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Results for “Epidemiologic Methods”

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PubMed1992

[Membrane proteins electrophoretic profiles study applied to Neisseria gonorrhoeae epidemiology].

The analysis of electrophoretic profiles of membrane proteins is one of the epidemiological methods of bacterial typing. The profiles of membrane proteins of 95 isolates were studied for valuing their usefulness in the epidemiology of N. gonorrhoeae. The results were compared with the obtained using other characterization methods (auxotyping, serotyping and antimicrobial sensibility). The proteins I and II (PI and PII) showed clear differences between isolates. Only protein-I (PI) with constant molecular weight for each isolate was valid to discriminate between strains. It was observed correlation between serovariety IA and molecular weight of PI 33.6-36 kD, and the serovariety IB with molecular weight 35.5-37 kD. Though it wasn't possible discriminated between the different serovarieties. It was proved a sensibility decrease to penicillin, tetracycline and cloramfenicol in those strains with molecular weight of PI greater than 35.5 kD (serogroup WII/WIII). In the 80% of the isolates considered multiple antibiotic-resistant it was observed a significant increase of the membrane protein dough of 52 kD. All the strains with this protein increased were multiple antibiotic-resistant.

Electrophoresis, Polyacrylamide Gel↗

PubMed2004

[Epidemiological study on an outbreak caused by E. coli O157:H7 in Jiangsu province].

OBJECTIVE: To carry out epidemiological study on an outbreak caused by E. coli O157:H7 infection in Jiangsu province in 1999. METHODS: Epidemiological, microbiological and moleculebiological methods were used to find out the source, route of transmission and risk factors. RESULTS: 95 severe O157:H7 infected patients with acute renal failure in 9 counties and districts of 2 municipalities were reported in Jiangsu province, 1999 while 83 of the patients died with a death rate of 87.37%. Most patients were seen in mid or late June. The ratio of male to female was 1 to 1.44 and 88.42% of the patients were over 50 years old. 38 patients occurred in 2000 with 34 deaths. Major factors contributing to the outbreak would include without drinking tap water, eating leftover food, poor sanitary status in kitchen, not washing hands before meal and after bowl movement. 2 strain of O157:H7 was isolated from severe patients and 3 from diarrhea cases. Carrier rate among animals was up to 9.62% and 99.41% of the strains carried toxic gene. Strains isolated from feces of patients and animals belonged to the same colonies. CONCLUSION: This outbreak was severe which caused by O157:H7 and was first seen in China, which was closely related to the high carrier rate of O157:H7 in animals and to the positive rate of high toxic gene of the strains. There were various routes of transmission and the main factors of infection would include poor personal health habits and poor sanitation of the household.

Acute Kidney Injury↗

PubMed1993

Bacterial typing methods suitable for epidemiological analysis. Applications in investigations of salmonellosis among livestock.

The ability to subtype bacteria by typing methods provides the bacteriologist with a powerful means to identify relationships between bacteria. This knowledge is used to identify routes of disease transmission among livestock and from livestock to humans. In the present paper, the principles of bacterial typing and the most commonly applied typing methods for use in veterinary public health are discussed in the context of their application in the investigation of salmonella epidemiology. Typing methods are now routinely used in most investigations on this subject and have provided insight into routes of transmission, reservoirs of infection and mechanisms of persistent infection. Under the EC order on zoonotic diseases, extended surveillance on the presence of zoonotic bacteria in livestock must be expected. To receive the maximum benefits of this surveillance, selected typing methods must be applied to all isolates of e.g. salmonella. At present, serotyping, and phage typing where applicable, are the most obvious choices for continuous surveillance of this organism. Random amplification of polymorphic DNA (PCR based typing) may have the potential for allocating strains into relevant groups quicker and without the requirement for additional manpower, and this method may be preferred in future.

Animals↗

PubMed2005

Epidemiological and clinical characteristics of classic Kaposi's sarcoma in Peru.

