Self-reported factors associated with community ambulation after stroke: The Canadian Longitudinal Study on Aging.

Community ambulation is frequently limited for people with stroke. It is, however, considered important to people with stroke. The objectives were to identify factors associated with self-reported community ambulation in Canadians aged 45+ with stroke and to identify factors associated with community ambulation specific to Canadian males and to Canadian females with stroke. Data were utilized from the Canadian Longitudinal Study on Aging Tracking Cohort. Multivariate logistic regression models were developed for community ambulation. Mean age was 68 (SE 0.5) years (45% female). In the final community ambulation model (n = 855), factors associated with being less likely to 'walk outdoors sometimes or often' included difficulty or being unable to walk 2-3 blocks (decreased endurance) vs. no difficulty. Being more likely to walk outdoors was associated with 'better weather' months and being 55-64 years of age vs 75-85. Differences were noted between the models of only males and only females. Decreased walking endurance is associated with a decreased likelihood of walking in the community-a factor that can be addressed by rehabilitation professionals and in community based programs.

Community ambulation in older adults and people with OA - a model verification using Canadian Longitudinal Study on Aging (CLSA) data.

BACKGROUND: There are health and well-being benefits of community ambulation; however, many older adults do not regularly walk outside of their home. Objectives were to estimate the associations between latent constructs related to community ambulation in older adults aged 65-85 (65+), and in adults with osteoarthritis (OA) aged 45-85. METHODS: Secondary data analysis of the comprehensive baseline and maintaining contact questionnaire data from the Canadian Longitudinal Study of Aging (CLSA) was completed. Based on a previous model of community ambulation post-stroke, structural equation modeling (SEM) was used to develop measurement and structural models for two groups: older adults 65+ and people with OA. Multi-group SEM was conducted to test measurement invariance across sex and age groups. Measurement models were developed for the following latent factors: ambulation (frequency of walking outside/week, hours walked/day, ability to walk without help, frequency and aids used in different settings); health perceptions (general health, pain frequency/intensity); timed functional mobility (gait speed, timed up-and-go, sit-to-stand, balance). Variables of depression, falls, age, sex, and fear of walking alone at night were covariates in the structural models. RESULTS: Data were used from 11,619 individuals in the 65+ group (mean age 73 years ±6, 49% female) and 5546 individuals in the OA group (mean age 67 ± 10, 60% female). The final 65+ model had a close fit with RMSEA (90% CI) = 0.018 (0.017, 0.019), CFI = 0.91, SRMR = 0.09. For the OA group, RMSEA (90% CI) = 0.021 (0.020, 0.023), CFI = 0.92, SRMR = 0.07. Health perceptions and timed functional mobility had a positive association with ambulation. Depression was associated with ambulation through negative associations with health perceptions and timed functional mobility. Multi-group SEM results reveal the measurement model was retained for males and females in the 65+ group, for males and females and for age groups (65+, < 65) in the OA group. CONCLUSIONS: The community ambulation model post-stroke was verified with adults aged 65+ and for those with OA. The models of community ambulation can be used to frame and conceptualize community ambulation research and clinical interventions.

Verification of a comprehensive framework for mobility using data from the Canadian Longitudinal Study on Aging: a structural equation modeling analysis.

