Global Spread Of Infectious Diseases Research Articles

Patient-Centered Medical Homes Offer a Model for Better, Cheaper Health Care

nated from wild nonhuman primate and rodent species, including baboon, chimpanzee, mangabey, guenon, green monkey, cane rat, and rat. Pathogen screening identified retroviruses (4 SFV strains), herpesviruses (cytomegalovirus and lymphocryptovirus), or both in 12 nonhuman primate tissue samples. “Because most emerging infectious diseases of humans are originating in animals, it is of concern that even in this small number of samples from a limited number of animal species, it was possible to identify retroviruses and herpesviruses of potential concern for human populations,” said Gerald Keusch, MD, who was not involved with the research. Keusch, a professor of medicine and international health at Boston University, cochaired the 2009 surveillance and response report with Pappaioanou. None of the samples contained SIV or STLV, which have adapted to humans and spread as HIV and human T-lymphotropic virus (which is capable of causing leukemia, lymphoma, and neurologic disease), respectively; however, SIV and STLV are often present in specimens at bushmeat markets and in hunted nonhuman primates. None of the rodent samples carried viruses: all were negative for leptospira, anthrax, herpesviruses, filoviruses, paramyxoviruses, coronaviruses, flaviviruses, and orthopoxviruses. Broader surveillance is needed to expand the study’s findings, which only begin to paint a picture of the potential risks of imported wildlife products and do not address live wildlife. “We need more and smarter surveillance of the wildlife trade, more control over what is being transported across national boundaries, more and stricter law enforcement measures to stop individuals involved in the business, and better and more meaningful ways to inform the public about the inherent dangers in a believable manner,” said Keusch. “In terms of global spread of infectious diseases, wildlife may be the mosquitoes of the 21st century: effective, elusive, and damned hard to stop.”

Global TravEpiNet: A National Consortium of Clinics Providing Care to International Travelers—Analysis of Demographic Characteristics, Travel Destinations, and Pretravel Healthcare of High-Risk US International Travelers, 2009–2011

International travel poses a risk of destination-specific illness and may contribute to the global spread of infectious diseases. Despite this, little is known about the health characteristics and pretravel healthcare of US international travelers, particularly those at higher risk of travel-associated illness. We formed a national consortium (Global TravEpiNet) of 18 US clinics registered to administer yellow fever vaccination. We collected data regarding demographic and health characteristics, destinations, purpose of travel, and pretravel healthcare from 13235 international travelers who sought pretravel consultation at these sites from January 2009 through January 2011. The destinations and itineraries of Global TravEpiNet travelers differed from those of the overall population of US international travelers. The majority of Global TravEpiNet travelers were visiting low- or lower-middle-income countries, and Africa was the most frequently visited region. Seventy-five percent of travelers were visiting malaria-endemic countries, and 38% were visiting countries endemic for yellow fever. Fifty-nine percent of travelers reported ≥1 medical condition. Atovaquone/proguanil was the most commonly prescribed antimalarial drug, and most travelers received an antibiotic for self-treatment of travelers' diarrhea. Hepatitis A and typhoid were the most frequently administered vaccines. Data from Global TravEpiNet provide insight into the characteristics and pretravel healthcare of US international travelers who are at increased risk of travel-associated illness due to itinerary, purpose of travel, or existing medical conditions. Improved understanding of this epidemiologically significant population may help target risk-reduction strategies and interventions to limit the spread of infections related to global travel.

Health recommendations for international travel: a review of the evidence base of travel medicine.

International travel is increasing, including travel to countries with emerging economies. Travel may pose health risks for the individual and contribute to the global spread of infectious diseases. The specialty of travel medicine is aimed at minimizing health risks associated with international travel. The field has emerged in the past 25 years, and the evidence base supporting its clinical practice is growing. This review will describe the evidence base underlying travel medicine, highlight recently updated travel medicine guidelines, and outline future research priorities. Recommendations for a number of common vaccines for travelers have been updated recently. More sophisticated detection methods are leading to the identification of a wider spectrum of pathogens associated with travelers' diarrhea, and antibiotic resistance is increasingly being identified. New treatment options for malaria are available, and a fifth Plasmodium species causing disease in humans has been identified. An evidence base for the practice of travel medicine is emerging. Expert opinion and consensus guidelines continue to play an important role in supporting clinical practice.

On the treatment of airline travelers in mathematical models.