BACKGROUND: Classic Kaposi sarcoma (KS) occurs predominantly among the elderly, with predominance among Jews, Italians, and Greeks. Classic KS has been seen relatively frequently in Peru. OBJECTIVE: Our purpose was to outline the epidemiological and clinical profile of classic KS in Peru. METHODS: Epidemiological and clinical features of all classic KS cases diagnosed between 1969 and 2003 at Hospital Nacional Cayetano Heredia (HNCH) and between 1946 and 2004 at Instituto Nacional de Enfermedades Neoplasicas (INEN) were reviewed and studied retrospectively. RESULTS: An overall incidence of 2.54 per 10,000 attended patients was obtained at the INEN during the 48-year period (mean, 2.39; standard deviation: 1.99; 95% confidence interval, 2.92-1.86). Twenty-one cases were discovered at HNCH and 106 cases at INEN. A male/female ratio of 2.62:1 was found. Mean age at diagnosis was 68.5 years. Lower limbs were involved in 109 patients (85.8%); the trunk was involved in 11 patients (8.6%). Nodules were the most common type of lesion (85.8%); less commonly found were plaques (27.5%), macules (12.5%), papules (12.5%), and ulcers (8.6%). Sixty-two patients had no symptoms (48.8%). Pain was the most common symptom (26.7%), followed by edema (21.2%), bleeding (14.9%), and pruritus (3.9%). A second primary malignancy was found in 11 patients (8.6%). LIMITATIONS: These results were obtained from patients with classic KS in Peru and may not be applicable to other populations. CONCLUSION: Classic KS is quite common in Peru with sporadic cases found throughout the country and some clustering in the coastal region. Classic KS in Peru has a clinical presentation that is very similar, but not identical, to the classic KS described in the Mediterranean region, exhibiting some special clinical and epidemiological characteristics with a nodular, nonsymmetric presentation that usually affects the lower extremities.

Adolescent↗

PubMed1981

Post-marketing surveillance: drug epidemiology.

A description of the need for and appropriateness of a multi-component application of epidemiological methods to the post-marketing evaluation of drugs is presented. There is a need for the development of the art and science of Drug Epidemiology. The large number of drugs introduced over the last 40 years and the number of interventions constitute an issue of public health interest. It is appropriate that scientifically sound information be collected about medications. There has been considerable discussion about the methods to be used in any such systematic approach. The choice of method is obviously dependent upon the questions to be addressed and the functions to be satisfied. The proposal is presented for the appropriate content functions of post-marketing drug evaluation, and a description of some and currently employed approaches show how they differentially satisfy the functions. It is concluded that there is a need for the development and application of multiple complementary methods to satisfy the requirements of a meaningful system for post-marketing drug evaluation.

Drug Information Services↗

PubMed2000

[Genetic predisposition to bilharziasis in humans: research methods and application to the study of Schistosoma mansoni infection].

The development of genetic epidemiology methods using recent human genetic mapping information together with the growing availability of candidate genes has led to major advances in the identification of host genes in human schistosomiasis. Two phenotypes have been studied so far in the infection by Schistosoma mansoni: infection levels by the parasite as measured by the faecal egg counts, and the severe hepatic fibrosis caused by S. mansoni assessed by ultrasound examination. The first study was performed on Brazilian pedigrees and provided strong evidence for a major gene controlling infection levels by S. mansoni denoted as SM1 which was mapped to chromosome 5q31-q33. This region contains several candidate genes involved in the regulation of the Th1/Th2 response, and the direct role of polymorphisms located within these genes is under investigation. The second study conducted in Sudan also showed the presence of a major gene influencing the development of severe hepatic fibrosis due to S. mansoni infection denoted as SM2. This gene is not located in the 5q31-q33 region, but maps to chromosome 6q22-q23 and is closely linked to the IFN-gamma R1 gene encoding the receptor of the strongly anti-fibrogenic cytokine Interferon-gamma. These findings indicate that two distinct genetic loci control human predisposition to schistosomiasis, SM1 located in the 5q31-q33 region which is likely to play a role in the Th1/Th2 differentiation, and SM2 in 6q22-q23 influencing disease progression with a possible involvement in the regulation of IFN-gamma.

Animals↗

PubMed1998

Comparison of five typing methods for the epidemiological study of Listeria monocytogenes.

Five typing methods were compared in a study designed to adapt a strategy for epidemiologically typing large numbers of Listeria monocytogenes strains. The methods studied were serotyping, electrophoretic typing of esterases (zymotyping), restriction fragment length polymorphism of ribosomal DNA (ribotyping), random amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE). Data were analysed by computer-assisted statistical analysis. Included in the analysis were 35 strains of L. monocytogenes, including 14 epidemic strains isolated during outbreaks in France in 1992 and 1993, and 21 strains isolated from food and the environment. Five serotypes, eight zymotypes, ten ribotypes, 13 RAPD patterns and 12 PFGE patterns were identified among the 35 strains. The most discriminating combination of typing methods was ribotyping and PFGE typing [27 types, discriminatory index (D.I.) = 0.978]. A factorial analysis of correspondence for each method differentiated the epidemic strains from the environmental strains. This study shows that computer-assisted statistical treatment of the data, combined with the use of discriminating typing methods, is a powerful tool for the epidemiological analysis of Listeria monocytogenes.

