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PubMed1997

Methods for assessing the extent of exposure and effects of air pollution.

BACKGROUND AND OBJECTIVES: In many places in Europe, the ambient air pollution exceeds the levels considered to be safe for health. The objective of the paper is to review and summarise the methods of assessment of its impact on health, and to indicate the contributions of various research disciplines, particularly environmental epidemiology. METHODS: The framework for assessment of impact is based on a four stage model: assessment of release of pollutant; assessment of exposure; assessment of the consequence; and risk estimation. RESULTS: Epidemiology is crucial in providing the data for the assessment of consequence. The criteria that determine the use of epidemiological studies for this task include lack of bias, correct control of confounding, and measured estimates of exposure. At present, those criteria are easier to satisfy for studies of short term effects on health than for the delayed consequences of exposure, or exposure accumulated over a prolonged period. Combinations of results from various populations through meta-analysis of existing studies or conducting multicentre studies is often necessary to increase the reliability of the consequence assessment stage. CONCLUSION: To assess the impact on health systematically helps to focus on actions to limit air pollutants with the greatest impacts on human health and on the most affected populations. This method allows identification of the most pertinent questions which have to be answered by studies on relations between pollution and health and on exposure of populations to air pollutants. Epidemiology has considerable potential to contribute to this research.

Air Pollutants↗

PubMed2000

Epidemiology: surveillance of fungal infections.

Surveillance for fungal diseases is essential to improve our understanding of their epidemiology and to enable research and prevention efforts to be prioritized. In order to conduct better surveillance for fungal diseases, it is important to develop more accurate and timely diagnostic tests, to follow rigorous epidemiological methods and to have adequate support from public health agencies and the pharmaceutical industry. Investigations of nosocomial and community outbreaks of fungal infection have also resulted in a better understanding of the sources and routes of transmission of these diseases, and of the risk factors for infection. This has led to more effective prevention and control strategies. In addition, outbreak investigations have offered excellent opportunities to develop new molecular sub-typing methods, and to evaluate and validate older ones. For example, results obtained from a global epidemiological study of the genomic structure of Cryptococcus neoformans have led to a better understanding of the epidemiology of cryptococcosis. Similarly, a study of variations in the genotype of Trichophyton rubrum has found that patients may become infected with multiple strains, which has important implications for study design when looking at the epidemiology of dermatophyte infections.

Arthrodermataceae↗

PubMed2002

Epidemiological analysis of tuberculosis in the Kingdom of Croatia and Slavonia during 1901-1910.

AIM: To analyze data on epidemiology and treatment of tuberculosis from the sources related to the history and epidemiology of tuberculosis in the Kingdom of Croatia and Slavonia in the 1900-1910 period. METHODS: Epidemiological data were obtained from the statistical yearbooks of the Kingdom of Croatia and Slavonia for years 1905 and 1910. A number of sources and publications on the history of medicine, especially on the history of tuberculosis in the studied period were analyzed. Mortality ratio, birth rate ratio, and population growth were calculated. Tuberculosis mortality per 100,000 inhabitants was calculated for four major cities and eight counties of the Kingdom of Croatia and Slavonia. The difference in tuberculosis mortality rates between urban and rural areas and socio-economic situation and organization of the health service were analyzed. The incidence, prevalence, and morbidity from tuberculosis were not analyzed because of the lack of data. RESULTS: The tuberculosis mortality ratio per 100,000 inhabitants in the Kingdom of Croatia and Slavonia were constantly high (above 400 on average), with higher mortality ratio in urban than in rural areas. According to the opinion of the Croatian physicians and statistical data of the period, this was due to the constant growth of population, insufficient health care system, and bad living conditions. The highest tuberculosis mortality rates were in the cities of Zemun (600-800) and Zagreb (500-700), and in the counties of Srijem (600-400), Virovitica (600-400), and Lika- Krbava (500-400). CONCLUSION: There was a concordance between the statistical data and the publications, reports, and articles written in the 19th and 20th century on tuberculosis situation in the Kingdom of Croatia and Slavonia. The analysis showed that tuberculosis was one of the major causes of death in the Kingdom of Croatia and Slavonia from 1901 to 1910. This fact had a significant influence on tuberculosis prevention and eradication efforts in the first half of the 20th century in Croatia and laid basis for further and more elaborate measures against tuberculosis epidemics.

