The European experience with testing and surveillance during the first phase of the COVID-19 pandemic.

BACKGROUND: COVID-19 pandemic provides a unique opportunity to learn the challenges encountered by public health emergency preparedness systems, both in terms of problems encountered and adaptations during and after the first wave, as well as successful responses to them. RESULTS: This work draws on published literature, interviews with countries and institutional documents as part of a European Centre for Disease Prevention and Control project that aims to identify the implications for preparedness measurement derived from COVID-19 pandemic experience in order to advance future preparedness efforts in European Union member states. The analysis focused on testing and surveillance themes and five countries were considered, namely Italy, Germany, Finland, Spain and Croatia. Our analysis shown that a country's ability to conduct testing at scale was critical, especially early in the pandemic, and the inability to scale up testing operations created critical issues for public health operations such as contact tracing. Countries were required to develop new strategies, approaches, and policies under pressure and to review and revise them as the pandemic evolved, also considering that public health systems operate at the national, regional, and local level with respect to testing, contact tracing, and surveillance, and involve both government agencies as well as private organizations. Therefore, communication among multiple public and private entities at all levels and coordination of the testing and surveillance activities was critical. CONCLUSION: With regard to testing and surveillance, three capabilities that were essential to the COVID-19 response in the first phase, and presumably in other public health emergencies: the ability to scale-up testing, contact tracing, surveillance efforts; flexibility to develop new strategies, approaches, and policies under pressure and to review and revise them as the pandemic evolved; and the ability to coordinate and communicate in complex public health systems that operate at the national, regional, and local level with respect and involve multiple government agencies as well as private organizations.

Public health preparedness and response synergies between institutional authorities and the community: a qualitative case study of emerging tick-borne diseases in Spain and the Netherlands.

BACKGROUND: Communities affected by infectious disease outbreaks are increasingly recognised as partners with a significant role to play during public health emergencies. This paper reports on a qualitative case study of the interactions between affected communities and public health institutions prior to, during, and after two emerging tick-borne disease events in 2016: Crimean-Congo Haemorrhagic Fever in Spain, and Tick-Borne Encephalitis in the Netherlands. The aim of the paper is to identify pre-existing and emergent synergies between communities and authorities, and to highlight areas where synergies could be facilitated and enhanced in future outbreaks. METHODS: Documentary material provided background for a set of semi-structured interviews with experts working in both health and relevant non-health official institutions (13 and 21 individuals respectively in Spain and the Netherlands), and focus group discussions with representatives of affected communities (15 and 10 individuals respectively). Data from all sources were combined and analysed thematically, initially independently for each country and then for both countries together. RESULTS: Strong synergies were identified in tick surveillance activities in both countries, and the value of pre-existing networks of interest groups for preparedness and response activities was recognised. However, authorities also noted that there were hard-to-reach and potentially vulnerable groups, such as hikers, foreign tourists, and volunteers working in green areas. While the general population received preventive information about the two events, risk communication or other community engagement efforts were not seen as necessary specifically for these sub-groups. Post-event evaluations of community engagement activities during the two events were limited, so lessons learned were not well documented. CONCLUSIONS: A set of good practices emerged from this study, that could be applied in these and other settings. They included the potential value of conducting stakeholder analyses of community actors with a stake in tick-borne or other zoonotic diseases; of utilising pre-existing stakeholder networks for information dissemination; and of monitoring community perceptions of any public health incident, including through social media. Efforts in the two countries to build on the community engagement activities that are already in place could contribute to better preparedness planning and more efficient and timely responses in future outbreaks.

Methodology for assessment of public health emergency preparedness and response synergies between institutional authorities and communities.

