This paper discusses five parasitic diseases: American trypanosomiasis (Chagas disease), dracunculiasis, lymphatic filariasis, onchocerciasis and schistosomiasis. The available technology and health infrastructures in developing countries permit the eradication of dracunculiasis and the elimination of lymphatic filariasis due to Wuchereria bancrofti. Blindness due to onchocerciasis and transmission of this disease will be prevented in eleven West African countries; transmission of Chagas disease will be interrupted. A well-coordinated international effort is required to ensure that scarce resources are not wasted, efforts are not duplicated, and planned national programmes are well supported. (+info)
Preventing zoonotic diseases in immunocompromised persons: the role of physicians and veterinarians.
We surveyed physicians and veterinarians in Wisconsin about the risk for and prevention of zoonotic diseases in immunocompromised persons. We found that physicians and veterinarians hold significantly different views about the risks posed by certain infectious agents and species of animals and communicate very little about zoonotic issues; moreover, physicians believe that veterinarians should be involved in many aspects of zoonotic disease prevention, including patient education. (+info)
NK cells and apoptosis.
Natural killer (NK) cells are a cell of the innate immune system that play an important role in the early response to viral infections and tumours. Natural killer cells are cytolytic, and secrete cytokines that influence the developing antigen-specific immune response. In the present article the NK cell surface molecules regulating effector function, the NK cell effector mechanisms involved in apoptosis, and the role of NK cell effector mechanisms in immune responses are reviewed. (+info)
Glycosaminoglycan-binding microbial proteins in tissue adhesion and invasion: key events in microbial pathogenicity.
Glycosaminoglycans such as heparin, heparan sulphate and dermatan sulphate, are distributed widely in the human body. Several glycosaminoglycans form part of the extracellular matrix and heparan sulphate is expressed on all eukaryotic surfaces. The identification of specific binding to different glycosaminoglycan molecules by bacteria (e.g., Helicobacter pylori, Bordetella pertussis and Chlamydia trachomatis), viruses (e.g., herpes simplex and dengue virus), and protozoa (e.g., Plasmodium and Leishmania), is therefore of great interest. Expression of glycosaminoglycan-binding proteins depends on growth and culture conditions in bacteria, and differs in various phases of parasite development. Glycosaminoglycan-binding microbial proteins may mediate adhesion of microbes to eukaryotic cells, which may be a primary mechanism in mucosal infections, and are also involved in secondary effects such as adhesion to cerebral endothelia in cerebral malaria or to synovial membranes in arthritis caused by Borrelia burgdorferi. It has been suggested that they may enhance intracellular survival in macrophages. Microbial binding of heparin may interfere with heparin-dependent growth factors. Whether or not glycosaminoglycan-binding proteins mediate invasion of epithelial cells is a matter of controversy. Heparin and other glycosaminoglycans may have potential uses as therapeutic agents in microbial infections and could form part of future vaccines against such infections. (+info)
Ocular linguatuliasis in Ecuador: case report and morphometric study of the larva of Linguatula serrata.
Linguatula serrata is a pentastomid, a cosmopolitan parasite belonging to the Phylum Pentastomida. Humans may act as an intermediate or accidental definitive host of this parasite, manifesting the nasopharyngeal or visceral form, with the latter having been described more frequently. The occurrence of ocular linguatuliasis is extremely rare, but it has been reported in the United States and Israel. The objective of the present paper was to report the first case of ocular linguatuliasis in Ecuador and to extend the morphologic study of L. serrata by morphometric analysis. The patient studied was a 34-year old woman from Guayaquil, Ecuador who complained of ocular pain with conjunctivitis and visual difficulties of two-months duration. Biomicroscopic examination revealed a mobile body in the anterior chamber of the eye. The mobile body was surgically removed. The specimen was fixed in alcohol, cleared using the technique of Loos, stained with acetic carmine, and mounted on balsam between a slide and a coverslip. It was observed with stereoscopic and common light microscopes in combination with an automatic system for image analysis and processing. The morphologic and morphometric characteristics corresponded to the third-instar larval form of L. serrata. To our knowledge, ocular linguatuliasis has not been previously described in South America, with this being the first report for Ecuador and South America. The present study shows that computer morphometry can adequately contribute both to the morphologic study and to the systematic classification of Pentastomids, and L. serrata in particular. (+info)
Assessing morbidity in the paediatric community.
INTRODUCTION: Morbidity information is easily available from medical records but its scope is limited to the population attended by the health services. Information on the prevalence of diseases requires community surveys, which are not always feasible. These two sources of information represent two alternative assessments of disease occurrence, namely demand morbidity and perceived morbidity. The present study was conceived so as to elicit a potential relationship between them so that the former could be used in the absence of the latter. METHODS: A community of 13,365 families on the outskirts of S. Paulo, Brazil, was studied during the period from 15/Nov/1994 to 15/Jan/1995. Data regarding children less than 5 years old were collected from a household survey and from the 2 basic health units in the area. Prevalence of diseases was ascertained from perceived morbidity and compared to estimates computed from demand morbidity. RESULTS: Data analysis distinguished 2 age groups, infants less than 1 year old and children 1 to less than 5. The most important groups of diseases were respiratory diseases, diarrhoea, skin problems and infectious & parasitical diseases. Basic health units presented a better coverage for infants. Though disease frequencies were not different within or outside these units, a better coverage was found for diarrhoea and infectious & parasitical diseases in the infant group, and for diarrhoea in the older age group. Equivalence between the two types of morbidity was found to be limited to the infant group and concerned only the best covered diseases. The odds of a disease being seen at the health service should be of at least 4:10 to ensure this equivalence. CONCLUSION: It was concluded that, provided that health service coverage is good, demand morbidity can be taken as a reliable estimate of community morbidity. (+info)
Anaemia and iron deficiency disease in children.
Iron deficiency is the single most common nutritional disorder world-wide and the main cause of anaemia in infancy, childhood and pregnancy. It is prevalent in most of the developing world and it is probably the only nutritional deficiency of consideration in industrialised countries. In the developing world the prevalence of iron deficiency is high, and is due mainly to a low intake of bioavailable iron. However, in this setting, iron deficiency often co-exists with other conditions such as, malnutrition, vitamin A deficiency, folate deficiency, and infection. In tropical regions, parasitic infestation and haemoglobinopathies are also a common cause of anaemia. In the developed world iron deficiency is mainly a single nutritional problem. The conditions previously mentioned might contribute to the development of iron deficiency or they present difficulties in the laboratory diagnosis of iron deficiency. (+info)
Economic evaluation of parasitic diseases: a critique of the internal and external validity of published studies.
It was estimated that in 1990, major parasitic diseases accounted for 11.7% of the disease burden from communicable disease. As advances in the prevention, diagnosis and treatment of parasitic diseases are made and implemented, there is a growing economic literature to help decision-makers choose the most efficient control method. The aim of this paper is to identify, describe and analyse the available published data on the efficiency of control strategies against parasitic diseases. Internal validity is assessed through the quality of economic evaluations over time using a series of standard questions, and external validity is assessed in terms of the potential to extrapolate results to other settings. This leads to a discussion of the legitimacy and feasibility of pooling data or results from studies for priority setting in the health sector, resulting in three recommendations: to increase the coverage of economic evaluations for parasitic diseases and types of interventions; to improve the internal validity of studies through guidelines and review procedures; and to explore the external validity of research results by examining their predictive validity across settings. (+info)