The Impact of Economic Crises on Communicable Disease Transmission and Control: A Systematic Review of the Evidence Marc Suhrcke1, David Stuckler2, Jonathan E. Suk3, Monica Desai4, Michaela Senek1, Martin McKee4, Svetla Tsolova3, Sanjay Basu5, Ibrahim Abubakar1, Paul Hunter1, Boika Rechel1, Jan C. Semenza3* 1 Norwich School of Medicine, University of East Anglia, Norwich, United Kingdom, 2 Harvard School of Public Health, Boston, Massachusetts, United States of America, 3 Future Threats and Determinants Section, Scientific Advice Unit, European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden, 4 London School of Hygiene and Tropical Medicine, London, United Kingdom, 5 Department of Medicine, University of California San Francisco, San Francisco, California, United States of America Abstract There is concern among public health professionals that the current economic downturn, initiated by the financial crisis that started in 2007, could precipitate the transmission of infectious diseases while also limiting capacity for control. Although studies have reviewed the potential effects of economic downturns on overall health, to our knowledge such an analysis has yet to be done focusing on infectious diseases. We performed a systematic literature review of studies examining changes in infectious disease burden subsequent to periods of crisis. The review identified 230 studies of which 37 met our inclusion criteria. Of these, 30 found evidence of worse infectious disease outcomes during recession, often resulting from higher rates of infectious contact under poorer living circumstances, worsened access to therapy, or poorer retention in treatment. The remaining studies found either reductions in infectious disease or no significant effect. Using the paradigm of the ‘‘SIR’’ (susceptible-infected-recovered) model of infectious disease transmission, we examined the implications of these findings for infectious disease transmission and control. Key susceptible groups include infants and the elderly. We identified certain high-risk groups, including migrants, homeless persons, and prison populations, as particularly vulnerable conduits of epidemics during situations of economic duress. We also observed that the long-term impacts of crises on infectious disease are not inevitable: considerable evidence suggests that the magnitude of effect depends critically on budgetary responses by governments. Like other emergencies and natural disasters, preparedness for financial crises should include consideration of consequences for communicable disease control. Citation: Suhrcke M, Stuckler D, Suk JE, Desai M, Senek M, et al. (2011) The Impact of Economic Crises on Communicable Disease Transmission and Control: A Systematic Review of the Evidence. PLoS ONE 6(6): e20724. doi:10.1371/journal.pone.0020724 Editor: Jos H. Verbeek, Finnish Institute of Occupational Health, Finland Received December 31, 2010; Accepted May 11, 2011; Published June 10, 2011 Copyright: 2011 Suhrcke et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was conducted by the European Centre for Disease Prevention and Control and contractors hired to support data collection and analysis. ECDC is an international public health agency, similar to CDC in Atlanta, and the authors have no financial interests in the outcome of the studies. No funding bodies had any role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: Jan.Semenza@ecdc.europa.eu Introduction Analyzing the complicated and myriad pathways through which economic crises may have impacted infectious disease transmission is fraught with difficulty. The global economic downturn of the past few years is the result of a financial crisis whose scale is unprecedented in the post-war period. With its proximal origins in overly complex credit instruments [1], the crisis initially led to a tightening of private sector credit, and ultimately the collapse of several financial institutions, sharp increases in public sector debt and declines in global trade, markedly lower and in some cases negative GDP growth, and rising unemployment in many industrialised countries [2]. Although the early signs suggest that a fragile recovery is underway [3], it is clear that recent economic damage, principally inflicted during 2008–2009, has led to severe economic hardship for many governments and citizens across the world. The effects of the financial crisis will almost certainly linger beyond any economic recovery. Inevitably, therefore, concerns have been raised that control of infectious diseases could have been and will continue to be adversely affected by budgetary constraints as well as the social effects of recession [4,5,6]. For example, some countries have cut budgets for infectious disease control, risking disruption of treatment and/or the exacerbation of drug-resistance [7]. Pharmaceutical companies report declines in sales of prescription drugs, especially in countries with high reliance on out-of-pocket spending [8]. Workers have been reluctant to take sick days, fearing unemployment while increasing the risk of disease transmission at work [9]. Marked rises in infectious disease incidence during previous economic crises and downturns raise concerns about the current situation. During the 1990s, countries of the former Soviet Union (FSU) and Eastern Europe experienced a devastating economic crisis, as GDP fell by one-third on average. Concurrently, the incidence, prevalence and mortality of tuberculosis rose markedly, and worsening treatment led to the emergence of drug-resistant strains [10,11]. HIV also increased from relatively low pre-crisis levels; outbreaks of diphtheria [12] and tick-borne encephalitis PLoS ONE | www.plosone.org 1 June 2011 | Volume 6 | Issue 6 | e20724