Once again on the professional language of epidemiologists

Grounds for the adoption of a unified, commonly accessible, professional terminology by specialists are presented. The emphasis is made on the unification and uniformity of using the terms "epidemiological" and "epidemic". A small dictionary explaining the true or false sense of terms in epidemiology is proposed.     

Terminologic aspects of infections associated with administration of medical aid

Evolution of key terms used in epidemiology of nosocomial infections is discussed. A modern point of view on terminology and comparison of Russian terms with foreign analogues are presented.     

Malaria on the Guiana Shield: a review of the situation in French Guiana

In a climate of growing concern that Plasmodium falciparum may be developing a drug resistance to artemisinin derivatives in the Guiana Shield, this review details our current knowledge of malaria and control strategy in one part of the Shield, French Guiana. Local epidemiology, test-treat-track strategy, the state of parasite drug resistance and vector control measures are summarised. Current issues in terms of mobile populations and legislative limitations are also discussed.     

Some remarks on definition and validity of terms used in models for infectious disease spread.

The epidemiology of infectious diseases makes use of a number of terms, such as exposure, infected, carrier, attack rate, and immunity. Researchers who intend to model the spread of epidemics should be aware of the problems with some of these terms. The role played by inapparent, or subclinical, infections is receiving increased attention in infectious disease epidemiology. Patients with such infections may never be reported as cases, which could give rise to problems when, for example, data from national surveillance bodies are being used for modeling. The assignment of patients to different transmission groups must, in most cases, rely on self-reported data from the medical interview. This possible source of bias should be recognized.     

Diaporthe woodii (anamorph Phomopsis leptostromiformis) — A toxigenic fungus infecting cultivated lupins

This review summarizes the effects of D. woodii infection of lupins in terms of symptomology, mycotoxicology and epidemiology of the fungus. Aspects of control are also discussed.     

Dogma driven science, the need to establish a common base line

This commentary examines hepatotoxicity and drug-drug interactions in terms of quoted epidemiology and, the compounds and concentrations used its relationship to the screen being proposed and asks if we have a common ground for validation.     

Production losses and control of helminths in ruminants of tropical regions

The magnitude of production losses and the epidemiology and control of gastro-intestinal nematodes, fascioliasis and paramphistomiasis in sheep, goats and cattle and of Onchocerca gutturosa and Cysticercus bovis in cattle in tropical regions is reviewed in broad terms.The limited information available indicates tremendous losses caused by gastro-intestinal nematodes. Acute outbreaks are commonly seen in the wet season in animals grazing at moderate to high densities. Control is commonly by anthelmintic medication but is limited by the cost of treatment.Fascioliasis causes enormous losses; acute outbreaks are generally seen in the mid-dry season in West Africa. Anthelmintic medication is the major means of control but in most cases drugs are applied haphazardly. Intestinal paramphistomiasis is responsible for some losses; the epidemiology of the disease is essentially as described for fascioliasis, but attempts at control are negligible.Although Onchocerca gutturasa causes considerable losses in cattle, little is known about its epidemiology and control attempts are rare.Cysticercus bovis causes losses in cattle. The habit of eating grilled meat, lack of meat inspection facilities and reluctance of infected persons to seek treatment are responsible for the perpetuation of infection.     

Environmental, cultural and social changes and their influence on parasite infections

The changes taking place within the societies, cultures and the environments in which we live are massive and complex. By referring to simple epidemiological models it is possible to build an objective framework with which to look at these changes in terms of their likely impact on the epidemiology of parasitic diseases within human communities. These parameters are listed for hosts and both micro- and macroparasites, as are epidemiologically significant cultural, social and environmental variables. Changes in these variables may be either detrimental or beneficial to human health and may, in addition, interact in complex ways. Examples of the complexity of changes which can influence epidemiology are provided for a cultural template of the population living in the north-east of Thailand.     

Correlation equations for endemic diseases: externally imposed and internally generated heterogeneity

The simple susceptible–infectious–recovered (SIR) model has provided many insights into the behaviour of a single epidemic. However, most of epidemiology is concerned with endemic infections, and for this to occur fresh susceptibles need to be generated. This is usually provided by individuals becoming susceptible soon after birth or by recruitment to cohorts at risk. This paper develops a correlation model, predicting the behaviour of connected pairs of individuals, which includes demographic processes as well as the basic epidemiology. In addition to the local spatial correlations, we consider three other forms of heterogeneity: internally generated heterogeneity in terms of stochasticity or imposed heterogeneity in terms of non-uniform vaccination or age-structure.     

