of sandflies, which is likely to become increasingly important while formulating any control strategy.

Asymptomatic infection with visceral leishmaniasis in a disease-endemic area in bihar, India

A prospective study was carried out in a cohort of 355 persons in a leishmaniasis-endemic village of the Patna District in Bihar, India, to determine the prevalence of asymptomatic persons and rate of progression to symptomatic visceral leishmaniasis (VL) cases. At baseline screening, 50 persons were positive for leishmaniasis by any of the three tests (rK39 strip test, direct agglutination test, and polymerase chain reaction) used. Point prevalence of asymptomatic VL was 110 per 1,000 persons and the rate of progression to symptomatic cases was 17.85 per 1,000 person-months. The incidence rate ratio of progression to symptomatic case was 3.36 (95% confidence interval [CI] = 0.75-15.01, P = 0.09) among case-contacts of VL compared with neighbors. High prevalence of asymptomatic persons and clinical VL cases and high density of Phlebotomus argentipes sand flies can lead to transmission of VL in VL-endemic areas.

Cost-effectiveness analysis of combination therapies for visceral leishmaniasis in the Indian subcontinent

Background

Visceral leishmaniasis is a systemic parasitic disease that is fatal unless treated. We assessed the cost and cost-effectiveness of alternative strategies for the treatment of visceral leishmaniasis in the Indian subcontinent. In particular we examined whether combination therapies are a cost-effective alternative compared to monotherapies.

Methods and Findings

We assessed the cost-effectiveness of all possible mono- and combination therapies for the treatment of visceral leishmaniasis in the Indian subcontinent (India, Nepal and Bangladesh) from a societal perspective using a decision analytical model based on a decision tree. Primary data collected in each country was combined with data from the literature and an expert poll (Delphi method). The cost per patient treated and average and incremental cost-effectiveness ratios expressed as cost per death averted were calculated. Extensive sensitivity analysis was done to evaluate the robustness of our estimations and conclusions. With a cost of US$92 per death averted, the combination miltefosine-paromomycin was the most cost-effective treatment strategy. The next best alternative was a combination of liposomal amphotericin B with paromomycin with an incremental cost-effectiveness of $652 per death averted. All other strategies were dominated with the exception of a single dose of 10mg per kg of liposomal amphotericin B. While strategies based on liposomal amphotericin B (AmBisome) were found to be the most effective, its current drug cost of US$20 per vial resulted in a higher average cost-effectiveness. Sensitivity analysis showed the conclusion to be robust to variations in the input parameters over their plausible range.

Conclusions

Combination treatments are a cost-effective alternative to current monotherapy for VL. Given their expected impact on the emergence of drug resistance, a switch to combination therapy should be considered once final results from clinical trials are available.

Visceral leishmaniasis (VL) is a serious health problem in the Indian subcontinent affecting the rural poor. It has a significant economic impact on concerned households. The development of drug resistance is a major problem and threatens control efforts under the VL elimination initiative. With an unprecedented choice of antileishmanial drugs (but no newer compound in clinical development), policies that protect these drugs against the emergence of resistance are required. A possible strategy that has been successfully used for malaria and tuberculosis is the use of combination therapies. This study is the first comprehensive assessment of the cost-effectiveness of all possible mono- and combination therapies for the treatment of visceral leishmaniasis in the Indian subcontinent. The analysis was done from the societal perspective, including both health provider and household costs. The present work shows that combination treatments are a cost-effective alternative to current monotherapy for VL. Given their expected impact on emergence of drug resistance, the use of combination therapy should be considered in the context of the VL elimination programme in the Indian subcontinent.

Annual incidence of visceral leishmaniasis in an endemic area of Bihar, India

The study presents the findings of a population-based survey of the annual incidence of visceral leishmaniasis (VL) in the rural areas of one VL-endemic district in Bihar, India. Stratified multi-stage sampling was applied in the selection of blocks, villages, hamlets, and households. We screened 15 178 households (91 000 individuals) in 80 villages in 7 of 27 administrative blocks of the district, East Champaran. We identified 227 VL cases that occurred in the past 12 months: 149 treated individuals who survived, 14 who died from VL, and 64 active cases. The high-incidence stratum had an estimated incidence of 35.6 cases per 10 000 persons per year (90% CI: 27.7-45.7). The annual incidence rate in the medium stratum areas was 16.8 cases per 10 000 (90% CI: 9.3-30.6). The combined annual incidence rate for the high and medium areas combined was 21.9 cases per 10 000 per year, (90% CI: 14.0-34.2). The Government of India's VL elimination goal is to reduce the VL incidence to one case per 10 000 at the sub-district level; thus, a 35-fold reduction will be required in those areas with the highest VL incidence.

