Anthropometric measures as a predictor of cephalopelvic disproportion

This study compared three body measurements, height, hip width (bitrochanteric) and foot length, in 120 Hispanic women who had their first birth by cesarean section (N = 60) or by spontaneous vaginal delivery (N = 60). The objective of the study was to see if there were differences in these measurements that could be useful in predicting cephalopelvic disproportion. Data were collected from two public hospitals in Houston Texas over a 10 month period from December 1994 to October 1995. The statistical technique used to evaluate the measures was discriminant analysis.^ Women who delivered by cesarean section were older, shorter, had shorter feet and delivered heavier infants. There were no differences in the bitrochanteric widths of the women or in the mean gestational age or Apgar scores of the infants.^ Significantly more of the mothers and infants were ill following cesarean section delivery. Maternal illness was usually infection; infant illness was primarily infection or respiratory difficulties.^ Discriminant analysis is a technique which allows for classification and prediction to which group a particular entity will belong given a certain set of variables. Using discriminant analysis, with a probability of cesarean section 50 percent, the best combination to classify who would have a cesarean section was height and hip width, correctly classifying 74.2 percent of those who needed surgery. When the probability of cesarean section was 10 percent and probability of vaginal delivery was 90 percent, the best predictor of who would need operative delivery was height, hip width and age, correctly classifying 56.2 percent. In the population from which the study participants were selected the incidence of cephalopelvic disproportion was low, approximately 1 percent.^ With the technologic assistance available in most of the developed world, it is likely that the further pursuit of different measures and their use would not be of much benefit in attempting to predict and diagnose disproportion. However, in areas of the world where much of obstetrics is "hands on", the availability of technology extremely limited, and the incidence of disproportion larger, the use of anthropometric measures might be useful and of some potential benefit. ^

Changes in blood lipids and their associations with changes in measures of height, weight and body mass index from age 8 to 18 years: Project Heartbeat!

A variety of studies indicate that the process of athrosclerosis begins in childhood. There was limited information on the association of the changes in anthropometric variables to blood lipids in school age children and adolescents. Previous longitudinal studies of children typically with insufficient frequency of observation could not provide sound inference on the dynamics of change in blood lipids. The aims of this analysis are (1) to document the sex- and ethnic-specific trajectory and velocity curves of blood lipids (TC, LDL-C, HDL-C and TG); (2) to evaluate the relationship of changes in anthropometric variables, such as height, weight and BMI, to blood lipids from age 8 to 18 years. ^ Project HeartBeat! is a longitudinal study designed to examine the patterns of serial change in major cardiovascular risk factors. Cohort of three different age levels, 8, 11 and 14 years at baseline, with a total of 678 participants were enrolled. Each member of these cohorts was examined three times per year for up to four years. ^ Sex- and ethnic-specific trajectory and velocity curves of blood lipids; demonstrated the complex and polyphasic changes in TC, LDL-C, HDL-C and TG longitudinally. The trajectory curves of TC, LDL-C and HDL-C with age showed curvilinear patterns of change. The velocity change in TC, HDL-C and LDL-C showed U-shaped curves for non-Blacks, and nearly linear lines in velocity of TG for both Blacks and non-Blacks. ^ The relationship of changes in anthropometric variables to blood lipids was evaulated by adding height, weight, or BMI and associated interaction terms separately to the basic age-sex models. Height or height gain had a significant negative association with changes in TC, LDL-C and HDL-C. Weight or BMI gain showed positive associations with TC, LDL-C and TC, and a negative relationship with HDL-C. ^ Dynamic changes of blood lipids in school age children and adolescents observed from this analysis suggested that using fixed screening criteria under the current NCEP guidelines for all ages 2–19 may not be appropriate for this age group. The association of increasing BMI or weight to an adverse blood lipid profile found in this analysis also indicated that weight or BMI monitoring could be a future intervention to be implemented in the pediatric population. ^

An ecologic comparison study of the impact of economic disadvantage on Texas Assessment of Knowledge and Skills performance, graduation rates, and readiness for higher education for students attending public and charter schools in Texas from 2004 to 2006

