Housing and allergens: A pooled analysis of nine US studies

Background

Housing conditions can contribute to allergen exposures that are linked to asthma, but little is known about which of those conditions are most likely to predict high levels of allergens in settled house dust.

Methods

We pooled allergen, housing condition, occupant behavior, demographic, and other data from nine asthma studies (n=950 homes in 6 US cities). Dust mite (Der f 1 or Der p 1), cockroach (Bla g 1 or Bla g 2), mouse (Mus m 1), cat (Fel d 1) and dog (Can f 1) allergens were measured in settled dust from kitchens or bedrooms, and concentrations were categorized according to previously published asthma symptom thresholds. We calculated odds ratios (OR) using logistic regression to identify those housing conditions and occupant behaviors that were associated with clinically significant allergen levels, after adjusting for numerous confounding variables.

Results

The adjusted results show that high cockroach allergen was associated with cracks or holes in walls (OR=2.1), high dust mite allergen was associated with mold odor (OR=2.5), housing built before 1951 (OR=2.1), and single-family home with slab on grade (OR=1.9); and mouse allergen was associated with rodent control or signs of rodents (OR=3.62) and inversely associated with presence of a cat (OR=0.20). Water leaks and below average housekeeping had unadjusted high odds ratios for high cockroach allergen.

Conclusion

We have identified a number of housing conditions that are consistently associated with increased allergen dust concentrations. This study indicates that screening for housing-based asthma triggers should include presence of cats, dogs, cockroaches, or rodents; water leaks; mold or mold odor; holes or cracks in walls; and below average housekeeping. Single family houses that have basements or crawl spaces or are built before 1951are also important predictors for increased allergens in housing.     

In vitro Actinomyces israelii biofilm development on IUD copper surfaces

Background

Female pelvic actinomycosis may involve fallopian tubes, ovaries, uterus and bladder. This condition is often associated with the use of intrauterine contraceptive devices (IUDs), vaginal pessaries and/or tampons. The predominant causative agent of human actinomycosis is Actinomyces israelii, which has been found on copper IUDs retrieved from patients.

Study Design

In this work, a biofilm of A. israelii was developed in vitro on copper surfaces immersed in a simulated uterine fluid under anaerobic conditions. The biofilm was characterized using scanning electron microscopy (SEM), energy dispersive X-ray and atomic force microscopy.

Results

The capacity of A. israelii to develop a biofilm over copper surfaces in synthetic media was demonstrated. SEM micrographies illustrate the exopolysaccharides production and bacterial distribution.

Conclusion

A. israelii was able to attach and grow in synthetic intrauterine media and to present on the copper surface is likely due to the production of biofilm.     

Indoor allergens in settled dust from kindergartens in city of Łódź, Poland

Objectives

The main objective of the study was to determine the levels of house dust mite (Der p1), dog (Can f1), cat (Fel d1) and cockroach (Bla g2) allergens in kindergartens localized in an urban agglomeration.

Material and Methods

A quantitative analysis of allergens was carried out in settled dust samples collected by vacuuming the floor surface in three kindergartens (N = 84) and children’s clothing (N = 36). The samples were collected in spring-summer and autumn-winter periods as well as at the beginning and end of the week. The allergen dust concentration was determined by enzyme-linked immunoenzymatic assay (ELISA).

Results

The mean geometric concentrations (±geometric standard deviations) of allergens Der p1, Can f1, Fel d1 and Bla g2 determined in kindergartens were: 0.02±3.21 μg/g of dust; 0.97±4.49 μg/g of dust; 0.30±4.43 μg/g of dust and 0.01±3.08 μg/g of dust, respectively. Younger classrooms (children aged from 3 to 4 years) were characterized by almost twice higher mean concentration of allergen Fel d1, as compared to older classrooms (children aged from 5 to 6 years) (p < 0.05). A significant impact of seasonality on the level of dog allergen Can f1 was found (p < 0.05). No significant weekly variation was found in average concentrations of the allergens. Children who had a dog and/or cat at home were characterized by high concentrations of allergens Can f1 and Fel d1 on their clothes (59.2±5.39 μg Can f1/g of dust; 3.63±1.47 μg Fel d1/g of dust), significantly higher than concentrations of allergens in children who did not have any pets (p < 0.001).

