Utility and justice in public health.

Background: Many public health practitioners and organizations view themselves as engaged in the promotion or achievement of equity. However, discussions around public health frequently assume that practitioners and policy-makers take a utilitarian approach to this work.
Methods: I argue that public health is better understood as a social justice endeavor. I begin by presenting the utility view of public health and then discuss the equity view. This is a theoretical argument, which should help public health to justify interventions for communicable and non-communicable diseases equally, and which contributes to breaking down the 'old/new' public health divide.
Results: This argument captures practitioners' views of the work they are engaged in and allows for the moral and policy justification of important interventions in communicable and non-communicable diseases. Systemic interventions are necessary to remedy high rates of disease among certain groups and, generally, to improve the health of entire populations. Conclusions: By viewing diseases as partly the result of failures of health protective systems in society, public health may justify interventions in communicable and non-communicable diseases equally. Public health holds a duty to improve the health of the worst-off in society; by prioritizing this group, the health of the whole community may improve.