Visceral Leishmaniasis in Bihar State, India

The World Health Organisation-supported visceral leishmaniasis (VL) elimination initiative in the Indian subcontinent does not aim at zero transmission of L.donovani, but at ‘reducing the VL incidence rates in the region below levels of public health concern’. These were empirically defined as an incidence rate below 1 per 10,000 population per year in each implementing unit (sub-district level in Bangladesh and India and district level in Nepal). The regional VL elimination initiative is well on track to achieve this target: Nepal has reached and maintained the target for the last 3 years, Bangladesh has achieved it in over 90% of its endemic subdistricts and India in 70% (Source: WHO). The total reported VL case load in the region has diminished from over 50,000 in 2006 to less than 10,000 in 2015 (see Figure 1), with India reporting more than 90 percent of the latter cases.
From a public health perspective, two main questions arise today. First, is the observed decrease in reported VL cases attributable to the elimination efforts or due to a natural decline in the cyclical VL trend? To answer this, one requires an intensification of epidemiological surveillance efforts in the next ten years, combined with intense outbreak investigation. Secondly, a major question for the international community remains whether there is a scope or not for extending the VL elimination target in this region to one of “zero transmission”. If this was technically possible and operationally achievable, it would dramatically change the investment case and the long-term perspectives for this elimination effort. The overall goal of this TMRC3 project is to consolidate the role of the TMRC as a center of excellence for the epidemiological surveillance of the VL elimination initiative, building on its unique position as a health and demographics surveillance site (HDSS).