The global spread of infectious diseases is facilitated by the ability of infected humans to travel thousands of miles in short time spans, rapidly transporting pathogens to distant locations. Mathematical models of the actual and potential spread of specific pathogens can assist public health planning in the case of such an event. Models should generally be parsimonious, but must consider all potentially important components of the system to the greatest extent possible. We demonstrate and discuss important assumptions relative to the parameterization and structural treatment of airline travel in mathematical models. Among other findings, we show that the most common structural treatment of travelers leads to underestimation of the speed of spread and that connecting travel is critical to a realistic spread pattern. Models involving travelers can be improved significantly by relatively simple structural changes but also may require further attention to details of parameterization.

Retrospective analysis of multi-drug resistant tuberculosis outbreak during a flight using computational fluid dynamics and infection risk assessment

Air travel brings convenience to humans but also hastens the global spread of infectious diseases. Not only transporting infectious individuals from one place to another, air travel also provides a chance for infectious diseases transmission during the flight, especially if the disease can be transmitted via the airborne route. A number of documented outbreaks of airborne transmissible diseases were associated with disease transmission during the air travel. This study performed retrospective analysis on an infamous multi-drug resistant Tuberculosis (MDR-TB) outbreak on a commercial flight, where 6 people were infected with the multi-drug resistant disease during the 8.75 h flight. Airflow pattern and the infectious particle dispersion in the aircraft cabin were simulated using computational fluid dynamics (CFD). Infection risks of the passengers under a range of infectious source strength values were then assessed using the dose-response model. Based on the risk data, the infectious source strength of the index case passenger was estimated by likelihood analysis. A concept of mix-ratio was introduced to estimate the impact of human movement and cough behavior on the disease transmission. From the maximum likelihood estimation, the index case passenger may have generated 17.2 millions of viable bacilli/hr during the flight. Spatial pattern of the infection case and the spatial variation of infection risk were reflected in this estimation. The findings of this study provide additional understanding of infectious disease transmission during air travel. The infectious source strength of MDR-TB estimated from this study can be used in further risk assessment on the disease.

Airline Operating Realities and the Global Spread of Infectious Diseases

The advent of long-haul travel in the past 10 years has considerably reduced the time of potential disease spread from one side of the world to the other. The implication for travelers is that they may unwittingly be in the prodromal phase of influenza and become symptomatic a few days after travel. Alternatively they may knowingly travel with an infectious disease by masking symptoms. This article outlines the myths that have abounded about the cabin environment being "unclean" and discusses the low likelihood of in-flight transmission with effective air-conditioning and filtration systems. The 2009 H1N1 pandemic highlighted the operational challenges of dealing with infectious disease, including the need for accurate passenger information to allow contact tracing, in contrast to futile measures such as thermal scanners. Containment attempts did not stop the rapid global spread of H1N1 influenza.

Conceptual Models for Global Health Governance

Globalization has led to an appreciation of a global politics beyond the control of nation-states and the traditional system of international relations. Global politics is characterized by a pluralization of governance mediated by a constant effort to establish shared norms of global public goods and bads to constrain the exercise of power or, expressed in another way, to attain a more equitable access to power resources. Traditional state institutions of national and international governance have become more diversified as a reaction to their inherent limitations and the increasing power of new forms of governance built by private actors. Though the state remains a powerful, often dominant, actor in governance, it competes with and sometimes is itself governed by a diverse set of non-state actors, including corporations, foundations, religious groups, social advocacy organizations and ‘dark networks’, such as al-Qaeda or narcotics cartels. States and traditional institutions of international governance are increasingly seen as complex assemblages in and of themselves, comprised of more or less well-networked nodes operating somewhere on the spectrum between cooperation and competition. States have actively embraced this pluralization, seeking to increase or protect their power by vigorous use of governance devices such as privatization and partnerships. These developments are clearly visible in the health sector, which has witnessed an institutional change from a structure that consisted primarily of independent national health systems and some international agencies devoted to controlling the cross-border effects of ill-health towards a system of global health governance (GHG). Contemporary GHG is characterized by a polycentric, distributed structure and a substantive concern with issues that affect populations worldwide directly (for example, the global spread of infectious diseases or antibiotic resistance) or indirectly (for example, political instability and global insecurity arising from extreme socio-economic inequality). Global health governance now requires management not merely of specific transborder epidemics, like SARS or avian influenza, but of the host of issues in health that arise at the intersection of a globalized economy and lives lived in particular localities. Dealing with ‘global’ health challenges increasingly requires attention not only to ‘horizontal’ coordination of global politics, but also to more effective vertical integration of global-level governance with governance at the national and local levels. Both practitioners and students of health policy require new conceptual tools to understand and influence GHG. During recent years, two models have been developed that, from different perspectives, address these characteristics of multiplicity of actors, flexibility of institutional arrangements and fluidity of relationships. The ‘nodal governance’ framework builds on network theories to describe distributed governance and the ways in which institutions project power across networks to govern the systems they inhabit. The concept of ‘interface’, refers to ‘a specific space, where two different social systems or fields of social order interact (here: global/national systems; institutional systems related to modes of regulation), which are characterized by specific institutions and specific backgrounds. Independently, the concepts of nodal governance and interfaces can help us to understand what constitutes the binding forces and the types of power mobilized among the multitude of actors in global health governance. Taken together, they illuminate key challenges to good GHG: improving democracy, efficacy and coordination. This chapter uses these two frameworks to understand the emerging dynamics of GHG and then illustrate their usefulness through a discussion of the global governance of HIV/AIDS.