Estimation of under-reporting of visceral leishmaniasis cases in Bihar, India

We estimated the level of under-reporting of visceral leishmaniasis (VL) cases by comparing the actual reported cases with those expected as estimated using age- and sex-stratified incidence proportions obtained in a cohort of 31,324 persons. The average incidence proportion of VL cases in study population was 5.7/1,000 (95% confidence interval [CI] = 4.88-6.54) and 1.09/1,000 persons (95% CI = 0.99-1.20) based on the reported cases in two primary health centers. The overall magnitude of VL cases not reported to the government agencies was higher by a factor 4.17 (95% CI = 3.75-4.63) than for reported cases. The levels of under-reporting were 4.74 (95% CI = 4.11-5.47) in males and 3.51 (95% CI = 2.99-4.11) in females with no significant difference (P > 0.05). It was significantly higher in persons >or= 30 years of age than in persons 30 years of age (P < 0.05).

Clinical risk factors for therapeutic failure in kala-azar patients treated with pentavalent antimonials in Nepal

Drug-related factors and parasite resistance have been implicated in the failure of pentavalent antimonials (Sb(v)) in the Indian subcontinent; however, little information is available on host-related factors. Parasitologically confirmed kala-azar patients, treatment naïve to Sb(v), were prospectively recruited at a referral hospital in Nepal and were treated under supervision with 30 doses of quality-assured sodium stibogluconate (SSG) 20mg/kg/day and followed for 12 months to assess cure. Analysis of risk factors for treatment failure was assessed in those receiving >or=25 doses and completing 12 months of follow-up. One hundred and ninety-eight cases were treated with SSG and the overall cure rate was 77.3% (153/198). Of the 181 cases who received >or=25 doses, 12-month follow-up data were obtained in 169, comprising 153 patients (90.5%) with definite cure and 16 (9.5%) treatment failures. In the final logistic regression model, increased failure to SSG was significantly associated with fever for >or=12 weeks [odds ratio (OR)=7.4], living in districts bordering the high SSG resistance zone in Bihar (OR=6.1), interruption of treatment (OR=4.3) and ambulatory treatment (OR=10.2). Early diagnosis and supervised treatment is of paramount importance to prevent treatment failures within the control programme.

Anthropometrically derived dosing and drug costing calculations for treating visceral leishmaniasis in Bihar, India

OBJECTIVE AND METHOD

To estimate drug costs of treating visceral leishmaniasis (VL) based on data on the VL population structure from the high-burden, antimony-resistant area of Northern Bihar, India.

RESULTS

Paromomycin is the cheapest option ($7450 to treat 1000 patients). Treating 1000 patients with oral miltefosine would cost $119,250 at the current private market price or $64,383-$75,129 at preferential public sector price depending on the size of the order. With AmBisome it would be $163,600 or $229,500 depending on the dose (10 or 15 mg/kg total). These costs are without considering other direct costs (daily intramuscular injections for 3 weeks for paromomycin; intravenous devices and hospitalization for AmBisome; directly observed treatment if applied for miltefosine) and indirect costs.

CONCLUSION

These calculations provide useful basic information for projections.