BACKGROUND: Mobility within and between life spaces is fundamental for health and well-being. Our objective was to verify a comprehensive framework for mobility. METHODS: This was a cross-sectional study. We used structural equation modeling to estimate associations between latent factors with data from the Canadian Longitudinal Study on Aging for participants 65-85 years of age (65+, n = 11,667) and for adults with osteoarthritis (OA) aged 45-85 (n = 5,560). Latent factors included life space mobility, and physical, psychosocial, environmental, financial, and cognitive elements. Personal variables (age, sex, education) were covariates. RESULTS: The models demonstrated good fit (65+: CFI = 0.90, RMSEA (90% CI) = 0.025 (0.024, 0.026); OA: CFI = 0.90, RMSEA (90% CI) = 0.032 (0.031, 0.033)). In both models, better psychosocial and physical health, and being less afraid to walk after dark (observed environmental variable) were associated with greater life space mobility. Greater financial status was associated with better psychosocial and physical health. Higher education was related to better cognition and finances. Older age was associated with lower financial status, cognition, and physical health. Cognitive health was positively associated with greater mobility only in the 65 + model. Models generated were equivalent for males and females. CONCLUSIONS: Associations between determinants described in the mobility framework were verified with adults 65-85 years of age and in an OA group when all factors were considered together using SEM. These results have implications for clinicians and researchers in terms of important outcomes when assessing life space mobility; findings support interdisciplinary analyses that include evaluation of cognition, depression, anxiety, environmental factors, and community engagement, as well as physical and financial health. Public policies that influence older adults and their abilities to access communities beyond their homes need to reflect the complexity of factors that influence life space mobility at both individual and societal levels.

Factors associated with social participation and community ambulation in people with osteoarthritis: Findings from the Canadian Longitudinal Study on Aging.

AIM: Walking in the community allows participation in meaningful activities which positively influences self-rated health and quality of life. Our objective was to identify factors associated with social participation and community ambulation in a representative sample of Canadian adults with osteoarthritis (OA). METHODS: Data were from >3800 participants in the Baseline Tracking Dataset of the Canadian Longitudinal Study on Aging with OA of the hip and/or knee. Outcomes included frequency of participation in 8 community-based activities (past year, social participation), and frequency walking outside the home (past 7 days, community ambulation). Explanatory variables (15 for social participation, 11 for community ambulation) established in previous literature were evaluated. Variables significant in univariate binary logistic regression models were entered into multivariable models. RESULTS: Frequency of social participation was greater for females, and individuals with higher levels of education. Those who were younger, dissatisfied with life, and had difficulty walking 2-3 blocks were less likely to participate. Having fewer chronic conditions, being younger, being single/widowed and being interviewed in spring/summer were associated with more frequent ambulation. Lower self-rated health, difficulty walking 2-3 blocks, pain and being female were associated with less frequent walking outside the home. CONCLUSION: Many factors influence frequency of social participation and community ambulation. The ability to walk short distances is positively associated with both outcomes. This important factor can and should be addressed clinically to improve health and quality of life in people with OA.

Subclinical Burkholderia pseudomallei Infection Associated with Travel to the British Virgin Islands.

Phylogenetic analysis of a clinical isolate associated with subclinical Burkholderia pseudomallei infection revealed probable exposure in the British Virgin Islands, where reported infections are limited. Clinicians should consider this geographic distribution when evaluating possible infection among persons with compatible travel history.

Examining social isolation and loneliness in combination in relation to social support and psychological distress using Canadian Longitudinal Study of Aging (CLSA) data.

BACKGROUND: Although a large body of research has focused on social isolation and loneliness, few studies have examined social isolation and loneliness together. The objectives of this study were to examine: 1) the relationship between four groups derived from combining social isolation and loneliness (socially isolated and lonely; only socially isolated; only lonely; neither socially isolated nor lonely) and the desire for more social participation, and social support; and 2) the relationship between the four groups and psychological distress. METHODS: The study was based on the Comprehensive Cohort of the Canadian Longitudinal Study on Aging. Using CLSA baseline data (unweighted N = 30,079), ordinary and logistic regression analysis was used to examine the cross-sectional relationship between the four social isolation/loneliness groups and desire for more social participation and four types of social support (tangible, positive interaction, affection, and emotional support). Prospective logistic regression analysis was possible for psychological distress, which was derived from the Maintaining Contact Questionnaire administered about 18 months after the baseline questionnaire (unweighted N = 28,789). RESULTS: Findings indicate that being socially isolated and lonely was associated with the most social support gaps; this group also had an increased likelihood of psychological distress, relative to those who were neither socially isolated nor lonely. Participants who were only socially isolated, and those only lonely also perceived some social support gaps. In addition, the only lonely group was more likely to be psychologically distressed than the only socially isolated group and the neither isolated nor lonely group. CONCLUSION: Examining the four social isolation/loneliness was useful, as it provided more nuanced risk profiles than would have been possible had we examined social isolation and loneliness separately. Findings may suggest avenues for interventions tailored to the unique needs of at-risk individuals.