Airports, localities and disease: Representations of global travel during the H1N1 pandemic

During summer 2009, the UK experienced one of the highest incidences of H1N1 infection outside of the Americas and Australia. Building on existing research into biosecurity and the spread of infectious disease via the global airline network, this paper explores the biopolitics of public health in the UK through an in-depth empirical analysis of the representation of H1N1 in UK national and regional newspapers. We uncover new discourses relating to the significance of the airport as a site for control and the ethics of the treatment of the traveller as a potential transmitter of disease. We conclude by highlighting how the global spread of infectious diseases is grounded in particular localities associated with distinctive notions of biosecurity and the traveller.

Of plagues, planes and politics: Controlling the global spread of infectious diseases by air

In recent years, the implications of globalisation for the spread of infectious diseases has begun to emerge as an area of concern to political geographers. Unsurprisingly, much of the contemporary literature focuses on the multifarious threats posed by human and, increasingly, non-human mobility. Prompted by current geopolitical concerns surrounding the public health implications of regular international air travel, this paper extends such research by exploring the ways in which the technology of the aeroplane stimulated the production of new international sanitary initiatives aimed at safeguarding global public health in an era of mass aeromobility. By tracing the development of sanitary regulations for aerial navigation, from their origins in the 1920s through the twentieth century in particular, we document the emergence of a series of public health interventions that were designed to limit the public health threat associated with increased international air travel and the concomitant rise in the mobility of infectious diseases. From inoculation certificates to quarantine and the routine ‘disinsection’ of passenger aircraft with powerful insecticides, modern air travel is replete with a complex set of procedures designed to lessen the risks associated with flying between different climatic and ecological zones. Our detailed examination of the historical context in which these procedures were devised and implemented leads us to consider the importance of time and space, power and efficacy, to the development of a more nuanced understanding of the shifting public health response to an increasingly fluid, mobile, and inter-connected society.

Strengthening field-based training in low and middle-income countries to build public health capacity: Lessons from Australia's Master of Applied Epidemiology program

BackgroundThe International Health Regulations (2005) and the emergence and global spread of infectious diseases have triggered a re-assessment of how rich countries should support capacity development for communicable disease control in low and medium income countries (LMIC). In LMIC, three types of public health training have been tried: the university-based model; streamed training for specialised workers; and field-based programs. The first has low rates of production and teaching may not always be based on the needs and priorities of the host country. The second model is efficient, but does not accord the workers sufficient status to enable them to impact on policy. The third has the most potential as a capacity development measure for LMIC, but in practice faces challenges which may limit its ability to promote capacity development.DiscussionWe describe Australia's first Master of Applied Epidemiology (MAE) model (established in 1991), which uses field-based training to strengthen the control of communicable diseases. A central attribute of this model is the way it partners and complements health department initiatives to enhance workforce skills, health system performance and the evidence-base for policies, programs and practice.SummaryThe MAE experience throws light on ways Australia could collaborate in regional capacity development initiatives. Key needs are a shared vision for a regional approach to integrate training with initiatives that strengthen service and research, and the pooling of human, financial and technical resources. We focus on communicable diseases, but our findings and recommendations are generalisable to other areas of public health.

