Emerging infectious disease: what are the relative roles of ecology and evolution?

The increasing threat of infectious diseases in humans has renewed interest in factors leading to the emergence of new diseases and the re-emergence of familiar diseases. Examples of seemingly novel diseases currently spreading in human populations include HIV, dengue hemorrhagic fever and Lyme disease; drug-resistant forms of well-known diseases such as tuberculosis are also increasing. The problem of disease emergence also extends to other animal and plant populations. In most current epidemics, ecological factors (e.g. migration, climate, agricultural practices) play a more significant role in disease emergence than evolutionary changes in pathogens or hosts. Evolutionary biologists and ecologists have much to offer to the development of strategies for the control of emerging diseases.     

Ethical models underpinning responses to threats to public health: a comparison of approaches to communicable disease control in Europe

Increases in international travel and migratory flows have enabled infectious diseases to emerge and spread more rapidly than ever before. Hence, it is increasingly easy for local infectious diseases to become global infectious diseases (GIDs). National governments must be able to react quickly and effectively to GIDs, whether naturally occurring or intentionally instigated by bioterrorism. According to the World Health Organisation, global partnerships are necessary to gather the most up-to-date information and to mobilize resources to tackle GIDs when necessary. Communicable disease control also depends upon national public health laws and policies. The containment of an infectious disease typically involves detection, notification, quarantine and isolation of actual or suspected cases; the protection and monitoring of those not infected; and possibly even treatment. Some measures are clearly contentious and raise conflicts between individual and societal interests. In Europe national policies against infectious diseases are very heterogeneous. Some countries have a more communitarian approach to public health ethics, in which the interests of individual and society are more closely intertwined and interdependent, while others take a more liberal approach and give priority to individual freedoms in communicable disease control. This paper provides an overview of the different policies around communicable disease control that exist across a select number of countries across Europe. It then proposes ethical arguments to be considered in the making of public health laws, mostly concerning their effectiveness for public health protection.     

近年来出现的几类新概念动物疫苗

动物疫病流行广泛、传播迅速,严重危害养殖业的发展。疫苗接种是预防和控制动物传染病最有效的策略之一。目前,随着生物技术的发展和疫病防控的需要,安全、高效、广谱、用量少、具有标记特征的新型疫苗成为研发重点。文中就近年来出现的黏膜疫苗、长效与速效疫苗、嵌合疫苗、纳米颗粒疫苗等新概念动物疫苗的发展、应用及优缺点进行了评述,并提出了其发展方向,以期为动物疫苗的研发提供借鉴。     

Diseases of amphibians

The development and refinement of amphibian medicine comprise an ongoing science that reflects the unique life history of these animals and our growing knowledge of amphibian diseases. Amphibians are notoriously fastidious in terms of captive care requirements, and the majority of diseases of amphibians maintained in captivity will relate directly or indirectly to husbandry and management. Investigators have described many infectious and noninfectious diseases that occur among various species of captive and wild amphibians, and there is considerable overlap in the diseases of captive versus free-ranging populations. In this article, some of the more commonly reported infectious and noninfectious diseases as well as their etiological agents and causative factors are reviewed. Some of the more common amphibian diseases with bacterial etiologies include bacterial dermatosepticemia or "red leg syndrome," flavobacteriosis, mycobacteriosis, and chlamydiosis. The most common viral diseases of amphibians are caused by the ranaviruses, which have an impact on many species of anurans and caudates. Mycotic and mycotic-like organisms cause a number of diseases among amphibians, including chytridiomycosis, zygomycoses, chromomycoses, saprolegniasis, and ichthyophoniasis. Protozoan parasites of amphibians include a variety of amoeba, ciliates, flagellates, and sporozoans Common metazoan parasites include various myxozoans, helminths (particularly trematodes and nematodes), and arthropods. Commonly encountered noninfectious disease etiologies for amphibians include neoplasia, absolute or specific nutritional deficiencies or overloads, chemical toxicities, and inadequate husbandry or environmental management.     

