Hospital-acquired listeriosis linked to a persistently contaminated milkshake machine.

One case of hospital-acquired listeriosis was linked to milkshakes produced in a commercial-grade shake freezer machine. This machine was found to be contaminated with a strain of Listeria monocytogenes epidemiologically and molecularly linked to a contaminated pasteurized, dairy-based ice cream product at the same hospital a year earlier, despite repeated cleaning and sanitizing. Healthcare facilities should be aware of the potential for prolonged Listeria contamination of food service equipment. In addition, healthcare providers should consider counselling persons who have an increased risk for Listeria infections regarding foods that have caused Listeria infections. The prevalence of persistent Listeria contamination of commercial-grade milkshake machines in healthcare facilities and the risk associated with serving dairy-based ice cream products to hospitalized patients at increased risk for invasive L. monocytogenes infections should be further evaluated.

Pre-school obesity is inversely associated with vegetable intake, grocery stores and outdoor play.

The study determined the association between body mass index (BMI) z score and fruit and vegetable intake, frequency and ratio of fast food outlets and grocery stores in concentric areas around the child's residence, outdoor play and total crime index. Data from 78 Louisiana pre-school children were analyzed using Pearson's correlation and multiple regression analysis. Parental-reported fruit intake was linearly associated with increased number of grocery store counts in concentric areas around the child's residence (P = 0.0406, P = 0.0281). Vegetable intake was inversely (P = 0.04) and the ratio of fast food outlets to grocery stores in a 2-mile concentric area around the child's residence was positively (P = 0.05) associated to BMI z score after applying Best Model regression analysis (F = 3.06, P = 0.0346). Children residing in neighbourhoods with greater access to fast foods and lower access to fruits and vegetables may be at higher risk for developing obesity during pre-school years.

Overweight and obesity among Grenadian adolescents: rural and urban differences in social determinants

OBJECTIVE: To examine the prevalence of overweight and obesity (OW/OB) among Grenadian adolescents and to determine associations with social determinants on urban and rural adolescents. DESIGN AND METHODS: A national sample of Form1 students (n = 689) aged 11 to 14 years, from all 23 secondary schools in Grenada were assessed as part of the Grenada School Nutrition Study (GSNS). Body Mass Index (BMI) was assessed using standard measures and standardized BMI percentile. Urban (n = 13) and rural (n = 10) schools were determined by location. Exposure to fast food outlets and shops which sold sugar sweetened beverages, candy, or highly processed foods was measured within a .75 km buffer surrounding each school and major transportation hub, between school and home. RESULTS: Overall, Grenadian adolescents had low rates of overweight (17.6%) and obesity (7.6%) compared to Grenadian adults. Girls, however, had nearly twice the rate of overweight compared to boys (i.e., 22.7% versus 12.2%). There were significant differences between rural and urban students for access to cars (40.7% versus 53.3%), computer access (61.6% versus 73.5%), and snacking after school (83.6% versus 90.5%) respectively. The rural school environment also had a lower mean density of snack shops (1.53 versus 3.39 shops/square km) and mean fast food outlet density (0 versus 1.17 outlets/square km). CONCLUSIONS: Grenadian adolescents demonstrate low rates of OW/OB compared to both Grenadian adults and their US counterparts. The low rates of OW/OB suggest Grenadian adolescents have not yet been affected by social determinants of the obesity epidemic.

Individual and school-level influences on moderate and vigorous physical activity in Grenada adolescents

