Tool For Disease Control Research Articles

Landscape Dynamics and Risk Modeling of Human Alveolar Echinococcosis

Human alveolar echinococcosis (AE) is a rare but fatal liver disease caused by a parasitic tapeworm. Between 1994 and 1997 a medical survey in a rural area in central China revealed the highest incidence rate of the disease recorded in the world to date, with 15.8 percent of the population infected in one village. Hypotheses on the nature of the transmission mechanisms from the natural to human environment focused on the effects of recent landscape change from forest to agricultural land. Archived Landsat MSS and TM data were used to examine relationships between landscape and human AE prevalence in 31 villages. The results showed a significant positive correlation between AE and the proximity of villages to forest, grassland, and shrubland vegetation, and a negative correlation with the area of cultivated land. A predictive model, based on spatial characteristics of the landscape, is now being developed with the aim of designing management tools for disease control.

MMR mass vaccination campaigns, vaccine-related adverse events, and the limits of the decision making process, in Brazil

Vaccination is unquestionably a very important tool for disease control. However, vaccines can cause adverse events that may damage the public trust. In recent experience in Brazil, the implementation of mass campaigns with MMR (measles, mumps, rubella) vaccine was associated with outbreaks of vaccine adverse events. The decision-making process regarding the continuation of the use of this vaccine proceeded in the context of uncertainties, fears and contradictions between information from the scientific literature and data generated by a post-licensure monitoring. This experience showed how important is to have a critical view of previous recommendations and to get local data addressing questions to guide the decision making process.

Anti-infectious immune effectors in marine invertebrates: potential tools for disease control in larviculture

The aquaculture of molluscs and crustaceans is an economical activity that is threatened by the repeated appearance of new diseases, non-infectious and infectious, which affect cultured species. Difficulties in controlling diseases in marine aquaculture come mainly from the differences in susceptibility of the animals according to their developmental stage (from larvae to adults) and from the diversity of pathogens that affect them. Among the causative agents encountered in marine aquaculture, viral and bacterial problems as well as fungal diseases dominate the larval production. Methods have been proposed for the control of disease in aquaculture, such as the use of probiotic bacteria, immunostimulants or the improvement of the larval quality via the nutrition, and zootechnical progress has been made. So far, antibiotics have been intensively used as preventive and curative measures, but such practices are now questioned because regular use of these chemical products has led to the appearance of drug-resistant bacteria and can also have harmful effects on the environment. In this context, alternative treatments as well as animal health monitoring have to be established as preventive measures. In the long term, the most effective way for sustainable aquaculture production will certainly rely upon the production of animals selected for increased resistance to disease, but until now, few papers can be found on this topic for marine invertebrates. Today, immune criteria as enhancement of non-specific defence responses are being considered. Investigation of the innate immune systems of molluscs and crustaceans may give new insights into the management and control of diseases in aquaculture. In particular, antimicrobial peptides present various application possibilities by their use as therapeutic agents, as tools for monitoring the health status of cultured animals, and by the use of encoding genes as selection markers for improving resistance to infections.

Co-ordinated Interdisciplinary Efforts on Research in Animal Production and Health