Opportunistic infections in immunologically compromised nonhuman primates

Despite advances in the husbandry of nonhuman primates, natural and experimentally induced diseases continue to pose risks to animal health. These risks are particularly important when such disease results in immunodeficient states that provide an opportunity for the development of opportunistic infections. Because opportunistic agents may serve as significant confounders to research and hold potential for zoonotic transmission, knowledge of disease pathogenesis, surveillance, and risk reduction is particularly important to individuals who work closely with primates. Endogenous diseases of primates that result in blunted immune responses and thus allow for the development of opportunistic infection include simian type D retroviruses and measles. In addition, simian immunodeficiency virus is a frequently studied experimental cause of immunosuppression. This article focuses on clinical and pathological aspects of the most common opportunistic infections that occur in nonhuman primates maintained in research settings. The complete elimination of all infectious agents from primate colonies may be impossible and unwarranted, but microbial surveillance programs can help both to define the complement of agents present in a colony and to elucidate their potential impacts on colony health, zoonotic risk, and experimental research. We discuss risk reduction through the use of quarantine procedures, specific pathogen-free animals, and environmental controls.     

A global view on fungal infections in humans and animals: opportunistic infections and microsporidioses

After cardiovascular diseases, infectious diseases are the second most common cause of death worldwide. Although these infections are caused mainly by viruses or bacteria, a systematically growing prevalence of human and animal opportunistic fungal infections is noticeable worldwide. More attention is being paid to this problem, especially due to the growing frequency of recalcitrant and recurrent mycoses. The latter are classically divided into superficial, which are the most common type, subcutaneous, and systemic. This work discusses opportunistic fungal pathogens without proven horizontal transmission between different animal species including humans and microsporidia as spore-forming unicellular parasites related to fungi; however, with a yet undetermined taxonomic position. The review also mentions aetiological agents, risk factors, epidemiology, geographical distribution, and finally symptoms characteristic for individual disease entities. This paper provides insight into fungal infections from a global perspective and simultaneously draws attention to emerging pathogens, whose prevalence is continuously increasing. Finally, this work also takes into consideration the correct nomenclature of fungal disease entities and the importance of secondary metabolites in the pathogenesis of fungal infections.     

HDAC inhibitors in parasitic diseases

Parasitic diseases cause significant global morbidity and mortality, particularly in underdeveloped regions of the world. Malaria alone causes ~800000 deaths each year, with children and pregnant women being at highest risk. There is no licensed vaccine available for any human parasitic disease and drug resistance is compromising the efficacy of many available anti-parasitic drugs. This is driving drug discovery research on new agents with novel modes of action. Histone deacetylase (HDAC) inhibitors are being investigated as drugs for a range of diseases, including cancers and infectious diseases such as HIV/AIDS, and several parasitic diseases. This review focuses on the current state of knowledge of HDAC inhibitors targeted to the major human parasitic diseases malaria, schistosomiasis, trypanosomiasis, toxoplasmosis and leishmaniasis. Insights are provided into the unique challenges that will need to be considered if HDAC inhibitors are to be progressed towards clinical development as potential new anti-parasitic drugs.     

Emerging and re-emerging bacterial diseases in India

There has been a remarkable progress in the prevention, control and even eradication of infectious diseases with improved hygiene and development of antimicrobials and vaccines. However, infectious diseases still remain a leading cause of global disease burden with high morbidity and mortality especially in the developing world. Furthermore, there have been threats of new diseases during the past three decades due to the evolution and adaptation of microbes and the re-emergence of old diseases due to the development of antimicrobial resistance and the capacity to spread to new geographic areas. The impact of the emerging and re-emerging diseases in India has been tremendous at socioeconomic and public health levels. Their control requires continuing surveillance, research and training, better diagnostic facilities and improved public health system. Emerging and reemerging zoonotic diseases, foodborne and waterborne diseases and diseases caused by multiresistant organisms constitute the major threats in India. This review of bacterial emerging and re-emerging diseases should be of critical importance to microbiologists, clinicians, public health personnel and policy makers in India.     

