Designing and Reporting Clinical Trials on Treatments for Cutaneous Leishmaniasis

Abstract

Cutaneous leishmaniasis is considered to be one of the most neglected and serious parasitic infectious skin diseases in many developing countries. We have assessed the design and reporting of randomized, controlled trials evaluating treatments included in 2 Cochrane systematic reviews on cutaneous leishmaniasis. The analysis of the methodological quality identified some potential bias that can make it difficult to determine whether truly effective therapies exist for this disease. We found important weaknesses in the adequacy and transparency of randomization, loss of participants, causative Leishmania species, outcome measures, and follow-up times. Given these distorting effects on the evidence base, we propose guidelines for authors who wish to conduct clinical trials aimed at the development of effective therapies in cutaneous leishmaniasis. The recommendations in this report will hopefully deserve the attention of the World Health Organization and assist in the planning and prioritization of global strategies for improving the interpretation and replication of clinical research on cutaneous leishmaniasis.

Species Typing in Dermal Leishmaniasis

“…This was slightly better in prospective studies, even though typing was done in only 49% of these reports. Based on extensive reviews in the Old World and the New World, Gonzalez et al (19) found similar numbers, with about 50% of clinical studies actually determining the causative species.…”

“…The need to determine the infecting Leishmania species depends largely on the specific context. For clinical and epidemiological studies, confirmation of the infecting species is definitely recommended in all cases (19), preferably using a globally applicable technique that has been validated on all species. In these studies, such an approach is certainly feasible.…”

Drug Discovery Algorithm for Cutaneous Leishmaniasis

“…Treatment may be topical or systemic, but the infecting Leishmania species/strain and geographic region impact treatment efficacy. Few clinical trials have been appropriately designed and reported, 3 especially when compared to the large number of possible combinations of treatments versus Leishmania species versus geographic regions. However, it may be said that because symptoms caused by L. major (Old World) and L. mexicana (New World) generally rapidly self-cure over several months, it is difficult to choose a drug with sufficiently low side effects to give a favorable risk-benefit ratio.…”

“…In contrast, L. tropica (Old World) CL heals more slowly and is generally treated with local or systemic chemotherapy, and New World CL (non-L. mexicana) is treated either to speed healing or prevent dissemination to the oro-nasal mucosa (mucosal leishmaniasis). [2][3][4] Thus, although these treatment strategies are used, each has uncertain cure rates and therapeutic indices. Several species of Leishmania that cause CL are shown in Figure 1.…”

Antileishmanial Activities of Greek Juniper (Juniperus excelsa M.Bieb.) Against Leishmania major Promastigotes

“…8 Additionally, nonpharmacological interventions such as cryotherapy, localized controlled heat, and photodynamic therapy are also used to treat the cutaneous type. [9][10][11] In spite of various chemical medicaments applied for the treatment of this disease, results have not yet been satisfactory. Thus, seeking for new and safe medication is considered crucial.…”