Over the last several decades, epidemics of chronic kidney disease of unknown aetiology (CKDu) have appeared in Mesoamerica, North Africa, and South Asia. Drawing on 14 months of ethnographic fieldwork in a CKDu-affected village in Sri Lanka, I explore how one CKDu ‘hotspot’ came into being following population screening interventions by a community development organisation, a philanthropic foundation, and a university research group. While the production of test results proved vital to the mobilisation of further research and public health resources for the community, this ethnography reveals philanthropy could be seen to have shaped by screening as much as screening was seen to have influenced by philanthropy. The example of medical screening and philanthropic interventions in Ginnoruwa illustrates how bioindicators of failing kidney function became a key metric for demarcating the community into populations of the deserving (or not so deserving) poorly, which in turn helped to create the pattern of disease prevalence and concentration that led to the community being designated a ‘hotspot’. In Ginnoruwa, philanthropy and screening did not operate independently but constituted a novel hybrid, which I refer to as ‘philanthropic science’.