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PubMedDate not supplied

[Factors associated with strongyloides stercoralis infection in an endemic area in Peru].

In order to determine the epidemiological factors and clinical symptoms associated with Strongyloides stercoralis infection, we carried out a descriptive study with a control group in the District of Chanchamayo, Province of Chanchamayo, Junin, Peru. Group I (n = 50) represented those individuals with strongyloidosis and group II (n = 50) were those who tested negative for S. stercoralis by parasitological methods. Epidemiological variables significantly associated with group I were: bathing in the river 3-4 times per week, consuming non-drinking water, defecating in the field; and with group II: drinking boiled water, wearing sneakers and living in houses with cement floor. The clinical symptoms of epigastric pain, daily abdominal pain, semi liquid feces, liquid feces, daily defecation frequency, urticaria and nausea were significantly associated with group 1; whereas more solid feces and defecating every other day were significantly associated with group II. Among individuals under the age of 20 there was a higher percentage of malnutrition according to the weight-age index in group I (p = 0.045). We conclude that infection by S. stercoralis should be suspected in persons from tropical areas who are in frequent contact with rivers or streams or live close to watercourses, who have gastroenterological or dermatological symptoms or who are malnourished, especially if they are children or adolescents.

Adolescent↗
PubMed2001

GSTP1 polymorphisms and gastric cancer in a high-risk Chinese population.

OBJECTIVES: In a population-based case-control study in Yangzhong, China, we investigated the relationship between genetic polymorphisms of GSTP1 and susceptibility to gastric cancer and its premalignant lesion, chronic gastritis. The possible gene-gene interactions between GSTP1 polymorphisms and GSTM1, GSTT1 genes were explored. METHODS: Epidemiologic data were collected by standard questionnaire from 133 gastric cancer cases, 166 chronic gastritis cases, and 433 cancer-free population controls. Blood samples for Helicobacter pylori and molecular marker assays were collected from 84 gastric cancer cases, 146 chronic gastritis, and 429 population controls. GSTP1 polymorphisms were determined by the PCR-RFLP method and H. pylori infection was measured by the ELISA method. Associations between certain GSTP1 genotypes and both gastric cancer and chronic gastritis were assessed by odds ratios (ORs) and 95% confidence intervals (CIs) derived from logistic regression. RESULTS: The distributions of three GSTP1 genotypes, Ile/Ile, Ile/Val, and Val/Val, were similar in gastric cancer cases, chronic gastritis, and controls. After adjusting for age, gender, education, body mass index, pack-year of smoking, alcohol drinking, H. pylori infection, salt and fruit intakes, the adjusted ORs of Val/Val were 1.3 (95% CI: 0.1-11.2) for gastric cancer and 0.9 (95% CI: 0.2-4.8) for chronic gastritis. Combining the Val alleles (Val/Val and Ile/Val) into one group, no association was observed between GSTP1 and both gastric cancer and chronic gastritis. In addition, the allelism at the GSTP1 locus did not increase gastric cancer and chronic gastritis risks associated with the GSTM1 or GSTT1 genotypes. CONCLUSION: Our data suggest that the GSTP1 genotype seems not to be associated with the risk of gastric cancer and chronic gastritis in a high-risk Chinese population.

Adult↗
PubMed1998

Review of social epidemiologic research on migrants' health: findings, methodological cautions, and theoretical perspectives.

The phenomenon of world-wide immigration and migration has major implications for the health of the migrants in addition to its impact upon social and other service providers. Studies of migrants that utilize social epidemiologic methods fall within the traditional boundaries of descriptive and analytic approaches; this article reviews some of the studies that exemplify these approaches. It then suggests specific methodological issues and cautions pertaining to research on migrants and provides a theoretical model for organizing the diverse research studies that have been conducted. By stimulating discussion regarding social epidemiologic research on migrants' health, this model is intended to serve as a compass point for future research and needed interventions.

Causality↗
PubMed2000

Hormone replacement therapy after epithelial ovarian cancer treatment.