Conclusions

Special attention should be paid to keeping the kindergarten rooms tidy and clean and to an appropriate choice of furnishings and fittings which would prevent the proliferation of the house dust mite and accumulation of allergens.     

Factorial trial found mixed evidence of effects of pre-notification and pleading on response to Web-based survey

Objectives

To evaluate the effectiveness of pre-notification and pleading invitations in Web surveys by embedding a randomized controlled trial (RCT) in a Web-based survey.

Study Design and Setting

E-mail addresses of 569 authors of published maternal health research were randomized in a 2×2 factorial trial of a pre-notification vs. no pre-notification e-mail and a pleading vs. a non-pleading invitation e-mail. The primary outcome was completed response rate, and the secondary outcome was submitted response rate (which included complete and partial responses).

Results

Pleading invitations resulted in 5.0% more completed questionnaires, although this difference did not reach statistical significance [odds ratio (OR) 1.23; 95% confidence interval (CI): 0.86, 1.74; P = 0.25]. Pre-notification did not increase the completion rate (OR 1.04; 95% CI 0.73, 1.48; P = 0.83). Response was higher among authors who had published in 2006 or later (OR 2.07; 95% CI: 1.43, 2.98; P = 0.001). There was some evidence that pre-notification was more effective in increasing submissions from authors with recent publications (P = 0.04).

Conclusion

The use of a “pleading” tone to e-mail invitations may increase response to a Web-based survey. Authors of recently published research are more likely to respond to a Web-based survey.     

Screen time and passive school travel as independent predictors of cardiorespiratory fitness in youth

Objective

The most prevalent sedentary behaviours in children and adolescents are engagement with small screen media (screen-time) and passive travel (by motorised vehicle). The objective of this research was to assess the independence of these behaviours from one another and from physical activity as predictors of cardiorespiratory fitness in youth.

Methods

We measured cardiorespiratory fitness in n = 6819 10-16 year olds (53% male) who self-reported their physical activity (7-day recall) school travel and screen time habits. Travel was classified as active (walking, cycling) or passive; screen time as < 2 h, 2-4 h or > 4 h.

Results

The multivariate odds of being fit were higher in active travel (Boys: OR 1.32, 95% CI: 1.09-1.59; Girls: OR 1.46, 1.15-1.84) than in passive travel groups. Boys reporting low screen time were more likely to be fit than those reporting > 4 h (OR 2.11, 95% CI: 1.68-2.63) as were girls (OR 1.66, 95% CI: 1.24-2.20). These odds remained significant after additionally controlling for physical activity.

Conclusion

Passive travel and high screen time are independently associated with poor cardiorespiratory fitness in youth, and this relationship is independent of physical activity levels. A lifestyle involving high screen time and habitual passive school travel appears incompatible with healthful levels of cardiorespiratory fitness in youth.     

Factors influencing uptake of influenza A (H1N1) vaccine amongst healthcare workers in a regional pediatric centre: lessons for improving vaccination rates

Background

Influenza A (H1N1) vaccination has been recommended for all frontline healthcare workers (HCWs) in the UK since October 2009, to protect individuals and their patients from infection. Understanding the factors influencing vaccine uptake by HCW may improve future vaccination programmes in current and subsequent years.

Aims

To assess the uptake of influenza A (H1N1) vaccine, and factors affecting vaccine uptake, in frontline healthcare workers in a large pediatric hospital.

Method

A cross-sectional questionnaire survey conducted in a regional Pediatric Hospital in Scotland incorporating intensive care and ECMO services. One page, anonymised questionnaires were distributed to all frontline HCW in high risk departments of the hospital.

Results

260 questionnaires were completed, capturing an estimated 52% of all staff. Vaccination rate was 49.6%, and was significantly higher amongst doctors (OR 2.4, 95% CI 1.3-4.5, P = 0.005). Commonest reasons for vaccine uptake were high risk of contact with H1N1 (88%) and responsibility to protect patients (71%). Uncertainty about vaccine side-effects (47%), concern about vaccine safety (33%) and being too busy to attend the vaccine clinic (22%) were the commonest reasons for non-vaccination. Reasons for vaccination varied between staff grouping and department. 36% of non-vaccinated staff would accept the vaccine if offered.

