Transmission dynamics of the Echinococcus granulosus sheep-dog strain (G1 genotype) in camels in Tunisia

Cystic echinococcosis, caused by Echinococcus grantilosus, is highly endemic in North Africa and the Middle East. This paper examines the abundance and prevalence of infection of E. granulosus in camels in Tunisia. No cysts were found in 103 camels from Kebili, whilst 19 of 188 camels from Benguerden (10.1%) were infected. Of the cysts found 95% were considered fertile with the presence of protoscolices and 80% of protoscolices were considered viable by their ability to exclude aqueous eosin. Molecular techniques were used on cyst material from camels and this demonstrated that the study animals were infected with the G1 sheep strain of E. granulosus. Observed data were fitted to a mathematical model by maximum likelihood techniques to define the parameters and their confidence limits and the negative binomial distribution was used to define the error variance in the observed data. The infection pressure to camels was somewhat lower in comparison to sheep reported in an earlier study. However, because camels are much longer-lived animals, the results of the model fit suggested that older camels have a relatively high prevalence rate, reaching a most likely value of 32% at age 15 years. This could represent an important source of transmission to dogs and hence indirectly to man of this zonotic strain. In common with similar studies on other species, there was no evidence of parasite-induced immunity in camels. (C) 2004 Elsevier B.V. All rights reserved.

Challenges to environmental toxicology and epidemiology: where do we stand and which way do we go?

Modern toxicology investigates a wide array of both old and new health hazards. Priority setting is needed to select agents for research from the plethora of exposure circumstances. The changing societies and a growing fraction of the aged have to be taken into consideration. A precise exposure assessment is of importance for risk estimation and regulation. Toxicology contributes to the exploration of pathomechanisms to specify the exposure metrics for risk estimation. Combined effects of co-existing agents are not yet sufficiently understood. Animal experiments allow a separate administration of agents which can not be disentangled by epidemiological means, but their value is limited for low exposure levels in many of today's settings. As an experimental science, toxicology has to keep pace with the rapidly growing knowledge about the language of the genome and the changing paradigms in cancer development. During the pioneer era of assembling a working draft of the human genome, toxicogenomics has been developed. Gene and pathway complexity have to be considered when investigating gene-environment interactions. For a best conduct of studies, modem toxicology needs a close liaison with many other disciplines like epidemiology and bioinformatics. (C) 2004 Elsevier Ireland Ltd. All rights reserved.

The epidemiology of dysphagia: Describing the problem - are we too late?

The assessment and management of dysphagia is a rapidly growing part of speech pathology clinical practice for both adult and paediatric populations, yet there is limited information available regarding the epidemiology of dysphagia. Very few studies have defined the characteristics of the disorder, its incidence/prevalence in various populations, the natural history of the disorder or the relative risks, comorbidities and outcomes associated with dysphagia. The current paper will identify some fundamental questions that as yet remain unanswered and highlight areas of future research that are required in order for us to have a better understanding of dysphagia and inform assessment and management. In conclusion, the authors propose an epidemiological framework and highlight information needs in the field of dysphagia. This framework urges future dysphagia research to be informed and underpinned by sound epidemiological principles.

Role of smoking in global and regional cancer epidemiology: current patterns and data needs

Although smoking is widely recognized as a major cause of cancer, there is little information on how it contributes to the global and regional burden of cancers in combination with other risk factors that affect background cancer mortality patterns. We used data from the American Cancer Society's Cancer Prevention Study II (CPS-II) and the WHO and IARC cancer mortality databases to estimate deaths from 8 clusters of site-specific cancers caused by smoking, for 14 epidemiologic subregions of the world, by age and sex. We used lung cancer mortality as an indirect marker for accumulated smoking hazard. CPS-II hazards were adjusted for important covariates. In the year 2000, an estimated 1.42 (95% CI 1.27-1.57) million cancer deaths in the world, 21% of total global cancer deaths, were caused by smoking. Of these, 1.18 million deaths were among men and 0.24 million among women; 625,000 (95% CI 485,000-749,000) smoking-caused cancer deaths occurred in the developing world and 794,000 (95% CI 749,000-840,000) in industrialized regions. Lung cancer accounted for 60% of smoking-attributable cancer mortality, followed by cancers of the upper aerodigestive tract (20%). Based on available data, more than one in every 5 cancer deaths in the world in the year 2000 were caused by smoking, making it possibly the single largest preventable cause of cancer mortality. There was significant variability across regions in the role of smoking as a cause of the different site-specific cancers. This variability illustrates the importance of coupling research and surveillance of smoking with that for other risk factors for more effective cancer prevention. (C) 2005 Wiley-Liss, Inc.

