The state of veterinary epidemiology and economics

Recent developments in the fields of veterinary epidemiology and economics are critically reviewed and assessed. The impacts of recent technological developments in diagnosis, genetic characterisation, data processing and statistical analysis are evaluated. It is concluded that the acquisition and availability of data remains the principal constraint to the application of available techniques in veterinary epidemiology and economics, especially at population level. As more commercial producers use computerised management systems, the availability of data for analysis within herds is improving. However, consistency of recording and diagnosis remains problematic. Recent trends to the development of national livestock databases intended to provide reassurance to consumers of the safety and traceability of livestock products are potentially valuable sources of data that could lead to much more effective application of veterinary epidemiology and economics. These opportunities will be greatly enhanced if data from different sources, such as movement recording, official animal health programmes, quality assurance schemes, production recording and breed societies can be integrated. However, in order to realise such integrated databases, it will be necessary to provide absolute control of user access to guarantee data security and confidentiality. The potential applications of integrated livestock databases in analysis, modelling, decision-support, and providing management information for veterinary services and livestock producers are discussed. (c) 2004 Elsevier B.V. All rights reserved.

Complete sequence and molecular epidemiology of IncK epidemic plasmid encoding bla(CTX-M-14)

Antimicrobial drug resistance is a global challenge for the 21st century with the emergence of resistant bacterial strains worldwide. Transferable resistance to beta-lactam antimicrobial drugs, mediated by production of extended-spectrum beta-lactamases (ESBLs), is of particular concern. In 2004, an ESBL-carrying IncK plasmid (pCT) was isolated from cattle in the United Kingdom. The sequence was a 93,629-bp plasmid encoding a single antimicrobial drug resistance gene, bla(CTX-M-14). From this information, PCRs identifying novel features of pCT were designed and applied to isolates from several countries, showing that the plasmid has disseminated worldwide in bacteria from humans and animals. Complete DNA sequences can be used as a platform to develop rapid epidemiologic tools to identify and trace the spread of plasmids in clinically relevant pathogens, thus facilitating a better understanding of their distribution and ability to transfer between bacteria of humans and animals.

Association of low adiponectin levels with the metabolic syndrome--the Chennai Urban Rural Epidemiology Study (CURES-4)

The aim of the study was to assess the relation of adiponectin levels with the metabolic syndrome in Asian Indians, a high-risk group for diabetes and premature coronary artery disease. The study was conducted on 100 (50 men and 50 women) type 2 diabetic subjects and 100 age and sex matched subjects with normal glucose tolerance selected from the Chennai Urban Rural Epidemiology Study, an ongoing population study in Chennai in southern India. Metabolic syndrome was defined using modified Adult Treatment Panel III (ATPIII) guidelines. Adiponectin values were significantly lower in diabetic subjects (men: 5.2 vs 8.3 microg/mL, P=.00l; women: 7.6 vs 11.1 microg/mL, P<.00l) and those with the metabolic syndrome (men: 5.0 vs 6.8 microg/mL, P=.01; women: 6.5 vs 9.9 microg/mL, P=.001) compared with those without. Linear regression analysis revealed adiponectin to be associated with body mass index (P<.05), waist circumference (P<.01), fasting plasma glucose (P=.001), glycated hemoglobin (P<.001), triglycerides (P<.00l), high-density lipoprotein (HDL) cholesterol (P<.001), cholesterol/HDL ratio (P<.00l), and insulin resistance measured by homeostasis assessment model (P<.00l). Factor analysis identified 2 factors: factor 1, negatively loaded with adiponectin and HDL cholesterol and positively loaded with triglycerides, waist circumference, and insulin resistance measured by homeostasis assessment model; and factor 2, with a positive loading of waist circumference and systolic and diastolic blood pressure. Logistic regression analysis revealed adiponectin to be negatively associated with metabolic syndrome (odds ratio [OR], 0.365; P<.001) even after adjusting for age (OR, 0.344; P<.00l), sex (OR, 0.293; P<.001), and body mass index (OR, 0.292; P<.00l). Lower adiponectin levels are associated with the metabolic syndrome per se and several of its components, particularly, diabetes, insulin resistance, and dyslipidemia in this urban south Indian population.

Epidemiology and Genetic Variability of Human Metapneumovirus During a 4-Year-Long Study in Southeastern Brazil

Epidemiological and molecular characteristics of human metapneumovirus (hMPV) were compared with human respiratory syncytial virus (hRSV) in infants and young children admitted for acute lower respiratory tract infections in a prospective study during four consecutive years in subtropical Brazil. GeneScan polymerase chain assays (GeneScan RT-PCR) were used to detect hMPV and hRSV in nasopharyngeal aspirates of 1,670 children during January 2003 to December 2006. hMPV and hRSV were detected, respectively, in 191 (11.4%) and in 702 (42%) of the children admitted with acute lower respiratory tract infections at the Sao Paulo University Hospital. Sequencing data of the hMPV F gene revealed that two groups of the virus, each divided into two subgroups, co-circulated during three consecutive years. It was also shown that a clear dominance of genotype B1 occurred during the years 2004 and 2005, followed by genotype A2 during 2006. J. Med. Virol. 81:915-921,2009. (C) 2009 Wiley-Liss, Inc.