PURPOSE: Our report deals with the presumed influence of hormone replacement therapy (HRT) on the recurrence of epithelial ovarian cancer. MATERIALS AND METHODS: Our study group consisted of 31 patients who had been treated for invasive epithelial carcinoma of the ovaries. In all the patients the primary treatment was surgery. The mean duration of follow-up was 55 months. All the patients received HRT with non-conjugated estrogens. The data were analyzed using analytical descriptive epidemiological methods. RESULTS: The mean duration of HRT was 25 months, starting on average 18 months after completed therapy for ovarian cancer. Progression of the disease was established in 3 patients with advanced disease, 2 patients with moderately- and poorly-differentiated serous adenocarcinoma respectively, and in one patient with well-differentiated endometrioid adenocarcinoma. The progression of ovarian cancer occurred 1, 2 and 10 months after the beginning of HRT. Two patients died due to progressive disease, while one patient is still alive with evidence of the disease. Eleven months after the beginning of HRT, one patient without evidence of ovarian cancer progression presented with a new primary cancer--carcinoma of the breast. CONCLUSIONS: According to the results of our review study, HRT does not seem to have a noteworthy effect on the progression of epithelial carcinoma of the ovary. However, only further--carefully designed--prospective studies could provide more conclusive results.

Adult↗
PubMed2002

Molecular typing of Mycobacterium tuberculosis strains with a common two-band IS6110 pattern.

We conducted a program of population-based molecular typing of all Mycobacterium tuberculosis isolates obtained in Alabama since 1994. Of 2452 isolates, 1013 (41%) had fewer than 6 bands of IS6110; 348 (14%) had a single two-band pattern (JH2). With conventional epidemiologic methods, we identified three groups of related patients with JH2 isolates. Spoligotyping and pattern of variable number of tandem repeats identified 10 molecular groups; two found by conventional methods were subdivided.

Alabama↗
PubMed2003

[Screening and evaluation of non-invasive diagnosis markers for compensated liver cirrhosis in patients with chronic hepatitis B].

OBJECTIVE: To evaluate the diagnostic value of liver fibrosis markers and ultrasonic examination for determining compensated liver cirrhosis in patients with chronic hepatitis B, and screen applicable non-invasive diagnostic marker for compensated liver cirrhosis. METHODS: Serum hyaluronic acid (HA), Type III procollagen (PCIII), laminin (LN) and Type IV collagen (CIV) were measured from 350 patients with chronic hepatitis B, who were also detected with liver biopsy and ultrasonography. To determine the cut-off value of every serum liver fibrosis marker for diagnosing compensated liver cirrhosis, data was analysed with clinical epidemiology methods. Then evaluated and compared all the markers. RESULTS: 85 out of 350 patients were diagnosed as compensated liver cirrhosis by liver biopsy, and 81 had liver cirrhosis images by ultrasonic examination. HA achieved the biggest area under the ROC curve. The cut-off values with best sensitivity and accuracy of HA, PCIII, LN and CIV were 154.35 microg/L, 198.44 microg/L, 137.58 microg/L and 100.80 microg/L respectively. The related diagnostic sensitivities of HA, PCIII, LN and CIV were 82.4%, 63.5%, 57.3% and 70.6%, specificities were 79.3%, 54.0%, 56.8%, 68.3%, and accuracies were 80.0%, 56.3%, 56.9%, 68.9%, respectively. Parallel tests could increase the diagnostic sensitivity, but decreased specificity and accuracy accordingly. Compared with other non-invasive diagnostic methods, HA was the best marker (mu > or =1.814, P<0.05). The level of HA at 119.17 microg/L was suitable for determining compensated cirrhosis, with a 87.1% sensitivity, 67.6% specificity, 72.3% accuracy, 46.25% positive predictive value and 94.7% negative predictive value. CONCLUSION: Among the non-invasive serum diagnostic markers for liver fibrosis and ultrasonic examination for cirrhosis image, HA is the best marker for diagnosing compensated liver cirrhosis.

Adolescent↗
PubMed2005

Pectus excavatum in a 112-year autopsy series: anatomic findings and the effect on survival.