OBJECTIVE: The effect of school level policies on the physical activity of Grenadian children had not been studied. The present study tested the hypothesis that schools with physical activity (PA)-promoting policies would positively impact student’s levels of moderate and vigorous physical activity in Grenada. DESIGN AND METHODS: Multilevel analysis of a nationally representative sample of first year students (i.e. Form 1) (n = 138) from the twenty-three secondary schools in Grenada were assessed as part of the Grenada School Nutrition Study (GSNS). At the individual level physical activity was measured using Actigraph GT3X accelerometers. In addition to socio-demographic measures, height, weight and waist circumference (WC) were collected using standard anthropometric procedures. School-level measures were self-reported by school administrators. The school PA policy index included: student to teacher ratio in physical education (PE) classes, minutes of PE per week, number of PE facilities/equipment, having at least one policy to address PE participation, having ≥1 policy for access to sports teams or activities, having a school board or council to address PE policies. RESULTS: No school-level variables were significantly related to student Moderate and Vigorous Physical Activity (MVPA). Waist circumference was the only variable that significantly predicted MVPA in both boys (p=0.03) and girls (p=0.005). In girls, overweight/obesity was significantly associated with decreased MVPA (p=0.004). CONCLUSIONS: Contrary to findings in United States children, Grenada school-level policies and environments were not related to student’s physical activity levels. Further research was needed to understand the variation in physical activity levels by schools in both male and female Grenada students.

Inverse correlation of serum inflammatory markers with metabolic parameters in healthy, Black and White prepubertal youth.

OBJECTIVE: To examine for the first time the associations between pro-inflammatory cytokines and obesity-related metabolic biomarkers in, exclusively prepubertal, otherwise healthy obese and non-obese Black and White children, 7-9 years of age. DESIGN AND METHODS: Body mass index (BMI), homeostasis model assessment-estimated insulin resistance, visceral adipose tissue and subcutaneous adipose tissue (SAT (magnetic resonance imaging)); total body fat (dual-energy X-ray absorptiometry), ectopic, intrahepatic lipid (IHL) and intramyocellular lipid (IMCL) fat (proton magnetic resonance spectroscopy) and serum levels of interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor alpha (TNF-α) and monocyte chemoattractant protein-1 were measured in 40 obese and non-obese children. Relationships between inflammatory cytokines and obesity were assessed by analysis of variance and Spearman's rank correlation. RESULTS: Significant inverse correlations were found between BMI z-score, SAT, total BF, and IHL and levels of TNF-α (Spearman's ρ=-0.36, -0.39, -0.43 and -0.39, respectively; P<0.05). Levels of IL-8 were significantly and inversely correlated with IMCL (-0.39; P=0.03) and remained significant after adjusting for race. IMCL was inversely associated with TNF-α only after adjusting for race (-0.37; P=0.04). CONCLUSIONS: Relationships between pro-inflammatory and metabolic markers commonly observed in adults are reversed in healthy, Black and White children before puberty. Prospective studies are warranted to determine how these inverse relationships modify chronic disease risk later in life.

An ex vivo biomechanical evaluation of an inflatable bone tamp used in the treatment of compression fracture.

STUDY DESIGN: Ex vivo biomechanical study using osteoporotic cadaveric vertebral bodies. OBJECTIVES: To determine if the inflatable bone tamp (tamp) restores height to compressed vertebral bodies and to compare the biomechanical properties of isolated, fractured osteoporotic vertebral bodies treated by kyphoplasty (tamp) or vertebroplasty. SUMMARY OF BACKGROUND DATA: Previous biomechanical studies have shown that vertebroplasty increases vertebral body strength and restores vertebral body stiffness, but does not restore vertebral body height lost as a result of compression fracture. METHODS: Compression fractures were experimentally created in 16 osteoporotic VBs assigned to either the tamp or percutaneous vertebroplasty group. The tamp treatment consisted of inserting balloon-like devices into the vertebral body, inflating the bone tamp, and filling the void with Simplex P (Howmedica, Rutherford, NJ) bone cement. The percutaneous vertebroplasty treatment consisted of directly injecting Cranioplastic bone cement (CMW, Blackpool, UK) into the vertebral body. Pre- and posttreatment heights were measured, and the repaired vertebral bodies were recompressed to determine posttreatment strength and stiffness values. RESULTS: The tamp treatment resulted in significant restoration (97%) of vertebral body height lost after compression, whereas percutaneous vertebroplasty treatment resulted in a significantly lower restoration of lost height (30%) (P < 0.05). Both treatments resulted in significantly stronger vertebral bodies relative to their initial state (P < 0.05). The tamp treatment restored vertebral body stiffness to initial values, but the percutaneous vertebroplasty treatment did not (P < 0.05). CONCLUSIONS: Tamp treatment resulted in significantly greater height restoration than did percutaneous vertebroplasty, without loss of vertebral body strength or stiffness.