Purpose. No Child Left Behind aimed to "improve the academic achievement of the disadvantaged." The primary research question considered how academic achievement of those from economic disadvantage compared to those not from disadvantage? ^ Economically disadvantaged students can potentially have added academic disadvantage. Research shows low academic achievement can potentially result in drug abuse, youth violence, and teen pregnancy. ^ Methods. To compare the student populations, measures included TAKS results and academic indicator data collected by the Texas Education Agency. ^ Results. T-test analyses showed a significant difference between the economically and non-economically disadvantaged student populations in meeting the TAKS passing standard, graduation, and preparation for higher education.^ Conclusions. The achievement gap between students remained as indicated by the Texas testing program. More research and time are needed to observe if the desired impact on those from economic disadvantage will be reflected by academic achievement data.^

Access to health care among children in the U.S.: Use of health inequalities measures to evaluate progress in reduction of disparities from 1997 to 2005

Much of the literature on disparities in access to health care among children has focused on measuring absolute and relative differences experienced by race/ethnic groups and, to a lesser extent, socioeconomic groups. However, it is not clear from existing literature how disparities in access to care may have changed over time for children, especially following implementation of the State Children’s Health Insurance Program (SCHIP). The primary objective of this research was to determine if there has been a decrease in disparities in access to care for children across two socioeconomic groups and race/ethnicity groups after SCHIP implementation. Methods commonly used to measure ‘health inequalities’ were used to measure disparities in access to care including population-attributable risk (PAR) and the relative index of inequality (RII). Using these measures there is evidence of a substantial decrease in socioeconomic disparities in health insurance coverage and to a lesser extent in having a usual source of care since the SCHIP program began. There is also evidence of a considerable decrease in non-Hispanic Black disparities in access to care. However, there appears to be a slight increase in disparities in access to care among Hispanic compared to non-Hispanic White children. While there were great improvements in disparities in access to care with the introduction of the SCHIP program, continuing progress in disparities may depend on continuation of the SCHIP program or similar targeted health policy programs. ^

Comparison of Bispectral Index (BIS) and Patient State Index (PSI) as objective measures of sedation and analgesia in critically ill/injured patients

Critically ill and injured patients require pain relief and sedation to reduce the body's stress response and to facilitate painful diagnostic and therapeutic procedures. Presently, the level of sedation and analgesia is guided by the use of clinical scores which can be unreliable. There is therefore, a need for an objective measure of sedation and analgesia. The Bispectral Index (BIS) and Patient State Index (PSI) were recently introduced into clinical practice as objective measures of the depth of analgesia and sedation. ^ Aim. To compare the different measures of sedation and analgesia (BIS and PSI) to the standard and commonly used modified Ramsay Score (MRS) and determine if the monitors can be used interchangeably. ^ Methods. MRS, BIS and PSI values were obtained in 50 postoperative cardiac surgery patients requiring analgesia and sedation from June to December 2004. The MRS, BIS and PSI values were assessed hourly for up to 6-h by a single observer. ^ The relationship between BIS and PSI values were explored using scatter plots and correlation between MRS, BIS and PSI was determined using Spearman's correlation coefficient. Intra-class correlation (ICC) was used to determine the inter-rater reliability of MRS, BIS and PSI. Kappa statistics was used to further evaluate the agreement between BIS and PSI at light, moderate and deep levels of sedation. ^ Results. There was a positive correlation between BIS and PSI values (Rho = 0.731, p<0.001). Intra-class correlation between BIS and PSI was 0.58, MRS and BIS 0.43 and MRS and PSI 0.27. Using Kappa statistics, agreement between MRS and BIS was 0.35 (95% CI: 0.27–0.43) and for MRS and PSI was 0.21 (95% CI: 0.15–0.28). The kappa statistic for BIS and PSI was 0.45 (95% CI: 0.37–0.52). Receiver operating characteristics (ROC) curves constructed to detect undersedation indicated an area under the curve (AUC) of 0.91 (95% CI = 0.87 to 0.94) for the BIS and 0.84 (95% CI = 0.79 to 0.88) for the PSI. For detection of oversedation, AUC for the BIS was 0.89 (95% CI = 0.84 to 0.92) and 0.80 (95% CI = 0.75 to 0.85) for the PSI. ^ Conclusions. There is a statistically significant positive correlation between the BIS and PSI but poor correlation and poor test agreement between the MRS and BIS as well as MRS and PSI. Both the BIS and PSI demonstrated a high level of prediction for undersedation and oversedation; however, the BIS and PSI can not be considered interchangeable monitors of sedation. ^