Conclusions

Vaccine uptake may be increased by addressing HCW knowledge and attitudes and access to vaccine. Future vaccination programmes should include targeted education and vaccine delivery, at the convenience of staff, and in their own department.     

Negative effects of serum p,p′-DDE on sperm parameters and modification by genetic polymorphisms

Objective

Effects of ambient exposure to DDT and its metabolites (DDE-DDT) on human sperm parameters and the role of genetic polymorphisms in modifying the association were investigated.

Methods

Demographics, medical history data, blood and semen samples were obtained from the first 336 male partners of couples presenting to 2 infertility clinics. Serum was analyzed for organochlorines (OC) and DNA for polymorphisms in GSTM1, GSTT1, GSTP1 and CYP1A1. Men with each sperm parameter considered low by WHO criteria (concentration <20 million/mL, motility <50%, morphology <4%) were compared to men with all normal sperm parameters in logistic regression models, controlling for sum of other OC pesticides.

Results

High DDE-DDT level was associated with significantly increased odds for all 3 low sperm parameters. The risk of low motility with high DDE-DDT exposure was increased in men with the GSTT1 null genotype compared to those with GSTT1 intact (odds ratio (OR)=4.19, 95% confidence interval (CI) 1.05-16.78 and OR=3.57, 1.43-8.93, respectively). Risk for low morphology in men with high DDE-DDT and one or both CYP1A1*2A alleles was lower compared to men with the common CYP1A1 alleles (OR=2.18, 0.78-6.07 vs. OR=3.45, 1.32-9.03, respectively). Similar results were obtained for men with low DDE-DDT exposure. Effects of high DDE-DDT on low sperm concentration (OR=2.53, 1.0-6.31) was unaffected by the presence of the polymorphisms.

Conclusion

High DDE-DDT exposure adversely affected all 3 sperm parameters and its effects were exacerbated by the GSTT1 null polymorphism and by the CYP1A1 common alleles.     

Malaria severity criteria and prognostic factors among children in Dakar

Introduction

Severity factors associated with malaria as well as prognostic factors for death were assessed at the Dakar Centre Hospitalier National d’Enfants Albert Royer de Fann (CHNEAR).

Patients and methods

A prospective study was carried out from January 1 to December 31, 2007 involving children from 0 to15 years of age, admitted for plasmodium falciparum malaria with positive thick drop examination, meeting at least one of the WHO 2000 malaria severity criteria. Acidosis was not studied.

Outcome

The rate of severe malaria cases in our hospital was 6.4%. The sex ratio was 1.4 and the median age of patients at 91 months. A peak was observed during the 4th trimester (75.5%). Convulsions (52.5%) and obtundation (49.4%) were the most common signs of clinical severity while hyperparasitemia and severe anemia ranged at 27.2% and 21.6%, respectively. Lethality was 11.1 % and the main death risk factors were young age (p = 0.025), coma (p = 0.007), respiratory distress (p = 0.04), or hypoglycemia (p = 0.001).

Conclusion

Reducing malaria hospital mortality in Senegal may be obtained by proper management of poor prognostic factors such as coma, respiratory distress, and hypoglycemia.     

In vitro activity of new antimicrobial agents against glycopeptide-resistant Enterococcus faecium clinical isolates from France between 2006 and 2008

Objective

The aim of this study was to determine the in vitro activity of six new antimicrobial agents against glycopeptide-resistant enterococci (GRE) strains from France.

Methods

Sixty epidemiologically unrelated clinical isolates of Enterococcus faecium (vanA or vanB), received at the National Reference Centre for Enterococci (CNR-Enc) between 2006 and 2008, were studied. The MICs of the following antibiotics were determined by broth microdilution according to Antibiogram Committee of the French Society for Microbiology (CA-SFM) guidelines: quinupristin-dalfopristin (Q-D), linezolid (LZD), daptomycin (DPT), tigecycline (TGC), ceftobiprole (CFT), and telavancin (TLV). Strains were classified using clinical breakpoints recommended by the CA-SFM (Q-D, LZD, TGC), or the Clinical and Laboratory Standards Institute (DPT).