BACKGROUND: This paper describes a participatory methodology that supports investigation of the synergistic collaboration between communities affected by infectious disease outbreak events and relevant official institutions. The core principle underlying the methodology is the recognition that synergistic relationships, characterised by mutual trust and respect, between affected communities and official institutions provide the most effective means of addressing outbreak situations. METHODS: The methodological approach and lessons learned were derived from four qualitative case studies including (i) two tick-borne disease events (Crimean-Congo haemorrhagic fever in Spain, 2016, and tick-borne encephalitis in the Netherlands, 2016); and (ii) two outbreaks of acute gastroenteritis (norovirus in Iceland, 2017, and verocytotoxin-producing Escherichia coli [VTEC] in Ireland, 2018). An after-event qualitative case study approach was taken using mixed methods. The studies were conducted in collaboration with the respective national public health authorities in the affected countries by the European Centre for Disease Prevention and Control (ECDC). The analysis focused on the specific actions undertaken by the participating countries' public health and other authorities in relation to community engagement, as well as the view from the perspective of affected communities. RESULTS: Lessons highlight the critical importance of collaborating with ECDC National Focal Points during preparation and planning and with anthropological experts. Field work for each case study was conducted over one working week, which although limiting the number of individuals and institutions involved, still allowed for rich data collection due to the close collaboration with local authorities. The methodology enabled efficient extraction of synergies between authorities and communities. Implementing the methodology required a reflexivity among fieldworkers that ackowledges that different versions of reality can co-exist in the social domain. The method allowed for potential generalisability across studies. Issues of extra attention included insider-outsider perspectives, politically sensitivity of findings, and how to deal with ethical and language issues. CONCLUSIONS: The overall objective of the assessment is to identify synergies between institutional decision-making bodies and community actors and networks before, during and after an outbreak response to a given public health emergency. The methodology is generic and could be applied to a range of public health emergencies, zoonotic or otherwise.

Potential scenarios for the progression of a COVID-19 epidemic in the European Union and the European Economic Area, March 2020.

Two months after the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the possibility of established and widespread community transmission in the European Union and European Economic Area (EU/EEA) is becoming more likely. We provide scenarios for use in preparedness for a possible widespread epidemic. The EU/EEA is moving towards the 'limited sustained transmission' phase. We propose actions to prepare for potential mitigation phases and coordinate efforts to protect the health of citizens.

Preparedness and response against diseases with epidemic potential in the European Union: a qualitative case study of Middle East Respiratory Syndrome (MERS) and poliomyelitis in five member states.

BACKGROUND: EU Decision 1082/2013/EU on serious cross-border health threats provides a legal basis for collaboration between EU Member States, and between international and European level institutions on preparedness, prevention, and mitigation in the event of a public health emergency. The Decision provides a context for the present study, which aims to identify good practices and lessons learned in preparedness and response to Middle East Respiratory Syndrome (MERS) (in UK, Greece, and Spain) and poliomyelitis (in Poland and Cyprus). METHODS: Based on a documentary review, followed by five week-long country visits involving a total of 61 interviews and group discussions with experts from both the health and non-health sectors, this qualitative case study has investigated six issues related to preparedness and response to MERS and poliomyelitis: national plans and overall preparedness capacity; training and exercises; risk communication; linking policy and implementation; interoperability between the health and non-health sectors; and cross-border collaboration. RESULTS: Preparedness and response plans for MERS and poliomyelitis were in place in the participating countries, with a high level of technical expertise available to implement them. Nevertheless, formal evaluation of the responses to previous public health emergencies have sometimes been limited, so lessons learned may not be reflected in updated plans, thereby risking mistakes being repeated in future. The nature and extent of inter-sectoral collaboration varied according to the sectors involved, with those sectors that have traditionally had good collaboration (e.g. animal health and food safety), as well as those that have a financial incentive for controlling infectious diseases (e.g. agriculture, tourism, and air travel) seen as most likely to have integrated public health preparedness and response plans. Although the formal protocols for inter-sectoral collaboration were not always up to date, good personal relations were reported within the relevant professional networks, which could be brought into play in the event of a public health emergency. Cross-border collaboration was greatly facilitated if the neighbouring country was a fellow EU Member State. CONCLUSIONS: Infectious disease outbreaks remain as an ongoing threat. Efforts are required to ensure that core public health capacities for the full range of preparedness and response activities are sustained.

Health system factors influencing management of multidrug-resistant tuberculosis in four European Union countries - learning from country experiences.

