An integrated assessment framework for climate change and infectious diseases.
(9/1873)
Many potential human health effects have been hypothesized to result either directly or indirectly from global climate change. Changes in the prevalence and spread of infectious diseases are some of the most widely cited potential effects of climate change, and could have significant consequences for human health as well as economic and societal impacts. These changes in disease incidence would be mediated through biologic, ecologic, sociologic, and epidemiologic processes that interact with each other and which may themselves be influenced by climate change. Although hypothesized infectious disease effects have been widely discussed, there have not yet been thorough quantitative studies addressing the many processes at work. In part this is because of the complexity of the many indirect and feedback interactions or mechanisms that bear on all aspects of the climate issue. It also results from the difficulty of including the multitude of always-changing determinants of these diseases. This paper proposes a framework for an integrated assessment of the impacts of climate change on infectious diseases. The framework allows identification of potentially important indirect interactions or mechanisms, identification of important research gaps, and a means of integrating targeted research from a variety of disciplines into an enhanced understanding of the whole system. (+info)
Resurgent and emergent disease in a changing world.
(10/1873)
Emerging infectious diseases pose important public health problems for both the developed and developing world. Many new or previously unrecognized bacterial, fungal, viral, and parasitic diseases have emerged within the past two decades. At the same time, many once-controlled infections have re-emerged or become resistant to antimicrobial therapy. This emergence is the result of changes in society, technology, the environment, and the microbes themselves, and these changes have had often unpredictable consequences. Important factors influencing emergence include changes in human demographics and behaviour, changes in technology and industry, changes in economic development and land use, increasing and rapid international travel and commerce, microbial adaptation and change, and the breakdown of public health measures. Addressing emerging infectious diseases will require international and interdisciplinary partnerships to build an appropriate infrastructure to detect and respond to these often unanticipated threats to health. (+info)
Iron loading and disease surveillance.
(11/1873)
Iron is an oxidant as well as a nutrient for invading microbial and neoplastic cells. Excessive iron in specific tissues and cells (iron loading) promotes development of infection, neoplasia, cardiomyopathy, arthropathy, and various endocrine and possibly neurodegenerative disorders. To contain and detoxify the metal, hosts have evolved an iron withholding defense system, but the system can be compromised by numerous factors. An array of behavioral, medical, and immunologic methods are in place or in development to strengthen iron withholding. Routine screening for iron loading could provide valuable information in epidemiologic, diagnostic, prophylactic, and therapeutic studies of emerging infectious diseases. (+info)
The effects of local spatial structure on epidemiological invasions.
(12/1873)
Predicting the likely success of invasions is vitally important in ecology and especially epidemiology. Whether an organism can successfully invade and persist in the short-term is highly dependent on the spatial correlations that develop in the early stages of invasion. By modelling the correlations between individuals, we are able to understand the role of spatial heterogeneity in invasion dynamics without the need for large-scale computer simulations. Here, a natural methodology is developed for modelling the behaviour of individuals in a fixed network. This formulation is applied to the spread of a disease through a structured network to determine invasion thresholds and some statistical properties of a single epidemic. (+info)
Review: infectious diseases and coagulation disorders.
(13/1873)
Infection, both bacterial and nonbacterial, may be associated with coagulation disorders, resulting in disseminated intravascular coagulation and multiorgan failure. In the last few decades a series of in vivo and in vitro studies has provided more insight into the pathogenetic mechanisms and the role of cytokines in these processes. Because of the growing interest in this field, the complexity of the subject, and the fact that many physicians must deal with a variety of infections, current data are reviewed on the association between infectious diseases and the coagulation system. Novel therapeutic intervention strategies that will probably become available in the near future are mentioned, along with those of special interest for infectious disorders for which only supportive care can be given. (+info)
The effects of host heterogeneity on pathogen population structure.
(14/1873)
We have shown that among pathogens, populations may self-organize into strains with non-overlapping repertoires of antigenic variants as a consequence of strong immune selection operating on polymorphic antigens. Recently, we have also demonstrated that over a wide range of intermediate levels of immune selection, pathogens may still be structured into discrete strains, but different sets of non-overlapping pathogen types will replace each other in a cyclical or chaotic manner. These models assume that the ranking of antigens in terms of the strength of the induced immune response is the same for every host. However, host immune responses may be restricted by the genotype of the individual. To explore this issue, a mathematical model was constructed under the assumption that a proportion of the host population responds principally to a variable antigen while the remainder of the population responds principally to a conserved antigen. The results of this analysis indicate that discrete strain structure (DSS) will be maintained even with a high frequency of hosts that do not respond in a variant-specific manner. Furthermore, the range of the immune selection pressure over which DSS prevails is increased (and the region of cyclical or chaotic behaviour reduced) by the inclusion of hosts that respond in a cross-reactive rather than a variant-specific manner. (+info)
Threats to global health and survival: the growing crises of tropical infectious diseases--our "unfinished agenda".
(15/1873)
Health, one of our most unassailable human values, transcends all geographic, political, and cultural boundaries. The health problems of the rapidly growing 80% of the world's population that live in the tropical developing countries of Asia, Africa, and Latin America pose major threats to industrialized as well as developing regions. These threats can be divided into three areas, or three "E"s: (1) emerging, reemerging, and antimicrobial-resistant infections; (2) exploding populations without improved health; and (3) erosion of our humanity or leadership if we ignore the growing health problems of the poor. Our assessment of current trends in global population distribution and resource consumption; DALY calculations, causes, and distribution of global mortality and morbidity; and the misperceptions about and maldistribution of resources for health point to the critical importance of addressing tropical infectious diseases and global health for preservation of democracy and civilization as we know it. (+info)
Control of infectious diseases.
(16/1873)
Deaths from infectious diseases have declined markedly in the United States during the 20th century. This decline contributed to a sharp drop in infant and child mortality and to the 29.2-year increase in life expectancy. In 1900, 30.4% of all deaths occurred among children aged <5 years; in 1997, that percentage was only 1.4%. In 1900, the three leading causes of death were pneumonia, tuberculosis (TB), and diarrhea and enteritis, which (together with diphtheria) caused one third of all deaths. Of these deaths, 40% were among children aged <5 years. In 1997, heart disease and cancers accounted for 54.7% of all deaths, with 4.5% attributable to pneumonia, influenza, and human immunodeficiency virus (HIV) infection. Despite this overall progress, one of the most devastating epidemics in human history occurred during the 20th century: the 1918 influenza pandemic that resulted in 20 million deaths, including 500,000 in the United States, in <1 year-more than have died in as short a time during any war or famine in the world. HIV infection, first recognized in 1981, has caused a pandemic that is still in progress, affecting 33 million people and causing an estimated 13.9 million deaths. These episodes illustrate the volatility of infectious disease death rates and the unpredictability of disease emergence. (+info)