Results

All strains were susceptible to LZD and DPT (MIC₉₀, 4 and 2 μg/ml, respectively) and only a single strain presented intermediate susceptibility to tigecycline (MIC₉₀, 0.25 μg/ml). Thirty percent of strains were resistant to Q-D (MIC₉₀, 4 μg/ml), and CFT was constantly inactive (MIC₉₀, 64 μg/ml). Finally, TLV showed low-level MICs (MIC₉₀, 0.5 μg/ml) against vanB-positive isolates but not against vanA-positive isolates (MIC₉₀, 8 μg/ml).

Conclusion

Although several antibiotics are still active against GRE, it is essential to maintain an active antimicrobial resistance surveillance for these microorganisms considered as a model of multidrug resistance with a potential to transfer resistance to other bacterial species (e.g. Staphylococcus aureus).     

Emerging and continuing trends in vaccine opposition website content

Context

Anti-vaccination websites appeal to persons searching the Internet for vaccine information that reinforces their predilection to avoid vaccination for themselves or their children. Few published studies have systematically examined these sites.

Objectives

The aim of this study was to employ content analysis as a useful tool for examining and comparing anti-vaccination websites for recurring and changing emphases in content, design, and credibility themes since earlier anti-vaccination website content analyses were conducted.

Methods

Between February and May 2010, using a commonly available search engine followed by a deep web search, 25 websites that contained anti-vaccination content were reviewed and analyzed for 24 content, 14 design, and 13 credibility attributes.

Results

Although several content claims remained similar to earlier analyses, two new themes emerged: (1) the 2009 H1N1 epidemic threat was “manufactured,” and (2) the increasing presence of so-called “expert” testimony in opposing vaccination.

Conclusion

Anti-vaccination websites are constantly changing in response to the trends in public health and the success of vaccination. Monitoring the changes can permit public health workers to mount programs more quickly to counter the opposition arguments. Additionally, opposition claims commonly appeal to emotions whereas the supporting claims appeal to reason. Effective vaccine support may be better served by including more emotionally compelling content.     

Hand-Held Indirect Calorimeter Offers Advantages Compared with Prediction Equations, in a Group of Overweight Women, to Determine Resting Energy Expenditures and Estimated Total Energy Expenditures during Research Screening

Objective

To compare standardized prediction equations to a hand-held indirect calorimeter in estimating resting energy and total energy requirements in overweight women.

Design

Resting energy expenditure (REE) was measured by hand-held indirect calorimeter and calculated by prediction equations Harris-Benedict, Mifflin-St Jeor, World Health Organization/Food and Agriculture Organization/United Nations University (WHO), and Dietary Reference Intakes (DRI). Physical activity level, assessed by questionnaire, was used to estimate total energy expenditure (TEE).

Subjects

Subjects (n=39) were female nonsmokers older than 25 years of age with body mass index more than 25.

Statistical analyses

Repeated measures analysis of variance, Bland-Altman plot, and fitted regression line of difference. A difference within ±10% of two methods indicated agreement.

Results

Significant proportional bias was present between hand-held indirect calorimeter and prediction equations for REE and TEE (P<0.01); prediction equations overestimated at lower values and underestimated at higher values. Mean differences (±standard error) for REE and TEE between hand-held indirect calorimeter and Harris-Benedict were −5.98±46.7 kcal/day (P=0.90) and 21.40±75.7 kcal/day (P=0.78); between hand-held indirect calorimeter and Mifflin-St Jeor were 69.93±46.7 kcal/day (P=0.14) and 116.44±75.9 kcal/day (P=0.13); between hand-held indirect calorimeter and WHO were −22.03±48.4 kcal/day (P=0.65) and −15.8±77.9 kcal/day (P=0.84); and between hand-held indirect calorimeter and DRI were 39.65±47.4 kcal/day (P=0.41) and 56.36±85.5 kcal/day (P=0.51). Less than 50% of predictive equation values were within ±10% of hand-held indirect calorimeter values, indicating poor agreement.

Conclusions

A significant discrepancy between predicted and measured energy expenditure was observed. Further evaluation of hand-held indirect calorimeter research screening is needed.     