The objectives are to review results and experiences from interdisciplinary research projects in Research Centre for the Management of Animal Production and Health (CEPROS) concerning scientific content, organisation, and collaboration. The Centre has been founded as a result of an agreement between four institutions: the Danish Institute of Agricultural Sciences (DIAS), the Danish Veterinary Laboratory (DVL), the Danish Veterinary Institute for Virus Research (DVIV) and The Royal Veterinary and Agricultural University (KVL). CEPROS is a "research centre without walls" and is physically located as an integrated part of the four institutions named above. The Centre has close collaboration with the industry. The superior goals of the Centre are to co-ordinate fundamental and applied research and simultaneously integrate the veterinary and the production oriented livestock research within animal health and welfare, taking into consideration the production economics and reduced use of medication. The assignment of the Centre is to initiate and carry out research, aiming to investigate the influence of breeding and production systems on animal health and welfare as well as on production and product quality. The Centre has since 1997 established 16 interdisciplinary research projects dealing with cattle, pigs, poultry, or mink. The scientific content can be divided into three research clusters: A. Management of animal production and health in production systems, B: Pathogenesis of production diseases, and C. Animal health economics. In Cluster A, the physical environments of production systems have been investigated, broader definitions of the concept health have been established and used in identification of risk factors. Cluster B has investigated physiological, immunological and genetic mechanisms behind development of production diseases and how to apply this knowledge in disease prevention. The cluster in animal health economics has developed decision support tools for disease control in swine and cattle herds. The interdisciplinary research groups organised in a centre without walls are found very useful for dealing with complex issues. The initial phases in the projects may be long as it takes time for different researchers to define common goals and identify methods. The individual researcher must get some insight in other disciplines without loosing his/her own area of expertise. In order to reach a synthesis of the different parts of a project, it is important that the project is well organised and there is participation of researchers with both specialised insight and researchers with a more broad insight in the problems. It is also important that the integration process is balanced, and not too many research disciplines are included in the same project.

Co-ordinated Interdisciplinary Efforts on Research in Animal Production and Health

The objectives are to review results and experiences from interdisciplinary projects in Research Centre for the Management of Animal Production and Health (CEPROS) concerning scientific content, organisation, and collaboration. The Centre has been founded as a result of an agreement between four institutions: the Danish Institute of Agricultural Sciences (DIAS), the Danish Veterinary Laboratory (DVL), the Danish Veterinary Institute for Virus Research (DVIV) and The Royal Veterinary and Agricultural University (KVL). CEPROS is a research centre without and is physically located as an integrated part of the four institutions named above. The Centre has close collaboration with the industry. The superior goals of the Centre are to co-ordinate fundamental and applied and simultaneously integrate the veterinary and the production oriented livestock within animal health and welfare, taking into consideration the production economics and reduced use of medication. The assignment of the Centre is to initiate and carry out research, aiming to investigate the influence of breeding and production systems on animal health and welfare as well as on production and product quality. The Centre has since 1997 established 16 interdisciplinary projects dealing with cattle, pigs, poultry, or mink. The scientific content can be divided into three clusters: A. Management of animal production and health in production systems, B: Pathogenesis of production diseases, and C. Animal health economics. In Cluster A, the physical environments of production systems have been investigated, broader definitions of the concept health have been established and used in identification of risk factors. Cluster B has investigated physiological, immunological and genetic mechanisms behind development of production diseases and how to apply this knowledge in disease prevention. The cluster in animal health economics has developed decision support tools for disease control in swine and cattle herds. The interdisciplinary groups organised in a centre without walls are found very useful for dealing with complex issues. The initial phases in the projects may be long as it takes time for different researchers to define common goals and identify methods. The individual researcher must get some insight in other disciplines without loosing his/her own area of expertise. In order to reach a synthesis of the different parts of a project, it is important that the project is well organised and there is participation of researchers with both specialised insight and researchers with a more broad insight in the problems. It is also important that the integration process is balanced, and not too many disciplines are included in the same project.

