A review of methods for misclassified categorical data in epidemiology.
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Accidents, Traffic↗
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Uniform methods for the epidemiologic assessment of malocclusion. Results obtained with the World Health Organization standard methods (1962 and 1971) in South Pacific populations.
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Adolescent↗
Distribution of distress in post-socialist Mongolia: a cultural epidemiology of yadargaa.
This study discusses quality of life in post-socialist Mongolia. Yadargaa, a fatigue-related illness in traditional Mongolian medicine, results from lifestyle imbalance. We examine the distribution of yadargaa and its association to socioeconomic changes under capitalism. Ethnographic interviews concerning yadargaa were conducted with health professionals, yadargaa patients, and laypersons. Epidemiological methods were used to identify risk groups, to estimate the point prevalence, and to assess the distribution of meanings and interpretations of yadargaa. The epidemiological sample included 194 individuals, half urban and half rural. Nearly half of the epidemiological sample suffered from yadargaa (49%). These yadargaa sufferers felt that they benefited less than non-yadargaa subjects from the current socioeconomic changes. Among these, perceived change in employment opportunities was one of the best predictors of yadargaa. Additionally, yadargaa sufferers were predominantly women, the elderly, and urban residents. Yadargaa varies greatly in presentation; Western psychiatric categories are only able to explain half of yadargaa cases. In conclusion, yadargaa strongly associates with disenfranchised groups in the capitalist economy. As a culturally constructed indicator of quality of life, yadargaa is a window into the lives of women and men in post-socialist Mongolia.
Adolescent↗
Molecular epidemiology: focus on infection.
Molecular biology techniques have become increasingly integrated into the practice of infectious disease epidemiology. The term "molecular epidemiology" routinely appears in the titles of articles that use molecular strain-typing ("fingerprinting") techniques-regardless of whether there is any epidemiologic application. What distinguishes molecular epidemiology is both the "molecular," the use of the techniques of molecular biology, and the "epidemiology," the study of the distribution and determinants of disease occurrence in human populations. The authors review various definitions of molecular epidemiology. They then comment on the range of molecular techniques available and present some examples of the benefits and challenges of applying these techniques to infectious agents and their affected host using tuberculosis and urinary tract infection as examples. They close with some thoughts about training future epidemiologists to best take advantage of the new opportunities that arise from integrating epidemiologic methods with modern molecular biology.
Communicable Diseases↗
[On the need for training in environmental epidemiology].
The growing awareness and understanding of the fact that the maintenance of the health status of population is affected by environment, implements new objectives in undergraduate and postgraduate training of medical doctors and a necessity in producing a new generation of epidemiologists being able to solve environment health--related problems. While in Western European countries an intensive training in environmental epidemiology takes place, not much is done in this respect in our country. The training programs in environmental epidemiology should be based on the good recognition of the nature of the environmental hazards and local health needs. These requirements are urgent as one expects from medical doctors to-day, not only a proper understanding of relations between environment and health status of population, but also certain skills and ability to use epidemiologic methods in everyday clinical practice.
Curriculum↗
Hospital carpeting and epidemiology of Clostridium difficile.
BACKGROUND: Clostridium difficile is the usual and most important cause of antibiotic-associated pseudomembranous enterocolitis. The source of nosocomial acquisition of the organism in nonepidemic settings has not been determined. METHODS: Epidemiologic and microbiologic studies were conducted in a community-teaching hospital complex to assess the impact of carpeting in patient rooms on environmental contamination with C. difficile, along with the prevalence of pseudomembranous enterocolitis. All C. difficile isolates were typed by means of a bacteriophage-bacteriocin typing scheme. RESULTS: No clear evidence of environmental acquisition of C. difficile in a nonepidemic setting of pseudomembranous enterocolitis was found. Carpeted floors were significantly more heavily contaminated for prolonged periods with clinical strains of C. difficile than were noncarpeted floors. CONCLUSION: There was no evidence that contamination of carpeting resulted in increased frequency of pseudomembranous enterocolitis in patients residing in carpeted rooms. Because there is strong evidence of exogenous acquisition of C. difficile during outbreaks, however, room carpeting should be considered a potential reservoir of this organism.
Clostridioides difficile↗
Linkage disequilibrium of interleukin-1 genetic polymorphisms with early-onset periodontitis.