Epidemiology and control of frontier malaria in Brazil: lessons from community-based studies in rural Amazonia

We describe the epidemiology of malaria in a frontier agricultural settlement in Brazilian Amazonia. We analysed the incidence of slide-confirmed symptomatic infections diagnosed between 2001 and 2006 in a cohort of 531 individuals (2281.53 person-years of follow-up) and parasite prevalence data derived from four cross-sectional surveys. Overall, the incidence rates of Plasmodium vivax and P. falciparaum were 20.6/100 and 6.8/100 person-years at risk, respectively, with a marked decline in the incidence of both species (81.4 and 56.8%, respectively) observed between 2001 and 2006. PCR revealed 5.4-fold more infections than conventional microscopy in population-wide cross-sectional surveys carried out between 2004 and 2006 (average prevalence, 11.3 vs. 2.0%). Only 27.2% of PCR-positive (but 73.3% of slide-positive) individuals had symptoms when enrolled, indicating that asymptomatic carriage of low-grade parasitaemias is a common phenomenon in frontier settlements. A circular cluster comprising 22.3% of the households, all situated in the area of most recent occupation, comprised 69.1% of all malaria infections diagnosed during the follow-up, with malaria incidence decreasing exponentially with distance from the cluster centre. By targeting one-quarter of the households, with selective indoor spraying or other house-protection measures, malaria incidence could be reduced by more than two-thirds in this community. (C) 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

Teaching research and epidemiology to undergraduate students in the health sciences

Objective: To identify and address particular challenges in the teaching of epidemiological concepts to undergraduate students in non-clinical health disciplines. Methods and Results: Relevant pedagogical literature was reviewed to identify a range of evidence-based teaching approaches. The authors also drew on their experience in curriculum development and teaching in this field to provide guidelines for teaching epidemiology in a way that is engaging to students and likely to promote deep, rather than surface, learning. Discussion of a range of practical strategies is included along with applied examples of teaching epidemiological content. Conclusions and Implications: Increasingly, there is a greater emphasis on improved learning outcomes in higher education. Graduates from non-clinical health courses are required to have a core understanding of epidemiology and teachers of epidemiology need to be able to access resources that are relevant and useful for these students. A theoretically grounded framework for effective teaching of epidemiological principles to non-clinical undergraduates is provided, together with a range of useful teaching resources (both paper and web-based). Implementation of the strategies discussed will help ensure graduates are able to appropriately apply epidemiological skills in their professional practice.

The epidemiology of overweight and obesity among Australian children and adolescents, 1995-97

A study attempts to determine the population prevalence of overweight and obesity among Australian children and adolescents, based on measured body mass index (BMI) to determine if overweight and obesity are distributed differentially across the population of young Australians. Data from three independent surveys were analyzed and results indicate that the population prevalence and distribution of overweight, obesity and overweight/obesity combined were 79%-81%, 14%-16%, 5% and 19%-21% (boys) respectively, and 76%-79%, 16%-18%, 5%-6% and 21%-24% (girls). There were no consistent relationships between the prevalence of overweight/obesity and sex, age or SES. It is concluded that some 19%-23% of Australian children and adolescents are either overweight or obese. Only cultural background differential warrant a targeted health promotion response.

Epidemiology of metabolic syndrome

Metabolic syndrome (MetS), also previously known by a variety of other names, including insulin resistance syndrome and the deadly quartet, is characterized by clustering of abdominal (visceral and retroperitoneal) obesity and other cardiovascular risk factors, including impaired glucose regulation, raised triglycerides, decreased high-density lipoprotein cholesterol (HDL-C), elevated blood pressure (BP).

Associated with increased risk of both type 2 diabetes and cardiovascular disease (CVD), MetS is believed to be a contributor to the modern-day epidemics of diabetes and CVD and has become a major public health challenge around the world [I]. Currently, there are five different sets of criteria which have been developed to characterize the syndrome. These definitions differ in the components included and the cut-points used for each component. The prevalence of MetS in the westernized world is significant (10-50%) and believed to be increasing over time. The pathophysiology of the syndrome is unclear, but it is thought that obesity and/or insulin resistance are key underlying components. Genetics, lifestyle and environment factors are also important causes of MetS.

This chapter provides:

• a historical overview of the evolution of MetS;
• a summary of the value of the different definitions used to characterize the syndrome;
• a summary of the underlying pathophysiology, the causes and other important risk factors of MetS;
• a summary of the evidence describing the association of MetS with CVD and diabetes;
• a summary of the prevalence of MetS using the various definitions in different countries.