Psoriatic arthritis: epidemiology, clinical features, course, and outcome

Psoriatic arthritis (PsA) has been defined as a unique inflammatory arthritis associated with psoriasis. Its exact prevalence is unknown, but estimates vary from 0.3% to 1% of the population. The clinical features described initially are recognised by most experienced clinicians, although they are most distinct in early disease. Initially, PsA typically presents as an oligoarticular and mild disease. However, with time PsA becomes polyarticular, and it is a severe disease in at least 20% of patients. Patients with PsA who present with polyarticular disease are at risk for disease progression. In addition to progression of clinical and radiological damage, health related quality of life is reduced among patients with PsA. It important to note that patients included in recent drug trials resemble patients followed prospectively in a clinic.

Myths and plain truths about schizophrenia epidemiology - the NAPE lecture 2004

Objective: Science needs to constantly match research models against the data. With respect to the epidemiology of schizophrenia, the widely held belief that the incidence of schizophrenia shows little variation may no longer be supported by the data. The aims of this paper are (i) to explore data-vs.-belief mismatch with respect to the incidence of schizophrenia, and (ii) to speculate on the causes and consequences of such discrepancies. Method: Based on a recently published systematic review of the incidence of schizophrenia, the distribution of incidence rates around the world was examined. In order to examine if the incidence of schizophrenia differed by sex, male vs. female risk ratios were generated. Results: The distribution of incidence rates for schizophrenia is asymmetrical with many high rates skewing the distribution. Based on the central 80% of rates, the incidence of schizophrenia varies in a five-fold range (between 7.7 and 43.0 per 100 000). Males have a significantly higher incidence of schizophrenia compared with females (median male to female risk ratio = 1.4), and this difference could not be accounted for by diagnostic criteria or age range. Conclusion: The beliefs that (i) the incidence of schizophrenia does not vary between sites and (ii) males and females are equally affected, may have persisted because of an unspoken deeper belief that schizophrenia is an egalitarian and exceptional disorder. Our ability to generate productive hypotheses about the aetiology of schizophrenia rests on an accurate appraisal of the data. Beliefs not supported by data should be identified and relabelled as myths.

Stress in veterinary science students: A study at the University of Queensland

This paper reports on the results of a survey of selected University of Queensland (UQ) veterinary students aimed at elucidating factors causing stress during the five undergraduate years of the program. Students from each of the five years were asked to form six- or seven-member focus groups. Each focus group was then interviewed and their opinions sought on causes of ongoing stress and the ranking of those causes into predetermined categories. They were also asked to give their opinions on counseling services available within the university and what, if any, services they would like to see in place to help students with stress-related problems. Students in the first, third, and fourth years of the program rated academic issues as the most likely causes of ongoing stress, while students in the second and fifth years of the program ranked lifestyle and financial issues as more likely to cause ongoing stress. in most cases, students coped well with these causes of stress and tended not to use counseling services available to all UQ students. When faced with stressful issues, students looked to their classmates or family members for help and not to university counseling services. Students were also happy to approach staff members in the Veterinary School when faced with a problem. The authors nevertheless conclude that mechanisms set in place at the undergraduate level to help veterinary students cope with stress should particularly benefit those students when they become new graduates and are faced with the stresses of veterinary practice.

A comparison of responses to group learning between first-year Asian and first-year Australian veterinary science students

Introduction - Group learning has been used to enhance deep (long-term) learning and promote life skills, such as decision making, communication, and interpersonal skills. However, with increasing multiculturalism in higher education, there is little information available as to the acceptance of this form of learning by Asian students or as to its value to them. Methodology - Group-learning projects, incorporating a seminar presentation, were used in first-year veterinary anatomical science classes over two consecutive years (2003 and 2004) at the School of Veterinary Science, University of Queensland. Responses of Australian and Asian students to survey forms evaluating the learning experience were analyzed and compared. Results - All students responded positively to the group learning, indicating that it was a useful learning experience and a great method for meeting colleagues. There were no significant differences between Asian and Australian students in overall responses to the survey evaluating the learning experience, except where Asian students responded significantly higher than Australian students in identifying specific skills that needed improving. Conclusions - Group learning can be successfully used in multicultural teaching to enhance deep learning. This form of learning helps to remove cultural barriers and establish a platform for continued successful group learning throughout the program.