Report on the MSSVD Spring meeting, Belfast, 24-26 May 2001

This year's spring meeting was held in Belfast's Waterfront Hall. We opened with a satellite meeting of the sexual dysfunction special interest group. Frances Keane assured us that assessment of the patient with an ejaculatory disorder started at reception, when their timeliness for appointments could give useful information. Low dose SSRIs or tricyclics have been used effectively for this unlicensed application but can themselves cause erectile dysfunction. Sildenafil (Viagra) may work by reassurance that their erection will last. We heard a highly entertaining discourse on the determinants of sexual orientation by John Green. He reckoned any genetic determinant for homosexuality should be selected out, since homosexual men have about one fifth as many children as heterosexuals. No hormonal or immunological theories have borne scrutiny. From family studies it would appear that birth order is important: the more older brothers a man has the more likely he is to be homosexual. There is a higher rate of homosexuality in siblings of homosexual men and women. We heard a lot about the internet and world wide web in the first plenary session, one presentation, and a poster. Three speakers explored the many ways in which the web could be used to our advantage. We were also reminded of security issues, and the difficulties of typing in key words pertaining to GUM. Just suppose your area of interest is prostitution! The benefits of collection of information through web based surveys and the dissemination of information to profession and public were discussed. Teaching, through web based lectures or interactive sites, can be accessible at any time and taken at the pace of the student. Sharing of epidemiological data and early warning of outbreaks can make the internet a useful tool for disease control. Syphilis rates are low but rising, principally among men who have …

Fièvre dengue : mise au point

Introduction. – Transmitted by Aedes mosquitoes all over the inter-tropical area, Dengue fever is the leading arboviral disease in humans. It is also an emerging disease. Current knowledge and key points. – Increasing morbidity-mortality, and geographical expansion are the drastic changes noted in the recent epidemiology of the disease. They are related to those occurring at the bio-climatic, socio-demographic and behavioural levels, which in turn may have led to enhanced viral circulation and virulence, and also vectorial resistance. The various clinical patterns (undifferentiated febrile episode of children, acute and algid classic form, the potentially fatal dengue hemorrhagic fever/dengue shock syndrome, and the atypical forms) are reviewed, as well as the diagnostic methods, and the pathogenesis (sequential infections, facilitating antibodies, capillary leakage). Future prospects and projects. – Dengue fever is actually much more than a traveller’s fever or an exotic curiosity. It presently threatens half the world’s population, and remains a puzzling disease in many aspects, such as the virus-vector and host-virus relationships, and clinical expression variability. In this respect, dengue fever appears as a model of viral disease. The current molecular approach is expected to provide us with new insights into pathophysiology, more efficient tools for disease control, and also an efficient vaccine in the near future.

Induced defence responses of cereals to pathogen attack

The defence responses of plants are usually composed of a multitude of structural and biochemical events. Some occur constitutively, whereas others, which are emphasised in this review, are formed in response to pathogen attack and are considered as active reactions of plants. Induction of defence mechanisms can be observed in all plants regardless of their genetic background. Thus, this phenomenon can occur in cultivars with or without known genes for disease resistance. The general defence features of plants may contribute significantly to the overall disease resistance of plants and increasing evidence for the role of different defence molecules are being obtained from molecular studies. In this review, induction of defence mechanisms, especially phenylpropanoid metabolism and its role in the defence responses of cereals to pathogen attack is addressed. Also, induced resistance as a potential tool for disease control in cereals will be briefly discussed.;

Parasite genome projects and the Trypanosoma cruzi genome initiative.

Since the start of the human genome project, a great number of genome projects on other "model" organism have been initiated, some of them already completed. Several initiatives have also been started on parasite genomes, mainly through support from WHO/TDR, involving North-South and South-South collaborations, and great hopes are vested in that these initiatives will lead to new tools for disease control and prevention, as well as to the establishment of genomic research technology in developing countries. The Trypanosoma cruzi genome project, using the clone CL-Brener as starting point, has made considerable progress through the concerted action of more than 20 laboratories, most of them in the South. A brief overview of the current state of the project is given.

Prospects for new interventions in the treatment and prevention of mycobacterial disease.

Mycobacterium tuberculosis claims more lives each year than any other single human pathogen. Despite the availability of effective drugs, the incidence of tuberculosis is increasing in much of the developing world and has recently reemerged as a public health problem in industrialized countries. In the first section of this chapter, current understanding of the fundamental biology of mycobacterial infection is reviewed from the perspective of development of new tools for disease control. A second section describes strategies for identification of novel antimycobacterial agents, with particular emphasis on recent progress in defining biosynthetic pathways for unique mycobacterial cell wall components. The third section focuses on current approaches to the development of new vaccine candidates consisting of live attenuated bacteria or individual antigenic subunits.

