Cost-effectiveness analysis of diagnostic-therapeutic strategies for visceral leishmaniasis in Brazil

Economic evaluations addressing diagnosis and treatment strategies for neglected tropical diseases: an overview

Neglected tropical diseases (NTDs) are those affecting vulnerable people and causing additional social and economic burden. The aim of this study was to carry out a general overview of the health economic assessments involving the diagnosis and treatment of six NTDs: cutaneous leishmaniasis (CL), Chagas disease, cysticercosis, filariasis, schistosomiasis and visceral leishmaniasis (VL). The literature search was based on two of the main medical literature databases (Medline and SciELO) and identified 46 studies. Twenty-six studies (57%) addressed therapeutic strategies, while other 20 (43%) assessed diagnostic or both diagnostic and therapeutic approaches. The studies were published between 1994 and 2021, and 57% of them (26/46) were carried out in four countries. Cost-effectiveness analyses were conducted in 59% (27/46) of the studies. Economic studies of NTDs have timidly increased in recent years. Despite the improvement of analytical methods, completeness and accuracy of information, there are few new technologies applied to NTDs and public health systems. In addition, economic studies for NTDs are concentrated in a few countries. Thus, this review points out the need for investment in research, development and training of human resources dedicated to the economic analysis in health, especially on NTDs, as a strategy to reduce inequalities by optimizing the use of health resources.

Estimating direct costs of the treatment for mucosal leishmaniasis in Brazil

INTRODUCTION

The objective of this study was to estimate the direct medical costs of the treatment for mucosal leishmaniasis (ML) using three therapeutic approaches in the Brazilian context.

METHODS

We performed this economic assessment from the perspective of the Brazilian public healthcare system. The following therapeutic approaches were evaluated: meglumine antimoniate, liposomal amphotericin B, and miltefosine. Direct medical costs were estimated considering four treatment components: a) drug, b) combined medical products, c) procedures, and d) complementary tests.

RESULTS

Treatment with meglumine antimoniate had the lowest average cost per patient (US$ 167.66), followed by miltefosine (US$ 259.92) in the outpatient treatment regimen. The average cost of treatment with liposomal amphotericin B was US$ 715.35 both in inpatient regimen. In all estimates, the drugs accounted for more than 60% of the total cost for each treatment approach.

CONCLUSIONS

These results demonstrate the marked differences in costs between the therapeutic alternatives for ML. In addition to efficacy rates and costs related to adverse events, our data have the potential to support a complete cost-effectiveness study in the future. Complete analyses comparing costs and benefits for interventions will assist health managers in choosing drugs for ML treatment in Brazil as well as in establishing effective public health policies.

LeishCare®: A Software Designed for the Management of Individuals with Leishmaniases

The aims of this study were to describe a smartphone app aimed at healthcare professionals who work in areas endemic for visceral and tegumentary leishmaniases, and to report the user's perception of the app in these areas. The software, called LeishCare^®, has the following features: data registration, image filter to record the evolution of skin lesions using photos, calculation of a score set to identify the risk of death from visceral leishmaniasis, and guides to the diseases. LeishCare^® was made available to healthcare professionals in endemic municipalities in Brazil, and the perception of potential users was evaluated at baseline and after 6 and 12 months. In the first meeting, 96 (94.1%) of the 102 professionals who knew the app reported positive expectations for its use. The installation of LeishCare^® on the individual device and the evaluation of user perception were completed at 6 months with 16 users and at 12 months with 20 users. More than 90% of the professionals evaluated in both assessments found the information of the app useful. The features related to the calculation of visceral leishmaniasis severity score, and the guides to leishmaniases were the most frequently accessed. Users reported competence gain attributed to the app for all items evaluated. In conclusion, LeishCare^® was found to be a promising tool to help healthcare professionals in endemic areas with leishmaniasis management.

Place of Serology in the Diagnosis of Zoonotic Leishmaniases With a Focus on Visceral Leishmaniasis Due to Leishmania infantum

Leishmaniases are a group of parasitic diseases transmitted through the bite of female phlebotomine sandflies. Depending on the Leishmania species, the reservoirs can be humans (anthroponosis) or different animals (zoonosis). Zoonotic leishmaniasis present several clinical forms in function of the species involved: visceral leishmaniasis (VL), cutaneous leishmaniasis (CL), and muco-cutaneous leishmaniasis (MCL). The biological diagnosis is of utmost importance because the clinical features are not specific. In addition to parasitological and molecular biology (polymerase chain reaction, PCR) assays, serology is routinely used for the diagnosis of leishmaniasis. Indeed, although PCR is more sensitive than serological assays, its implementation is limited to referral laboratories and research centers. Therefore, serology is still a key element for their diagnosis. Here, we discuss the different serological assays available for the diagnosis of zoonotic leishmaniasis. We will review the enzyme-linked immunosorbent assay, immunofluorescence antibody test, immunochromatography test (ICT), direct agglutination test, and western blot as well as the different diagnostic strategies in function of the clinical form (VL, CL, and MCL). We will also discuss the place of serology for detecting asymptomatic carriers and for the follow-up of VL. Depending on the laboratory, different assays can be used, from ICT, which is appropriate for field testing, to a combination of serological tests to improve the sensitivity.

Evaluation of Leishmania infantum pyridoxal kinase protein for the diagnosis of human and canine visceral leishmaniasis

Visceral leishmaniasis (VL) is a highly neglected disease that is present in several countries worldwide. Present-day treatments against this disease are unsuitable, mainly due to the toxicity and/or high cost of drugs. In addition, the development of vaccines is still insufficient. In this scenario, a prompt VL diagnosis was deemed necessary, although sensitivity and/or specificity values of the tests have been. In this context, new antigenic candidates should be identified to be employed in a more precise diagnosis of canine and human VL. In this light, the present study evaluated the diagnostic efficacy of the Leishmania infantum pyridoxal kinase (PK) protein, applied in its recombinant version (rPK). In addition, one specific B-cell epitope derived of the PK sequence was predicted, synthetized, and evaluated as diagnostic marker. Results in ELISA tests showed that the antigens were highly sensitive to VL identification in dogs and human sera, presenting a low reactivity with VL-related disease samples. The recombinant A2 (rA2) protein and L. infantum antigenic preparation (SLA), used as controls, also proved to be highly sensitive in detecting symptomatic cases, although a low sensitivity was found when asymptomatic sera were analyzed. High cross-reactivity was also found when these antigens were evaluated against VL-related disease samples. The post-therapeutic serological follow-up showed that anti-rPK and anti-peptide IgG antibody levels decreased in significant levels after treatment. By contrast, the presence of high levels of the anti-rA2 and anti-SLA antibodies was still detected after therapy. In conclusion, rPK and its specific B-cell epitope should be considered for future studies as a diagnostic marker for canine and human VL.