Letter to the Editor
May 2018

Metaphorically or Not, Violence Is Not a Contagious Disease

Michael B. Greene, PhD
AMA J Ethics. 2018;20(5):513-515. doi: 10.1001/journalofethics.2018.20.5.corr1-1805.


Slutkin, Ransford, and Zvetina argue that violence is an epidemic that is efficaciously treated as a contagious disease. The tradition of framing violence as a preventable public health issue, dating from the 1979 Surgeon General’s report [1], certainly has proven invaluable in developing violence prevention strategies and has helped in our understanding of the multiple and reciprocal links among violent victimization and health and behavioral health problems. For example, the American Academy of Pediatrics issued a protocol in 1996 to respond to adolescent assault victims and outlined the dangers of a treat-and-release approach [2]. We have also learned much about the nature and treatment of the psychological trauma that arises from exposure to violence as a witness and as a victim. These advances are certainly highlighted and endorsed in this article. Nevertheless, to approach violence with a “disease” model is misleading at best, and could be harmful.

First, the authors describe violence—more particularly, homicide—as an epidemic. However, for a “disease” to be categorized as an epidemic, the observed prevalence rate must increase over the expected prevalence rate. Thus we need to be careful about which baseline we choose for the expected prevalence. If, for example, we choose the late 1980s and early 1990s as our base—a period in which homicide rates spiked across the country [3]—we would conclude that current levels of violence represent a substantial reduction in violence perpetration and victimization. Moreover, the homicide rate in the United States has generally declined since the mid-1990s [4]. This is not to suggest that current homicide rates are acceptable but rather that we need to be careful in the terminology we use to describe these rates.

More importantly, we need to be clear that there are no “violence bacteria” or “violence viruses,” no violence parasites or pathogens. Violence is not airborne or contagious by touch or breath. There is no violence “germ” within individuals that can be suppressed. Certainly, as acknowledged by the authors, there are neighborhoods and communities in which violence is substantially concentrated. However, this geographic concentration of violence is driven not by contagion from person to person. Rather, geographic concentration of violence, as documented in a large literature on the structural covariates of homicide and related topics, is driven by known geographic risk factors, including but not limited to urbanicity or higher levels of population size and density [5]; high levels of intergenerational and concentrated poverty and associated poor housing, unemployment, and underfunded schools [5, 6]; structural racism [7]; high levels of lead exposure [8]; low levels of trust between community members and law enforcement and no accountability for unwarranted use of force by the police [9]; low levels of collective efficacy (i.e., social cohesion and willingness to intervene for the common good) [10]; absence of family cohesion as measured by male divorce rates [5]; and inadequate outlets for participation in prosocial and empowering activities as measured by the number of not-for-profit neighborhood organizations [5, 11].

The primary driver of violence is not some abstract violence germ but rather has to do severe deprivations and oppression that the residents in such neighborhoods face on a daily basis. So the parallel in public health should not be the contagious disease model but rather the effects of toxic environments that we know are the root of noncontagious diseases such as asthma and malaria. The most efficacious strategies to reduce the prevalence of such diseases involve efforts to reduce the environmental toxins responsible for the diseases—infectious mosquitoes, contaminated water, and so on. We should all welcome programs like Cure Violence that undertake to alter the norms, such as retaliatory violence, that fuel violence. Nevertheless, an exclusive focus on such norms will not substantially reduce the problem. Without a central focus on the reduction of oppressive economic factors that kill hope, the omnipresence of failing schools, the absence of opportunities to thrive and to make a difference, and the ever-present impact of structural racism, we will never cure the so-called epidemic of violence.


  1. US Department of Health, Education, and Welfare. Healthy People: The Surgeon General’s Report on Health Promotion and Disease Prevention. Washington, DC: US Government Printing Office; 1979. PHS publication 79-55071. https://profiles.nlm.nih.gov/ps/access/NNBBGK.pdf. Accessed March 27, 2018.

  2. American Academy of Pediatrics Task Force on Adolescent Assault Victim Needs. Adolescent assault victim needs: a review of issues and a model protocol. Pediatrics. 1996;98(5):991-1001.
  3. Cooper A, Smith EL. Homicide trends in the United States, 1980-2008. Washington, DC: US Department of Justice Office; November 2011. https://www.bjs.gov/content/pub/pdf/htus8008.pdf. Accessed March 27, 2018.

  4. Friedman M, Grawert AC, Cullen J. Crime trends: 1990-2016. New York, NY: Brennan Center for Justice; 2017. https://www.brennancenter.org/sites/default/files/publications/
    . Accessed March 27, 2018.

  5. McCall PL, Land KC, Parker KF. An empirical assessment of what we know about structural covariates of homicide rates: a return to a classic 20 years later. Homicide Stud. 2010;14(3):219-243.
  6. Alexander K, Entwisle D, Olson L. The Long Shadow: Family Background, Disadvantaged Urban Youth, and the Transition to Adulthood. New York, NY: Russel Sage Foundation; 2014.

  7. Jacoby SF, Dong B, Beard JH, Wiebe DJ, Morrison CN. The enduring impact of historical and structural racism on urban violence in Philadelphia. Soc Sci Med. 2018;199:87-95.

  8. Narag RE, Pizarro J, Gibbs C. Lead exposure and its implications for criminological theory. Crim Justice Behav. 2009;36(9):954-973.
  9. Tyler TR, Fagan J. Legitimacy and cooperation: why do people help the police fight crime in their communities? Ohio State J Crim Law. 2008;6(1):231-275.

  10. Sampson RJ, Raudenbush SW. Neighborhoods and violent crime: a multilevel study of collective efficacy. Science. 1997;277(5328):918-924.
  11. Sharkey P, Torrats-Espinosa G, Takyar D. Community and the crime decline: the causal effect of local nonprofits on violent crime. Am Sociol Rev. 2017;82(6):1214-1240.


AMA J Ethics. 2018;20(5):513-515.



The viewpoints expressed in this article are those of the author(s) and do not necessarily reflect the views and policies of the AMA.