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.)^

Goals, plans, and behavior changes: A relevant part of the post-treatment cancer experience

Background. Colorectal cancer (CRC) survivors have to manage treatment side effects, psychosocial issues, and co-morbidities, as well as modify their lifestyles to decrease risk of recurrence and prolong life. Identifying survivors’ goals and key factors that influence their goals will highlight the issues cancer survivors face post-treatment and the resources needed to help them engage in health-promoting behaviors.^ Objectives and methods. This dissertation examines the health-related goals of post-treatment CRC survivors using two studies: (1) a qualitative study to identify and describe the health goals of CRC survivors during the transition from active treatment to post-treatment survivorship and follow-up care; and (2) a cross-sectional survey to identify CRC survivors’ goals, and key factors that influence their goals.^ Results. (1) The 41 qualitative interviews indicated participants’ health-related goals were to be healthy, get back to normal, and not have a cancer recurrence. Most of the CRC survivors reported they maintained healthy behaviors, made healthy behavior changes, or had goals to change their behavior. Respondents were empowered to improve their health by maintaining follow-up care and regular health screenings, and many were managing treatment side effects in an effort to improve functional abilities. (2) The cross-sectional study found that CRC survivors’ most prevalent goals were related to healthy behaviors (i.e., eat a healthy diet and engage in physical activity), and cancer care or disease management (i.e., keep up with health screenings and monitor symptoms). Goals that survivors identified as important were similar to goals they perceived were important to their providers (i.e., goals related to cancer care, disease management). Certain goals were statistically associated with age, barriers to achieving goals, social support and health-related quality of life.^ Conclusions. CRC survivors have health-promoting goals post-treatment and are interested in making health behavior changes. Goals ranged from cancer care/surveillance and disease management to healthy lifestyle modifications. Patients may need help resolving or managing treatment side effects or co-morbidities prior to implementing health promoting behaviors. Healthcare providers’ recommendations may be a powerful resource to encourage survivors to engage in health-promoting behaviors. Self-management and goal setting support could be an appropriate strategy to assist patients with achieving their post-treatment health goals.^

Future pandemic influenza control (FPIC) related strategic management plan based on the 2009 H1N1 pandemic influenza review of health policy decisions, their practice and implications

This cross-sectional study is based on the qualitative and quantitative research design to review health policy decisions, their practice and implications during 2009 H1N1 influenza pandemic in the United States and globally. The “Future Pandemic Influenza Control (FPIC) related Strategic Management Plan” was developed based on the incorporation of the “National Strategy for Pandemic Influenza (2005)” for the United States from the U.S. Homeland Security Council and “The Canadian Pandemic Influenza Plan for the Health Sector (2006)” from the Canadian Pandemic Influenza Committee for use by the public health agencies in the United States as well as globally. The “global influenza experts’ survey” was primarily designed and administered via email through the “Survey Monkey” system to the 2009 H1N1 influenza pandemic experts as the study respondents. The effectiveness of this plan was confirmed and the approach of the study questionnaire was validated to be convenient and the excellent quality of the questions provided an efficient opportunity to the study respondents to evaluate the effectiveness of predefined strategies/interventions for future pandemic influenza control.^ The quantitative analysis of the responses to the Likert-scale based questions in the survey about predefined strategies/interventions, addressing five strategic issues to control future pandemic influenza. The effectiveness of strategies defined as pertinent interventions in this plan was evaluated by targeting five strategic issues regarding pandemic influenza control. For the first strategic issue pertaining influenza prevention and pre pandemic planning; the confirmed effectiveness (agreement) for strategy (1a) 87.5%, strategy (1b) 91.7% and strategy (1c) 83.3%. The assessment of the priority level for strategies to address the strategic issue no. (1); (1b (High Priority) > 1a (Medium Priority) > 1c (Low Priority) based on the available resources of the developing and developed countries. For the second Strategic Issue encompassing the preparedness and communication regarding pandemic influenza control; the confirmed effectiveness (agreement) for the strategy (2a) 95.6%, strategy (2b) 82.6%, strategy (2c) 91.3% and Strategy (2d) 87.0%. The assessment of the priority level for these strategies to address the strategic issue no. (2); (2a (highest priority) > 2c (high priority) >2d (medium priority) > 2b (low priority). For the third strategic issue encompassing the surveillance and detection of pandemic influenza; the confirmed effectiveness (agreement) for the strategy (3a) 90.9% and strategy (3b) 77.3%. The assessment of the priority level for theses strategies to address the strategic Issue No. (3) (3a (high priority) > 3b (medium/low priority). For the fourth strategic issue pertaining the response and containment of pandemic influenza; the confirmed effectiveness (agreement) for the strategy (4a) 63.6%, strategy (4b) 81.8%, strategy (4c) 86.3%, and strategy (4d) 86.4%. The assessment of the priority level for these strategies to address the strategic issue no. (4); (4d (highest priority) > 4c (high priority) > 4b (medium priority) > 4a (low priority). The fifth strategic issue about recovery from influenza and post pandemic planning; the confirmed effectiveness (agreement) for the strategy (5a) 68.2%, strategy (5b) 36.3% and strategy (5c) 40.9%. The assessment of the priority level for strategies to address the strategic issue no. (5); (5a (high priority) > 5c (medium priority) > 5b (low priority).^ The qualitative analysis of responses to the open-ended questions in the study questionnaire was performed by means of thematic content analysis. The following recurrent or common “themes” were determined for the future implementation of various predefined strategies to address five strategic issues from the “FPIC related Strategic Management Plan” to control future influenza pandemics. (1) Pre Pandemic Influenza Prevention, (2) Seasonal Influenza Control, (3) Cost Effectiveness of Non Pharmaceutical Interventions (NPI), (4) Raising Global Public Awareness, (5) Global Influenza Vaccination Campaigns, (6)Priority for High Risk Population, (7) Prompt Accessibility and Distribution of Influenza Vaccines and Antiviral Drugs, (8) The Vital Role of Private Sector, (9) School Based Influenza Containment, (10) Efficient Global Risk Communication, (11) Global Research Collaboration, (12) The Critical Role of Global Public Health Organizations, (13) Global Syndromic Surveillance and Surge Capacity and (14) Post Pandemic Recovery and Lessons Learned. The future implementation of these strategies with confirmed effectiveness to primarily “reduce the overall response time’ in the process of ‘early detection’, ‘strategies (interventions) formulation’ and their ‘implementation’ to eventually ensure the following health outcomes: (a) reduced influenza transmission, (b) prompt and effective influenza treatment and control, (c) reduced influenza related morbidity and mortality.^

