Epidemiology of candidemia: 3-year results from the emerging infections and the epidemiology of Iowa organisms study.
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Bloodstream infections due to Candida species cause significant morbidity and mortality. Surveillance for candidemia is necessary to detect trends in species distribution and antifungal resistance. We performed prospective surveillance for candidemia at 16 hospitals in the State of Iowa from 1 July 1998 through 30 June 2001. Using U.S. Census Bureau and Iowa Hospital Association data to estimate a population denominator, we calculated the annual incidence of candidemia in Iowa to be 6.0 per 100,000 of population. Candida albicans was the most common species detected, but 43% of candidemias were due to species other than C. albicans. Overall, only 3% of Candida species were resistant to fluconazole. However, Candida glabrata was the most commonly isolated species other than C. albicans and demonstrated some resistance to azoles (fluconazole MIC at which 90% of the isolates tested are inhibited, 32 microg/ml; 10% resistant, 10% susceptible dose dependent). C. glabrata was more commonly isolated from older patients (P = 0.02) and caused over 25% of candidemias among persons 65 years of age or older. The investigational triazoles posaconazole, ravuconazole, and voriconazole had excellent in vitro activity overall against Candida species. C. albicans is the most important cause of candidemia and remains highly susceptible to available antifungal agents. However, C. glabrata has emerged as an important and potentially antifungal resistant cause of candidemia, particularly among the elderly. (+info)
Neuroaxonal dystrophy in raccoons (Procyon lotor) from Iowa.
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During a 12-month period (1998-1999), microscopic evidence of neuroaxonal dystrophy (NAD) in medullae oblongata of raccoons (Procyon lotor) was observed in 17/39 (47% prevalence in adults) from Iowa, USA. Three of the animals were kits (<3 months), 26 were between 1 and 2 years, and 10 were over 7 years. Lesions were not seen in the medullae of the 3 kits. In young adults, the lesions were mild and were seen in 7 animals. More severe lesions were present in the 10 older raccoons. Grossly, the brains were unremarkable. Microscopically, NAD was confined to the dorsal caudal medulla, where certain nuclei (predominantly gracilis and cuneate) were bilaterally affected. Severely affected animals had vacuolar degeneration of neurons or neuronal loss and extensive areas of spongiosis. Tests for the presence of PrP(res) in the brain were negative. Spongiotic areas often contained axonal spheroids. Degenerate neurons and axons occasionally contained amphophilic periodic acid-Schiff-positive granular material. There was a paucity of inflammatory cells in the affected areas. Since lesions were not present in kits, were either absent or mild in young adults, and were severe in older raccoons, the findings may be related to advancing age. Neuroaxonal dystrophy has not been previously reported in raccoons. Retrospective examination of raccoon brains from the eastern and northwestern areas of the country revealed very low prevalence of NAD. Because of the apparently high prevalence of this condition at this geographic location, factors other than age (genetic, nutritional, and/or environmental) may influence this degenerative process in the brains of raccoons in Iowa. (+info)
Health-related quality of life in Gulf War era military personnel.
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The Gulf War's impact on veterans' health-related quality of life (HRQL) remains unclear. The authors examined the HRQL of military personnel deployed to the Gulf War Theater compared with those not deployed. In 1995-1996, a structured, population-based telephone survey was conducted 5 years postconflict among a cohort originally from Iowa on active duty during the conflict. The sample included 4,886 eligible subjects stratified by deployment and military status and proportionately distributed within five substrata. The Medical Outcome Study Short Form-36 (SF-36) assessed HRQL, and multivariable linear regression identified pre- and perideployment risk factors. A total of 3,695 respondents (76%) participated. Nondeployed participants reported excellent health more often than deployed participants (31% vs. 21%, p < 0.01). SF-36 scores for deployed participants were poorer than those for nondeployed controls across all health domains. Modifiable factors such as smoking and military preparedness, and other factors such as predeployment physical and mental health morbidity, were independent risk factors for poorer HRQL after deployment. Deployed veterans reported slightly poorer HRQL even after the authors adjusted for other risk factors. Further investigation of factors influencing postdeployment HRQL is needed. Routine collection of health information by using standardized instruments pre- and perideployment should be implemented. (+info)
Factors associated with refusal to provide a buccal cell sample in the Agricultural Health Study.
