Surveillance and the global fight against cholera: Setting priorities and tracking progress

Prior to 1961, there were six known cholera pandemics. In each case, after 6–24 years of global spread cholera appears to have died out. In contrast, the current seventh pandemic that emerged around 1961 continues to cause significant disease globally. Recent outbreaks occurring in the wake of conflict and natural disasters, notably those in Haiti, Yemen and South Sudan, have highlighted the human toll of cholera. Annual cholera seasons throughout South Asia and sub-Saharan Africa have become the norm. At the same time, new tools for cholera control are increasingly available, in particular, effective low-cost oral cholera vaccines (OCVs). These developments have catalyzed global cholera control efforts including the call for an international effort to end cholera as a public health threat by 2030. Past experience with smallpox, polio and malaria has taught us that such disease elimination efforts not only call for expanded control activities, but also substantial improvements in surveillance – from its essential role in allocating resources to how case finding, and case definitions, must change as we come closer to reaching our goals. However, cholera’s specific epidemiology poses unique challenges that must be addressed to move forward. Here, building on lessons from historical efforts, we propose three pillars for success in setting priorities and measuring progress in the fight against cholera: consistent reporting across time and space, appropriate indicators and matching interventions to populations.