AN OCCUPATIONAL INJURY MANAGEMENT INFORMATION SYSTEM FOR THE UNIVERSITY OF TEXAS HEALTH SCIENCE CENTER AT HOUSTON

The purpose of this research and development project was to develop a method, a design, and a prototype for gathering, managing, and presenting data about occupational injuries.^ State-of-the-art systems analysis and design methodologies were applied to the long standing problem in the field of occupational safety and health of processing workplace injuries data into information for safety and health program management as well as preliminary research about accident etiologies. The top-down planning and bottom-up implementation approach was utilized to design an occupational injury management information system. A description of a managerial control system and a comprehensive system to integrate safety and health program management was provided.^ The project showed that current management information systems (MIS) theory and methods could be applied successfully to the problems of employee injury surveillance and control program performance evaluation. The model developed in the first section was applied at The University of Texas Health Science Center at Houston (UTHSCH).^ The system in current use at the UTHSCH was described and evaluated, and a prototype was developed for the UTHSCH. The prototype incorporated procedures for collecting, storing, and retrieving records of injuries and the procedures necessary to prepare reports, analyses, and graphics for management in the Health Science Center. Examples of reports, analyses, and graphics presenting UTHSCH and computer generated data were included.^ It was concluded that a pilot test of this MIS should be implemented and evaluated at the UTHSCH and other settings. Further research and development efforts for the total safety and health management information systems, control systems, component systems, and variable selection should be pursued. Finally, integration of the safety and health program MIS into the comprehensive or executive MIS was recommended. ^

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. ^

Emerging arboviruses in Harris County, Texas

Harris County, which includes Houston, Texas, is an endemic and epidemic area for two viruses transmitted by arthropods (arboviruses). These viruses are maintained in cycles involving mosquitoes and wild birds, and transmission to humans is accidental. The majority of human infections is asymptomatic or may result in a flu-like syndrome. However, some infections can result in meningitis or encephalitis. These neuroinvasive infections may cause death, and those who survive may experience serious neurological complications requiring costly and lengthy medical care. The most important arboviruses in terms of morbidity are St. Louis encephalitis (SLEV) and West Nile (WNV) viruses. In fact, Harris County reports more SLEV encephalitis cases than any other county in the U.S. Most arboviral human cases occur from July through September, when mosquitoes are most active. Those at risk for encephalitis and death are the elderly and those with a history of hypertension or immunosuppresion. There is no specific treatment and no human vaccines are commercially available in the U.S. The approach for control of arboviruses in Harris County during epidemics is multidisciplinary and executed by several agencies. It includes surveillance, vector control, and educational messages for the population. Prevention of outbreaks consists of elimination of the vector and its breeding grounds, and practicing personal protective measures to prevent exposure to mosquitoes. ^ Current findings indicate that mosquito-borne viruses other than SLEV and WNV could pose an additional threat for the population. Eastern equine encephalitis virus (EEEV) activity has been detected in dogs and sentinel chickens in Houston and surrounding areas. Several serotypes of dengue virus have caused recent outbreaks in south Texas, and some locally-acquired cases have been detected in Houston. Since the clinical presentation of all arboviruses that cause encephalitis is very similar, and current surveillance is focused on detecting SLEV and WNV, there is a possibility that other arboviruses could be present in the area but are not being detected. Additionally, Harris County's ample annual rainfall and flooding problems, warm weather, multiple mosquito species, local and migrating birds that are susceptible to arboviral infection, and a constant flow of goods and travelers from many parts of the world could favor the emergence or re-emergence of other arboviruses. ^ The aims of this project were to determine if other arboviruses were circulating in the county, to assess the knowledge and attitudes about mosquito-borne viruses in a sample of the population, and to conduct an analysis of the initial WNV epidemic in Harris County. Through the retrospective analysis of clinical specimens collected during the 2002-2005 epidemic seasons, serologic evidence of dengue infection was detected suggesting the possibility that this virus may be co-circulating with SLEV and WNV. A cross-sectional survey revealed high awareness about arboviruses but not a consistent use of protective measures to avoid mosquitoes. The third component for this project included a retrospective review and geographical analysis of the 2002 WNV epidemic. ^ Overall, this study documented valuable information about the dengue virus, a potentially emerging arbovirus in Texas, revealed the need for more educational preventative programs, reinforced the value of mosquito and avian surveillance, and indicated the importance of continuing to investigate the factors that contribute to the development of outbreaks. ^