BACKGROUND/PURPOSE: The purpose of this study was to determine the frequency of pectus excavatum and associated conditions in a large autopsy series. It also sought to determine whether there were different survival patterns for pectus excavatum patients than for patients without pectus excavatum. METHODS: A computer-assisted search of autopsy files maintained by Johns Hopkins University was conducted, dating from 1889 to 2001. Each patient's Autopsy Pathology Information System report was reviewed for diagnosis and comorbid conditions. To determine whether there were differences in survival patterns, we tested whether pectus excavatum patients survived longer than controls, using a standard epidemiological method. Each patient in the autopsy series was compared with the 2 patients entered in the autopsy database chronologically immediately before and the 2 patients immediately after the case. A Kaplan-Meier survival analysis was conducted. RESULTS: Pectus excavatum was identified at autopsy in 62 of 50,496 cases. Of these 62 patients, 17 were 65 years or older and appeared to have died of causes unrelated to pectus excavatum, the oldest being 91 years. Twenty-one were between the ages of 14 and 65 years and were found to have coexisting conditions or syndromes. Six were between the ages of 1 and 4 years. One of the 6 died in 1947 because of complications from pectus repair. No autopsied patient with pectus excavatum died between the ages of 5 and 14 years. Eighteen were infants younger than 1 year, and all 18 died because of conditions unrelated to pectus excavatum. There were no reported cases of pectus excavatum before 1947, and the severity of deformity could not be determined from the autopsy data. Survival analysis indicated that pectus excavatum patients had a different survival than the controls. Pectus excavatum patients tended to die earlier (P = .0001). However, pectus excavatum patients who survived past the age of 56 years tended to survive longer than their matched controls (P = .0001). CONCLUSION: Although there were no histological abnormalities noted in the cartilage of the pectus excavatum patient's conditions, pectus excavatum was associated with several connective tissue abnormalities. Analysis is consistent with the theory that this condition can impact survival.

Adolescent↗
PubMedDate not supplied

Molecular epidemiology of methicillin-resistant Staphylococcus aureus in Ilorin, Nigeria.

BACKGROUND: Nosocomial infections caused by methicillin-resistant strains of Staphylococcus aureus constitute significant epidemiologic problems. Defining an outbreak requires the use of rapid and highly discriminatory epidemiologic methods to determine the epidemic strains involved in such outbreak. STUDY DESIGN: A descriptive laboratory based surveillance study for MRSA was undertaken. One hundred and forty seven Staphylococcus aureus isolates from clinical specimens were screened for methicillin resistance at the University of Ilorin Teaching Hospital between January and December 2001. Fifty one (34.7%) methicillin resistant strains recovered were epidemiologically characterized using Eco R1 restriction enzyme analysis of their plasmid DNAs. RESULT: Forty five (88.2%) MRSA isolates were associated with infections and 6 (11.8 %) were colonizing strains; 36 (70.6%) and 15 (29.4%) were hospital and community acquired respectively. Skin and soft tissues were sites of infection in 36 (70.6 %) cases and surgical, emergency and ICU accounted for 33 (64.7%) isolates. All isolates were resistant to more than two antibiotics but sensitive to vancomycin. Forty two (82.4 %) isolates contained plasmids including 9 (21.4 %) that contained more than one plasmid. Restriction Enzyme Analysis of the Plasmid DNA (REAP) divided the isolates into 9 Eco R1 profiles, with profile 2 accounting for 41.7% of all nosocomial infections in the wards, implying that it is endemic. The remaining nosocomial profiles occurred less frequently, suggesting that they are sporadic strains originating from outside the hospital. The community strains showed diverse digestion pattern indicating that they are from different clones. CONCLUSION: The spread of MRSA can be controlled through reinforcement of appropriate use of antibiotics, hand washing and laboratory surveillance for MRSA, particularly in the surgical wards and intensive care units, in order to identify sources of outbreaks.

Cross Infection↗
PubMed1998

Dietary fat and obesity: an epidemiologic perspective.

The observation that dietary fat has an effect on weight gain and the development of obesity that is larger than would be expected on the basis of fat's energy value is mainly experimental. Several methodologic problems limit the interpretation of epidemiologic studies of the association between dietary fat intake and obesity. Among the issues relevant in this context are underreporting of energy and fat intakes, dieting behavior, inadequate control for variables such as energy expenditure, and limited between-subject variation in fat intake in developed countries. Different types of epidemiologic studies suffer from different types and magnitudes of bias and many conflicting results can be obtained. Ecologic and cross-sectional studies especially suffer from these biases. The more appropriate type of study (ie, prospective studies of fat intake and subsequent weight gain) was carried out in several countries but conflicting results were obtained. Overall, the observed associations seem to depend on the stage of cultural transition of the population studied (eg, modernization compared with postmodernization). Current epidemiologic methods are inadequate for performing valid studies of the relation between percentage of energy from dietary fat and obesity. Specifically designed prospective studies of unbiased estimates of energy balance are necessary. Appropriate control for confounders and emphasis on the possibility that genetic predisposition plays a role will also be necessary. At this stage there is no conclusive evidence from epidemiologic studies that under isoenergetic conditions dietary fat intake promotes the development of obesity more so than other macronutrients.

Body Mass Index↗
PubMed1999

Applications of new technology in molecular epidemiology and their relevance to occupational medicine.