Psychosocial measures reported by parents in studies of skin cancer prevention

Background. Because it is important to minimize children's sun exposure to reduce skin cancer risk, much of the extensive skin cancer prevention literature consists of studies of children's sun protection, sun avoidance and ultraviolet radiation (UVR) exposure. Little attention has been focused on the measurement of psychosocial constructs in these studies. Identification of the psychosocial correlates or determinants of children's skin cancer risk or risk-reduction behavior is critical to more fully understand and predict behavior. Furthermore, psychosocial variables may be influenced by interventions to reduce risk. Thus, it is important to examine the psychosocial measures used in studies of children's skin cancer prevention. Information on the validity and reliability of psychosocial measures may increase confidence in study findings based on these measures. In particular, self-efficacy and barriers are key constructs in several major theoretical frameworks and parental measures have been associated with children's sun protection. However, there is conceptual overlap of self-efficacy and barriers measures and little is known about the psychometric properties of these measures.^ Study Aims and Methods. The overall goal of this dissertation was to examine the measurement of psychosocial constructs relevant to children's skin cancer prevention. Because children depend primarily on their parents for skin cancer prevention, measures of parents' psychosocial constructs are the focus. Study 1 was a systematic review of parental psychosocial measures used in studies of children's sun protection, sun avoidance and UVR exposure. The specific aims of Study 1 were to (1) describe psychosocial measures reported by parents, including available information on the psychometric properties of these measures and their use in analyses and (2) provide recommendations for the development, refinement and standardized reporting of measures. ^ Study 2 examined the psychometric properties of measures of parental self-efficacy and barriers regarding children's sun protection. Melanoma patients (N=205) who were parents of children ≤ 12 years of age completed a telephone interview that included self-efficacy and barriers measures specific to sunscreen, clothing, shade and limiting time outdoors. The specific aims of Study 2 were to (1) use a confirmatory factor analytic approach to examine the factorial validity of parental self-efficacy and barriers measures, (2) examine the convergent and discriminant validity of behavior-specific measures of self-efficacy and barriers and (3) assess the reliability of item and scale measures.^ Results. In Study 1, a search of standard databases yielded 48 eligible studies. Most studies assessed only one or two psychosocial constructs. Knowledge was measured most frequently. There was little discussion of measure source, development, theoretical background or psychometric properties, besides internal consistency reliability. There was conceptual overlap of some measures. In Study 2, confirmatory factor analytic findings supported the factorial validity of the self-efficacy and barriers measures. When all eight self-efficacy and barriers measures were included in the same model, a modified eight-factor model adequately fit the data, providing preliminary evidence that the measures are distinct. Measure associations supported the convergent validity of all measures and the discriminant validity of most measures. The self-efficacy and barriers measures were reliable.^ Conclusions. Recommendations based on the literature review include developing and refining psychosocial measures based on theory. Describing a measure's theoretical basis and psychometric properties would facilitate critical evaluation. Standardized reporting of source, development, theory, construct, items and analytic role would facilitate comparison of findings, continual refinement and future applications of measures. In the validation study, self-efficacy and barriers measures were examined in a sample of parents with a personal history of melanoma. Findings suggested that these measures are valid and reliable for use in studies of children's sun protection. There was preliminary evidence that these measures are distinct but additional study is needed. ^

Evaluation of the association between cryptosporidiosis outbreaks and two interactive water fountain parks: Epidemiologic analysis and implications for public health