BACKGROUND: In the European Union and European Economic Area only 38% of multidrug-resistant tuberculosis patients notified in 2011 completed treatment successfully at 24 months' evaluation. Socio-economic factors and patient factors such as demographic characteristics, behaviour and attitudes are associated with treatment outcomes. Characteristics of healthcare systems also affect health outcomes. This study was conducted to identify and better understand the contribution of health system components to successful treatment of multidrug-resistant tuberculosis. METHODS: We selected four European Union countries to provide for a broad range of geographical locations and levels of treatment success rates of the multidrug-resistant tuberculosis cohort in 2009. We conducted semi-structured interviews following a conceptual framework with representatives from policy and planning authorities, healthcare providers and civil society organisations. Responses were organised according to the six building blocks of the World Health Organization health systems framework. RESULTS: In the four included countries, Austria, Bulgaria, Spain, and the United Kingdom, the following healthcare system factors were perceived as key to achieving good treatment results for patients with multidrug-resistant tuberculosis: timely diagnosis of drug-resistant tuberculosis; financial systems that ensure access to a full course of treatment and support for multidrug-resistant tuberculosis patients; patient-centred approaches with strong intersectoral collaboration that address patients' emotional and social needs; motivated and dedicated healthcare workers with sufficient mandate and means to support patients; and cross-border management of multidrug-resistant tuberculosis to secure continuum of care between countries. CONCLUSION: We suggest that the following actions may improve the success of treatment for multidrug-resistant tuberculosis patients: deployment of rapid molecular diagnostic tests; development of context-specific treatment guidance and criteria for hospital admission and discharge in the European context; strengthening patient-centred approaches; development of collaborative mechanisms to ensure cross-border care, and development of long-term sustainable financing strategies.

Highly pathogenic avian influenza A(H5N8) outbreaks: protection and management of exposed people in Europe, 2014/15 and 2016.

Introduction of highly pathogenic avian influenza (HPAI) virus A(H5N8) into Europe prompted animal and human health experts to implement protective measures to prevent transmission to humans. We describe the situation in 2016 and list public health measures and recommendations in place. We summarise critical interfaces identified during the A(H5N1) and A(H5N8) outbreaks in 2014/15. Rapid exchange of information between the animal and human health sectors is critical for a timely, effective and efficient response.

Measles outbreak in Bulgaria: poor maternal educational attainment as a risk factor for medical complications.

BACKGROUND: An 8-year era of interrupted indigenous measles transmission in Bulgaria came to an end in April 2009 when a large epidemic occurred that would eventually claim 24,253 cases and 24 deaths; infants, children and young adults of the Roma community were disproportionally affected. Compared with Western Europe, case-fatality rate and proportion of medical complications were uncharacteristically high. METHODS: To disentangle underlying drivers of the outbreak and reasons for these medical complications, we assembled a number of national ecologic variables as well as regional individual-level data for 206 measles cases, randomly selected from national medical records. We conducted a logit regression analysis of data from individuals with medical complications. RESULTS: Ecologic socio-economic predictors were not associated with measles cases by region, although the proportion of medical complications differed considerably. Individual-level data from a region with high medical complications revealed that mother's education [odds ratio (OR) 0.79; 95% confidence interval (CI) 0.68-0.92], immunization status of the child (OR 0.28; 95% CI 0.08-0.94) and households declaring an income (OR 0.31; 95% CI 0.10-0.93) decreased the risk for developing severe medical complications such as pneumonia or encephalitis from a measles infection. DISCUSSION: The extent of this outbreak with a high case-fatality rate and high proportion of medical complications calls for resolute public health action. We found vaccination and maternal education to be crucial conduits of curbing medical complications from measles infections. Ultimately, the goal is measles elimination in Europe by 2015, and these data hint at intervention entry points.

Tools for Assessment of Country Preparedness for Public Health Emergencies: A Critical Review.

Recent international communicable disease crises have highlighted the need for countries to assure their preparedness to respond effectively to public health emergencies. The objective of this study was to critically review existing tools to support a country's assessment of its health emergency preparedness. We developed a framework to analyze the expected effectiveness and utility of these tools. Through mixed search strategies, we identified 12 tools with relevance to public health emergencies. There was considerable consensus concerning the critical preparedness system elements to be assessed, although their relative emphasis and means of assessment and measurement varied considerably. Several tools identified appeared to have reporting requirements as their primary aim, rather than primary utility for system self-assessment of the countries and states using the tool. Few tools attempted to give an account of their underlying evidence base. Only some tools were available in a user-friendly electronic modality or included quantitative measures to support the monitoring of system preparedness over time. We conclude there is still a need for improvement in tools available for assessment of country preparedness for public health emergencies, and for applied research to increase identification of system measures that are valid indicators of system response capability.