Croatia↗

PubMed1997

Epidemiology in obstetrics and gynaecology.

This paper delineates in short the way in which epidemiology and obstetrics and gynaecology could profit from each other's expertise and why. Epidemiology addresses the rates of occurrence in illnesses and their outcomes in relation to potential determinants of these in any realm of medicine. Obstetrics and gynaecology concern themselves with the female reproductive system, notably. Epidemiologic methods are essential to valid research, and obstetrics and gynaecology are essential to valid inference of epidemiologic research.

Epidemiology↗

PubMed2004

Systematic review: green tea and gastrointestinal cancer risk.

BACKGROUND: Gastrointestinal cancer is one of the leading causes of cancer mortality in the world. Therefore, numerous efforts are being made to find chemoprotective substances able to reduce its incidence. Amongst these, green tea, one of the most popular beverages world-wide, has been reported to provide protective effects against gastrointestinal cancer. AIM: To critically evaluate all epidemiological studies reporting an association between green tea consumption and a reduced risk of gastrointestinal cancer. METHODS: Epidemiological studies of green tea consumption in relation to gastrointestinal cancer or preneoplastic lesions were identified through computerized literature searches using the following databases: Medline (Pubmed), Embase, Amed, CISCOM, Phytobase and Cochrane Library. Only epidemiological studies indicating the type of tea (green tea) and the site of either cancer or precancerous lesions (stomach or intestine) were included. No language restrictions were imposed. RESULTS: Twenty-one epidemiological investigations met our inclusion/exclusion criteria. CONCLUSION: These studies seemed to suggest a protective effect of green tea on adenomatous polyps and chronic atrophic gastritis formations. By contrast, there was no clear epidemiological evidence to support the suggestion that green tea plays a role in the prevention of stomach and intestinal cancer.

Beverages↗

PubMed1997

Discovering environmental cancer: Wilhelm Hueper, post-World War II epidemiology, and the vanishing clinician's eye.

Today, our understanding of and approach to the exogenous causes of cancer are dominated by epidemiological practices that came into widespread use after World War II. This paper examines the forces, considerations, and controversies that shaped postwar risk factor epidemiology in the United States. It is argued that, for all of the new capabilities it brought, this risk factor epidemiology has left us with less of a clinical eye for unrecognized cancer hazards, especially from limited and localized exposures in the work-place. The focus here is on Wilhelm Hueper, author of the first textbook on occupational cancer (1942). Hueper became the foremost spokesman for earlier identification practices centering on occupational exposures. The new epidemiological methods and associated institutions that arose in the 1940s and 1950s bore an unsettled relation to earlier claims and methods that some, Hueper among them, interpreted as a challenge. Hueper's critique of the new epidemiology identified some of its limitations and potentially debilitating consequences that remain with us today.

Epidemiology↗

PubMed2002

[Molecular epidemiology of Norwalk virus].

Norwalk virus is one of the most important diarrheal viruses. Although the virus was discovered in 1970, the genetic analysis has started from 1990. The virus appears in sporadic cases but also in outbreaks in children and adults. The symptoms are vomiting and diarrhea, but rarely are convulsion and others. The molecular epidemiological method is useful to detect the pathogen in environments and hosts. As the results of molecular epidemiology, it was found that the common virus with the identical sequence spreads in the world and the virus with unique sequence spreads in a limited area. In Japan, Norwalk virus infection occurs in early winter in children, while, rotavirus infection in late winter. In addition to food borne transmission, air borne transmission is strongly suggested. Norwalk virus infection is recognized to be higher prevalence following rotavirus infection.