Background. A community-wide outbreak of cryptosporidiosis occurred in Dallas County during the summer of 2008. A subset of cases occurring with onset of illness within a 2 week interval was epidemiologically linked to 2 neighborhood interactive water fountain parks. ^ Methods. A case control study was conducted to evaluate risk factors associated with developing illness with cryptosporidiosis from the fountain parks. Cases were selected from a line list from the epidemiological study. The selection for the controls was either healthy family members or a daycare center nearby. Cases and controls were not matched. ^ Results. Interviews were completed for 44 fountain park attendees who met case definition and 54 community controls. Twenty-seven percent (27.3%) of the cases and 13.0% of the controls were between the ages of 0–4 years. Thirty-nine percent (38.6%) of the cases and 24.1% of the controls were between the ages of 5–13 years. Fourteen percent (13.6%) of the cases and 33.3% of the controls were between the ages of 14–31 years. Twenty percent (20.5%) of the cases and 29.6% of the controls were between the ages of 32–63 years. 47.7% of the cases and 42.6% of the controls were males. Fountain park attendees who reported having been splashed in the face with water were 10 times more likely to become ill than controls (OR = 10.0, 95% CI = 2.8–35.1). Persons who reported having swallowed water from the interactive fountains were 34 times more likely to become ill than controls (OR = 34.3, 95%CI = 9.3–125.7). ^ Conclusion. Prompt reporting of cases, identification of outbreak sources, and immediate implementation of remediation measures were critical in curtailing further transmission from these particular sites through the remainder of the season. This investigation underscores the potential for cryptosporidiosis outbreaks to occur in interactive fountain parks, and the need for enhanced preventive measures in these settings. Education of the public regarding avoidance of behaviors such as drinking water from interactive fountains is also an important component of public health prevention efforts. ^

Affect and cognition measures in preference-based decisions: Validity testing of the Ottawa Decisional Conflict Scale and a decision-specific anxiety measure with men eligible for prostate cancer screening

Background. At present, prostate cancer screening (PCS) guidelines require a discussion of risks, benefits, alternatives, and personal values, making decision aids an important tool to help convey information and to help clarify values. Objective: The overall goal of this study is to provide evidence of the reliability and validity of a PCS anxiety measure and the Decisional Conflict Scale (DCS). Methods. Using data from a randomized, controlled PCS decision aid trial that measured PCS anxiety at baseline and DCS at baseline (T0) and at two-weeks (T2), four psychometric properties were assessed: (1) internal consistency reliability, indicated by factor analysis intraclass correlations and Cronbach's α; (2) construct validity, indicated by patterns of Pearson correlations among subscales; (3) discriminant validity, indicated by the measure's ability to discriminate between undecided men and those with a definite screening intention; and (4) factor validity and invariance using confirmatory factor analyses (CFA). Results. The PCS anxiety measure had adequate internal consistency reliability and good construct and discriminant validity. CFAs indicated that the 3-factor model did not have adequate fit. CFAs for a general PCS anxiety measure and a PSA anxiety measure indicated adequate fit. The general PCS anxiety measure was invariant across clinics. The DCS had adequate internal consistency reliability except for the support subscale and had adequate discriminate validity. Good construct validity was found at the private clinic, but was only found for the feeling informed subscale at the public clinic. The traditional DCS did not have adequate fit at T0 or at T2. The alternative DCS had adequate fit at T0 but was not identified at T2. Factor loadings indicated that two subscales, feeling informed and feeling clear about values, were not distinct factors. Conclusions. Our general PCS anxiety measure can be used in PCS decision aid studies. The alternative DCS may be appropriate for men eligible for PCS. Implications: More emphasis needs to be placed on the development of PCS anxiety items relating to testing procedures. We recommend that the two DCS versions be validated in other samples of men eligible for PCS and in other health care decisions that involve uncertainty. ^

Policy implications of public health workforce development for disaster preparedness in the United States