Cost-effectiveness of emergency preparedness measures in response to infectious respiratory disease outbreaks: a systematic review and econometric analysis.

OBJECTIVES: Respiratory infectious disease outbreaks pose a threat for loss of life, economic instability and social disruption. We conducted a systematic review of published econometric analyses to assess the direct and indirect costs of infectious respiratory disease outbreaks that occurred between 2003 and 2019. SETTING: Respiratory infectious disease outbreaks or public health preparedness measures or interventions responding to respiratory outbreaks in OECD countries (excluding South Korea and Japan) so as to assess studies relevant to the European context. The cost-effectiveness of interventions was assessed through a dominance ranking matrix approach. All cost data were adjusted to the 2017 Euro, with interventions compared with the null. We included data from 17 econometric studies. PRIMARY AND SECONDARY OUTCOME MEASURES: Direct and indirect costs for disease and preparedness and/or response or cost-benefit and cost-utility were measured. RESULTS: Overall, the economic burden of infectious respiratory disease outbreaks was found to be significant to healthcare systems and society. Indirect costs were greater than direct costs mainly due to losses of productivity. With regard to non-pharmaceutical strategies, prehospitalisation screening and the use of protective masks were identified as both an effective strategy and cost-saving. Community contact reduction was effective but had ambiguous results for cost saving. School closure was an effective measure, but not cost-saving in the long term. Targeted antiviral prophylaxis was the most cost-saving and effective pharmaceutical intervention. CONCLUSIONS: Our cost analysis results provide evidence to policymakers on the cost-effectiveness of pharmaceutical and non-pharmaceutical intervention strategies which may be applied to mitigate or respond to infectious respiratory disease outbreaks.

Offspring of parents with Balkan Endemic Nephropathy have higher C-reactive protein levels suggestive of inflammatory processes: a longitudinal study.

BACKGROUND: Despite the characteristic extensive tubulointerstitial fibrosis, Balkan Endemic Nephropathy (BEN) is usually considered a non-inflammatory disease. METHODS: We examined a marker of inflammation, C-reactive protein (CRP), in the offspring of patients with BEN, a population at risk for BEN, prior to development of established disease to determine if an inflammatory process could be identified in the early stages of the disease. In 2003/04, 102 adult offspring whose parents had BEN and a control group of 99 adult offspring of non-BEN patients were enrolled in this prospective study. This cohort was re-examined yearly for four consecutive years. Levels of serum CRP were measured in years 3 and 4 and compared between groups. The data were analyzed with mixed models. RESULTS: Compared to controls, offspring of BEN parents had statistically higher CRP levels in two consecutive years, suggestive of early inflammatory reactivity. Whenever the mother was affected by BEN (both parents, or mother only), serum CRP was significantly increased, but not if only the father had BEN. CRP was inversely related to kidney cortex width but not to markers or renal function. CONCLUSION: Early stages of BEN may involve inflammatory processes. The observation of a maternal involvement supports the concept of fetal programming, which has been implicated in the pathogenesis of other chronic kidney diseases.

European Pandemic Influenza Preparedness Planning: A Review of National Plans, July 2016.

Pandemic influenza A (H1N1) commenced in April 2009. Robust planning and preparedness are needed to minimize the impact of a pandemic. This study aims to review if key elements of pandemic preparedness are included in national plans of European countries. Key elements were identified before and during the evaluations of the 2009 pandemic and are defined in this study by 42 items. These items are used to score a total of 28 publicly available national pandemic influenza plans. We found that plans published before the 2009 influenza pandemic score lower than plans published after the pandemic. Plans from countries with a small population size score significantly lower compared to national plans from countries with a big population (P <.05). We stress that the review of written plans does not reflect the actual preparedness level, as the level of preparedness entails much more than the existence of a plan. However, we do identify areas of improvement for the written plans, such as including aspects on the recovery and transition phase and several opportunities to improve coordination and communication, including a description of the handover of leadership from health to wider sector management and communication activities during the pre-pandemic phase. (Disaster Med Public Health Preparedness. 2019;13:582-592).