Visceral leishmaniasis is preventable in a highly endemic village in West Bengal, India

In 2004, following a cluster of kala-azar cases in Chatrakhali, West Bengal, India, we screened and treated this endemic village for leishmaniasis infection. In 2005, following new reports of kala-azar, we screened the village again and conducted a retrospective cohort study (exposure period: August 2004 to July 2005). We defined an incident case of leishmaniasis as a new seropositive sample (>or=1:1600 dilution in a direct agglutination test) in a person seronegative in 2004. We obtained information about potential risk factors and calculated the relative risk (RR) of infection for exposure to these factors. One hundred and fifty (20%) of the 751 residents acquired leishmaniasis in 1 year. Factors associated with infection included residing in homes with mud walls (RR 4.3), dampness in the home (RR 2.5), proximity to bodies of water (RR 2.5) and livestock ownership (RR 2.4). Sleeping dressed (RR 0.4), or under a bed net (RR 0.5) or in a cot (RR 0.6) were associated with a lower risk. High rates of infection indicated that transmission persisted in this community. Poor housing conditions were associated with a higher risk, while personal protection measures against vectors were effective. Major housing improvement and personal protection efforts are needed to protect this vulnerable population from leishmaniasis.

Complexities of assessing the disease burden attributable to leishmaniasis

Among parasitic diseases, morbidity and mortality caused by leishmaniasis are surpassed only by malaria and lymphatic filariasis. However, estimation of the leishmaniasis disease burden is challenging, due to clinical and epidemiological diversity, marked geographic clustering, and lack of reliable data on incidence, duration, and impact of the various disease syndromes. Non-health effects such as impoverishment, disfigurement, and stigma add to the burden, and introduce further complexities. Leishmaniasis occurs globally, but has disproportionate impact in the Horn of Africa, South Asia and Brazil (for visceral leishmaniasis), and Latin America, Central Asia, and southwestern Asia (for cutaneous leishmaniasis). Disease characteristics and challenges for control are reviewed for each of these foci. We recommend review of reliable secondary data sources and collection of baseline active survey data to improve current disease burden estimates, plus the improvement or establishment of effective surveillance systems to monitor the impact of control efforts.

Amphotericin B Treatment for Indian Visceral Leishmaniasis: Response to 15 Daily versus Alternate-Day Infusions

BACKGROUND

For patients with Indian visceral leishmaniasis, amphotericin B deoxycholate is usually given as 15 alternate-day infusions of 1 mg/kg over 30 days (total dose, 15 mg/kg); daily treatment with 1 mg/kg for 20 days (total dose, 20 mg/kg) is also used. This study was done to address the unsettled therapeutic questions of administration schedule (alternate-day vs. daily administration) and dose (1 vs. 0.75 mg/kg) and to determine whether the duration of amphotericin B treatment in Bihar, India, can be shortened to 15 days.

METHODS

To compare alternate-day versus daily administration and 1-mg/kg versus 0.75-mg/kg doses and to determine whether the duration of treatment could be abbreviated, Indian subjects randomly received 15 infusions of 1 mg/kg (group A; 245 patients) or 0.75 mg/kg (group B; 244 patients) on alternate days or 1 mg/kg (group C; 500 patients) or 0.75 mg/kg (group D; 496 patients) daily. Noninferiority testing compared 6-month cure rates using a 5% margin.

RESULTS

Overall, 1439 of the 1485 subjects completed treatment and responded. Treatment interruptions (nephrotoxicity) but not infusion-associated reactions or study removals were more common with daily administration. Final cure rates at 6 months were similar: group A, 234 patients (96%; 95% confidence interval [CI], 92%-98%); group B, 225 patients (92%; 95% CI, 88%-95%); group C, 483 patients (97%; 95% CI, 95%-98%); and group D, 476 patients (96%; 95% CI, 94%-97%; P>.05).

CONCLUSIONS

Provided that the serum creatinine level is repeated once, daily treatment with amphotericin B, 0.75 mg/kg for 15 days (total dose, 11.25 mg/kg), is efficient and effective for visceral leishmaniasis in India.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00310505.

Drug policy for visceral leishmaniasis: a cost-effectiveness analysis

OBJECTIVE

To facilitate the choice of the best visceral leishmaniasis (VL) treatment strategy for first-line health services in (VL)-endemic areas, we compared in a formal decision analysis the cost and the cost-effectiveness of the different available options.

METHODS

We selected four drug regimens for VL on the basis of frequency of use, feasibility and reported efficacy studies. The point estimates and the range of plausible values of effectiveness and cost were retrieved from a literature review. A decision tree was constructed and the strategy minimizing the cost per death averted was selected.