Public health efforts were initiated in the United States with legislative actions for enhancing food safety and ensuring pure drinking water. Some additional policy initiatives during the early 20th century helped organize and coordinate relief efforts for victims of natural disasters. By 1950's the federal government expanded its role for providing better health and safety to the communities, and its disaster relief activities became more structured. A rise in terrorism related incidents during the late 1990's prompted new proactive policy directions. The traditional policy and program efforts for rescue, recovery, and relief measures changed focus to include disaster preparedness and countermeasures against terrorism.^ The study took a holistic approach by analyzing all major disaster related policies and programs, in regard to their structure, process, and outcome. Study determined that United States has a strong disaster preparedness agenda and appropriate programs are in place with adequate policy support, and the country is prepared to meet all possible security challenges that may arise in the future. The man-made disaster of September 11th gave a major thrust to improve security and enhance preparedness of the country. These new efforts required large additional funding from the federal government. Most existing preparedness programs at the local and national levels are run with federal funds which is insufficient in some cases. This discrepancy arises from the fact that federal funding for disaster preparedness programs at present are not allocated by the level of risks to individual states or according to the risks that can be assigned to critical infrastructures across the country. However, the increased role of the federal government in public health affairs of the states is unusual, and opposed to the spirit of our constitution where sovereignty is equally divided between the federal government and the states. There is also shortage of manpower in public health to engage in disaster preparedness activities, despite some remarkable progress following the September 11th disaster.^ Study found that there was a significant improvement in knowledge and limited number of studies showed improvement of skills, increase in confidence and improvement in message-mapping. Among healthcare and allied healthcare professionals, short-term training on disaster preparedness increased knowledge and improved personal protective equipment use with some limited improvement in confidence and skills. However, due to the heterogeneity of these studies, the results and interpretation of this systematic review may be interpreted with caution.^

Integrated pest management in multi-story public housing for the elderly in Houston, Texas

Integrated pest management is a viable alternative to traditional pest control methods. A paired sample design was utilized to measure the effect of IPM education on the number of cockroaches in a 200 unit, seven story public housing building for the elderly in Houston, TX. Glue traps were placed in 71 randomly selected apartments (5traps/unit) and left in place for two nights. Baseline cockroach counts were shared with the property manager, maintenance/janitorial staff, service coordinator, pest control professional and tenant representatives at the end of a one day “Integrated Pest Management in Multi-Family Housing” training course.^ There was a significant decrease in the average number of cockroaches after IPM education and implementation of IPM principles (P < 0.0003). Positive changes in behavior by members of the IPM team and changes in the housing authority operational plan were also found. Paired t-tests comparing the difference between mean cockroach counts at baseline and follow-up by location within the apartment all demonstrated a significant decrease in the number of cockroaches.^ Results supported the premise that IPM education and the implementation of IPM principles are effective measures to change pest control behaviors and control cockroaches. Cockroach infestations in multi-story housing are not solely determined by the actions of individual tenants. The actions of other residents, property managers and pest control professionals are also important factors in pest control.^ Findings support the implementation of IPM education and the adoption of IPM practices by public housing authorities. This study adds to existing evidence that clear communication of policies, a team approach and a commitment to ongoing inspection and monitoring of pests combined with corrective action to eliminate food, water and harborage and the judicial use of low risk pesticides have the potential to improve the living conditions of elderly residents living in public housing.^

The association between CD4+ lymphocyte count and measures of body composition in HIV-infected men

Purpose. This project was designed to describe the association between wasting and CD4 cell counts in HIV-infected men in order to better understand the role of wasting in progression of HIV infection.^ Methods. Baseline and prevalence data were collected from a cross-sectional survey of 278 HIV-infected men seen at the Houston Veterans Affairs Medical Center Special Medicine Clinic, from June 1, 1991 to January 1, 1994. A follow-up study was conducted among those at risk, to investigate the incidence of wasting and the association between wasting and low CD4 cell counts. Wasting was described by four methods. Z-scores for age-, sex-, and height-adjusted weight; sex-, and age-adjusted mid-arm muscle circumference (MAMC); and fat-free mass; and the ratio of extra-cellular mass (ECM) to body-cell mass (BCM) $>$ 1.20. FFM, ECM, and BCM were estimated from bioelectrical impedance analysis. MAMC was calculated from triceps skinfold and mid-arm circumference. The relationship between wasting and covariates was examined with logistic regression in the cross-sectional study, and with Poisson regression in the follow-up study. The association between death and wasting was examined with Cox's regression.^ Results. The prevalence of wasting ranged from 5% (weight and ECM:BCM) to almost 14% (MAMC and FFM) among the 278 men examined. The odds of wasting, associated with baseline CD4 cell count $<$200, was significant for each method but weight, and ranged from 4.6 to 12.7. Use of antiviral therapy was significantly protective of MAMC, FFM and ECM:BCM (OR $\approx$ 0.2), whereas the need for antibacterial therapy was a risk (OR 3.1, 95% CI 1.1-8.7). The average incidence of wasting ranged from 4 to 16 per 100 person-years among the approximately 145 men followed for 160 person-years. Low CD4 cell count seemed to increase the risk of wasting, but statistical significance was not reached. The effect of the small sample size on the power to detect a significant association should be considered. Wasting, by MAMC and FFM, was significantly associated with death, after adjusting for baseline serum albumin concentration and CD4 cell count.^ Conclusions. Wasting by MAMC and FFM were strongly associated with baseline CD4 cell counts in both the prevalence and incidence study and strong predictors of death. Of the two methods, MAMC is convenient, has available reference population data, may be the most appropriate for assessing the nutritional status of HIV-infected men. ^