Epidemiology and disease control in everyday beef practice

It is important for food animal veterinarians to understand the interaction among animals, pathogens, and the environment, in order to implement herd-specific biosecurity plans. Animal factors such as the number of immunologically protected individuals influence the number of individuals that a potential pathogen is able to infect, as well as the speed of spread through a population. Pathogens differ in their virulence and contagiousness. In addition, pathogens have various methods of transmission that impact how they interact with a host population. A cattle population's environment includes its housing type, animal density, air quality, and exposure to mud or dust and other health antagonists such as parasites and stress; these environmental factors influence the innate immunity of a herd by their impact on immunosuppression. In addition, a herd's environment also dictates the "animal flow" or contact and mixing patterns of potentially infectious and susceptible animals. Biosecurity is the attempt to keep infectious agents away from a herd, state, or country, and to control the spread of infectious agents within a herd. Infectious agents (bacteria, viruses, or parasites) alone are seldom able to cause disease in cattle without contributing factors from other infectious agents and/or the cattle's environment. Therefore to develop biosecurity plans for infectious disease in cattle, veterinarians must consider the pathogen, as well as environmental and animal factors.     

The key to enabling biosurveillance is cooperative technology development

The world population will continue to face biological threats, whether they are naturally occurring or intentional events. The speed with which diseases can emerge and spread presents serious challenges, because the impact on public health, the economy, and development can be huge. The U.S. government recognizes that global public health can also have an impact on national security. This global perspective manifests itself in U.S. policy documents that clearly articulate the importance of biosurveillance in providing early warning, detection, and situational awareness of infectious disease threats in order to mount a rapid response and save lives. In this commentary, we suggest that early recognition of infectious disease threats, whether naturally occurring or man-made, requires a globally distributed array of interoperable hardware and software fielded in sufficient numbers to create a network of linked collection nodes. We argue that achievement of this end state will require a degree of cooperation that does not exist at this time-either across the U.S. federal government or among our global partners. Successful fielding of a family of interoperable technologies will require interagency research, development, and purchase ("acquisition") of biosurveillance systems through cooperative ventures that likely will involve our strategic allies and public-private partnerships. To this end, we propose leveraging an existing federal interagency group to integrate the acquisition of technologies to enable global biosurveillance.     

Research and control of parasitic diseases in Japan: current position and future perspectives

Between 1950 and 1980, Japan eliminated several major parasitic diseases. In 1998, the Japanese Hashimoto Initiative was the first global programme to target parasitic diseases. Thereafter, Japan expanded its international cooperation to cover infectious diseases through integrated development programmes to improve health, to alleviate poverty and to help to achieve the Millennium Development Goals of the United Nations. Parasite control remains a major component of all subsequent operations. Opportunities to build upon past successes in order to improve the situation in the developing world - in addition to tackling emerging national threats - are promising. Substantial challenges remain and Japan has introduced major national reforms to try to overcome them.     

Reflecting on ethical and legal issues in wildlife disease

Disease in wildlife raises a number of issues that have not been widely considered in the bioethical literature. However, wildlife disease has major implications for human welfare. The majority of emerging human infectious diseases are zoonotic: that is, they occur in humans by cross‐species transmission from animal hosts. Managing these diseases often involves balancing concerns with human health against animal welfare and conservation concerns. Many infectious diseases of domestic animals are shared with wild animals, although it is often unclear whether the infection spills over from wild animals to domestic animals or vice versa. Culling is the standard means of managing such diseases, bringing economic considerations, animal welfare and conservation into conflict. Infectious diseases are also major threatening processes in conservation biology and their appropriate management by culling, vaccination or treatment raises substantial animal ethics issues. One particular issue of great significance in Australia is an ongoing research program to develop genetically modified pathogens to control vertebrate pests including rabbits, foxes and house mice. Release of any self‐replicating GMO vertebrate pathogen gives rise to a whole series of ethical questions. We briefly review current Australian legal responses to these problems. Finally, we present two unresolved problems of general importance that are exemplified by wildlife disease. First, to what extent can or should ‘bioethics’ be broadened beyond direct concerns with human welfare to animal welfare and environmental welfare? Second, how should the irreducible uncertainty of ecological systems be accounted for in ethical decision making?     

我国疾病动物模型的研究现状和展望

由于医学科学研究的需要,各类疾病动物模型被广泛用来研究人类疾病的发生发展机制、药物筛选以及治疗评价等.本文全面梳理了我国疾病动物模型的研究和发展现状,分析了我国在这方面的特色优势以及与国际上的差距,内容涵盖了肿瘤、神经及精神疾病、感染及免疫性疾病、心血管与代谢性疾病、药物筛选等不同领域.简要介绍了国家自然科学基金对疾病动物模型项目的资助情况,同时指出了我国疾病模型今后的主要发展方向.     