RESULTS

Treatment with amphotericin B deoxycholate was the most effective approach in the baseline analysis and averted 87.2% of all deaths attributable to VL. The least expensive and the most cost-effective treatment was the miltefosine regimen, and the most expensive and the least cost-effective was AmBisome treatment. The cost of drug and medical care are the main determinants of the cost-effectiveness ranking of the alternative schemes. Sensitivity analysis showed that antimonial was competitive with miltefosine in the low-resistance regions.

CONCLUSION

In areas with >94% response rates to antimonials, generic sodium stibogluconate remains the most cost-effective option for VL treatment, mainly due to low drug cost. In other regions, miltefosine is the most cost-effective option of treatment, but its use as a first-line drug is limited by its teratogenicity and rapid resistance development. AmBisome in mono- or combination therapy is too expensive to compete in cost-effectiveness with the other regimens.

Costs of patient management of visceral leishmaniasis in Muzaffarpur, Bihar, India

OBJECTIVES

To identify and quantify the direct and indirect economic cost of treatment for visceral leishmaniasis (VL) with conventional Amphotericin B deoxycholate, currently the first-line treatment in Muzaffarpur.

METHODS

Costs of patient management for VL were estimated from a societal and household perspective by means of a questionnaire designed for this study, interviews and financial reports.

RESULTS

The total cost of care per episode of VL from the societal perspective was estimated at US$355, equivalent to 58% of annual household income. The largest cost category was medical costs (55%), followed by indirect costs (36%) and non-medical costs (9%). The cost from the household perspective was equivalent to US$217. The largest cost category was indirect costs (59%), followed by medical costs (27%) and non-medical costs (15%). Loss of income because of illness and hospitalization and expenses for drugs were the largest cost components.

CONCLUSIONS

The economic costs related to VL are substantial, both to society and the patient. Public health authorities in Bihar should focus on policies that detect VL in the early stage and implement interventions that minimize the burden to households affected by VL.

Leishmaniasis and poverty

Leishmaniasis, a neglected tropical disease, has strong but complex links with poverty. The burden of leishmaniasis falls disproportionately on the poorest segments of the global population. Within endemic areas, increased infection risk is mediated through poor housing conditions and environmental sanitation, lack of personal protective measures and economically driven migration and employment that bring nonimmune hosts into contact with infected sand flies. Poverty is associated with poor nutrition and other infectious diseases, which increase the risk that a person (once infected) will progress to the clinically manifested disease. Lack of healthcare access causes delays in appropriate diagnosis and treatment and accentuates leishmaniasis morbidity and mortality, particularly in women. Leishmaniasis diagnosis and treatment are expensive and families must sell assets and take loans to pay for care, leading to further impoverishment and reinforcement of the vicious cycle of disease and poverty. Public investment in treatment and control would decrease the leishmaniasis disease burden and help to alleviate poverty.

The economic impact of visceral leishmaniasis on households in Bangladesh

OBJECTIVES

To explore current patterns of diagnosis and treatment, quantify household economic impact and identify household strategies to cover the costs of visceral leishmaniasis (VL) care in rural Bangladesh.

METHOD

Structured interviews with 113 VL patients from 87 households documenting all provider visits and expenditures for health care for VL, and the ways in which the expenditures were covered.

RESULTS

Patients paid a median of 7 visits to six different providers before beginning VL treatment. All visited the subdistrict government hospital at least once. While health care, including antileishmanial drug therapy, is officially available free of charge at government facilities, 79% of patients reported making informal payments for provider access, diagnostics and drug administration; only 14% of patients received their full drug course from this source. For the 58% of patients who purchased the full treatment course, drug cost constituted 34% of direct expenditure. Median direct expenditure for one VL patient was US$87 and median income lost was $40; median total expenditure was 1.2 times annual per capita income of our study population. Households employed multiple coping strategies to cover expenditures, most commonly sale or rental of assets (62%) and taking out loans (64%).

CONCLUSIONS

Visceral leishmaniasis treatment causes a major economic burden in affected families. Control strategies for VL should facilitate timely, affordable diagnosis and treatment of patients to decrease the infection reservoir and to alleviate the economic burden of VL on households.