Polybrominated diphenyl ethers: Potential human exposure through household dust and dryer lint

This MPH thesis consists of (1) literature review of the relatively new synthetic persistent organic pollutants (POP), polybrominated diphenyl ethers (PBDEs), a type of flame retardant posing a potential public health hazard, (2) Presentation of data on PBDE levels in dryer lint from Dallas, TX and Hamburg, Germany. ^ PBDEs are used as additive fire retardants in plastics, polyurethane foam and electronic equipment to reduce flammability and thus save life and property. PBDEs have been widely used beginning in the 1970s. They resemble polychlorinated biphenyls (PCBs) in structure and toxicity. PBDEs are found in environmental sediments, sludges, and wildlife and even in human blood, milk and tissues. ^ PBDEs, due to their lipophilicity, accumulate in fat and other tissues and biomagnify up the food chain, with increasing concentrations. Animal studies have suggested potential health effects including thyroid disruption, permanent learning and memory impairment, fetal malformations, developmental neurotoxicity and, at high doses, possibly cancer. ^ PBDE levels are increasing in blood and breast milk in North America, but PBDEs intake unlike PCBs appears to be not primarily through food; food PBDE levels in the U.S. are not markedly higher than in Europe yet U.S. human blood and milk levels are much higher. For this reason various exposure pathways including PBDE contaminated dust and air have been studied to better characterize routes of PBDE intake into humans. ^ The scientific literature on PBDE levels in household dust reports higher PBDE concentration in dust than that found in dryer lint; levels in the U.S are elevated compared to other countries with congeners such as BDE 47, 99, 100 and 209 predominating. The United Kingdom has elevated BDE 209 due to high usage of Deca commercial mixture. These studies suggest that indoor PBDE contamination through household dust could be a potential source of PBDE exposure and body burden especially in young children. ^ PBDE levels in dryer lint from U.S ranged from 321 to 3073 ng/g (Mean: 1138 ng/g, Median: 803 ng/g) and from Germany were from 330 to 2069 ng/g (Median: 71ng/g, Mean: 361 ng/g). High median levels in U.S samples indicate contamination of lint with PBDEs although the source of the PBDEs in lint may be from dryer electrical components or air deposition onto clothes, lint may be one source of PBDE exposure to humans. ^

Latino patients' desire to participate in informed decisions regarding colorectal cancer screening

Colorectal cancer (CRC) has become a public health concern due to the underutilization of the various screening methods. There is a need to understand a patient's decision making process in regards to their health and obtaining the appropriate screening. Previous research has defined patient autonomy in two dimensions: The patient's involvement in the decision making process and their desire to be informed (Ende, Kazis, Ash, & Moskowitz, 1989). Past research shows that patients have a high desire to be informed, but a low desire to be involved in the medical decision process. Deber, Kraetschmer, and Irvine (1996) developed a measure which consisted of two subscales that measures patients' involvement: Patient's desire to be involved in the problem solving (PS) and decision making (DM) process. Little research has examined the desire for involvement and decision making of Latino populations. The present study sought to investigate the psychometric properties of the Deber et al. (1996) measure. In general, Latino patients in the present sample had low desire for autonomy in health decisions or to be involved in the decision making processes of their health related issues. ^

Self medication behaviors of illegal immigrants living along the U.S.-Mexico border

Mexican immigrants make up the largest subgroup of Hispanics living in the United States. The largest percentage of illegal immigrants comes from México. As such they are a subpopulation with limited access to health care and social services; their health seeking behaviors including self-medication behaviors that, aside from the intake of antibiotics, have not been studied in depth. The analysis of the data presented sought to document the medication behaviors of illegal immigrants living in El Paso County along the U.S.-México border. Of the 80 participants, 31 were taking medication on a regular basis. Of these, 28 claimed that at least one of the medications had been prescribed by a physician, 13 people had bought at least one of their medications in México, nine participants claimed that they had not paid for at least one of the medications they were taking, ten participants reported that they had skipped the doses of at least one of their medications due to monetary constraints. Participants were also asked if they had purchased medication in México during the year prior to the study, 68 of the 80 (85%) participants had bought 295 pharmaceutical products across the border themselves or through a third party. The most frequently purchased medications were antibiotics (17%), followed by syrups, pomades, creams, eardrops, and cold medicine as a group (15%), followed by analgesics (13%) and other non steroidal anti-inflammatory drugs (12%) and oral hypoglycemic agents (6%). ^