Adult↗

PubMed1993

[Investigations on the epidemiology of brucellosis in some villages (pasturelands) of Su Nan County, Gansu Province].

During April-May 1991, by using SAT. CFT. and Coomb's methods epidemiological surveillance on brucellosis among human beings and animals in some villages and pasturelands of Su Nan County was conducted. We found out that the serum brucella antibody was positive in 61 cases (19.06% out of 320 human beings) and 49 cases were diagnosed as brucellosis. We also made an investigation on 497 cattle and 1989 sheep with SAT methods. The result showed that 15 sera showing a positive reaction all came from sheep. The rate was 0.75%.

Adolescent↗

PubMed1983

The drug acquisition curve: a method for the analysis and prediction of drug epidemiology.

A method is presented to chart how a group acquires exposure to a drug. The resulting drug acquisition curve has a number of different parameters that describe the group's drug involvement. Key parameters include: (1) the age of exposure when the group begins to use the drug in greater numbers, probably because of exposure to drug-using peers; (2) the acquisition rate, the percent of the group who are newly exposed each year, a rate that is surprisingly constant over as much as 5 years; and (3) the asymptote, establishing the total percent of the group who will eventually try the drug. Acquisition curves for sequential age cohorts show changing trends in these parameters and can also be used to predict future drug epidemiology. A 4-year prediction based on this method proved to be very accurate for two of three drugs. For the third drug, a large increase in use was predicted, but the increase was even greater than expected.

Adolescent↗

PubMed1997

Classic Kaposi's sarcoma in Greece: a clinico-epidemiological profile.

BACKGROUND: Classic Kaposi's sarcoma (CKS) is not uncommon in Greece with a reported incidence of 0.20 per 100,000 per year. METHODS: Epidemiological, clinical and histological features of all CKS cases, diagnosed in 'A. Sygros' hospital, Athens, Greece during the years 1989-1994, have been recorded and studied prospectively. RESULTS: During the five-year period studied, 66 CKS patients have been diagnosed in our hospital. Incidence among dermatologic patients was 2.11 per 10,000 patients examined, representing 1.35% of total skin malignancies. Patients' age at diagnosis ranged from 53 to 94 years (mean 72 +/- 8.8). The male to female ratio was 2.47:1. A high proportion of the patients were born in Peloponnesos (42.42%) and were residing in Athens (51.51%) or in Peloponnesos (24.24%). Nodules and/or plaques were the most frequent type of lesion, most commonly located on the feet (43.93%) or the hands (28.78%). Accompanying edema was seen in 51.51% of the patients. There were 16 stage I patients (24.24%), 40 stage II (60.60%), 0 stage III and 10 stage IV (15.15%). Involvement of visceral organs was detected in seven patients (10.60%), while 10 had lymph node involvement (15.15%) and three, involvement of the underlying bones (4.54%). Second primary malignancy was diagnosed in 6 cases (9.09%), most often of the reticuloendothelial system (83.33%). CONCLUSIONS: CKS in Greece exhibits some special characteristics, including older age of onset; lower male to female ratio; endemic clustering; disseminated skin disease at diagnosis, often accompanied by lymphedema; not unusual visceral or lymph node involvement and association with second malignancies. We suggest that CKS in Greece possibly represents a distinct endemic subtype of CKS.

Age Factors↗

PubMed2002

Epidemiological and histopathological study of relevance of Guizhou Maotai liquor and liver diseases.

