Vector control is key to the success of the global elimination strategy Visceral leishmaniasis, the most severe form of leishmaniasis, is usually fatal in the absence of treatment. Together India, Nepal, and Bangladesh represent the biggest focus of visceral leishmaniasis in the world. Human to human transmission occurs through the bite of an infected sandfly, with no animal reservoir, a phenomenon known as anthroponotic transmission. Deadly epidemics occur periodically. The two main strategies to control the disease are case management and vector control. In the linked randomised controlled trial (doi:10.1136/bmj.c6760), Picado and colleagues assess the effect of the large scale distribution of longlasting insecticide treated nets on the incidence of visceral leishmaniasis in India and Nepal⇓.1 Randomised controlled trials have shown that insecticide treated bed nets and curtains prevent anthroponotic cutaneous leishmaniasis in Afghanistan, Iran, and Syria.2 3 4 Observational studies in Bangladesh and Nepal found a significantly reduced risk of visceral leishmaniasis in residents who used untreated nets nightly during the hot season.5 6 However, an observational study in Bangladesh found that bed nets had no effect on asymptomatic leishmanial seroconversion.7 Picado and colleagues report the first large scale randomised controlled trial of the effectiveness of a comprehensive distribution programme …