Analysis is ongoing with expected completion of the research activity by March-2022. Publication is expected by mid-2022 and dissemination of results will follow.

Visceral Leishmaniasis (VL) is a vector-borne disease transmitted by sandflies and caused by protozoan parasites of the genus Leishmania. An estimated 50,000 to 90,000 new cases of VL occur worldwide annually. The disease is fatal if untreated. The ultimate endpoint of parasitological efficacy is defined as the absence of relapse within the follow-up period after achieving initial cure upon the completion of treatment. Most clinical efficacy studies adopt a 6-month follow-up post-treatment to capture relapsing cases. Relapses after 6 months have been reported in observational cohorts leading to suggestion that a longer follow-up period may be warranted [1].

This project aims to quantify the proportion of relapses observed in VL patients at 6 and 12 months of follow-up after treatment with an antileishmanial drug. The specific objectives are:

1. To estimate the proportion of relapses observed in VL clinical trials stratified by drug regimen, geographical region, follow-up duration, and mg/kg drug dosage administered
2. To estimate the proportion of relapses captured at 6-months and at 12-months in studies with a follow-up duration longer than 6 months

This research will utilise data from the studies indexed in the IDDO VL living systematic review of all published clinical studies.

The following inclusion criteria is adopted:

1. Studies with at least 6 months of post-treatment follow-up period
2. Studies that aimed to capture relapse during the post-treatment follow-up period

The following studies will be excluded

1. Studies with unclear information regarding the follow-up duration
2. Studies not reporting the number of patients who were initially cured
3. Studies that enrolled patients with HIV co-infection

Data on the following aspects of the included studies were extracted: study design, location, publication year, age range of the participants, total number of participants enrolled including the number of patients achieving initial cure, relapse. When reported, the number of the patients with these outcomes were extracted for each of the following time-interval: within 6 months of post-treatment follow-up, between 6-12 months or after 1 year of follow-up. The proportion of patients with relapse will be combined using random effects meta-analysis after applying logit transformation. The pooled estimates will be presented together with the associated 95% confidence intervals (95% CIs) and sub-group meta-analyses will be undertaken to explore potential sources of heterogeneity. 

For further information on this research activity, please contact Rutuja Chhajed (vl@iddo.org) or Prabin Dahal (prabin.dahal@iddo.org) or Sauman Singh (sauman.singh@iddo.org).

1. Burza S, Sinha PK, Mahajan R, Lima MA, Mitra G, Verma N, et al. Risk Factors for Visceral Leishmaniasis Relapse in Immunocompetent Patients following Treatment with 20 mg/kg Liposomal Amphotericin B (Ambisome) in Bihar, India. PLoS Negl. Trop. Dis. 2014;8:44.