Evidence of a structural effect for alcohol outlet density: a multilevel analysis.

BACKGROUND: Ecological studies reveal that alcohol-related outcomes tend to occur in high alcohol outlet density neighborhoods. The ecological design of these studies limits the interpretation of the findings in terms of the level of the effect. The effect of alcohol outlet density could be related to greater individual access to alcohol, an individual level effect, or to the grouping of drinkers by neighborhood, a structural effect at the neighborhood level. METHODS: To differentiate between individual and neighborhood level possibilities, we conducted a multilevel study. Individual distance to the closest alcohol outlet was the individual level measure of the effect of alcohol outlet density, whereas the mean distance to the closest alcohol outlet for all individuals within a census tract was the neighborhood level measure for the effect of alcohol outlet density. We analyzed telephone surveys of 2604 telephone households within 24 census tracts stratified by poverty status and alcohol outlet density. Individual distance to alcohol outlets, age, sex, race/ethnicity, and level of education were entered as individual level covariates, and their corresponding aggregated means were entered as census tract level covariates (i.e., mean distance to outlets, mean age, percentage male, percentage Black, mean education). RESULTS: Analysis of variance revealed that 16.2% of the variance in drinking norms and 11.5% of the variance in alcohol consumption were accounted for at the census tract level. In multivariate hierarchical analysis, individual distance to the closest alcohol outlet was unrelated with drinking norms and alcohol consumption, whereas mean distance to the closest alcohol outlet demonstrated a negative relation with drinking norms (betae = -5.50+/-2.37) and with alcohol consumption (betae = -0.477+/-0.195); that is, the higher the mean distance to the closest alcohol outlet, the lower the mean drinking norms score and mean level of alcohol consumption. CONCLUSIONS: The findings suggest that the effect of alcohol outlet density on alcohol-related outcomes functions through an effect at the neighborhood level rather than at the individual level. Problem drinkers tend to be grouped in neighborhoods, an effect predicted by alcohol outlet density.

Effect of augmentation on the mechanics of vertebral wedge fractures.

STUDY DESIGN: The effect of cement augmentation of wedge-fractured vertebral bodies on spine segment compliance was studied in 16 cadaver specimens. OBJECTIVES: 1) To assess the mechanical effects of cement augmentation of vertebral wedge fractures. 2) To determine whether a new reduction/injection procedure has the same mechanical effects as the established direct injection procedure. SUMMARY OF BACKGROUND DATA: Although wedge fractures cause pain and disability in hundreds of thousands of people, few effective treatments are available. Clinical studies have shown that cement augmentation, a new procedure, effectively relieves pain and restores mobility in patients suffering from weak or fractured vertebrae. However, only a few studies have examined the mechanics of vertebral augmentation. METHODS: A wedge fracture was created in the middle vertebra of 16 three-vertebra cadaver spine segments. Neutral and full-load compliance of each fractured spine segment in flexion/extension and lateral bending were assessed by measuring the relative rotation of the vertebral bodies in response to applied moments. Eight of the fractured vertebral bodies were then augmented using direct injection, while the remaining eight fractured vertebral bodies were augmented using a combined reduction/injection procedure. Compliance of the augmented segments was then assessed. RESULTS: Augmentation significantly reduced the neutral compliance (reduction of 25% +/- 23%) (mean +/- standard deviation) and the full-load compliance (reduction of 23% +/- 20%) in flexion/extension (P < 0.005). Augmentation also significantly reduced the neutral compliance (reduction of 34% +/- 20%) and the full-load compliance (reduction of 26% +/- 17%) in lateral bending (P < 0.0001). No significant difference was found between the two procedures for compliance reduction. CONCLUSIONS: Augmentation of wedge fractures using both direct injection and reduction/injection reduces spine segment compliance significantly.