Observations on the development of Echinococcus multilocularis in cats

The development of a European isolate of Echinococcus multilocularis was compared in cats and dogs at the end of the prepatent period. Echinococcus multilocularis established in all dogs and cats, but worm recovery was significantly greater from dogs than from cats. Overall, worms in cats were not as advanced as those in dogs in terms of development and maturation, but there was no evidence of retarded development or stunted forms. These results confirm that dogs are highly susceptible to E. multilocularis, whereas cats have lower and more variable recovery rates. However, because cats produce thick-shelled eggs of E. multilocularis after experimental and natural infections, they have to be regarded as potential sources of infection both for intermediate and accidental hosts, including humans. However, their general role in the epidemiology of the infection has yet to be determined.     

Tuberculosis Epidemiology in Islands: Insularity,Hosts and Trade

Because of their relative simplicity and the barriers to gene flow, islands are ideal systems to study the distribution of biodiversity. However, the knowledge that can be extracted from this peculiar ecosystem regarding epidemiology of economically relevant diseases has not been widely addressed. We used information available in the scientific literature for 10 old world islands or archipelagos and original data on Sicily to gain new insights into the epidemiology of the Mycobacterium tuberculosis complex (MTC). We explored three nonexclusive working hypotheses on the processes modulating bovine tuberculosis (bTB) herd prevalence in cattle and MTC strain diversity: insularity, hosts and trade. Results suggest that bTB herd prevalence was positively correlated with island size, the presence of wild hosts, and the number of imported cattle, but neither with isolation nor with cattle density. MTC strain diversity was positively related with cattle bTB prevalence, presence of wild hosts and the number of imported cattle, but not with island size, isolation, and cattle density. The three most common spoligotype patterns coincided between Sicily and mainland Italy. However in Sicily, these common patterns showed a clearer dominance than on the Italian mainland, and seven of 19 patterns (37%) found in Sicily had not been reported from continental Italy. Strain patterns were not spatially clustered in Sicily. We were able to infer several aspects of MTC epidemiology and control in islands and thus in fragmented host and pathogen populations. Our results point out the relevance of the intensity of the cattle commercial networks in the epidemiology of MTC, and suggest that eradication will prove more difficult with increasing size of the island and its environmental complexity, mainly in terms of the diversity of suitable domestic and wild MTC hosts.     

Spatial modelling of individual-level parasite counts using the negative binomial distribution

We present a spatial model for the mean and correlation of highly dispersed count data, and apply it to individual-level counts of the nematode Wuchereria bancrofti, a parasite of humans which causes the disease lymphatic filariasis. Our model uses the negative binomial distribution, whose shape parameter is a convenient index of over-dispersion. Spatial association is quantified in terms of a characteristic length, which has an intuitive interpretation as the distance over which correlation decreases by half. Demographic surveillance and mapping enable us to include individual-level covariates such as age and sex. We discuss the distinctive features of our model and interpret the results in terms of the epidemiology of lymphatic filariasis and possible implications for control programmes.     

Antibiotic use in humans and bacterial resistance.

As with any public health problem, the evolution of antibacterial resistance must be viewed from a perspective of risk, and analysed in terms of probabilities within the populations. It is necessary to be able to predict the risk of antibacterial resistance, in the future, and two main strategies have recently been developed in mathematical models that may help to evaluate these risks. It is also important to understand how antibiotics are used and how their use affects the evolution of antibacterial resistance. Understanding the epidemiology of antibacterial resistance will enable us to develop preventive strategies to limit existing resistance and to avoid the emergence of new strains of resistant bacteria.     

Statistical modelling of the spatial distribution of prevalence of Calicophoron daubneyi infection in sheep from central Italy

Statistical modelling for Disease Mapping and Ecological Analysis is of particular importance in veterinary parasitology because environmental characteristics can affect parasite distribution. However, the main difficulties relate to the concentration of animal populations within farms, which contrasts to the study of wild animal populations. In the present paper we report the results of a cross-sectional coprological survey designed to study the presence and distribution of the rumen fluke Calicophoron daubneyi--which causes paramphistomosis, a snail borne disease--in pastured sheep living in the Latina province of central Italy. We show how techniques derived from human epidemiology can be used to study the spatial distribution of parasite infection in animals. We proposed a hierarchical Bayesian model with random terms for unstructured variability (heterogeneity) to account for local farm characteristics and spatially structure terms (clustering) to cope with medium-large scale environmental characteristics.     

Features of epidemiological activity in medicine

The article deals with the main elements of scientific knowledge in epidemiology, viz. its subject matter, goals and methods. The statement is substantiated that the main subject of epidemiology, determining its specificity, is the morbidity of the population, and the content of the epidemiological goals and methods are disclosed. The determination of the term "epidemiological approach" as well as a scheme reflecting the structure of epidemiology are presented.     