BACKGROUND: Genetic polymorphisms at interleukin (IL)-1alpha and IL-1beta were recently suggested to be associated with severity of adult periodontitis. We evaluated whether these polymorphisms might also be associated with early-onset periodontitis (EOP) in 28 African American families and 7 Caucasian American families with 2 or more affected members. METHODS: Genomic DNA from peripheral blood was amplified, followed by restriction endonuclease digestion and acrylamide gel electrophoresis to distinguish alleles of different fragment sizes. Genetic epidemiological methods suitable for family data were used that are robust to false-positive findings due to mismatching of cases and controls or mixed subpopulations of different ethnic or geographic origin. The 2 major EOP subtypes, localized juvenile periodontitis (LJP), and generalized early-onset periodontitis (G-EOP, encompassing rapidly progressive periodontitis and generalized juvenile periodontitis), were analyzed both separately and together. RESULTS: We obtained highly significant evidence of linkage disequilibrium for both African American and Caucasian G-EOP subjects. A similar trend was noted for LJP. The IL- alleles associated with high risk of EOP had been suggested previously to be correlated with low risk for severe adult periodontitis. Disequilibrium with G-EOP was equally strong for smoking and non-smoking subjects. IL-1alpha and IL-1beta polymorphisms were in strong disequilibrium with each other in Caucasians, but not in African Americans. Haplotype analyses evaluating both polymorphisms simultaneously indicated that the IL-1beta variant is likely to be most important for EOP risk. Sibpair linkage analyses, by contrast, provided only marginal support for a gene of very major effect on EOP risk attributable to these IL-1 polymorphisms. CONCLUSIONS: Recent theoretical analyses indicate that our findings are most consistent with an interpretation of EOP as a complex, oligogenic disorder, with IL-1 genetic variation contributing an important but not exclusive influence on disease risk.
Adolescent↗
Malaria in Turkey: a review of 33 cases.
AIM: To evaluate epidemiologic and clinical features of the patients with malaria followed in our clinic, and to review current status of malaria in our country. PATIENTS AND METHODS: Epidemiologic, clinical, diagnostic, and therapeutic features of 33 patients with malaria (4 female, 29 male, mean age: 28 +/- 11 years, range: 15-60) followed in our clinic between 1981 and 2000 were evaluated retrospectively. Malaria data of our country for 1926-2000 were obtained from Health Ministry. RESULTS: Diagnosis was established by thin smears of blood preparations obtained in the febrile period in all cases. Plasmodium vivax was detected in 26 patients (25 domestic and one imported), and P. falciparum in seven (two domestic and five imported). Sixty-one percent of the patients had the prodromal symptoms of the disease and used various antibiotics. All cases demonstrated the typical pattern of fever with chills. Fever (100%), splenomegaly (91%), hepatomegaly (55%), anemia (70%), leukopenia (48%), thrombocytopenia (48%), a rise in sedimentation rate (100%), and abnormalities in hepatic enzymes (30%) were determined in the patients. Chloroquine + primaquine were given to all patients with P. vivax, chloroquin (for three) or mefloquin (for four) alone were given to the patients with P. falciparum. One patient with P. falciparum died soon after admission, all the remaining recovered. Data from Health Ministry revealed that the most common (approximately 100%) species in our country is P. vivax. Although an eradication program against malaria initiated in 1926 achieved success, it still remains as an important health problem. CONCLUSION: Every febrile patient with a history of travel to the regions where malaria is endemic (tropical regions for the world, southeast regions for our country) should raise the suspicion of malaria. Every country should fight against malaria and global cooperation is essential.
Adolescent↗
Book citations: influence of epidemiologic thought in the academic community.
Whilst their 'death' has often been certified, books remain highly important to most professions and academic disciplines. Analyses of citations received by epidemiologic texts may complement other views on epidemiology. The objective was to assess the number of citations received by some books of epidemiology and public health, as a first step towards studying the influence of epidemiological thought and thinking in academia. For this purpose, Institute for Scientific Information/ Thomson Scientific - Web of Science/ Web of Knowledgedatabase was consulted, in May 2006. The book by Rothman & Greenland appeared to have received the highest number of citations overall (over 8,000) and per year. The books by Kleinbaum et al, and by Breslow & Day received around 5,000 citations. In terms of citations per year the book by Sackett et al ranks 3rd, and the one by Rose, 4th of those included in this preliminary study. Other books which were influential in the classrooms collected comparatively less citations. Results offer a rich picture of the academic influences and trends of epidemiologic methods and reasoning on public health, clinical medicine and the other health, life and social sciences. They may contribute to assess epidemiologists' efforts to demarcate epidemiology and to assert epistemic authority, and to analyze some historical influences of economic, social and political forces on epidemiological research.