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Epidemiological studies are increasingly collecting buccal cells and other sources of DNA for genetic analysis. However, high refusal rates raise concerns about possible selection bias. This study examines the subject characteristics associated with refusal or failure to provide a buccal cell sample. Subjects were male farmers in the Agricultural Health Study, which is being conducted in Iowa and North Carolina. As part of a 5-year follow-up, cohort members were contacted by telephone and asked to participate in a telephone interview and to consent to providing a buccal cell sample using a kit that was mailed to them. Demographic, lifestyle, disease, and occupational characteristics were compared between consenters who returned a sample ("compliers"), nonconsenters ("refusers"), and consenters who failed to return a sample ("noncompliers"). Compliers (n = 8794), refusers (n = 3178), and noncompliers (n = 3008) were quite similar, although compliers tended to be slightly older. Although some significant differences between these groups were observed, the magnitude of these differences was generally small, usually no more than a few percentage points. In conclusion, this study found little difference between male farmers who agreed to provide buccal cell samples versus those who either refused to provide a sample or who agreed but failed to return the sample. Observed differences were typically small and would be unlikely to compromise etiologic associations identified in such a prospective study. In short, there appears to be little selection bias in the Agricultural Health Study buccal cell collection process, further supporting the use of such mailed collection kits in epidemiological research. (+info)
Residential radon exposure and lung cancer: variation in risk estimates using alternative exposure scenarios.
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The most direct way to derive risk estimates for residential radon progeny exposure is through epidemiologic studies that examine the association between residential radon exposure and lung cancer. However, the National Research Council concluded that the inconsistency among prior residential radon case-control studies was largely a consequence of errors in radon dosimetry. This paper examines the impact of applying various epidemiologic dosimetry models for radon exposure assessment using a common data set from the Iowa Radon Lung Cancer Study (IRLCS). The IRLCS uniquely combined enhanced dosimetric techniques, individual mobility assessment, and expert histologic review to examine the relationship between cumulative radon exposure, smoking, and lung cancer. The a priori defined IRLCS radon-exposure model produced higher odds ratios than those methodologies that did not link the subject's retrospective mobility with multiple, spatially diverse radon concentrations. In addition, the smallest measurement errors were noted for the IRLCS exposure model. Risk estimates based solely on basement radon measurements generally exhibited the lowest risk estimates and the greatest measurement error. The findings indicate that the power of an epidemiologic study to detect an excess risk from residential radon exposure is enhanced by linking spatially disparate radon concentrations with the subject's retrospective mobility. (+info)
A quantitative approach for estimating exposure to pesticides in the Agricultural Health Study.
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We developed a quantitative method to estimate long-term chemical-specific pesticide exposures in a large prospective cohort study of more than 58000 pesticide applicators in North Carolina and Iowa. An enrollment questionnaire was administered to applicators to collect basic time- and intensity-related information on pesticide exposure such as mixing condition, duration and frequency of application, application methods and personal protective equipment used. In addition, a detailed take-home questionnaire was administered to collect further intensity-related exposure information such as maintenance or repair of mixing and application equipment, work practices and personal hygiene. More than 40% of the enrolled applicators responded to this detailed take-home questionnaire. Two algorithms were developed to identify applicators' exposure scenarios using information from the enrollment and take-home questionnaires separately in the calculation of subject-specific intensity of exposure score to individual pesticides. The 'general algorithm' used four basic variables (i.e. mixing status, application method, equipment repair status and personal protective equipment use) from the enrollment questionnaire and measurement data from the published pesticide exposure literature to calculate estimated intensity of exposure to individual pesticides for each applicator. The 'detailed' algorithm was based on variables in the general algorithm plus additional exposure information from the take-home questionnaire, including types of mixing system used (i.e. enclosed or open), having a tractor with enclosed cab and/or charcoal filter, frequency of washing equipment after application, frequency of replacing old gloves, personal hygiene and changing clothes after a spill. Weighting factors applied in both algorithms were estimated using measurement data from the published pesticide exposure literature and professional judgment. For each study subject, chemical-specific lifetime cumulative pesticide exposure levels were derived by combining intensity of pesticide exposure as calculated by the two algorithms independently and duration/frequency of pesticide use from the questionnaire. Distributions of duration, intensity and cumulative exposure levels of 2,4-D and chlorpyrifos are presented by state, gender, age group and applicator type (i.e. farmer or commercial applicator) for the entire enrollment cohort and for the sub-cohort of applicators who responded to the take-home questionnaire. The distribution patterns of all basic exposure indices (i.e. intensity, duration and cumulative exposure to 2,4-D and chlorpyrifos) by state, gender, age and applicator type were almost identical in two study populations, indicating that the take-home questionnaire sub-cohort of applicators is representative of the entire cohort in terms of exposure. (+info)
Contrasts in cancer prevalence in Connecticut, Iowa, and Utah.