Technological advances in molecular biology over the past 2 decades have offered more complex techniques that can be used to study the role of specific exogenous agents and host variables that cause ill health. Increasingly, studies in human populations use this new technology, combined with epidemiological methods, to shed light on the understanding of the biological processes associated with development of disease. This approach has many potential applications in occupational and environmental medicine (OEM), and some aspects of the work in this growing field are reviewed. An understanding of biochemistry and genetics at the molecular level, specific knowledge on metabolism and mechanisms of action, and epidemiology have become increasingly important for the OEM practitioner. This is necessary to consider the major question of validation and relevance of these molecular biomarkers. As end users, OEM practitioners should also consider the impact of these advances on their practices. For example, the availability of genetic tests to identify susceptible workers raises issues of ethics, individual privacy, right to work, and the relevance of such tests. Several studies have presented data on the association of environmental measurements and various biomarkers for internal and biologically effective dose, genetic polymorphisms, and early response markers. Given the limitations of individual molecular biomarkers in assessing risk to health, and the multifactorial nature of environmental disease, it is likely that such an approach will increase our understanding of the complex issue of mechanisms of disease and further refine the process of risk assessment.

Genetic Markers↗
PubMed1997

Epidemiology and prevention of transfusion-associated human immunodeficiency virus transmission in sub-Saharan Africa.

BACKGROUND AND OBJECTIVES: Compared to industrialised nations, countries in sub-Saharan Africa experience a greater amount of transfusion-associated HIV transmission due to high rates of transfusion in some groups of patients, a higher incidence and prevalence of HIV infection in donor populations, a lack of HIV antibody screening in some areas, and a higher residual risk of contamination in blood supplies despite antibody screening. MATERIALS AND METHODS: Epidemiologic review. RESULTS: Epidemiologic evidence supports the effectiveness of three relatively inexpensive strategies to prevent transfusion-associated HIV transmission in sub-Saharan Africa: HIV antibody screening, avoidance of unnecessary use of blood products, and exclusion of donors at high risk of infection. Such prevention strategies have not been universally implemented. CONCLUSIONS: International aid to establish and maintain HIV antibody screening programmes, implementation of sound criteria for transfusion, and the search for HIV risk factors to use as donor exclusion criteria must be expanded in the region.

Africa South of the Sahara↗
PubMed2001

Drug epidemiology in Italy: methods and ethical issues. The example of psychiatry.

PURPOSE: These notes aim at analysing current methods, ethical issues and major legislation changes related to drug epidemiology in Italy. METHODS: The design and conduct of two pharmacoepidemiological surveys carried out in the context of recent law dispositions on psychiatric care and confidentiality are presented. RESULTS: In 1978 law 180 stated that no more patients had to be admitted to psychiatric hospitals, and no more psychiatric hospitals had to be built. Chronic long-stay patients were allowed to remain in hospitals. In 1994, however, financial law 724 established a deadline for the final closure of Italian psychiatric hospitals. A survey of more than 1000 patients living in eight state psychiatric hospitals was carried out to describe the social and clinical characteristics of the inpatient population and to monitor their community placement. In 1996 law 675 established that private and confidential information could not be used for any purpose without the patient's informed consent. However, this law was not implemented that year. A survey of benzodiazepine use among general practice patients was conducted without written informed consent. CONCLUSIONS: The Italian legislation has been changing for some years, and regulations might still be modified in the near future. To increase ethical practices in pharmacoepidemiology scientists and clinical researchers should guarantee high standards in terms of research objectives, design and analyses. Potential conflict of interest should always be declared.

Anti-Anxiety Agents↗
PubMed1982

Assessing environmental toxins by human population effects.

The impact of toxins on the health of human populations can only be accurately assessed by epidemiologic methods. The investigation of toxin-disease associations in human populations and the accurate interpretation of data are often very difficult because of the existence of multiple confounding variables and the unrepresentativeness of sample or study populations. Factors influencing the deduction of cause and effect relationship rather than simple association are discussed, as is the need for continued development of epidemiological surveillance techniques.

Environmental Pollutants↗
PubMed2004

The economic burden of smoking in California.