呼吸道传染病治疗中抗体药物的研发进展

呼吸系统疾病影响着全世界数百万人,主要病变发生在气管、支气管、肺部及胸腔,病变轻者多咳嗽、胸痛,重者呼吸困难、缺氧甚至呼吸衰竭,可造成多种并发症,导致患者严重残疾甚至死亡。治疗性抗体的临床使用为肺癌、哮喘以及各类呼吸道传染病等的治疗开辟了新途径。目前已有数十种抗体（antibodies,Abs）获得市场批准,而且还有更多的抗体药物正在临床开发中。这些Abs中的大多数是针对哮喘、肺癌、慢性阻塞性肺病、特发性肺纤维化以及呼吸道传染病等疾病。其中,呼吸道传染病的爆发具有传播迅猛、传染性强的特点,常引发全球关注,如当下肆虐全球的新型冠状病毒肺炎。针对呼吸道传染病的多种Abs为其临床治疗提供了新策略。基于此,综述了已获准和正在临床开发的适用于治疗呼吸道传染病的Abs,通过综述抗体治疗的分子机制、优势和发展趋势,以期为呼吸道传染病治疗中抗体药物的研发提供参考。     

NRAMP1 gene: structure,function, and human infectious diseases

The human infectious disease become of the great importance for Health Welfare. The infectious diseases mortality rate reaches one third of total mortality among 51 million patients died annually. The genetic factors seem to be most responsible for potency of human body to withstand to infections, caused by a variety of causative agents. The detection of the coincident factors and understanding the mechanisms of formation of susceptibility and resistance to infectious agents appeared to be important aspects for development of the new methods of prevention and treatment the infectious diseases. In inbred mice the natural resistance to infections, caused by Mycobacterium bovis, Mycobacterium avium, Mycobacterium lepraemurium, Leishmania donovani and Salmonella typhimurium is controlled by gene Nrampl (natural resistance associated macrophage protein gene). The gene codes for integral membrane protein, expressed by phagocytes. Protein is localized in the endosomal/lysosomal compartment of the silent macrophage, being recruited to the membrane of the phagosome containing particles under phagocytosis. This function is to transfer bivalent cations of metals from phagosome inward macrophage, that appears to affect negatively on destiny of microbes consumed. The human homologue of the Nrampl gene, denoted as NRAMP1, is situated on human chromosome 2q35. The gene Nrampl consists of 15 exones of different spread disparted by intrones of various sizes. Several polymorphous variants of the gene are described. The experimental presuppositions to more extensive investigation of the role of the gene NRAMPl in development of human pathology are pointed out.     

Diseases and causes of death in European bats: dynamics in disease susceptibility and infection rates

Background

Bats receive increasing attention in infectious disease studies, because of their well recognized status as reservoir species for various infectious agents. This is even more important, as bats with their capability of long distance dispersal and complex social structures are unique in the way microbes could be spread by these mammalian species. Nevertheless, infection studies in bats are predominantly limited to the identification of specific pathogens presenting a potential health threat to humans. But the impact of infectious agents on the individual host and their importance on bat mortality is largely unknown and has been neglected in most studies published to date.

Methodology/Principal Findings

Between 2002 and 2009, 486 deceased bats of 19 European species (family Vespertilionidae) were collected in different geographic regions in Germany. Most animals represented individual cases that have been incidentally found close to roosting sites or near human habitation in urban and urban-like environments. The bat carcasses were subjected to a post-mortem examination and investigated histo-pathologically, bacteriologically and virologically. Trauma and disease represented the most important causes of death in these bats. Comparative analysis of pathological findings and microbiological results show that microbial agents indeed have an impact on bats succumbing to infectious diseases, with fatal bacterial, viral and parasitic infections found in at least 12% of the bats investigated.

Conclusions/Significance

Our data demonstrate the importance of diseases and infectious agents as cause of death in European bat species. The clear seasonal and individual variations in disease prevalence and infection rates indicate that maternity colonies are more susceptible to infectious agents, underlining the possible important role of host physiology, immunity and roosting behavior as risk factors for infection of bats.     