Bibliometrics↗
The epidemiology of renal cell carcinoma.
PURPOSE: We identified and examined risk factors for renal cell cancer, some of which may explain in part the trends of steadily increasing incidence rates, particularly in black Americans. MATERIALS AND METHODS: Epidemiological studies were identified through a MEDLINE(R) search of the literature through February 2006. A qualitative summary of the results of individual studies is presented. RESULTS: Cigarette smoking and obesity are the most consistently established causal risk factors, accounting for about 20% and 30% of renal cell cancers, respectively. Hypertension appears to independently influence renal cell cancer risk. Neither acetaminophen nor other analgesics have been convincingly linked with renal cell cancer. With respect to diet a general protective effect of fruit and vegetable consumption is the only consistently reported finding. For occupational factors the weight of the evidence provides no consistent support for the hypotheses that renal cell cancer may be caused by asbestos, gasoline or trichloroethylene exposure. Self-reported family history is associated with 2 to 3-fold increases in risk and the major inherited forms of renal cell cancer together account for about 2% of this malignancy. CONCLUSIONS: A further reduction in cigarette smoking, and a decrease in the rates of obesity and hypertension would likely moderate the increasing incidence of renal cell cancer. Epidemiological studies, including evaluation of gene-environment interactions, are needed to specifically identify reasons for the increasing incidence, particularly for assessing the roles of obesity and hypertension. Special attention should be focused on black Americans since their incidence rate recently increased to significantly surpass that in white Americans.
Adolescent↗
[Principles and methods of influenza epidemiology: with special reference to field evaluation of vaccine efficacy].
In Western countries, prevention of influenza has been a major public health concern, promoting the vaccination program to high-risk individuals including the elderly. On the other hand, in Japan, there has been no systematic approach to such a selective vaccination on the social basis. This is due to the deep-rooted skepticism on vaccine efficacy. A number of epidemiologic studies have so far reported conflicting results in this country. We investigated the principles and methods of influenza epidemiology focusing on the field evaluation of vaccine efficacy. General and methodologic problems in vaccine field trials with naturally occurring influenza include; unpredictability of the time of its occurrence; antigenic differences between the vaccine strains and epidemic viruses; preexistence of already-immune individuals; indirect effect of hard immunity by vaccination on nonvaccinees; possible difference in the virus exposure between compared groups, particularly when epidemic scale is small; possible misdiagnosis of cases, if not laboratory-confirmed. To cope with these, the following measures are essential in conducting epidemiologic study on influenza. 1) Influenza epidemics show differential occurrence by time and place. Therefore, much attention should be pain when analyzing the pooled data obtained from various study samples at different locations. 2) It should be the first step of a research to consider whether the outbreak of acute respiratory illnesses observed among subjects is caused by influenza virus exposures. 3) In general, failings to detect vaccine efficacy are attributable to the dilution of outcome with noninfluenzal illnesses; cases defined by clinical symptoms include substantial number of acute respiratory illnesses other than influenza. To minimize this nondifferential misclassification, three methods are thought to be important; confining observation period during the peak epidemic; applying a strict criteria to measure the outcome, preferably with laboratory examination; and conducting the study in the season with large-scale epidemic. 4) It is also important to take into account the preexistence of already-immune individuals. "Antibody efficacy" is a keen index to assess vaccine effectiveness in this instance. Besides, further research is required to clarify the individual characteristics related to influenza attack, which affect the validity of analytic epidemiologic study on vaccine efficacy by yielding bias or confounding effect.
Epidemiologic Methods↗
Pharmaco-epidemiology and -economics should be developed more extensively in veterinary medicine.