Spatially Consistent High-Resolution Land Surface Temperature Mosaics for Thermophysical Mapping of the Mojave Desert.

Daytime and nighttime thermal infrared observations acquired by the ASTER and MODIS instruments onboard the NASA Terra spacecraft have produced a dataset that can be used to map thermophysical properties across large regions, which have implications on surface processes, thermal environments and habitat suitability for desert species. ASTER scenes acquired between 2004 and 2012 are combined using new mosaicking and data-fusion techniques to produce a map of daytime and nighttime land surface temperature with coverage exclusive of the effects of clouds and weather. These data are combined with Landsat 7 visible imagery to generate a consistent map of apparent thermal inertia (ATI), which is related to the presence of exposed bedrock, rocks, fine-grained sediments and water on the surface. The resulting datasets are compared to known geomorphic units and surface types to generate an interpreted mechanical composition map of the entire Mojave Desert at 100 m per pixel that is most sensitive to large clast size distinctions in grain size distribution.

Examining individual and geographic factors associated with social isolation and loneliness using Canadian Longitudinal Study on Aging (CLSA) data.

BACKGROUND: A large body of research shows that social isolation and loneliness have detrimental health consequences. Identifying individuals at risk of social isolation or loneliness is, therefore, important. The objective of this study was to examine personal (e.g., sex, income) and geographic (rural/urban and sociodemographic) factors and their association with social isolation and loneliness in a national sample of Canadians aged 45 to 85 years. METHODS: The study involved cross-sectional analyses of baseline data from the Canadian Longitudinal Study on Aging that were linked to 2016 census data at the Forward Sortation Area (FSA) level. Multilevel logistic regression analyses were conducted to examine the association between personal factors and geographic factors and social isolation and loneliness for the total sample, and women and men, respectively. RESULTS: The prevalence of social isolation and loneliness was 5.1% and 10.2%, respectively, but varied substantially across personal characteristics. Personal characteristics (age, sex, education, income, functional impairment, chronic diseases) were significantly related to both social isolation and loneliness, although some differences emerged in the direction of the relationships for the two measures. Associations also differed somewhat for women versus men. Associations between some geographic factors emerged for social isolation, but not loneliness. Living in an urban core was related to increased odds of social isolation, an effect that was no longer significant when FSA-level factors were controlled for. FSAs with a higher percentage of 65+ year old residents with low income were consistently associated with higher odds of social isolation. CONCLUSION: The findings indicate that socially isolated individuals are, to some extent, clustered into areas with a high proportion of low-income older adults, suggesting that support and resources could be targeted at these areas. For loneliness, the focus may be less on where people live, but rather on personal characteristics that place individuals at risk.

Assessing Communities' Age-Friendliness: How Congruent Are Subjective Versus Objective Assessments?

The notion of age-friendliness is gaining increasing attention from policy makers and researchers. In this study, we examine the congruence between two types of age-friendly surveys: subjective assessments by community residents versus objective assessments by municipal officials. The study was based on data from 39 mostly rural communities in Manitoba, Canada, in which a municipal official and residents (M= 25 residents per community) completed a survey to assess age-friendly features in a range of domains, such as transportation and housing. Congruence between the two surveys was generally good, although the municipal official survey consistently overestimated communities' age-friendliness, relative to residents' ratings. The findings suggest that a survey completed by municipal officials can provide a reasonable assessment of age-friendliness that may be useful for certain purposes, such as cross-community comparisons. However, some caution is warranted when using only these surveys for community development, as they may not adequately reflect residents' views.

How Important Is Having Amenities Within Walking Distance to Middle-Aged and Older Adults, and Does the Perceived Importance Relate to Walking?