The control of eriophyoid mites: state of the art and future challenges

The superfamily of the Eriophyoidea is a large and diverse group of mites, including a number of species of economic importance, mainly on perennial plants in agriculture and forestry. This review focuses on the economic importance and pest status of this group of mites, with emphasis on some genera. The available acaricide portfolio is reviewed and the influence of EU legislation policy on the sustainable control of Eriophyoidea is investigated. Possible generic guidelines for sustainable control and resistance management with special reference to the European situation are discussed. Recent advances in biological and integrated control of eriophyid mite pests and the implementation of these techniques in crops are explored. Furthermore, the relevance of studies on behaviour, epidemiology and diagnostics in general terms and as a strategic necessity is pointed out.     

Molecular techniques for the investigation of meningococcal disease epidemiology

Meningococcal disease remains a major cause of childhood morbidity and mortality world wide and no comprehensive vaccine is available against the causative organism, Neisseria meningitidis. Molecular studies of the diversity of this bacterium have provided a number of key insights into its biology, which have implications for control of meningococcal disease. These have included the identification of hyperinvasive lineages and the correlation of genetic type with antigenic type and disease epidemiology. In practical terms, such studies have enabled the application of DNA-based technologies in the development of improved methods for diagnosis and epidemiological monitoring. These data are of especial importance with the current, and ongoing, development and introduction of new meningococcal vaccines.     

Molecular epidemiology of the late radiation effects

The scientific bases, problems, methods and prospects for the development of a new scientific direction "Molecular epidemiology of late consequences of ionizing radiation influence on the man" are reviewed. It is marked, that for two decades on the basis of achievements in the field of molecular biology, biochemistry, genetics and genomics it has arisen and is developing the important direction in infectious and non-infectious epidemiology--molecular epidemiology. Molecular epidemiology is a new section of epidemiology on border with molecular biology and genetics, integrating efforts of epidemiologists, molecular biologists, genetics and researchers from many other areas of knowledge in a direction of an estimation of individual risk of development of chronic diseases at practically healthy people, development of recommendations on their preventive maintenance in cohorts of risk and, hence, in all population by studying by molecular methods of an etiology of illnesses, mechanisms of a susceptibility to them, and also biological mechanisms and frequency of their development in human cohorts. Special development in molecular epidemiology was noticed for the methods named biomarkers, subdivided on 4 categories: 1) markers of an internal dose; 2) markers of an effective dose; 3) markers of preclinical biological effects; 4) markers of a susceptibility. Use of biomarkers in molecular-epidemiological researches appeared especially productive in oncology. As radiogenic cancers are the main remote consequence of exposure to ionizing radiations, approaches and achievements of molecular epidemiology of nonradiation cancers are perspective at becoming of molecular epidemiology of radiation effects, with an object to solve problems concerning mechanisms and features of radiation carcinogenesis, risk assessment, distribution and preventive maintenance of radiogenic cancers in cohorts of professionals of the various branches having contact to sources of ionizing radiation, and the population, exposed to radiation medically.     

Relationship between mycobacteria and amoebae: ecological and epidemiological concerns

Since the discovery that Legionella pneumophila can survive and grow within free-living amoebae, there has been an increasing number of microbial species shown to have similar relationships. These include many bacterial species, fungi, other protozoa (e.g. Cryptosporidium) and viruses. Among bacteria, mycobacteria are of particular importance because of their role in human and animal infections. This review will consider the progress made in understanding the relationships between mycobacteria and amoebae, and their consequences in terms of ecology and epidemiology.     

Modelers' perception of mathematical modeling in epidemiology: a web-based survey

Background

Mathematical modeling in epidemiology (MME) is being used increasingly. However, there are many uncertainties in terms of definitions, uses and quality features of MME.

Methodology/Principal Findings

To delineate the current status of these models, a 10-item questionnaire on MME was devised. Proposed via an anonymous internet-based survey, the questionnaire was completed by 189 scientists who had published in the domain of MME. A small minority (18%) of respondents claimed to have in mind a concise definition of MME. Some techniques were identified by the researchers as characterizing MME (e.g. Markov models), while others–at the same level of sophistication in terms of mathematics–were not (e.g. Cox regression). The researchers'' opinions were also contrasted about the potential applications of MME, perceived as higly relevant for providing insight into complex mechanisms and less relevant for identifying causal factors. The quality criteria were those of good science and were not related to the size and the nature of the public health problems addressed.

Conclusions/Significance

This study shows that perceptions on the nature, uses and quality criteria of MME are contrasted, even among the very community of published authors in this domain. Nevertheless, MME is an emerging discipline in epidemiology and this study underlines that it is associated with specific areas of application and methods. The development of this discipline is likely to deserve a framework providing recommendations and guidance at various steps of the studies, from design to report.