A structural model of health behavior: a pragmatic approach to explain and influence health behaviors at the population level.

BACKGROUND: Behavior is influenced by individual-level attributes as well as by the conditions under which people live. Altering policies, practices, and the conditions of life can directly and indirectly influence individual behavior. This paper builds on existing ecological theories of health behavior by specifying structural mechanisms by which population-level factors effect change in individual health behaviors. METHODS: This paper moves ecological theory from model building to a pragmatic characterization of structural interventions. We examined social and environmental factors beyond individual control and mechanisms as to how they influence behavior. RESULTS: Four categories of structural factors are identified: (1) availability of protective or harmful consumer products, (2) physical structures (or physical characteristics of products), (3) social structures and policies, and (4) media and cultural messages. The first three can directly influence individuals through facilitating or constraining behavior. The fourth, media, operates by changing individual-level attitudes, beliefs, and cognitions, as well as group norms. CONCLUSION: Interventions that target the four identified structural factors are a means to provide conditions that not only reduce high-risk behavior but also prevent the adoption of high-risk behaviors. Structural interventions are important and underutilized approaches for improving our nation's health.

"Broken windows" and the risk of gonorrhea.

OBJECTIVES: We examined the relationships between neighborhood conditions and gonorrhea. METHODS: We assessed 55 block groups by rating housing and street conditions. We mapped all cases of gonorrhea between 1994 and 1996 and calculated aggregated case rates by block group. We obtained public school inspection reports and assigned findings to the block groups served by the neighborhood schools. A "broken windows" index measured housing quality, abandoned cars, graffiti, trash, and public school deterioration. Using data from the 1990 census and 1995 updates, we determined the association between "broken windows," demographic characteristics, and gonorrhea rates. RESULTS: The broken windows index explained more of the variance in gonorrhea rates than did a poverty index measuring income, unemployment, and low education. In high-poverty neighborhoods, block groups with high broken windows scores had significantly higher gonorrhea rates than block groups with low broken windows scores (46.6 per 1000 vs 25.8 per 1000; P < .001). CONCLUSIONS: The robust association of deteriorated physical conditions of local neighborhoods with gonorrhea rates, independent of poverty, merits an intervention trial to test whether the environment has a causal role in influencing high-risk sexual behaviors.

An STD/HIV prevention intervention framework.

Historically, interventions to prevent STD/HIV transmission have been categorized by program methodology rather than defining the content and nature of the intervention. A new taxonomy is needed to help expand the scope of interventions that can be used to prevent STD and HIV transmission. The taxonomy defines two major types of interventions, individual-level and structural level. The former targets risk factors attributable to individuals. Structural interventions target conditions outside the control of the individual. Individual-level interventions focus on counseling, screening, and treatment. They include psychological and biological interventions. Structural-level interventions address accessibility of relevant consumer products (condoms, needles), physical structures (e.g. blighted and abandoned housing, lighting, design of social facilities), social structures (policies that facilitate or constrain behaviors such as supervision of youth, and enforcement of alcohol beverage laws); and media messages (messages and images in the broadcast and print media that portray high-risk behaviors as positive and without serious consequences). A new taxonomy not only clarifies the content of preventive interventions but highlights neglected strategies involving individual biological interventions and structural interventions to prevent STD/HIV transmission.

Alcohol availability and homicide in New Orleans: conceptual considerations for small area analysis of the effect of alcohol outlet density.