AN ASSESSMENT OF THE CURRENT STATUS OF MENTAL ILLNESS IN BENDEL STATE OF NIGERIA: IMPLICATIONS FOR PUBLIC MENTAL HEALTH POLICY AND EDUCATION

This descriptive study assesses the current status of mental illness in Bendel State of Nigeria to determine its implications for mental health policy and education. It is a study of the demographic characteristics of psychiatric patients in the only two modern western psychiatric facilities in Bendel State, the various treatment modalities utilized for mental illness, and the people's choice of therapeutic measures for mental illness in Bendel State.^ This study investigated ten aspects of mental illness in Bendel State (1) An increase of the prevalence of mental illness (psychiatric disorder) in Bendel State. (2) Unaided, unguided, and uncared for mentally ill people roaming about Bendel State. (3) Pluralistic Treatment Modalities for mentally ill patients in Bendel State. (4) Traditional Healers treating more mentally ill patients than the modern western psychiatric hospitals. (5) Inadequate modern western psychiatric facilities in Bendel State. (6) Controversy between Traditional Health and modern western trained doctors over the issue of possible cooperation between traditional and modern western medicine. (7) Evidence of mental illness in all ethnic groups in Bendel State. (8) More scientifically based and better organized modern western psychiatric hospitals than the traditional healing centers. (9) Traditional healers' level of approach with patients, and accessibility to patients' families compared with the modern western trained doctors. (10) An urgent need for an official action to institute a comprehensive mental health policy that will provide an optimum care for the mentally ill in Bendel State, and in Nigeria in general.^ Of the eight popular treatment modalities generally used in Bendel State for mental illness, 54% of the non-patient population sampled preferred the use of traditional healing, 26.5% preferred the use of modern western treatment, and 19.5% preferred religious healers.^ The investigator concluded at this time not to recommend the integration of Traditional Healing and modern western medicine in Nigeria. Rather, improvement of the existing modern western psychiatric facilities and a proposal to establish facilities to enable traditional healing and modern western medicine to exist side by side were highly recommended. ^

THE EVALUATION OF PUBLIC HEALTH COMPONENTS OF INTERNATIONAL DISASTER RELIEF OPERATIONS: INDOCHINESE REFUGEES IN THAILAND, 1979-1982

Refugee populations suffer poor health status and yet the activities of refugee relief agencies in the public health sector have not been subjected previously to comprehensive evaluation. The purpose of this study was to examine the effectiveness and cost of the major public health service inputs of the international relief operation for Indochinese refugees in Thailand coordinated by the United Nations High Commissioner for Refugees (UNHCR). The investigator collected data from surveillance reports and agency records pertaining to 11 old refugee camps administered by the Government of Thailand Ministry of Interior (MOI) since an earlier refugee influx, and five new Khmer holding centers administered directly by UNHCR, from November, 1979, to March, 1982.^ Generous international funding permitted UNHCR to maintain a higher level of public health service inputs than refugees usually enjoyed in their countries of origin or than Thais around them enjoyed. Annual per capita expenditure for public health inputs averaged approximately US$151. Indochinese refugees in Thailand, for the most part, had access to adequate general food rations, to supplementary feeding programs, and to preventive health measures, and enjoyed high-quality medical services. Old refugee camps administered by MOI consistently received public health inputs of lower quantity and quality compared with new UNHCR-administered holding centers, despite comparable per capita expenditure after both types of camps had stabilized (static phase).^ Mortality and morbidity rates among new Khmer refugees were catastrophic during the emergency and transition phases of camp development. Health status in the refugee population during the static phase, however, was similar to, or better than, health status in the refugees' countries of origin or the Thai communities surrounding the camps. During the static phase, mortality and morbidity generally remained stable at roughly the same low levels in both types of camps.^ Furthermore, the results of multiple regression analyses demonstrated that combined public health inputs accounted for from one to 23 per cent of the variation in refugee mortality and morbidity. The direction of associations between some public health inputs and specific health outcome variables demonstrated no clear pattern. ^