OBJECTIVE: This study examined how important walking to amenities (e.g., food store, park) is to middle-aged and older adults and whether this relates to walking. The relationship between walking to amenities and overall activity level was also explored. METHOD: The study was based on interviews conducted with 778 individuals aged 45 to 94 years. Overall activity level was measured objectively using pedometers. RESULTS: A large proportion of participants did not think it was very important to have amenities within walking distance, and the majority of participants drove to get there, even among individuals who reported it was very important to have the amenities within walking distance. Self-reported walking to certain amenities (e.g., park) was associated with overall activity. DISCUSSION: The study underscores the impact of a car culture where the tendency to drive is paramount. It suggests the need to promote the importance of walking as part of an active, healthy lifestyle.

Examining the relationship between communities' 'age-friendliness' and life satisfaction and self-perceived health in rural Manitoba, Canada.

INTRODUCTION: Population aging is a worldwide phenomenon. As a response, the World Health Organization (WHO) introduced the concept of 'age-friendliness' in 2006. Age-friendliness is defined in terms of a range of domains, such as housing, opportunities for participation, and transportation. Communities that accommodate the needs of older adults in these domains will, it is thought, promote healthy, active aging. The purpose of the present study was to examine communities' age-friendliness and its relationship to health-related outcomes in a rural context. METHODS: The study included 29 communities located in Manitoba, a mid-Western Canadian province, that are part of the Province of Manitoba's Age-Friendly Manitoba Initiative. As part of a needs assessment process in these communities, 593 individuals, including seniors and younger adults, completed an Age-Friendly Survey. The survey was designed to measure a variety of features in seven domains (the physical environment, housing options, the social environment, opportunities for participation, community supports and healthcare services, transportation options, and communication and information), as well as containing measures of life satisfaction and self-perceived health. Community characteristics were derived from census data. Moreover, communities were categorized on a rural-urban continuum. RESULTS: Multi-level regressions indicated that an overall Age-Friendly Index was positively related to both life satisfaction (b=0.019, p<0.0001) and self-perceived health (b=0.013, p<0.01). When examining more specifically each of the seven age-friendly domains, all but housing was positively related to life satisfaction. Results were not as consistent for self-perceived health, with significant relationships emerging only for the physical environment, social environment, opportunities for participation, and transportation options. A subsequent analysis for seniors versus younger participants, respectively, indicated that significant relationships between age-friendly domains and life satisfaction and self-perceived health were restricted primarily to seniors. None of the community characteristics were related to life satisfaction and self-perceived health, nor was degree of rurality. CONCLUSIONS: The concept of age-friendliness has been garnering considerable attention from policy-makers as a way to promote healthy aging. For example, in Canada, several provinces have launched age-friendly initiatives. Although causality cannot be inferred from the present, cross-sectional study, the findings are encouraging as they show that age-friendliness is associated with enhanced life satisfaction and self-perceived health in a rural context. The study further supports the notion that a wide range of domains within the community environment are important in older adults' lives and need to be considered. Public policy initiatives, such as the Province of Manitoba's Age-Friendly Initiative, may thus be one approach to enhancing healthy aging in rural settings.

In-region versus out-of-region hospitalizations at the end of life among older rural residents: the relationship between personal and system-related factors.

BACKGROUND: Even though a large segment of the population lives in rural areas, relatively little attention has been paid in the literature to date to hospital use at the end of life among rural residents. The objective of this study was to examine factors associated with in- or out-of-region hospitalizations at the end of life among older rural residents. METHODS: The study included all community-dwelling adults aged 65 or older living in rural regions of a mid-Western Canadian province who had died in fiscal years 2003-04 to 2005-06, as determined from Vital Statistics data (N = 5,550). Complete hospital discharge abstract data were used to identify in- or out-of-region hospitalizations in the last 6 months before death and on the day of death. The type of out-of-region hospitals older adults were admitted to was also examined (urban tertiary hospital, urban community hospital, and rural hospital). RESULTS: Twenty percent of hospitalizations and 21% of hospital deaths occurred in a hospital that was out of older adults' region of residence. Compared with decedents aged 65-74, those aged 75-84 and even more so those aged 85+ had reduced odds of being hospitalized out of region or dying in an out-of-region hospital. Those 85+ years old also had reduced odds of being hospitalized in a (out-of-region) tertiary hospital. Higher hospital bed rates and physician rates were associated with reduced odds of out-of-region hospitalization and hospital death. CONCLUSION: Efforts should focus on recruiting physicians to those rural areas with low physician rates, as well as finding mechanisms to retain physicians in those rural regions.