Trauma care capacity and performance in Texas: Regional comparisons

Objective. The study reviewed one year of Texas hospital discharge data and Trauma Registry data for the 22 trauma services regions in Texas to identify regional variations in capacity, process of care and clinical outcomes for trauma patients, and analyze the statistical associations among capacity, process of care, and outcomes. ^ Methods. Cross sectional study design covering one year of state-wide Texas data. Indicators of trauma capacity, trauma care processes, and clinical outcomes were defined and data were collected on each indicator. Descriptive analyses were conducted of regional variations in trauma capacity, process of care, and clinical outcomes at all trauma centers, at Level I and II trauma centers and at Level III and IV trauma centers. Multilevel regression models were performed to test the relations among trauma capacity, process of care, and outcome measures at all trauma centers, at Level I and II trauma centers and at Level III and IV trauma centers while controlling for confounders such as age, gender, race/ethnicity, injury severity, level of trauma centers and urbanization. ^ Results. Significant regional variation was found among the 22 trauma services regions across Texas in trauma capacity, process of care, and clinical outcomes. The regional trauma bed rate, the average staffed bed per 100,000 varied significantly by trauma service region. Pre-hospital trauma care processes were significantly variable by region---EMS time, transfer time, and triage. Clinical outcomes including mortality, hospital and intensive care unit length of stay, and hospital charges also varied significantly by region. In multilevel regression analysis, the average trauma bed rate was significantly related to trauma care processes including ambulance delivery time, transfer time, and triage after controlling for age, gender, race/ethnicity, injury severity, level of trauma centers, and urbanization at all trauma centers. Transfer time only among processes of care was significant with the average trauma bed rate by region at Level III and IV. Also trauma mortality only among outcomes measures was significantly associated with the average trauma bed rate by region at all trauma centers. Hospital charges only among outcomes measures were statistically related to trauma bed rate at Level I and II trauma centers. The effect of confounders on processes and outcomes such as age, gender, race/ethnicity, injury severity, and urbanization was found significantly variable by level of trauma centers. ^ Conclusions. Regional variation in trauma capacity, process, and outcomes in Texas was extensive. Trauma capacity, age, gender, race/ethnicity, injury severity, level of trauma centers and urbanization were significantly associated with trauma process and clinical outcomes depending on level of trauma centers. ^ Key words: regionalized trauma systems, trauma capacity, pre-hospital trauma care, process, trauma outcomes, trauma performance, evaluation measures, regional variations ^

Folic acid fortification, maternal obesity and neural tube defects: Policy implications

In 1996, the Food and Drug Administration (FDA) mandated that beginning in January 1998, flour and other enriched grain products be fortified with 140 μg of folic acid per 100 g of grain to prevent neural tube defects (NTDs) that occur in approximately 1 in 1,000 pregnancies in the United States (U.S.). Although this program has demonstrated important public health effects, it is argued that current fortification levels may not be enough to prevent all folic acid-preventable NTD cases. This study reviews published literature, on folic acid fortification in the U.S. and countries with mandatory folic acid fortification programs reported after 1992 and through January 2008. Published studies are evaluated to determine if the current level of folic acid fortification in the U.S. is adequate to prevent the most common forms of NTDs (spina bifida and anencephaly), particularly among overweight and obese women. ^ Although consistent improvement in blood folate levels of child bearing age women is reported in almost all studies, the RBC folate concentration has not reached the level associated with the most significant reduction of risk for NTDs (906 nmol/L); approximately half of the potentially preventable NTDs are prevented by fortification at the current U.S. level. Furthermore, the blood folate status of women in higher BMI categories (obese or overweight) has not improved as much as among women in lower BMI categories. Therefore, women classified as overweight or obese have not benefited from the preventive effects of folic acid fortification as much as normal or underweight women. ^ To reduce risk of folate preventable NTDs, especially in overweight and obese women, it may be necessary to increase the current level of folic acid fortification. However, further research is required to determine the optimal levels of fortification to achieve this goal without causing adverse health effects in the general population. ^

Relationship between Clostridium difficile toxin type and clinical features, severity and outcome in patients with C. difficile diarrhea (CDAD)