Animals↗

PubMed2004

[Relationship between epidemiological evidence and fatality rate in patients with severe acute respiratory syndrome].

OBJECTIVE: To investgate the relationship between epidemiological diagnosis and fatality rate in patients with severe acute respiratory syndrome (SARS). METHODS: Epidemiological evidences and the outcomes of 304 patients with confirmed SARS were retrospectively analyzed. Patients included highly contagious cases, cluster cases, and sporadic cases. RESULTS: The case fatality rate was 8.2%. The fatality rate had a tendency of increase in an order of sporadic cases, cluster cases, and highly contagious cases (3.9%, 11.4%, and 17.2%, respectively, chi2trend=7.561, P < 0.01). Chi square-test also proved that the fatality rate was higher in older people (chi2trend=27.024, P < 0.01) and in male (male vs female: 12.2% vs 5.5%). A logistic regression model showed that the epidemiological evidence, age, and gender were correlated to fatality rate. By observing changes of the odds ratio for epidemic evidence, age, and gender using forward method, we found epidemic evidence was an independent risk factor related to fatality rate in SARS patients. CONCLUSION: The epidemiological evidence is an independent factor related to fatality rate in SARS patients. Highly contagious case has a worse prognosis and higher fatality rate than sporadic cases and cluster cases.

Adolescent↗

PubMed1998

The epidemiology of oral contraceptive use: a critical review of the studies on oral contraceptives and the health of young women.

Recent observational studies show a slightly increased risk of venous thromboembolism among users of newer combined oral contraceptives with odds ratios between 0.8 and 2.3 when compared with users of older oral contraceptives. The controversy regarding the newer oral contraceptives is reviewed by analyzing the recent studies with epidemiologic methods. Key studies on venous thromboembolism may be subject to bias related to prescribing criteria, diagnostics, hospital referral, cohort effects, and residual confounding, resulting in an overestimate of the risk of venous thromboembolism associated with the newer oral contraceptives. The studies on stroke showed no difference between newer and older oral contraceptives, and studies on myocardial infarction show that newer oral contraceptives carry no risk of this event. Newer-generation oral contraceptives are unlikely to constitute a significant hazard to the user population with regard to venous thromboembolism. The results for other disease entities also need to be taken into account when the results on venous thromboembolism are assessed on a population basis.

Adolescent↗

PubMed1997

Sexually abused children in a national survey of parents: methodological issues.

In a national survey of 1,000 parents, which primarily concerned disciplinary practices and violence toward their children, two questions were asked about whether the children had been sexually abused. This was to assess the feasibility of epidemiological research on contemporaneous sexual abuse using parental interviews rather than the usual adult retrospective approach. From these questions, rates of sexual abuse for children currently 0-17 were estimated at 1.9% in the last year and 5.7% ever. The cases making up these rates included a nearly equal number of boys and girls and no female victims between the ages of 9 and 12, a distribution different from those generally obtained by other epidemiological methods, but due possibly in this case to normal sampling variation. Cases were more likely to be disclosed for children whose parents had themselves been sexually abused, who were from lower income households, or who were living with only one biologic parent. Although some of the findings suggest caution in generalizing about child sexual abuse from survey samples of parents, the method is worthy of exploration if only to gain better epidemiologic data about parent knowledge, reaction, reporting, and coping strategies.

Adolescent↗

PubMed1997

Epidemiology and the health care revolution.

PURPOSE: Revolutions in the health care marketplace, with their implied dependence upon the population perspective, have renewed interest in epidemiologic methods and their application. METHODS: As a way of organizing questions, data, and answers, epidemiology is once again the core scientific discipline for a multidimensional paradigm shift that emphasizes five facets of health care. First, the health of enrolled populations, rather than merely treatment of sick individuals presenting for care. Second, assessment of the "time, place, and person" of disease burden--who is healthy, who is not, and what it will take to maximize their health. Third, the causative factors for disease and the factors or characteristics that promote health. Fourth, the development of evidence-based clinical guidelines for clinicians and consumers alike. Fifth, evaluation of the impact providers are having on the health of populations (outcomes), individually and collectively. RESULTS: Thoughtful consideration of all of the above factors depends upon epidemiologic data and insights brought to a firm and conclusive end point capable of supporting policy. CONCLUSIONS: Credibility will require that epidemiologists (and the symbiotic media) exercise far greater restraint in drawing definitive conclusions and speculations from often starting but meager data.