Timeliness of national notifiable diseases surveillance system in Korea: a cross-sectional study

BackgroundWith the increase of international travels, infectious disease control is gaining a greater importance across regional borders. Adequate surveillance system function is crucial to prevent a global spread of infectious disease at the earliest stage. There have been limited reports on the characteristics of infectious disease surveillance in Asia. The authors studied the timeliness of the Korean National Notifiable Disease Surveillance System with regard to major notifiable diseases from 2001 to 2006.MethodsSix notifiable infectious diseases reported relatively frequently were included in this study. Five diseases were selected by the criteria of reported cases > 100 per year: typhoid fever, shigellosis, mumps, scrub typhus, and hemorrhagic fever with renal syndrome. In addition, dengue fever was also included to represent an emerging disease, despite its low number of cases. The diseases were compared for the proportion notified within the recommended time limits, median time lags, and for the cumulative distribution of time lags at each surveillance step between symptom onset and date of notification to the Korea Centers for Disease Control and Prevention (KCDC).ResultsThe proportion of cases reported in time was lower for disease groups with a recommended time limit of 1 day compared with 7 days (60%–70% vs. > 80%). The median time from disease onset to notification to KCDC ranged between 6 and 20 days. The median time from onset to registration at the local level ranged between 2 and 15 days. Distribution of time lags showed that main delays arose in the time from onset to diagnosis. There were variations in timeliness by disease categories and surveillance steps.ConclusionTime from disease onset to diagnosis generally contributed most to the delay in reporting. It is needed to promote public education and to improve clinical guidelines. Rapid reporting by doctors should be encouraged, and unification of recommended reporting time limit can be helpful. Our study also demonstrates the utility of the overall assessment of time-lag distributions for disease-specific strategies to improve surveillance.

A transcutaneous vaccination system using a hydrogel patch for viral and bacterial infection

One of the most important anthropic missions is preventing the global spread of infectious diseases. Vaccination is the only available preventive treatment for infectious diseases, but the availability of vaccines in developing countries is not adequate. We report a simple, easy-to-use, noninvasive hydrogel patch transcutaneous vaccination system. Antigen (Ag)-specific IgG production was induced by applying an Ag-immersed patch to non-pretreated mouse auricle or hairless rat back skin. Immunofluorescence histochemical analysis revealed that Langerhans cells resident in the epidermal layer captured the antigenic proteins delivered by the hydrogel patch, which promoted the penetration of antigenic proteins through the stratum corneum, and that Ag-capturing Langerhans cells migrated into draining lymph nodes. Humoral immunity elicited by our transcutaneous vaccination system demonstrated neutralizing activity in both adenoviral infection and passive-challenge tetanus toxin experiments. The use of this hydrogel patch transcutaneous vaccination system will facilitate the global distribution of effective and convenient vaccines.

Pathogens Transmitted by Migratory Birds: Threat Perceptions to Poultry Health and Production

Pathogens Transmitted by Migratory Birds: Threat Perceptions to Poultry Health and Production

Trends in US approvals: new biopharmaceuticals and vaccines

The efficient development and approval of new therapeutics and vaccines is vital to the health and welfare of patients. Tufts Center for the Study of Drug Development has collected and analyzed data for new protein therapeutics and vaccines approved in the USA during the past decade. Our results suggest trends toward longer clinical and approval phases for the therapeutics, particularly for oncology products. In this Opinion article, we discuss various legislative acts and FDA initiatives that might improve the efficiency of drug development and approval. Furthermore, few new vaccines have been approved in the past 10 years owing, at least in part, to the lack of incentives for the development of the products. We predict that this might change in the future as government and industry respond to the twin threats of the global spread of infectious diseases and potential bioterrorism.

GLOBAL SPREAD OF INFECTIOUS DISEASES

We develop simple models for the global spread of infectious diseases, emphasizing human mobility via air travel and the variation of public health infrastructure from region to region. We derive formulas relating the total and peak number of infections in two countries to the rate of travel between them and their respective epidemiological parameters.

Global Public Health Trumps the Nation-State

It is generally agreed that governments are responsible for the protection of their citizens, a responsibility that falls under the rubric security. Today, the concept of national security, and even the idea of national sovereignty, is being challenged by the spread of infectious disease, particularly by the global pandemic of Hiv/AIDS. The term security has traditionally referred to safety from some form of violent attack. A decade ago, the United Nations, in the Declaration of Principles on Human Rights and the Environment (1994), broadened the definition of the term to include access to such basic requirements for human well-being as food, healthcare, education, and the like. Disease, which recognizes no borders, attracts less attention than warfare and civil strife, yet it can be even more threatening to state survival. Three times as many people die from AIDS each day as died in the attacks on September 11, and the disease has killed more people than all the wars of the twentieth century. It is the leading cause of death in Africa and is on the rise in many of the world's most populous countries. These facts should concern us not solely for humanitarian reasons but because, as the political scientist Andrew Price-Smith warns, Rapid negative change in the health status of a population and pathogen-induced demographic collapse may.. .figure in the destabilization of states.1 Ironically, our notion of sovereignty, which prohibits both state and nonstate actors from intervening in the affairs of sovereign states, has aided the global spread of infectious disease. As Price-Smith notes, In the case of states like South Africa and Zim-