Background. Clostridium difficile infection is one of the major causes of antibiotic associated diarrhea and colitis in the United States. Currently, there is a dearth of literature on the risk factors and outcomes differences between the patients with infection due to the hypervirulent strain vs. the non-hypervirulent strains. The objective of this study was to determine the relationship between C. difficile toxin type and clinical features, severity and outcome in patients with C. difficile diarrhea. ^ Methods. The case group included 37 patients who had infections due to hypervirulent strain (tcdC deletion) and the control group included 55 patients with other toxin types (toxin A, B, binary toxin). A univariate analysis was performed followed by a multivariable logistic regression analysis to assess the differences between cases and controls. ^ Results. In the multivariate analyses, we found out that being a male was a protective factor for developing the infection due to the hypervirulent strain [OR 0.33; 95% CI 0.12-0.90]. Also, the hypervirulent group has worse clinical and economic outcomes, although the differences were small and nonsignificant. ^ Conclusions. There may likely be no predictive risk factor for acquiring infection due to the hypervirulent strain and the acquisition may be more linked to the infection control practices of the individual hospitals or location of patients. Hence, better infection control practices may prove helpful in decreasing the overall disease burden and thus improve patient outcomes. ^

Dengue risk factor distribution in Harris County, Texas

As an important emerging arboviral disease in Texas and throughout the world, dengue fever has the potential to make a re-emergence in the Harris County/Houston metropolitan area. Harris County has seen dengue epidemics in the past. The area has a competent vector, Aedes aegypti, capable of transmission of the virus should it be introduced. It is important to examine areas of highest risk for dengue emergence and transmission in Harris County so that surveillance and educational programs can be properly implemented. This study uses mapping software to visually represent risk factor information with areas of known Ae. aegypti populations. This study focused on known demographic risk factors such as race/ethnicity, place of birth, gender as well as socioeconomic status represented by educational attainment and income. This study found that there are several areas, particularly in central Harris County that are at particular risk for dengue transmission. The findings support the hypothesis that in areas of lower socioeconomic status there were increased populations of foreign born populations, Hispanic populations, and identified locations of a competent vector present. These findings suggest that more specific surveillance of Ae. aegypti, testing of the mosquitoes for dengue virus, and active surveillance for human cases should be implemented in these areas. ^

Diagnosis of sexually transmitted infections in developing nations using syndromic management: Is it working?

Sexually transmitted infections (STIs) are a major public health problem, and controlling their spread is a priority. According to the World Health Organization (WHO), there are 340 million new cases of treatable STIs among 15–49 year olds that occur yearly around the world (1). Infection with STIs can lead to several complications such as pelvic inflammatory disorder (PID), cervical cancer, infertility, ectopic pregnancy, and even death (1). Additionally, STIs and associated complications are among the top disease types for which healthcare is sought in developing nations (1), and according to the UNAIDS report, there is a strong connection between STIs and the sexual spread of HIV infection (2). In fact, it is estimated that the presence of an untreated STI can increase the likelihood of contracting and spreading HIV by a factor up to 10 (2). In addition, developing countries are poorer in resources and lack inexpensive and precise diagnostic laboratory tests for STIs, thereby exacerbating the problem. Thus, the WHO recommends syndromic management of STIs for delivering care where lab testing is scarce or unattainable (1). This approach utilizes the use of an easy to use algorithm to help healthcare workers recognize symptoms/signs so as to provide treatment for the likely cause of the syndrome. Furthermore, according to the WHO, syndromic management offers instant and legitimate treatment compared to clinical diagnosis, and that it is also more cost-effective for some syndromes over the use of laboratory testing (1). In addition, even though it has been shown that the vaginal discharge syndrome has low specificity for gonorrhea and Chlamydia and can lead to over treatment (1), this is the recommended way to manage STIs in developing nations. Thus, the purpose of this paper is to specifically address the following questions: is syndromic management working to lower the STI burden in developing nations? How effective is it, and should it still be recommended? To answer these questions, a systematic literature review was conducted to evaluate the current effectiveness of syndromic management in developing nations. This review examined published articles over the past 5 years that compared syndromic management to laboratory testing and had published sensitivity, specificity, and positive predicative value data. Focusing mainly on vaginal discharge, urethral discharge, and genital ulcer algorithms, it was seen that though syndromic management is more effective in diagnosing and treating urethral and genial ulcer syndromes in men, there still remains an urgent need to revise the WHO recommendations for managing STIs in developing nations. Current studies have continued to show decreased specificity, sensitivity and positive predicative values for the vaginal discharge syndrome, and high rates of asymptomatic infections and healthcare workers neglecting to follow guidelines limit the usefulness of syndromic management. Furthermore, though advocate d as cost-effective by the WHO, there is a cost incurred from treating uninfected people. Instead of improving this system, it is recommended that better and less expensive point of care and the development of rapid test diagnosis kits be the focus and method of diagnosis and treatment in developing nations for STI management. ^