Failure of Miltefosine Treatment for Visceral Leishmaniasis in Children and Men in South-East Asia

Background: High frequency of relapse in miltefosine-treated visceral leishmaniasis (VL) patients in India and Nepal followed up for twelve months. Objective: To identify epidemiological and clinical risk factors for relapse of VL in patients recently treated with standard dosing of miltefosine in India and Nepal. Design: Prospective observational study in three Primary Health Centers and one reference center in Muzaffarpur district, Bihar, India; and two zonal hospitals and a university hospital in South-east Nepal; records of all consenting patients diagnosed with VL and treated with miltefosine according to the current treatment guidelines of the Kala azar elimination program between 2009 and 2011. Results: We compared the clinical records of 78 cases of relapse with those of 775 patients who had no record of subsequent relapse. Relapse was 2 times more common amongst male patients (IRR 2.14, 95 % CI 1.27–3.61), and 2 to 3 times more frequent in the age groups below 15 compared to the over 25 year olds (age 10 to 14: IRR 2.53; 95 % CI 1.37–4.65 and Age 2 to 9: IRR 3.19; 95 % CI 1.77–5.77). History of earlier VL episodes, or specific clinical features at time of diagnosis such as duration of symptoms or spleen size were no predictors of relapse. Conclusions: Young age and male gender were associated with increased risk of VL relapse after miltefosine, suggestin