Salmonella typhimurium infections associated with peanut products.

BACKGROUND: Contaminated food ingredients can affect multiple products, each distributed through various channels and consumed in multiple settings. Beginning in November 2008, we investigated a nationwide outbreak of salmonella infections. METHODS: A case was defined as laboratory-confirmed infection with the outbreak strain of Salmonella Typhimurium occurring between September 1, 2008, and April 20, 2009. We conducted two case-control studies, product "trace-back," and environmental investigations. RESULTS: Among 714 case patients identified in 46 states, 166 (23%) were hospitalized and 9 (1%) died. In study 1, illness was associated with eating any peanut butter (matched odds ratio, 2.5; 95% confidence interval [CI], 1.3 to 5.3), peanut butter-containing products (matched odds ratio, 2.2; 95% CI, 1.1 to 4.7), and frozen chicken products (matched odds ratio, 4.6; 95% CI, 1.7 to 14.7). Investigations of focal clusters and single cases associated with nine institutions identified a single institutional brand of peanut butter (here called brand X) distributed to all facilities. In study 2, illness was associated with eating peanut butter outside the home (matched odds ratio, 3.9; 95% CI, 1.6 to 10.0) and two brands of peanut butter crackers (brand A: matched odds ratio, 17.2; 95% CI, 6.9 to 51.5; brand B: matched odds ratio, 3.6; 95% CI, 1.3 to 9.8). Both cracker brands were made from brand X peanut paste. The outbreak strain was isolated from brand X peanut butter, brand A crackers, and 15 other products. A total of 3918 peanut butter-containing products were recalled between January 10 and April 29, 2009. CONCLUSIONS: Contaminated peanut butter and peanut products caused a nationwide salmonellosis outbreak. Ingredient-driven outbreaks are challenging to detect and may lead to widespread contamination of numerous food products.

Does the relationship between neighborhood socioeconomic status and health outcomes persist into very old age? A population-based study.

OBJECTIVE: The purpose of this article is (a) to extend previous research on the relationship between neighborhood socioeconomic status (SES) and health by considering a wide range of health-related measures derived from administrative health care records and (b) to explore whether this relationship persists into old age. METHOD: The study involved a complete cohort of community-dwelling residents in Winnipeg, Canada, who were 65 years or older in 2004/2005 (N = 77,930). Health measures were derived from administrative claims data. Census data were used to derive neighborhood-level SES. RESULTS: Multilevel logistic regressions indicated that, relative to individuals living in the most affluent areas, those in the poorest areas had significantly higher odds of having arthritis, diabetes, hypertension, congestive heart failure, ischemic heart disease, chronic obstructive pulmonary disease, depression, and stroke. Significant neighborhood income effects tended to be evident among individuals age 65 to 75 as well as those age 75+. DISCUSSION: A wide range of health conditions among older adults are disproportionately clustered into the poorest areas. Programs and services should be designed to meet the needs of older adults of any age in such neighborhoods.

Transfers to acute care hospitals at the end of life: do rural/remote regions differ from urban regions?