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BACKGROUND: Cancer prevalence--the proportion of a population with cancer, including those recently diagnosed, those in treatment, and survivors--is an important indicator of future health care requirements. Only limited information on cancer prevalence is available for the United States. In particular, comparative interstate studies are not available. In this study, we estimate and analyze the prevalence of seven major cancers in Connecticut, lowa, and Utah using the tried and tested PREVAL method applied to National Cancer Institute registry data. METHODS: We analyzed data on 242,851 carcinomas of the stomach, colorectum, pancreas, breast, uterus (corpus), ovary, and non-Hodgkin lymphoma (NHL), diagnosed in white Americans from 1973 through 1992. Observed prevalence was estimated by applying the PREVAL method to incidence and life status data from the cancer registries. Complete prevalence was estimated by applying correction factors obtained by modeling incidence and survival rates. RESULTS: The ratio of the highest to the lowest prevalence (as proportions) ranged from 1.69 for uterine carcinoma to 2.73 for stomach carcinoma, showing that marked differences in cancer prevalence exist within the United States. Utah had the lowest prevalence for each carcinoma. Connecticut and lowa had similar prevalence levels for carcinomas of the colorectum, pancreas, and ovary and for NHL. Breast carcinoma was the most prevalent, with 826 cases per 100,000 of population in Utah, 1518 per 100,000 in lowa, and 1619 per 100,000 in Connecticut. Cancer survival did not differ greatly among the three registry populations. The major determinants of prevalence differences were incidence and the population age distribution. CONCLUSIONS: PREVAL provides reliable estimates of the numbers of living people in a population who have had a cancer diagnosis. Prevalence depends on incidence and survival and on the age structure of population. All these factors have changed markedly in recent years and will continue to do so in the future. Cancer prevalence should be monitored over time to evaluate changes by area, sex, age, and cancer site. The prevalence figures presented are directly comparable with those from European cancer registries. (+info)
Physician surveys to assess customary care in medical malpractice cases.
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OBJECTIVE: Physician experts hired and prepared by the litigants provide most information on standard of care for medical malpractice cases. Since this information may not be objective or accurate, we examined the feasibility and potential value of surveying community physicians to assess standard of care. DESIGN: Seven physician surveys of mutually exclusive groups of randomly selected physicians. SETTING: Iowa. PARTICIPANTS: Community and academic primary care physicians and relevant specialists. INTERVENTIONS: Included in each survey was a case vignette of a primary care malpractice case and key quotes from medical experts on each side of the case. Surveyed physicians were asked whether the patient should have been referred to a specialist for additional evaluation. The 7 case vignettes included 3 closed medical malpractice cases, 3 modifications of these cases, and 1 active case. MEASUREMENTS AND MAIN RESULTS: Sixty-three percent of 350 community primary care physicians and 51% of 216 community specialists completed the questionnaire. For 3 closed cases, 47%, 78%, and 88% of primary care physician respondents reported that they would have made a different referral decision than the defendant. Referral percentages were minimally affected by modifying patient outcome but substantially changed by modifying patient presentation. Most physicians, even those whose referral decisions were unusual, assumed that other physicians would make similar referral decisions. For each case, at least 65% of the primary care physicians disagreed with the testimony of one of the expert witnesses. In the active case, the response rate was high (71%), and the respondents did not withhold criticism of the defendant doctor. CONCLUSIONS: Randomly selected peer physicians are willing to participate in surveys of medical malpractice cases. The surveys can be used to construct the distribution of physician self-reported practice relevant to a particular malpractice case. This distribution may provide more information about customary practice or standard of care than the opinion of a single physician expert. (+info)