Spores of Paenibacillus larvae,Ascosphaera apis,Nosema ceranae and Nosema apis in bee products supervised by the Brazilian Federal Inspection Service

Due to their ecological and economic importance, honey bees have attracted much scientific attention, which has intensified due to the recent population decline of these insects in the several parts of the world. Among the factors related to these patterns, infection by pathogens are the most relevant, mainly because of the easy dissemination of these microorganisms. Although no zoonotic diseases are associated with these insects, the presence of infectious agents in bee products should still be considered because they play a role as disease dispersers, increasing the risk to animal health. Because of the possibility of dispersion of pathogens via bee products, this work aimed to identify the presence of spores of the pathogens Paenibacillus larvae, Ascosphaera apis and Nosema spp. in samples of honey, pollen and royal jelly that are registered with Brazil's Federal Inspection Service (S.I.F.) and commercially available in the state of São Paulo. Of the 41 samples of bee products analyzed, only one showed no contamination by any of these pathogens. N. ceranae and P. larvae had the highest prevalence considering all the samples analyzed (present in 87.80% and 85.37% of the total, respectively), with N. apis present in 26.83% and A. apis present in 73.17% of the samples. These results provide support for the formulation of government regulations for sanitary control of exotic diseases by preventing dispersion of pathogens, including through illegal importation, since local and international trade and the transfer of colonies between regions play important roles in the dispersion of these microorganisms.     

Prion protein scrapie and the normal cellular prion protein

Prions are infectious proteins and over the past few decades, some prions have become renowned for their causative role in several neurodegenerative diseases in animals and humans. Since their discovery, the mechanisms and mode of transmission and molecular structure of prions have begun to be established. There is, however, still much to be elucidated about prion diseases, including the development of potential therapeutic strategies for treatment. The significance of prion disease is discussed here, including the categories of human and animal prion diseases, disease transmission, disease progression and the development of symptoms and potential future strategies for treatment. Furthermore, the structure and function of the normal cellular prion protein (PrP^C) and its importance in not only in prion disease development, but also in diseases such as cancer and Alzheimer's disease will also be discussed.     

The muskrat in biomedical research

Muskrats are aquatic rodents of moderate size which are plentiful throughout North America, but are not used commonly in the laboratory. Recently, we tested the feasibility of muskrats as experimental models and have found them to be acquired and cared for easily in conventional laboratory animal facilities. Some of their natural characteristics and diseases are described. The husbandry techniques that we used are presented and form a base for the preparation of future guidelines for the maintenance and use of feral animals in research. The results of some initial experiments testing the muskrat's utility for investigations of cardiorespiratory control mechanisms also are presented. Our data show that even anesthetized muskrats possess brisk and dramatic cardiovascular and respiratory reflexes. Our findings that their brains possess the cytoarchitectural and myeloarchitectural features comparable to other mammals, combined with their relative uniformity in size, has allowed us to locate specific neuronal loci stereotaxically. We suggest that the muskrat be considered as an experimental animal model for studies of the neural control of cardiorespiratory systems.     

Developing vaccines against foot-and-mouth disease and some other exotic viral diseases of livestock

Vaccines remain the main tool for the control of livestock viral diseases that pose a serious threat to animal and occasionally human health, reduce food security, distort trade in animals and their products, and undermine agricultural development in poor countries. Globalization and climate change increase the likelihood for new patterns of emergence and spread of livestock viruses. Conventionally attenuated and killed virus products have had spectacular success, and recent examples include the global eradication of rinderpest and the control of bluetongue in the UK and northern Europe. However, in many cases, livestock vaccines could benefit from improvement in some properties (e.g. stability, speed of onset and duration of immunity, and breadth of cross-protection to different serotypes or strains) and in some cases are not available at all. Compared with human vaccines, uptake of livestock products is highly cost-sensitive and their use may also need to be compatible with post-vaccination screening methods to determine whether or not animals continue to be infected. Requirements and prospects for new or improved vaccines are described for some priority viral diseases with potential for transboundary spread, particularly for foot-and-mouth disease.