Metals and kidney markers in adult offspring of endemic nephropathy patients and controls: a two-year follow-up study.

BACKGROUND: The etiology of Balkan Endemic Nephropathy, (BEN), a tubulointerstitial kidney disease, is unknown. Although this disease is endemic in rural areas of Bosnia, Bulgaria, Croatia, Romania, and Serbia, similar manifestations are reported to occur in other regions, for instance Tunisia and Sri Lanka. A number of explanations have been stated including lignites, aristolochic acid, ochratoxin A, metals, and metalloids. Etiologic claims are often based on one or a few studies without sound scientific evidence. In this systematic study, we tested whether exposures to metals (cadmium and lead) and metalloids (arsenic and selenium) are related to Balkan Endemic Nephropathy. METHODS: In 2003/04 we recruited 102 adults whose parents had BEN and who resided in one of three communities (Vratza, Bistretz, or Beli Izvor, Bulgaria). A control group comprised of 99 adults having non-BEN hospitalized parents was enrolled in the study during the same time. We conducted face-to-face interviews, ultrasound kidney measurements, and determined kidney function in two consecutive investigations (2003/04 and 2004/05). Metals and metalloids were measured in urine and blood samples. To assess the agreement between these consecutive measurements, we calculated intraclass correlation coefficients. Repeated measurement data were analyzed using mixed models. RESULTS: We found that cadmium and arsenic were associated with neither kidney size nor function. Lead had a significant but negligible effect on creatinine clearance. Selenium showed a weak but significant negative association with two of the four kidney parameters, namely creatinine clearance and beta2-microglobulin. It was positively related to kidney length. These associations were not restricted to the offspring of BEN patients. Adding credence to these findings are reports showing comparable kidney effects in animals exposed to selenium. CONCLUSION: The findings of this 2-year follow-up study indicate that metals and metalloids do not play a role in the etiology of Balkan Endemic Nephropathy. Against the assumption in the literature, selenium was not protective but a risk factor. Since comparable associations were observed in animals, future studies are needed to explore whether selenium may have adverse renal effects in humans.

How close are countries of the WHO European Region to achieving the goal of vaccinating 75% of key risk groups against influenza? Results from national surveys on seasonal influenza vaccination programmes, 2008/2009 to 2014/2015.

BACKGROUND: Influenza vaccination is recommended especially for persons at risk of complications. In 2003, the World Health Assembly urged Member States (MS) to increase vaccination coverage to 75% among older persons by 2010. OBJECTIVE: To assess progress towards the 2010 vaccination goal and describe seasonal influenza vaccination recommendations in the World Health Organization (WHO) European Region. METHODS: Data on seasonal influenza vaccine recommendations, dose distribution, and target group coverage were obtained from two sources: European Union and European Economic Area MS data were extracted from influenza vaccination surveys covering seven seasons (2008/2009-2014/2015) published by the Vaccine European New Integrated Collaboration Effort and European Centre for Disease Prevention and Control. For the remaining WHO European MS, a separate survey on policies and uptake for all seasons (2008/2009-2014/2015) was distributed to national immunization programmes in 2015. RESULTS: Data was available from 49 of 53 MS. All but two had a national influenza vaccination policy. High-income countries distributed considerably higher number of vaccines per capita (median; 139.2 per 1000 population) compared to lower-middle-income countries (median; 6.1 per 1000 population). Most countries recommended vaccination for older persons, individuals with chronic disease, healthcare workers, and pregnant women. Children were included in < 50% of national policies. Only one country reached 75% coverage in older persons (2014/2015), while a number of countries reported declining vaccination uptake. Coverage of target groups was overall low, but with large variations between countries. Vaccination coverage was not monitored for several groups. CONCLUSIONS: Despite policy recommendations, influenza vaccination uptake remains suboptimal. Low levels of vaccination is not only a missed opportunity for preventing influenza in vulnerable groups, but could negatively affect pandemic preparedness. Improved understanding of barriers to influenza vaccination is needed to increase uptake and reverse negative trends. Furthermore, implementation of vaccination coverage monitoring is critical for assessing performance and impact of the programmes.