OBJECTIVE: To determine the geographic relation between homicide rate and two competing measures of exposure to alcohol outlets, alcohol outlets per square mile and alcohol outlets per person. METHOD: Homicides occurring in 1994 and 1995 and on-sale and off-sale alcohol outlets with active 1995 licenses were geocoded by address for aggregation at the census tract level. Ecologic analysis of the 155 urban residential census tracts in New Orleans was conducted with controls for potential sociodemographic confounders (% black, % adults unemployed, % unmarried households, and ratio males 15-24/males 35-44). RESULTS: After logarithmic transformation of all study variables, sociodemographic confounders alone accounted for 58% (R2 = .58) of the variance of homicide rates. Adding off-sale alcohol outlet density to the models, measured (beta +/- SE) either as outlets per square mile (beta = .211 +/- .062) or outlets per person (beta = .244 +/- .063), yielded strong geographic relations with homicide and increased the amount of variance explained (R2 = .62). A 10% higher off-sale outlet density accounted for a 2.4% higher homicide rate. CONCLUSIONS: Both off-sale alcohol outlets per square mile and off-sale outlets per person demonstrate strong geographic associations with homicide rates among urban residential census tracts in New Orleans. These findings suggest that communities faced with high rates of assaultive violence might consider policy interventions that address alcohol outlet related factors.

Cost as a barrier to condom use: the evidence for condom subsidies in the United States.

OBJECTIVES: This study sought to determine the impact of price on condom use. METHODS: A program based on distribution of condoms at no charge was replaced with one providing low-cost condoms (25 cents). Pretest and posttest surveys asked about condom use among persons reporting 2 or more sex partners. RESULTS: At pretest, 57% of respondents had obtained free condoms, and 77% had used a condom during their most recent sexual encounter. When the price was raised to 25 cents, the respective percentages decreased to 30% and 64%. CONCLUSIONS: Cost is a barrier to condom use. Free condoms should be distributed to encourage their use by persons at risk for HIV and other sexually transmitted diseases.

Implementation of condom social marketing in Louisiana, 1993 to 1996.

OBJECTIVES: This article describes the implementation and impact of the first statewide condom social marketing intervention in the United States. METHODS: A statewide social marketing program made condoms freely available in 93 public health clinics, 39 community mental health centers, 29 substance abuse treatment sites, and more than 1000 businesses in neighborhoods with high rates of sexually transmitted diseases (STDs) and HIV. Surveys about condom use were conducted annually. RESULTS: Between 1994 and 1996, more than 33 million condoms were distributed without significant opposition. Over time, self-reported condom use at the last sexual encounter increased among African American women (from 28% in 1994 to 36% in 1996), particularly African American women with 2 or more sex partners (from 30% to 48%). Condom use at the last sexual encounter increased among African American men (from 40% in 1994 to an average of 54% in 1996). The number of reported sex partners did not increase. CONCLUSIONS: Condom social marketing can be successfully implemented in the United States. The widespread availability of free condoms is associated with increased condom use, particularly among persons at high risk for STDs and HIV.

A geographic relation between alcohol availability and gonorrhea rates.

BACKGROUND AND OBJECTIVES: The availability of alcohol measured as alcohol outlet density is associated with numerous alcohol-related outcomes in small area analysis. A number of studies suggest that high-risk sexual behavior should also be considered an alcohol-related outcome. GOAL OF THIS STUDY: To assess the geographic relationship between alcohol availability and high-risk sexual behavior at the neighborhood level. STUDY DESIGN: Ecological analysis of the geographic relation between off-premise, on-premise, and total alcohol outlet density and reported gonorrhea rates among 155 urban residential census tracts in New Orleans during 1995. RESULTS: All alcohol outlet density variables were positively related to gonorrhea rates. Off-premise outlets per square mile was most strongly related to gonorrhea rates (beta +/- SE) (beta = 0.582+/-0.073), accounting for 29% of the variance in gonorrhea rates. Interpreted as an elasticity, a 10% increase in off-sale alcohol outlet density accounts for a 5.8% increase in gonorrhea rates. Including the covariates percent black and percent unemployed to the model reduced but did not remove the effect of off-sale outlet density (beta = 0.192+/-0.047). CONCLUSIONS: These results indicate there is a geographic relationship between alcohol outlet density and gonorrhea rates at the census tract level. Although these results cannot be interpreted causally, they do justify a public health intervention as a next step in defining the relation between alcohol availability and high-risk sexual behavior.