Cost-Benefit Analysis↗

PubMed1997

Rhodococcus equi infection in non-HIV-infected patients. Two case reports and review.

OBJECTIVE: To review two recent cases in HIV-negative subjects in the light of literature reports (52 patients without HIV infection till 1994). METHODS: Epidemiology (animal contacts, risk factors, year, country), clinical presentation, diagnostic methods (X-ray, tomography, microbiological techniques), therapeutic approach (antibiotics, surgery) and outcome were evaluated on the basis of clinical literature reports. RESULTS: Tumors constituted an important predisposing factor and less frequently hepatobiliary pathology, rheumatologic diseases, iatrogenic causes, psychiatric pathology and trauma. Exposure to animals was reported by 55% of the patients. Pneumonia and pleurisy, without preferential localization, were detected in 50% of the patients. Etiologic diagnosis was usually obtained after an invasive collection. Combined medical therapy and surgery were required by 27.8% of the patients, and 16.7% of the patients died. CONCLUSIONS: In recent years the number of Rhodococcus equi cases has been rising also in HIV-negative patients. The infection is ubiquitous. Accurate diagnosis and the prompt selection of the most appropriate therapy depend on close cooperation between clinicians and microbiologists.

Journal Article↗

PubMed2002

Relationship of tobacco smoking CYP1A1 GSTM1 gene polymorphism and esophageal cancer in Xi'an.

AIM: To analyze the association of tobacco smoking polymorphism of CYP1A1 (7th exon) and GSTM1 genotype and esophageal cancer(EC) in Xi'an. METHODS: A hospital based case-control study, with molecular epidemiological method, was carried out. Polymorphism of CYP1A1 and GSTM1 of samples from 127 EC cases and 101 controls were detected by PCR method. RESULTS: There were no significant difference of age and gender between cases and controls. Tobacco smoking was the main risk factor OR=1.97;95% CI=1.12-3.48 for EC in Xi'an. The proportions of CYP1A1 Ile/Ile, Ile/Val and Val/Val gene types in cases and controls was 19.7% 45.7% 34.6% and 30.7%,47.5%, 21.8% respectively(P=0.049). Individuals with CYP1A1 Val/Val genotype compared to those with CYP1A1 Ile/Ile genotype had higher risk for EC increased (OR=2.48, 95%CI=1.12-5.54). The proportions of GSTM1 deletion genotype in cases and controls were 58.3% and 43.6%(OR=1.81, 95%CI=1.03-3.18, P=0.028). Analysis of gene-environment interaction showed that tobacco smoking and CYP1A1 Val/Val genotype; tobacco smoking and GSTM1 deletion genotype had synergism interaction respectively. Analysis of gene-gene interaction did not find synergistic interaction between these two genes. But in GSTM1 deletion group there was significant difference of distribution of CYP1A1 genotype between cases and controls (P=0.011). CONCLUSION: CYP1A1 Val/Val and GSTM1 deletion genotypes are genetic susceptibility biomarkers for EC. The risk increases, when person with CYP1A1 Val/Val and/or GSTM1 deletion genotype. And these two-metabolic enzymes seem to have interactions with tobacco smoking, in which the mechanism still needs further study.

Case-Control Studies↗

PubMedDate not supplied

Genetic epidemiology of colorectal cancer.

Genetic epidemiological methods have played an integral role in the characterisation of the genetic susceptibilities to colorectal cancer. Classic epidemiological approaches, such as case-control and prospective cohort studies, that utilise family history information have laid the foundation for the more specialised family-based genetic methods, segregation analysis and linkage analysis. The genetic epidemiology of colorectal cancer can be characterised by several themes: the consistently increased risk of colorectal cancer in first-degree relatives of patients with colorectal cancer; genetic predisposition to some, if not the majority of colorectal neoplasms; and genetic heterogeneity of the inherited colorectal cancer syndromes. With the rapid development of molecular genetic techniques, new opportunities for further research include studies to estimate the proportion of colorectal cancer that is accounted for by genetic susceptibility, the number of loci that may be involved, and most importantly, gene-environment interaction studies, not only of the inherited syndromes, but of common colorectal cancer.

Case-Control Studies↗

PubMed2006

Campylobacter spp. subtype analysis using gel-based repetitive extragenic palindromic-PCR discriminates in parallel fashion to flaA short variable region DNA sequence analysis.