Pharmaco-epidemiology, which has emerged within the last 20 years as a new discipline in human medicine, deals with the quantities of drugs consumed and their effects on populations in terms of epidemiological concepts and tools. To a lesser extent, it is also practised in veterinary medicine. The applications presented in this review are illustrative of pharmaco-epidemiological and -economical concepts. Assessment of drug consumption, the study of adverse drug effects, and the economic implications of drug use are the three main fields considered. Developments can be expected in veterinary medicine within the next few years relative to novel areas of interest such as antimicrobial resistance and new therapeutic class uses. These applications will require methodological progress and the elimination of current gaps. Pharmaco-epidemiological methods need to be developed, which implies close co-operation between statisticians, pharmacologists, veterinary practitioners and epidemiologists. A greater use of the term 'pharmaco-epidemiology' as a keyword in literature would facilitate recognition of this domain which associates closely epidemiology and pharmacology.
Animals↗
Epidemiological considerations about retinal opportunistic infections in HIV-infected patients in France.
PURPOSE: To evaluate the evolution of the epidemiology of retinal opportunistic infections in HIV-infected patients from 1994 to 1997 and to assess the effect of HAART initiated in 1996. MATERIALS AND METHODS: Epidemiological prospective study using the data collected during ocular examinations of HIV-infected patients conducted in a single referral center specialized in HIV infection. RESULTS: From 1995 to 1997, the total number of examined HIV-infected patients and the incidence of retinitis related to CMV, VZV, tuberculosis, and toxoplasmosis decreased. The incidence of CMV retinitis, which was by far the most frequent ocular infection, fell from 6.2% to 1.2%. COMMENTS: The dramatic decrease in retinal opportunistic infections since 1996 may be related to the use of HAART. However, a close follow-up is still justified due to the increasing occurrence of resistance to protease inhibitors.
AIDS-Related Opportunistic Infections↗
Epidemiology of burn unit infections in children.
OBJECTIVE: The aim of this study was to determine the epidemiology of burn unit infections, the effect of these infections on the mortality rate, and antibiotic resistance pattern of the predominant bacteria isolated from children. Patients and method Epidemiologic data for 610 children, aged 0 to 15 years, admitted to the burn unit at Dicle University Hospital during a 5-year period were collected and analyzed. RESULTS: In 207 patients (33.9%), 279 nosocomial infections were identified. The most common types of infections were burn wound infections (72.4%), urinary tract infections (10.8%), pneumonia (9.3%), and septicemia (7.5%). Pseudomonas aeruginosa (181 isolates) was the most common microorganism. Thirty-six patients (5.9%) died at the hospital. Sepsis was associated with mortality in 18 (50%) cases, pneumonia in 6 (17%), and varied noninfectious reasons in 12 patients (33%). P aeruginosa isolates showed high resistance to commonly used antimicrobials. Antibiotic susceptibility test results suggested that imipenem was the most effective agent for P aeruginosa and Escherichia coli strains. CONCLUSION: The major type of nosocomial infections in the burn unit was burn wound infections, and the majority of nosocomial infections resulted from multiple drug-resistant, gram-negative bacteria.
Adolescent↗
Epidemiological, clinical and laboratory distinction between human granulocytic ehrlichiosis and the initial phase of tick-borne encephalitis.
OBJECTIVE: To establish epidemiological, clinical and laboratory differences between adult patients with proven acute human granulocytic ehrlichiosis (HGE) and patients with the initial phase of tick-borne encephalitis (TBE). METHODS: Epidemiological, clinical and laboratory findings were compared in nine patients with acute HGE (established by the presence of specific DNA sequences of Ehrlichia phagocytophila in whole blood by polymerase chain reaction and/or by seroconversion or at least a four-fold change of serum antibody titres to E. phagocytophila by indirect immunofluorescence assay) and 29 patients with the initial phase of TBE (demonstrated in ELISA tests by the presence of serum IgM antibodies to TBE virus). RESULTS: Findings were similar for the majority of the general parameters examined, which included sex, age, incubation period, duration of fever, and frequency of additional tick bites. However, a statistically significant difference was found for the duration of fever before the first visit (median 7 days in patients with acute HGE and 4 days in patients with the initial phase of TBE; p = 0.0169), and for the frequency of hospitalisation, which was higher for patients with the initial phase of TBE (29/29) than for those with acute HGE (5/9; p = 0.0017). Comparison of clinical signs and symptoms and laboratory findings in the two groups revealed significant differences: in patients with acute HGE there was a higher frequency of chills (4/9 versus 3/29, respectively; p = 0.0407), myalgia (8/9 versus 13/29, respectively; p = 0.0263), and arthralgia (7/9 versus 3/29, respectively; p = 0.0003), and elevated values of lactate dehydrogenase (7/9 versus 3/29, respectively; p = 0.0003) and concentration of C-reactive protein (9/9 versus 6/29, respectively; p = 0.0000). CONCLUSIONS: In a patient with febrile illness occurring after a tick bite, a clinical report of chills, myalgia and arthralgia, and laboratory findings of elevated values for lactate dehydrogenase and concentration of C-reactive protein direct towards a diagnosis of acute HGE rather than the initial phase of TBE.
