Cholera is a contagious disease. It spreads by water and food that has been contaminated with human feces containing the bacteria. Risk factors for the disease are poor sanitation, not enough clear drinking water, and poor hygiene. Cholera occurs both in outbreaks and, in certain areas, it is chronically present. One of the main ways to prevent cholera is by improving sanitation and access to clean water. These public health approaches help combat cholera, and prevent it from spreading further.

Violence is typically studied within the criminal justice domain, rather than in the public health domain. This is surprising, particularly given the wide-range impact violence has on individuals, communities and society at large. Similar to cholera, violence is most prevalent in developing countries, and clustered around poor neighborhoods. Also, similar to infectious diseases, there are clear predictors: The greatest predictor of a case of violence is a preceding case of violence. Why not treat violence, then, as a contagious disease?

For any contagious disease, public health approaches use primary prevention, secondary and tertiary prevention. Primary prevention is aimed at the whole population, for example by giving access to clean water. Secondary prevention targets those who are at-risk to get ill, for example by screening or selective examination. Tertiary prevention aims at already infected individuals, by giving them medication or surgery. In violence, this could work in very similar ways. At the Conference on Governance, Crime and Justice Statistics, organized by the United Nations Office on Drugs and Crime and the Mexican Instituto Nacional de Estadística y Geografía, Richard Wortley, from University College London, advocates this approach.

To combat violence from a public health approach, primary prevention should aim at shifting norms about violence on a societal level. Secondary prevention should tackle those at risk: Here, neighborhood programs come in to identify at-risk individuals and offer intervention programs to prevent further spread. That means to find out who has been exposed to violence. Much like in the case of cholera, this may be someone who has witnessed violence, who is part of the same group whose members have been violent or who have been victims of violence, and is at similar risk of being infected. Tertiary violence, then, consists of punishing and at the same time, rehabilitating those who have been violent and heal the wounds of those who have been the victims of violence.

By now, this approach has gained much support. And it has paid off. In areas of the world where violence is rampant, these interventions have shown 40% to 70% reductions in shootings and killings. In other words, just like public health interventions were able to combat cholera using primary, secondary and tertiary prevention, so have these interventions been able to combat violence. This allows for a new approach, and a new set of evidence-based methods, moving away from emotions that oftentimes obscure our judgment.