Endemic tuberculosis, the homeless, and public transportation: A merging of geographical information systems surveillance and the Houston Tuberculosis Initiative Surveillance project

To reach the goals established by the Institute of Medicine (IOM) and the Centers for Disease Control's (CDC) STOP TB USA, measures must be taken to curtail a future peak in Tuberculosis (TB) incidence and speed the currently stagnant rate of TB elimination. Both efforts will require, at minimum, the consideration and understanding of the third dimension of TB transmission: the location-based spread of an airborne pathogen among persons known and unknown to each other. This consideration will require an elucidation of the areas within the U.S. that have endemic TB. The Houston Tuberculosis Initiative (HTI) was a population-based active surveillance of confirmed Houston/Harris County TB cases from 1995–2004. Strengths in this dataset include the molecular characterization of laboratory confirmed cases, the collection of geographic locations (including home addresses) frequented by cases, and the HTI time period that parallels a decline in TB incidence in the United States (U.S.). The HTI dataset was used in this secondary data analysis to implement a GIS analysis of TB cases, the locations frequented by cases, and their association with risk factors associated with TB transmission. ^ This study reports, for the first time, the incidence of TB among the homeless in Houston, Texas. The homeless are an at-risk population for TB disease, yet they are also a population whose TB incidence has been unknown and unreported due to their non-enumeration. The first section of this dissertation identifies local areas in Houston with endemic TB disease. Many Houston TB cases who reported living in these endemic areas also share the TB risk factor of current or recent homelessness. Merging the 2004–2005 Houston enumeration of the homeless with historical HTI surveillance data of TB cases in Houston enabled this first-time report of TB risk among the homeless in Houston. The homeless were more likely to be US-born, belong to a genotypic cluster, and belong to a cluster of a larger size. The calculated average incidence among homeless persons was 411/100,000, compared to 9.5/100,000 among housed. These alarming rates are not driven by a co-infection but by social determinants. The unsheltered persons were hospitalized more days and required more follow-up time by staff than those who reported a steady housing situation. The homeless are a specific example of the increased targeting of prevention dollars that could occur if TB rates were reported for specific areas with known health disparities rather than as a generalized rate normalized over a diverse population. ^ It has been estimated that 27% of Houstonians use public transportation. The city layout allows bus routes to run like veins connecting even the most diverse of populations within the metropolitan area. Secondary data analysis of frequent bus use (defined as riding a route weekly) among TB cases was assessed for its relationship with known TB risk factors. The spatial distribution of genotypic clusters associated with bus use was assessed, along with the reported routes and epidemiologic-links among cases belonging to the identified clusters. ^ TB cases who reported frequent bus use were more likely to have demographic and social risk factors associated with poverty, immune suppression and health disparities. An equal proportion of bus riders and non-bus riders were cultured for Mycobacterium tuberculosis, yet 75% of bus riders were genotypically clustered, indicating recent transmission, compared to 56% of non-bus riders (OR=2.4, 95%CI(2.0, 2.8), p<0.001). Bus riders had a mean cluster size of 50.14 vs. 28.9 (p<0.001). Second order spatial analysis of clustered fingerprint 2 (n=122), a Beijing family cluster, revealed geographic clustering among cases based on their report of bus use. Univariate and multivariate analysis of routes reported by cases belonging to these clusters found that 10 of the 14 clusters were associated with use. Individual Metro routes, including one route servicing the local hospitals, were found to be risk factors for belonging to a cluster shown to be endemic in Houston. The routes themselves geographically connect the census tracts previously identified as having endemic TB. 78% (15/23) of Houston Metro routes investigated had one or more print groups reporting frequent use for every HTI study year. We present data on three specific but clonally related print groups and show that bus-use is clustered in time by route and is the only known link between cases in one of the three prints: print 22. (Abstract shortened by UMI.)^