Transmission, Movement, and Inactivation of Cymbidium Mosaic and Odontoglossum Ringspot Viruses

Transmission and movement studies were conducted on orchids mechanically inoculated with cymbidium mosaic virus (CyMV) or odontoglossum ringspot virus (ORSV). Transmission of CyMV and ORSV to University of Hawaii (UH) Dendrobium hybrids was efficient; both viruses were detected in inoculated leaves a minimum of 3 days after inoculation. Cymbidium mosaic virus moved systemically from inoculated leaves to roots (minimum 10 days after inoculation) and then to other leaves (minimum 20 days after inoculation). Thirty-two of 33 CyMV-inoculated orchid plants were systemically infected. Systemic movement of ORSV took about 7 mo and occurred in only one of 38 inoculated orchid plants. Seven chemicals were evaluated for inactivation of CyMV on pruning tools for disease control [...]

Case studies from the biomedical and health systems research activities of the Swiss Tropical Institute in Africa

Neither high theoretical efficacy of disease control tools, nor diagnostic accuracy, nor good compliance, nor adequate coverage can lead on its own to the final goal of community effectiveness. There is a complex relationship between these factors. The different steps in the process leading to effective health care in the community are discussed on the basis of biomedical and health systems research activities of the Swiss Tropical Institute. Schistosomiasis and malaria control provide the background to problems related to the efficacy of tools. In particular, information on the trial of a malaria vaccine candidate (SPf66) is given. Approaches to the rapid, accurate and economical diagnosis of communities at risk are discussed with reference to Schistosoma haematobium and S. mansoni. Health service support projects in Tanzania and Chad are presented to exemplify problems linked to the compliance of users/providers and coverage. Finally, it is shown that community effectiveness depends on the highest possible success rate for each step. This requires the co-operative efforts of all those involved: the scientist, the manager, the community health worker and, last but not least, the community itself.

The relevance of rapid assessment to health research and interventions

This paper introduces the special issue on rapid assessment methods for tropical disease research. It highlights disease control problems that the combined skills of social and biomedical scientists must address, as well as problems hampering multidisciplinary research. Traditional social science and epidemiological methods are often too time-consuming to address the immediate and urgent needs of disease control programmes. Rapid assessment methods to provide information on health status, health impact, health services and health behaviour are therefore essential. A distinction is made between the efficacy of disease control tools and community effectiveness (the efficacy of the tools as applied at the community level), and the potential for rapid assessment to improve community effectiveness is emphasized. The development and validation of rapid assessment methods is discussed, and the techniques described more fully in subsequent papers are introduced.

Perspectives in research on and control of African trypanosomiasis

African trypanosomiasis affects both man and his domestic animals, and is fatal if untreated. The risk of epidemics makes the disease a major public health problem in 36 sub-Saharan African countries, where some 50 million people are at risk of contracting the disease. Continued suppression of the disease through medical surveillance is indispensable to prevent epidemics which are difficult and costly to control. Recent epidemics and flare-ups have occurred in certain countries due to breakdown in medical surveillance occasioned by political, social and economic factors. The development of new tools through research over the last decade has improved the diagnosis of patients and vector control. The development of eflornithine (DFMO) for the treatment of gambiense sleeping sickness is a major breakthrough in view of its safety compared with current treatment alternatives, and it has been nicknamed the 'resurrection drug'. In spite of these achievements, however, there is no radical solution to the problem of sleeping sickness. The use by the endemic countries of improved tools for disease control depends upon the availability of resources from national, bilateral and multilateral sources, and commitment of the countries concerned.

The Problem of Acquired Physiological Immunity in Plants

The Problem of Acquired Physiological Immunity in Plants