Graphical modeling can be used to illustrate associations between variables describing functioning in head and neck cancer patients

Objective

To examine the associations between variables of functioning measured by the International Classification of Functioning, Disability and Health (ICF) in head and neck cancer (HNC) patients by means of graphical modeling.

Study Design and Setting

Graphical modeling was used on a data set of a cross-sectional multicentric study of 145 patients with HNC. Functioning was qualified using the extended ICF checklist. Multiple imputation was used to handle missing data. The least absolute shrinkage and selection operator for generalized linear models was used to identify conditional associations between the ICF categories. Bootstrap aggregating was used to enhance the accuracy and validity of model selection.

Results

The resulting graph shows largely meaningful associations between the ICF categories. One central point could be visualized consisting of a circular path of d330 Speaking, d350 Conversation, b510 Ingestion functions, s320 Structure of mouth, and b310 Voice functions. Another important structure in the graph were the bow-shaped associations beginning with d335 Producing nonverbal messages to b130 Energy and drive functions.

Conclusion

Graphical modeling can be used to describe associations between different areas of functioning in HNC patients. They found associations can be the basis for improved rehabilitation and gives a deeper understanding of functioning in HNC patients.     

Polychlorinated biphenyls and thyroid hormone serum concentrations among people living in a highly polluted area: a cross-sectional population-based study

Background

Polychlorinated biphenyls (PCBs) may interact with several thyroid functions. Severe environmental pollution by PCBs has been observed in Brescia, Italy, due to the presence of a factory that produced these compounds until 1984.

Objectives

We aimed to investigate the correlation between serum levels of total PCBs and PCB 153 and thyroid hormone serum levels in adults in a cross-sectional population-based study.

Methods

A total of 527 subjects were enrolled; they were face-to-face interviewed about their history of thyroid disease and provided a blood sample under fasting conditions. The serum levels of free and total triiodothyronine (FT3 and TT3), thyroxine (FT4 and TT4) and thyroid-stimulating hormone (TSH), anti-thyroperoxidase (anti-TPO) and anti-thyroglobulin (anti-TGA), and lipid-adjusted total PCBs and PCB 153 were determined.

Results

There was no statistically significant difference in total PCB and PCB 153 concentrations in subjects with and without thyroid disease. Inverse, weak, statistically significant correlations were found between total PCBs and FT3 (Spearman's r=−0.09) and between total PCBs and PCB 153 and TSH (Spearman's r=−0.16 and −0.12, respectively). However, multiple regression analysis with FT3 and TSH serum levels as dependent variables and total PCBs and PCB 153 serum levels as predictors, including age, gender and BMI, showed a positive, rather than negative, association of PCBs and PCB 153 with FT3 and no association with TSH.

Conclusions

This study does not support the hypothesis that relatively high PCB environmental exposure can determine substantial alterations in thyroid function among adult people.     

Results from simulated data sets: probabilistic record linkage outperforms deterministic record linkage

Objective

To gain insight into the performance of deterministic record linkage (DRL) vs. probabilistic record linkage (PRL) strategies under different conditions by varying the frequency of registration errors and the amount of discriminating power.

Study Design and Setting

A simulation study in which data characteristics were varied to create a range of realistic linkage scenarios. For each scenario, we compared the number of misclassifications (number of false nonlinks and false links) made by the different linking strategies: deterministic full, deterministic N-1, and probabilistic.

Results

The full deterministic strategy produced the lowest number of false positive links but at the expense of missing considerable numbers of matches dependent on the error rate of the linking variables. The probabilistic strategy outperformed the deterministic strategy (full or N−1) across all scenarios. A deterministic strategy can match the performance of a probabilistic approach providing that the decision about which disagreements should be tolerated is made correctly. This requires a priori knowledge about the quality of all linking variables, whereas this information is inherently generated by a probabilistic strategy.

Conclusion

PRL is more flexible and provides data about the quality of the linkage process that in turn can minimize the degree of linking errors, given the data provided.     

Carbon dioxide (CO2) demand-controlled ventilation in university computer classrooms and possible effects on headache, fatigue and perceived indoor environment: an intervention study

Purpose

To study the effects of a CO₂ demand-controlled ventilation system (variable flow) in computer classrooms on perceived air quality and sick building syndrome.