The interconnected and cross-border nature of risks posed by infectious diseases.

Infectious diseases can constitute public health emergencies of international concern when a pathogen arises, acquires new characteristics, or is deliberately released, leading to the potential for loss of human lives as well as societal disruption. A wide range of risk drivers are now known to lead to and/or exacerbate the emergence and spread of infectious disease, including global trade and travel, the overuse of antibiotics, intensive agriculture, climate change, high population densities, and inadequate infrastructures, such as water treatment facilities. Where multiple risk drivers interact, the potential impact of a disease outbreak is amplified. The varying temporal and geographic frequency with which infectious disease events occur adds yet another layer of complexity to the issue. Mitigating the emergence and spread of infectious disease necessitates mapping and prioritising the interdependencies between public health and other sectors. Conversely, during an international public health emergency, significant disruption occurs not only to healthcare systems but also to a potentially wide range of sectors, including trade, tourism, energy, civil protection, transport, agriculture, and so on. At the same time, dealing with a disease outbreak may require a range of critical sectors for support. There is a need to move beyond narrow models of risk to better account for the interdependencies between health and other sectors so as to be able to better mitigate and respond to the risks posed by emerging infectious disease.

Causal inference regarding infectious aetiology of chronic conditions: a systematic review.

BACKGROUND: The global burden of disease has shifted from communicable diseases in children to chronic diseases in adults. This epidemiologic shift varies greatly by region, but in Europe, chronic conditions account for 86% of all deaths, 77% of the disease burden, and up to 80% of health care expenditures. A number of risk factors have been implicated in chronic diseases, such as exposure to infectious agents. A number of associations have been well established while others remain uncertain. METHODS AND FINDINGS: We assessed the body of evidence regarding the infectious aetiology of chronic diseases in the peer-reviewed literature over the last decade. Causality was assessed with three different criteria: First, the total number of associations documented in the literature between each infectious agent and chronic condition; second, the epidemiologic study design (quality of the study); third, evidence for the number of Hill's criteria and Koch's postulates that linked the pathogen with the chronic condition. We identified 3136 publications, of which 148 were included in the analysis. There were a total of 75 different infectious agents and 122 chronic conditions. The evidence was strong for five pathogens, based on study type, strength and number of associations; they accounted for 60% of the associations documented in the literature. They were human immunodeficiency virus, hepatitis C virus, Helicobacter pylori, hepatitis B virus, and Chlamydia pneumoniae and were collectively implicated in the aetiology of 37 different chronic conditions. Other pathogens examined were only associated with very few chronic conditions (≤ 3) and when applying the three different criteria of evidence the strength of the causality was weak. CONCLUSIONS: Prevention and treatment of these five pathogens lend themselves as effective public health intervention entry points. By concentrating research efforts on these promising areas, the human, economic, and societal burden arising from chronic conditions can be reduced.

Economic crisis and communicable disease control in Europe: a scoping study among national experts.

OBJECTIVES: The effects of the current global economic crisis on the spread and control of communicable diseases remain uncertain. This study aimed to explore experts' views about the impact of the current crisis and measures that have been undertaken by governments to mitigate an alleged adverse effect of the crisis on communicable diseases. METHODS: An online survey was conducted during November 2009-February 2010 among experts from national agencies for communicable disease control from European Union (EU) and European Free Trade Association (EFTA) countries. RESULTS: There were few specific national policies and programmes aimed at mitigating the impact of the economic crisis. Prevention services were deemed particularly susceptible to budget cuts (68%) as a result of the economic crisis compared to primary care (28%), according to survey respondents. Services targeted at vulnerable and hard-to-reach population groups were perceived to be at particular risk of deterioration (67%) in contrast to travel medicine (11%), according to respondents. CONCLUSIONS: There is a need for sustainability of financial resources, public health workforce and infrastructures to ensure that the services and programmes for the surveillance and control of the spread of communicable disease are maintained and developed. There is also a need to explore and foster better linkage in data on socioeconomic circumstances and communicable disease outcomes.

The impact of economic crises on communicable disease transmission and control: a systematic review of the evidence.

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.