Dietary calcium, calcium supplementation, and blood pressure in African American adolescents.

BACKGROUND: Intake of calcium from the diet is inversely associated with blood pressure in observational studies and animal models but randomized trials in humans have found only small effects of calcium supplementation on blood pressure. A blood pressure-lowering effect of calcium supplementation may thus be restricted to persons with a low intake of calcium from the diet and specific genetic or other characteristics. OBJECTIVE: A randomized trial was conducted to assess the effect of calcium supplementation on blood pressure in African American adolescents. Rapid growth during adolescence may increase calcium requirements, and avoidance of milk and milk products by some African Americans can result in low intake of calcium. DESIGN: One hundred sixteen adolescents (65 girls, 51 boys; mean age: 15.8 y) were given calcium (1.5 g/d) or placebo for 8 wk in a randomized, double-blind, crossover design. Blood pressure was measured after 2, 4, and 8 wk. Dietary calcium was determined with a validated food-frequency questionnaire. RESULTS: The net effect (+/-SE) of calcium supplementation on diastolic blood pressure was a reduction of 1.9 +/- 1.1 mm Hg (P = 0.04, one-tailed t test). Blood pressure reduction was greater in adolescents with lower intake of calcium from the diet (P = 0.003, one-tailed t test for interaction): -4.9 +/- 1.6, -2.3 +/- 1.6, and 1.4 +/- 1.8 mm Hg for change in the lower (0.024-0.067 g Ca/MJ), middle (0.069-0.091 g Ca/MJ), and upper (0.093-0.217 g Ca/MJ) tertiles, respectively. No main effect on systolic blood pressure was detected. CONCLUSION: These findings suggest that calcium supplementation may lower diastolic blood pressure in African American adolescents with low dietary intakes of calcium.

Blood pressure and self-concept among African-American adolescents.

Differences in blood pressure among individuals of African ancestry living in the United States compared with those living in Africa suggest that the high prevalence of hypertension among African Americans may be due in part to environmental factors. There are a number of environmental models that attempt to account for the high rate of hypertension among African Americans. One model proposes that a strong African self-concept protects African-American adolescents from the hypertensive effects of social stress. This model was tested during a blood pressure survey of 333 adolescents in three urban Los Angeles high schools. African self-concept was assessed using a three-item scale. The average score for the three items was strongly related to systolic blood pressure among African-American male adolescents. After controlling for age, body mass index, and parent's education in regression analyses, the relation was reduced, but an effect remained. The model suggests that the hypertensive effects of the environment will operate unless the pathway from environmental stress to hypertension is blocked by a strong African-American self-concept.

The risk of assaultive violence and alcohol availability in Los Angeles County.

OBJECTIVES: Although there is considerable evidence that alcohol consumption facilitates assaultive violence, the extent to which alcohol outlets in a community influence assaultive violence remains controversial. METHODS: To assess the geographic association between city-specific rates of assaultive violence and alcohol-outlet density, an ecologic analysis of the 74 larger cities in Los Angeles County was conducted for the 1990 reporting year. RESULTS: Sociodemographic factors alone accounted for 70% (R2 = .70) of the variance in the rate of assaultive violence in a multiple regression model. Adding the variable for alcohol-outlet density to the model yielded a significant positive slope. The magnitude of this relation indicates that in a typical Los Angeles County city (50,000 residents, 100 outlets, 570 offenses per year), one outlet was associated with 3.4 additional assaultive violence offenses in 1990. CONCLUSIONS: These findings indicate that higher levels of alcohol-outlet density are geographically associated with higher rates of assaultive violence. This association is independent of measured confounders, including city-level measures of unemployment, ethnic/racial makeup, income, age structure, city size, household size, and female-headed households.