INTRODUCTION: In population-based studies, transfers into hospitals and hospital deaths are typically considered to be indicators of potentially inappropriate care settings at the end of life. Despite a plethora of research into where people die, few studies have examined whether hospital transfers at the end of life differ in rural versus urban areas. In the present study hospitalizations in the last month before death in one mid-Western Canadian province were examined. The study had three main objectives, to: (1) compare hospitalizations in rural/remote with urban regions; (2) examine the role of healthcare resources in hospitalizations; and (3) explore more specifically whether day-to-day patterns of hospitalization shortly before death differ between rural/remote and urban areas. METHODS: The source of data was administrative healthcare records, with the study including all adults (aged over 19 years; excluding nursing home residents) who died in the province of Manitoba in 2003-2004 (n = 6523). Whether the decedents were hospitalized in the 30 days before death was determined from hospital files. The number of hospital days incurred was counted. Region of residence was defined along regional health authority boundaries, with 7 regions identified as rural/remote and 2 as urban. Healthcare resources were measured in terms of the number of: physicians, hospital beds, nursing home beds, and home care services per 1000 population. Age, sex and trajectory groups, which categorized decedents according to their cause of death, were included in all analyses. RESULTS: Residents of 4 of the 7 rural/remote regions had increased odds of being hospitalized relative to the comparison, the larger urban region (adjusted odds ratios [AOR] ranged from 1.25 to 1.70). Hospital days did not differ across regions. Further analyses showed that having more physicians (AOR = .75) and more hospital beds per 1000 population (AOR = .95) both significantly reduced the odds of being hospitalized. Nursing home beds and home care services were not related to hospitalizations. Growth curve models indicated that daily patterns of hospitalizations generally did not differ across rural/remote versus urban regions. CONCLUSION: The findings suggest that residents of some rural/remote regions were at a disadvantage in terms of access to an appropriate care setting at the end of life. The regional variation in hospitalization can, at least in part, be attributed to the availability of healthcare resources, specifically the number of physicians and hospital beds (per 1000 population). However, the variation that emerged across regions also suggests that conclusions should not be over-generalized to all rural/remote regions; rather, local differences in healthcare resources should be considered when examining healthcare usage at the end of life.

Hospitalizations at the end of life among long-term care residents.

BACKGROUND: Concerns have been raised over transfers into acute care hospitals at the end of life. The objective of this study was to examine (a) the extent of and (b) factors related to hospitalization in the last 180 days before death among long-term care (LTC) residents. METHODS: The study included all LTC residents from 60 facilities in the province of Manitoba, Canada, who died in 2003/04 (N = 2,379), with data derived from administrative health care records. Multilevel regression analyses were conducted to examine the relationship between resident and facility characteristics and the following: location of death (in hospital vs the LTC facility); whether individuals were hospitalized in the last 180 days before death; and number of hospital days in the last 180 days. RESULTS: Overall, 19.1% of LTC residents died in hospital; however, 40.7% were hospitalized at least once in the last 6 months before death. Several resident characteristics (age, trajectory group, and level of care) were related to the outcome measures. Living in a not-for-profit LTC facility decreased the odds of dying in hospital (adjusted odds ratio [OR] = 0.589; 95% confidence interval [CI] = 0.402-0.863) or being hospitalized (adjusted OR = 0.647; 95% CI = 0.452-0.926). CONCLUSIONS: Hospitalization at the end of life is common among LTC residents, and the likelihood of hospital transfers is increased for residents who are younger, have organ failure, lower care level needs, as well as among those who live in for-profit facilities. Particular emphasis should, therefore, be placed on targeting these groups to determine the appropriateness of hospital admission and possible ways of reducing transfers.

Creutzfeldt-Jakob disease in recipients of corneal transplants.

PURPOSE: Creutzfeldt-Jakob disease (CJD) transmission has been documented to occur from the use of corneal grafts. We report 4 cases of CJD with a history of corneal transplantation and assess the frequency of coincidental CJD among corneal transplant recipients. METHODS: Medical records and eye bank documents were reviewed. Genetic and neuropathologic tests on available specimens were performed at the National Prion Disease Pathology Surveillance Center. Statistical analyses were used to determine the expected number of coincidental CJD cases among the US population with a history of corneal transplantation. RESULTS: Four CJD decedents with histories of corneal transplantation were identified: 3 from the United States and 1 from Japan. The time from transplant to onset of CJD symptoms ranged from 2 years, 11 months to 18 years. Available eye bank records did not suggest evidence of neurologic illness in the donors. Using corneal transplantation and CJD death data from 1990 through 2006, statistical analyses suggest that a case of coincidental sporadic CJD will occur among the population of corneal transplant recipients approximately every 1.5 years. CONCLUSIONS: It is likely that these 4 recipients of transplanted corneas had sporadic CJD. Because of the many corneal transplantations performed each year in the United States, occasional cases of sporadic CJD in this population are expected.