AIMS: The repetitive extragenic palindromic-PCR (rep-PCR) subtyping technique, which targets repetitive extragenic DNA sequences in a PCR, was optimized for Campylobacter spp. These data were then used for comparison with the established genotyping method of flaA short variable region (SVR) DNA sequence analysis as a tool for molecular epidemiology. METHODS AND RESULTS: Uprime Dt, Uprime B1 or Uprime RI primers were utilized to generate gel-based fingerprints from a set of 50 Campylobacter spp. isolates recovered from a variety of epidemiological backgrounds and sources. Analysis and phenogram tree construction, using the unweighted pair group method with arithmetic mean, of the generated fingerprints demonstrated that the Uprime Dt primers were effective in providing reproducible patterns (100% typability, 99% reproducibility) and at placing isolates into epidemiological relevant groups. Genetic stability of the rep-PCR Uprime Dt patterns under nonselective, short-term transfer conditions revealed a Pearson's correlation approaching 99%. These same 50 Campylobacter spp. isolates were analysed by flaA SVR DNA sequence analysis to obtain phylogenetic relationships. CONCLUSIONS: The Uprime Dt primer-generated rep-PCR phenogram was compared with a phenogram generated from flaA SVR DNA sequence analysis of the same isolates. Comparison of the two sets of resulting genomic relationships revealed that both methods segregated isolates into similar groups. SIGNIFICANCE AND IMPACT OF THE STUDY: These results indicate that rep-PCR analysis performed using the Mo Bio Ultra Clean Microbial Genomic DNA Isolation Kit for DNA isolation and the Uprime DT primer set for amplification is a useful and effective tool for accurate differentiation of Campylobacter spp. for subtyping and epidemiological analyses.

Bacterial Typing Techniques↗

PubMed2002

Research methods in psychiatric epidemiology: an overview.

OBJECTIVE: To provide an introduction to the concepts and methods of psychiatric epidemiology for non-specialist readers. METHODS: An overview of concepts and research procedures based on the published literature. CONCLUSION: Psychiatric epidemiology is a key mental health discipline that has adopted and developed a variety of methods and procedures for the study of complex mental disorders. In its future development, psychiatric epidemiology is likely to seek an integration of the conceptual and methodological advances of molecular biology and neuroscience within the population-based and social framework of epidemiology as a basic science of public health.

Epidemiologic Research Design↗

PubMed2006

Emerging role of epidemiologic literacy.

BACKGROUND: The ability to understand and apply epidemiology methods is a growing part of pharmacy practice, pharmacy accreditation standards, and evidence-based practice. OBJECTIVE: To examine the trends in epidemiology-related terminology used in the literature over the past 20 years. METHODS: The frequency of the use of epidemiology-related terminology in 3 representative pharmacy journals, 2 representative medical journals, and 1 public health journal from January through December 1984, 1994, and 2004 was recorded. The 3 pharmacy journals were the American Journal of Health-System Pharmacy (formerly American Journal of Hospital Pharmacy), The Annals of Pharmacotherapy (formerly Drug Intelligence and Clinical Pharmacy), and Pharmacotherapy. The 2 medical journals were the New England Journal of Medicine and The Journal of the American Medical Association (JAMA), and the public health journal was the American Journal of Public Health. The number of times an epidemiology-related term was used was summed for each year and each journal. RESULTS: For all the journals examined in this study combined, the proportion of epidemiologic terms used in the literature has increased over the past 20 years. In 1984, of the total articles published in the 6 journals, 7.02% contained epidemiologic terms increasing to 12.27% and 15.46% in 1994 and 2004, respectively. The most dramatic differences in the 20-year comparisons were noted for Pharmacotherapy (0 to 17.75%) and JAMA (7.32 to 26.72%). CONCLUSIONS: The increase in the use of epidemiology-related terms has implications for both curricular planning in schools and colleges of pharmacy, as well as for continuing education programs and effective interprofessional communication.

Epidemiology↗

PubMed2006

Back to the basics: epidemiology in the Journal of Antimicrobial Chemotherapy.

Good epidemiological methods and appropriate statistical analysis are cornerstones of any valid, reliable and publishable epidemiological study. This editorial summarizes epidemiological studies published in the Journal of Antimicrobial Chemotherapy (12 issues, May 2005--April 2006) with respect to study objective, type and design. A significant proportion of these studies started off with a single study group. Drawing on this finding, various methodological aspects of choosing a sampling frame and of sampling methods are reviewed.

Epidemiologic Studies↗