AIM: To explore the relevance of Maotai liquor and liver diseases. METHODS: Epidemiological study was conducted on groups of subjects, each consisting of 3 subjects from the Maotai liquor group consisting of 99 individuals and one from the non-alcoholic control group consisting of 33 individuals. Liver biopsy was performed on 23 volunteers from Guizhou Maotai Distillery who had a constant and long history of drinking Maotai liquor. Experimental histopathological study was conducted as follows: sixty male Wistar rats were divided into 3 groups randomly and fed with Maotai liquor, ordinary white wine, and physiological saline respectively for a period of 8 and 12 weeks. The rats were sacrificed in batches, then serum ALT, AST, TBil, and AKP were measured. Rat livers were harvested to measure the liver indexes, GSH, and MDA. Histopathological examinations were also performed. Another eighty mice were randomly divided into 4 groups and fed with Maotai (at different dosages of 10 ml.kg(-1) and 20 ml.kg(-1)), ethanol, and physiological saline. The animals were sacrificed after 4 weeks and serum ALT was determined. Then the livers were harvested and liver indexes and MDA were measured. RESULTS: The incidence rate of hepatic symptoms, splenomegaly, liver function impairment, reversal of Albumin/Globulin and increased diameter of portal veins in the Maotai liquor group were 1.0% 1/99 , 1.0% 1/99 , 1.0% 1/99 , 1.0% 1/99 , 0 0/99 and 0 0/99 , 0 0/99 ,0 0/99 , 0 0/99 , 0 0/99 , respectively. There was no significant difference between the Maotai group and the non-alcoholic control group P>0.05 . Various degree of fatty infiltration of hepatocytes was found in the 23 volunteers receiving liver biopsy, but there was no obvious hepatic fibrosis or cirrhosis. A comparison was made between the Maotai liquor group and the ordinary white wine group. It was found that hepatic MDA in rats and mice were 0.33+/-0.10 and 0.49+/-0.23 respectively in Maotai group and 0.61+/-0.22 and 0.66+/-0.32 in the ordinary white wine group; MDA had an obvious decrease in the Maotai liquor group (P<0.05); hepatic GSH were 0.12 mg.g(-1)+/-0.06 mg.g(-1) in rats of the Maotai liquor group and (0.08+/-0.02)mg.g(-1) in white wine group, it was obviously increased in the Maotai liquor group (P<0.05). After the 20 rats had been fed with ordinary white wine for 8 weeks consecutively, disarranged hepatocyte cords, fatty infiltration of hepatocytes, and fibrous septa of varying widths due to hepatic connective tissues proliferation were observed; after 12 weeks, the fibrous tissue proliferation continued and early cirrhosis appeared. Compared with the ordinary white wine group, fatty infiltration was observed in the 8-week and 12-week groups, but no necrosis or fibrosis or cirrhosis was found in the Maotai liquor group (P<0.05). CONCLUSION: Maotai liquor may cause fatty liver but not hepatic fibrosis or cirrhosis, and it can strengthen lipid peroxidation in the liver.

Adult↗

PubMed1999

Inherited genetic predisposition in breast cancer. A population-based perspective.

Two classes of inherited susceptibility genes may be considered in the etiology of breast and other common cancers. First, genes have been identified that confer a high degree of breast cancer (BC) risk, usually associated with hereditary syndromes, but disease-associated germline variants in these genes are relatively rare in the general population. These include BRCA1, BRCA2, and TP53. The proportion of BC in the general population that can be explained by these genes is relatively small. Second, variant genotypes at other loci may confer a relatively smaller degree of cancer risk, but they are carried by a larger proportion of the general population. As a result, the proportion of BC that could be explained by these genes may be relatively large. To understand the genetic basis for BCs in the general population, both of these classes of genes may need to be considered. This paper presents an overview of genes thought to be involved in BC susceptibility. Genes that confer a high degree of risk are more likely to result in hereditary patterns of cancer that are amenable to identification by genetic epidemiologic methods using pedigree data. More common (e.g., nonhereditary) forms of BC may be optimally analyzed by molecular epidemiologic studies using case-case, case-control, or cohort designs. The use of an appropriate study design is crucial to the identification of genes with relatively small effects on BC risk. To understand the inherited factors that explain BC in the general population, consideration should be given to genes with different allele frequencies and magnitudes of effect, using appropriate analytical approaches. By understanding the complex interactions of these genes with one another and with exposures, improved risk assessment and potential for targeted cancer prevention strategies may be possible.