Adult↗
Complex transmission dynamics of clonally related virulent Mycobacterium tuberculosis associated with barhopping by predominantly human immunodeficiency virus-positive gay men.
Limited data suggest that measures to reduce tuberculosis transmission should be based on locations rather than on personal contacts. Molecular epidemiologic methods (analysis of IS6110 patterns, spoligotypes, variable numbers of tandem DNA repeats, and automated DNA sequence data) identified a cohort of 48 persons who were infected with progeny of the same Mycobacterium tuberculosis strain. Epidemiologic investigation documented that a large proportion of the patients were gay white human immunodeficiency virus-positive men. Most practiced barhopping, an activity that involved patronizing many bars in the same neighborhood each night. Few subjects were directly linked to more than 1 or 2 other persons by conventional investigation methods, which shows that the transmission dynamics were unusually complex compared with most previously described episodes of strain spread. The data support the concept that identification of locations where pathogen dissemination likely occurs may provide additional strategies for targeted tuberculosis control.
Alcohol Drinking↗
Outbreaks of nosocomial bloodstream infections associated with multiresistant Klebsiella pneumoniae in a pediatric intensive care unit.
BACKGROUND: Between June and October 1997, and during April 1998, a cluster of nosocomial bloodstream infections (BSIs) associated with Klebsiella pneumoniae was observed in 8 premature neonates from 1 pediatric intensive care unit (TPICU) in a 4000-bed medical center in northern Taiwan. An investigation was conducted to identify the possible reservoirs and mode of transmission. METHODS: Epidemiologic surveillance and infection control interventions were executed. The environment was checked by submitting several swab samples for microbiological studies. The antibiograms and results from 2 molecular typing methods (pulsed-field gel electrophoresis and infrequent-restriction site polymerase chain reaction) of all bacteremic and environmental isolates of K. pneumoniae were compared. RESULTS: Totally 39 K. pneumoniae isolates, including 9 from bacteremia, 26 from the environment, and 4 controls, were analyzed. One major pattern was found in 21 isolates, which included 8 bacteremic isolates with identical antibiograms, a single isolate from rectal swab screening, 2 of 8 isolates from hand cultures of medical staff, and 10 of 17 isolates from swabs of sinks in the TPICU. All 21 isolates illustrated identical antibiograms, while the other 18 isolates shared 4 antibiograms and 15 unique patterns. CONCLUSIONS: The nosocomial BSIs appeared to be an outbreak induced by 1 multiresistant K. pneumoniae strain. The sinks may have acted as reservoirs for this outbreak strain. During washing, splattered water droplets containing the bacterial particles may have contaminated the hands of medical personnel and were then further transmitted to patients.
Bacteremia↗
Northern New Zealand Rhegmatogenous Retinal Detachment Study: epidemiology and risk factors.
BACKGROUND: The incidence of retinal detachment in New Zealand is not currently documented in the literature. This study sought to determine the annual incidence of rhegmatogenous retinal detachment (RRD) and associated risk factors in northern New Zealand. METHODS: Epidemiological and clinical data were collected for all patients presenting with a RRD in a 12-month interval in a confined geographical area of New Zealand. RESULTS: One hundred and forty-one patients presented between May 1997 and April 1998 with a RRD. Five patients presented with bilateral RRD. The mean age at presentation was 53.9 years and the annual incidence for RRD was 11.8 cases per 100,000 people. RRD was more common in males than in females (1.3:1). Ocular trauma, high myopia and cataract extraction were found to be significant risk factors in the development of RRD. CONCLUSIONS: The annual incidence of RRD in northern New Zealand is comparable to values reported for other parts of the world and, consistent with previous studies, the incidence of RRD was found to increase with age, and in association with trauma, high myopia and cataract surgery.
Adolescent↗