OBJECTIVE: To develop estimates of the direct and indirect costs of smoking for California in 1999. METHODS: A prevalence based approach was used to estimate the annual costs of smoking. Econometric models were used to estimate the smoking attributable fraction (SAF) for direct costs (hospitalisations, ambulatory care, prescription drugs, home health care, and nursing home services) and indirect costs due to lost productivity from smoking related illness. The models controlled for socioeconomic factors and other risk behaviours. Epidemiological methods were used to estimate the SAF for indirect costs due to lost productivity from premature deaths. The SAFs were applied to total health care expenditures, days lost, and deaths to obtain smoking attributable total costs. RESULTS: In 1999, the total costs of smoking in California were 15.9 billion dollars, 475 dollars per resident, and 3331 dollars per smoker. Direct costs were 8.6 billion dollars (54% of the total), indirect costs due to lost productivity from illness were 1.5 billion dollars (10%), and indirect costs due to premature deaths were 5.7 billion dollars (36%). The cost of smoking was 9.4 billion dollars for men and 6.3 billion dollars for women. There were 43,137 deaths attributed to smoking, representing a total of 535,000 years of life lost. The value of life lost per death averaged 132,000 dollars, or 12.4 years. CONCLUSIONS: California smoking related costs are high. The cost methodology presented is useful for other states and nations interested in estimating their costs of smoking. Cost estimates can be used to evaluate the level of cigarette taxes and other policies related to smoking.

Absenteeism↗
PubMed1994

Preparation for phase III HIV vaccine efficacy trials: methods for the determination of HIV incidence.

OBJECTIVE: Accurate estimates of HIV incidence that reflect the effect of non-vaccine interventions (education, counselling, condom promotion, and possibly sexually transmitted disease treatment) and that may be provided in a Phase III vaccine efficacy trial, are needed so that vaccine trial population sample sizes can be accurately determined. In order to avoid delays in the implementation of efficacy trials, well characterized cohorts must also be developed and available to participate in such trials. We reviewed the potential study populations, the epidemiologic methods for the determination of HIV incidence (using open cohort, closed cohort, and seroprevalence data methods), and the need for the development of population cohorts in preparation for Phase III HIV vaccine efficacy trials. SETTING: Phase III trials in developed and developing countries. METHODS: Comparison of open and closed cohorts and those using seroprevalence data to estimate HIV incidence. RESULTS: Open and closed cohorts each have disadvantages and advantages. However, the open cohort may be more suitable for determining estimates of HIV incidence that reflect non-vaccine interventions and for the development of a well characterized cohort available to participate in efficacy trials. CONCLUSION: Careful preparation of research infrastructures and population cohorts will help ensure the successful conduct of scientifically and ethically sound HIV vaccine efficacy trials in the future.

AIDS Vaccines↗
PubMed2005

Multidrug-resistant Acinetobacter baumannii.

To understand the epidemiology of multidrug-resistant (MDR) Acinetobacter baumannii and define individual risk factors for multidrug resistance, we used epidemiologic methods, performed organism typing by pulsed-field gel electrophoresis (PFGE), and conducted a matched case-control retrospective study. We investigated 118 patients, on 27 wards in Israel, in whom MDR A. baumannii was isolated from clinical cultures. Each case-patient had a control without MDR A. baumannii and was matched for hospital length of stay, ward, and calendar time. The epidemiologic investigation found small clusters of up to 6 patients each with no common identified source. Ten different PFGE clones were found, of which 2 dominated. The PFGE pattern differed within temporospatial clusters, and antimicrobial drug susceptibility patterns varied within and between clones. Multivariate analysis identified the following significant risk factors: male sex, cardiovascular disease, having undergone mechanical ventilation, and having been treated with antimicrobial drugs (particularly metronidazole). Penicillins were protective. The complex epidemiology may explain why the emergence of MDR A. baumannii is difficult to control.

Acinetobacter Infections↗
PubMed2000

[Determinants of health and health policies. Part I. Causality in medicine and its modeling].

Causality is the relation between the antecedent and consequence. Association between those two notions represents causal determinacy allowing understanding the subject, and the theory of probability, which deals with supposed contradiction of the chance and necessity. Understanding how health can be impaired enables to precede the disease, to change its natural history and to cure it. Causality in medicine is based on the conception of complex action of biological, psychological and social factors, which may have either positive or negative effects on our health. Empirical data forming basis for the search of aetiology represent a conglomerate of causal and indifferent elements. To identify them, various models are employed (black box, Rubik's cube, Chinese box, model of multiple accidental phenomena and others). Appropriate epidemiological methods enable not only to determine the preference, but also to signalize fallacies of looking for the origin of disease. Permanent problem of the medicine reveals the existence of the objective accident and the uncertainty in the professional decision.

Causality↗