Breast Neoplasms↗

PubMed2003

Proposed international clinical diabetic retinopathy and diabetic macular edema disease severity scales.

PURPOSE: To develop consensus regarding clinical disease severity classification systems for diabetic retinopathy and diabetic macular edema that can be used around the world, and to improve communication and coordination of care among physicians who care for patients with diabetes. DESIGN: Report regarding the development of clinical diabetic retinopathy disease severity scales. PARTICIPANTS: A group of 31 individuals from 16 countries, representing comprehensive ophthalmology, retina subspecialties, endocrinology, and epidemiology. METHODS: An initial clinical classification system, based on the Early Treatment Diabetic Retinopathy Study and the Wisconsin Epidemiologic Study of Diabetic Retinopathy publications, was circulated to the group in advance of a workshop. Each member reviewed this using e-mail, and a modified Delphi system was used to stratify responses. At a later workshop, separate systems for diabetic retinopathy and macular edema were developed. These were then reevaluated by group members, and the modified Delphi system was again used to measure degrees of agreement. MAIN OUTCOME MEASURES: Consensus regarding specific classification systems was achieved. RESULTS: A five-stage disease severity classification for diabetic retinopathy includes three stages of low risk, a fourth stage of severe nonproliferative retinopathy, and a fifth stage of proliferative retinopathy. Diabetic macular edema is classified as apparently present or apparently absent. If training and equipment allow the screener to make a valid decision, macular edema is further categorized as a function of its distance from the central macula. CONCLUSIONS: There seems to be a genuine need for consistent international clinical classification systems for diabetic retinopathy and diabetic macular edema that are supported with solid evidence. The proposed clinical classification systems provide a means of appropriately categorizing diabetic retinopathy and macular edema. It is hoped that these systems will be valuable in improving both screening of individuals with diabetes and communication and discussion among individuals caring for these patients.

Diabetic Retinopathy↗

PubMed1997

Epidemiology of temporomandibular disorders: implications for the investigation of etiologic factors.

Epidemiology is the study of the distribution, determinants, and natural history of disease in populations. Epidemiology has several uses in addition to its traditional role of documenting the public health significance of a condition. Notably, epidemiologic methods and data can be used to identify and verify causes of disease. This article reviews the epidemiologic data on pain in the temporomandibular region, and on signs and symptoms associated with specific subtypes of temporomandibular disorders, with the aim of identifying possible etiologic factors for these conditions that deserve further study. Despite methodologic and population differences, several consistencies are apparent in the epidemiologic literature. Pain in the temporomandibular region appears to be relatively common, occurring in approximately 10% of the population over age 18; it is primarily a condition of young and middle-aged adults, rather than of children or the elderly, and is approximately twice as common in women as in men. This prevalence pattern suggests that etiologic investigations should be directed at biologic and psychosocial factors that are more common in women than in men, and diminish in older age groups. Most signs and symptoms associated with particular temporomandibular disorders (e.g., joint sounds, pain in the joint) also appear to be more prevalent in women than in men, although age patterns for these signs and symptoms are not as clear as for temporomandibular pain. The available data highlight the need for further research on etiologic factors associated with temporomandibular pain and with specific diagnostic subtypes of temporomandibular disorders.

Adolescent↗

PubMed2000

Eye cancer incidence in Singapore.

