During the 1920s, international experts on malaria attempted to find standard ways of measuring the disease's prevalence. The project was fraught with technical difficulties. But it also induced conflicts of interpretation, as the relation between economic development and the decline of malarial prevalence was a hot and divisive topic among specialists. The debate among malaria experts illustrates the emergence of a new, internationalised field of expertise, malariology. It further shows, at a time when international organisations were nascent, how complex making transnational indicators of development can be, and how uncertain the task of elaborating normative international recommandations of policy, based on indicators.