Methods

University students (27 % women) participated in a blinded study. Two classrooms had variable flow (mean 5.56 ac/h); two others had constant ventilation flow (mean 5.07 ac/h). After one week, ventilation conditions were shifted. The students reported symptoms/perceptions during the last hour on rating scales. Temperature, air humidity, CO₂, PM10 and number concentration of particles were measured simultaneously. Cat (Fel d 1), dog (Can f 1), horse (Equ cx) and house dust mites (Der f 1 and Der p 1) allergens were measured in dust. Those participating twice in the same classroom (N = 61) were analysed longitudinally.

Results

Mean CO₂ was 784 ppm (9 % of time >1,000 ppm) with variable flow and 809 ppm with constant flow conditions (25 % of time >1,000 ppm). Mean temperature (22.6 °C), PM10 (18 μg/m³) and number concentration (1,860 pt/cm³) were unchanged. The median levels of cat, dog, horse and Der f 1 allergens were 10,400 ng/g, 4,900 ng/g, 13,700 U/ng and 260 ng/g dust, respectively. There were slightly less headache (p = 0.003), tiredness (p = 0.007) and improved perceived air quality (p = 0.02) with variable flow.

Conclusions

Use of a CO₂-controlled ventilation system, reducing elevated levels of CO₂, may slightly reduce headache and tiredness and improve perceived air quality. The high levels of pet allergens, due to track in of allergens from the home and possible accumulation due to electrostatic forces, illustrate a need for improved cleaning.     

Correlates of use of long-acting reversible methods of contraception among adolescent and young adult women

Background

Most pregnancies among adolescent and young adult women are unintended, and adolescent birth rates have risen. Use of long-acting reversible contraception may be an effective strategy to reduce the rate of unintended pregnancy.

Study Design

We conducted a secondary data analysis of nationally representative, cross-sectional data from the 2002 National Survey of Family Growth. Our sample included 1722 sexually active women aged 15-24 years. We used multivariable logistic regression to identify correlates of ever-use of depot-medroxyprogesterone acetate (DMPA) or the intrauterine device (IUD).

Results

One-quarter of our sample had ever used DMPA, and less than 2% had ever used the IUD. In multivariable analysis, increasing parity was associated with ever-use of DMPA (OR 2.07, 95% CI 1.55-2.77) and ever-use of the IUD (OR 4.57, 95% CI 1.60-13.03), but age and measures of socioeconomic status were not. Having ever been married (OR 5.54, 95% CI 1.23-24.82) and current cohabitation (OR 4.89, 95% CI 1.10-21.71) were associated with ever-use of the IUD. A history of an adolescent pregnancy was associated with ever-use of DMPA (OR 1.79, 95% CI 1.19-2.70) but not of the IUD.

Conclusions

While similarities exist between the correlates of use of DMPA and the IUD, we discovered important differences, some of which may reflect provider biases regarding IUD provision.     

Temporal relationships between screen-time and physical activity with cardiorespiratory fitness in English schoolchildren: a 2-year longitudinal study

Objective

To determine the temporal relationships screen-time and physical activity have with cardiorespiratory fitness.

Method

Measures were made over two years (2008-2010) in 1500 participants aged 11.5 (SD 0.5) years at baseline.

Results

Tracking coefficients were low-to-moderate for all measures. At follow-up, 25% of participants moved from having low (< 2 h) to high (≥ 2 h) daily screen-time and 6% became unfit according to FITNESSGRAM standards. Baseline screen-time was the strongest univariate predictor of becoming unfit. Multivariate analysis controlling for decimal age, BMI and deprivation confirmed baseline screen-time as the strongest independent predictor of becoming unfit over the 2-year study period (OR 2.4; 95%CI:1.4-4.0). Current (OR 2.3; 95%CI:1.3-4.0) and previous (OR 1.7; 95%CI:1.0-2.9) physical activity levels also independently predicted becoming unfit.

Conclusion

There is currently no guidance for limiting screen-time in UK children. These longitudinal data add to the cross-sectional evidence of lower physical activity and fitness in children reporting ≥ 2 h daily screen-time. More importantly, these data demonstrate that high screen-time during childhood is an independent predictor of lower cardiorespiratory fitness in adolescence.