AIM: To describe the epidemiological characteristics of patients with primary intraocular, conjunctival, and orbital cancers seen in Singapore from 1968 to 1995. METHODS: Epidemiological data of all cancers diagnosed in Singapore are collected by the Singapore Cancer Registry. The data of all cases of Singapore residents with eye cancers (ICD-9, site 190) were retrieved for analysis. This includes intraocular, conjunctival, and orbital cancers but excludes cancer of the eyelids. RESULTS: There were 125 patients of which 67 (53.6%) were male and 58 (46.4%) were female. The average annual age standardised incidences for male and female Singapore residents were 1.89 and 1.81 per million respectively. The most common cancer was retinoblastoma (53.6%), followed by malignant melanoma (19.2%) and squamous cell carcinoma (11.2%). The most common cancer among patients younger than 15 years was retinoblastoma (95.7%) and that for those 15 years and older was malignant melanoma (42.6%). The most common subsite was the retina (53.6%), followed by conjunctiva (12.8%), orbit (8.8%), and lacrimal gland (6.4%). CONCLUSION: The annual age standardised incidence have been stable for the 28 years studied. Retinoblastoma is much more common than melanoma in Singapore. These expanded epidemiological characteristics serve to provide ophthalmologists and epidemiologists with a foundation to monitor future disease patterns in Singapore and provide a basis for comparison with other selected populations elsewhere.

Adolescent↗

PubMed2006

Carcinogens in the construction industry.

The construction industry is a complex work environment. The work sites are temporary and rapidly changing. Asbestos has been widely used in construction industry, but the risks were primarily detected in specialized trades, such as insulation workers and plumbers. Today, the majority of cases related to asbestos exposure will occur in other occupational groups in the construction industry. In a large cohort of Swedish construction workers, insulators and plumbers constituted 37% of all cases of pleural mesothelioma between 1975 and 1984 while they constituted 21% of the cases between 1998 and 2002. It is estimated that 25-40% of all male cases of pleural mesothelioma in Sweden are caused by asbestos exposure in the construction trades. There are many other known carcinogens occurring in the construction industry, including PAHs, diesel exhausts, silica, asphalt fumes, solvents, etc., but it is difficult to estimate exposures and thus the size of the risk. The risk of cancer is less easy to detect with traditional epidemiological methods in the construction industry than in other industrial sectors. It is not sufficient to rely upon broad epidemiological data to estimate the risk of cancer due chemicals in the construction industry. Thus, a strategy to decrease exposure, e.g., to dust, seems a feasible way to reduce the risk.

Asbestos↗

PubMed1997

Controlling tuberculosis in an urban emergency department: a rapid decision instrument for patient isolation.

OBJECTIVES: This study examined whether data routinely available in emergency departments could be used to improve isolation decisions for tuberculosis patients. METHODS: In a large emergency department in New York City, we compared the exposure histories of tuberculosis culture-positive and culture-negative patients and used these data to develop a rapid decision instrument to predict culture-positive tuberculosis. The screen used only data that are routinely available to emergency physicians. RESULTS: The method had high sensitivity (.96) and moderate specificity (.54). CONCLUSIONS: The method is easily adaptable for a broad range of settings and illustrates the potential benefits of applying basic epidemiologic methods in a clinical setting.

Adult↗

PubMed2006

Drug resistance in Mycobacterium tuberculosis.

Anti-tuberculosis drugs are a two-edged sword. While they destroy pathogenic M. tuberculosis they also select for drug resistant bacteria against which those drugs are then ineffective. Global surveillance has shown that drug resistant Tuberculosis is widespread and is now a threat to tuberculosis control programs in many countries. Application of molecular methods during the last decade has greatly changed our understanding of drug resistance in tuberculosis. Application of molecular epidemiological methods was also central to the description of outbreaks of drug resistance in Tuberculosis. This review describes recommendations for Tuberculosis treatment according to the WHO guidelines, the drug resistance problem in the world, mechanisms of resistance to first line and second line drugs and applications of molecular methods to detect resistance causing gene mutations. It is envisaged that molecular techniques may be important adjuncts to traditional culture based procedures to rapidly screen for drug resistance. Prospective analysis and intervention to prevent transmission may be particularly helpful in areas with ongoing transmission of drug resistant strains as recent mathematical modeling indicate that the burden of MDR-TB cannot be contained in the absence of specific efforts to limit transmission.

Antitubercular Agents↗