Health care use at the end of life among older adults: does it vary by age?

BACKGROUND: Issues around end-of-life health care have attracted increasing attention in the last decade. One question that has arisen is whether very elderly individuals receive overly aggressive treatment at the end of life. The purpose of this study was to address this issue by examining whether health care use at the end life varies by age. METHODS: The study included all adults 65 years old or older who died in Manitoba, Canada in 2000 (N = 7678). Measures were derived from administrative data files and included location of death, hospitalizations, intensive care unit (ICU) admission, long-term care (LTC) use, physician visits, and prescription drug use in the last 30 days versus 180 days before death, respectively. RESULTS: Individuals 85 years old or older had increased odds of being in a LTC institution and also dying there than did individuals 65-74 years old. They had, correspondingly, lower odds of being hospitalized and being admitted to an ICU. Although some statistically significant age differences emerged for physician visits, the effects were small. Prescription drug use did not vary by age. CONCLUSIONS: These findings indicate that very elderly individuals tended to receive care within LTC settings, with care that might be considered aggressive declining with increasing age. However, health care use among all age groups was substantial. A critical issue that needs to be examined in future research is how to ensure quality end-of-life care in a variety of clinical contexts and care settings for individuals of all ages.

An outbreak of Escherichia coli O157 infection following exposure to a contaminated building.

CONTEXT: Infection with Escherichia coli O157 causes an estimated 70 000 diarrheal illnesses per year in the United States and can result in hemolytic-uremic syndrome and death. Environmental contamination with E coli O157 may be a public health problem. OBJECTIVES: To determine risk factors for E coli O157 infection during an outbreak investigation at a county fair and to evaluate environmental contamination as a possible cause of the outbreak. DESIGN, SETTING, AND PARTICIPANTS: Case-control study of 23 patients (median age, 15 years) and 53 age-matched controls who had attended the Lorain County, Ohio, fair between August 20 and August 26, 2001. Case-patients had laboratory-confirmed E coli O157 infection, hemolytic-uremic syndrome, or bloody diarrhea within 7 days of attending the fair; controls attended the fair and did not have diarrhea. MAIN OUTCOME MEASURES: Risk factors for infection and isolates of E coli O157 from environmental specimens. RESULTS: Six (26%) case-patients were hospitalized and 2 (9%) developed hemolytic-uremic syndrome. Case-patients were more likely than controls to have visited building A (a multipurpose community facility on the fairgrounds; matched odds ratio [MOR], 21.4 [95% confidence interval [CI], 2.7-170.7]). Among visitors to building A, illness was independently associated with attending a dance in the building (MOR, 7.5; 95% CI, 1.4-41.2), handling sawdust from the floor (MOR, 4.6; 95% CI, 1.1-20.0), or eating and/or drinking in the building (MOR, 4.5; 95% CI, 1.2-16.6). Twenty-four (44%) of 54 specimens collected from building A 6 weeks after the fair grew Shiga toxin-producing E coli O157. Isolates from sawdust, the rafters, and other surfaces were identical by molecular fingerprinting to patient isolates. Sawdust specimens collected 42 weeks after the fair also grew the same E coli O157 strain. CONCLUSIONS: Absence of evidence implicating specific food or beverage sources and the recovery of E coli O157 from the rafters suggest that airborne dispersion of bacteria contributed to the contamination. Because E coli O157 can survive in the environment for more than 10 months, humans may be at risk of infection long after an environment is initially contaminated.