West Nile virus in the Rio Grande Valley: A seroprevalence study of juvenile dogs

This study used canine sentinel surveillance and collected a sample of adult mosquitoes to investigate the potential impact of West Nile virus (WNV) in human populations in the Rio Grande Valley along the Texas-Mexico border. Samples for this study were collected from juvenile dogs two months to one year of age in animal shelters located in the Rio Grande Valley. The sample was comprised of stray dogs in order to include animals with maximum nighttime exposures to Culex mosquitoes. Serum samples were collected following the 2007 WNV transmission season and were tested for IgG antibodies against WNV. Evidence of antibodies to WNV was found in 35.1% of the sample population consisting of 74 dogs. During this same time period, mosquitoes in Brownsville were trapped and morphologically identified to develop greater understanding of the mosquito populations in the region and to further understand other potential mosquito vectors for disease transmission. The vast majority of mosquitoes living in this area were Aedes albopictus (47.6%), Culex quinquefasciatus (23.7%), and Aedes aegypti (20.1%). This study shows that WNV and the vector responsible for WNV transmission are active in the Rio Grande Valley and pose a threat to the human and animal populations. ^

The seroprevalence of Rocky Mountain spotted fever in shelter dogs in Harris County

Rocky Mountain spotted fever (RMSF) is a tick-borne illness caused by the bacteria Rickettsia rickettsii, with infections occurring in humans and dogs. The prominent tick vector of RMSF, Dermacantor variabilis, and another potential vector, Rhipacephalus sanguineus, are prevalent in Texas. The goal of this study was to determine the prevalence of past infections by testing for IgG antibodies to R. rickettsii in dogs in an animal shelter in Harris County using an immunofluorescence assay (IFA) test. We found that 12.6% (24) of 191 dogs tested had a positive IFA test at 1:64 serum dilution, indicating infection at some time in the past. We also sampled the ticks present on dogs in the animal shelter to understand the prevalence of potential vector species. Of a total of 58 ticks, 86% were D. variabilis and the remaining 14% were R. sanguineus. The results of this study demonstrate that RMSF has the potential to be, and may already be, endemic to the Harris County area. Public health actions such as heightened surveillance and education that RMSF is present would be appropriate in the Harris County area.^

Shigellosis in Hidalgo County, Texas 2005--2009: A descriptive study

Shigellosis is a communicable disease harbored primarily by humans. The low infective dose, no vaccine availability, and mild or asymptomatic nature of disease has prevented eradication of Shigella in the United States. In addition, the lack of water and sewage infrastructures which normally contribute to the spread of disease in developing countries, for the most part, is a non-issue in the U.S. making surveillance and risk factor identification important prevention and control measures utilized to reduce the incidence rates of Shigellosis.^ The purpose of this study was to describe the Shigellosis disease burden among the Hidalgo County, Texas population during the 2005-2009 study period and compare these findings with national data available. The potential identification and publication of a health disparity in the form of increased Shigellosis rates among Hidalgo County residents when compared to national rates, especially age-specific rates, are intended to generate public health attention and public health action that will address this issue.^ There were 1,007 confirmed Shigellosis cases reported in Hidalgo County, Texas. An overwhelming majority (79%) of the Shigellosis cases during this time frame occurred in children less than ten years of age. Over the age of 10 through the age of 39, females constituted the majority of cases. Age-specific rates for children four years of age and younger were compared to national rates. The rates for Hidalgo County were higher at 9.2 and 1.8 cases for every one case reported nationally in 2005 and 2006, respectively. The total crude rates of Shigellosis were also higher than the rates available from the Foodborne Diseases Active Surveillance Network (FoodNet) of CDC’s Emerging Infections Program from 2005-2009. As a result, compared to the FoodNet surveillance rates, Hidalgo County experienced above average rates of Shigellosis throughout the study period. The majority of cases were identified in young children under the age of ten.^ The information gathered in this analysis could be used to implement and monitor infection control measures such as hand washing education at facilities that tend to the groups identified at higher risk of infection. In addition, the higher burden of disease found in Hidalgo County requires further study to determine if there are factors associated with an increased risk of Shigellosis in this community and other border communities along the U.S.-Mexico border exist.^

Deciphering the C-Type Lectin Receptor Signaling Pathway in Macrophages in Response to Candida albicans

Candida albicans causes opportunistic fungal infections in humans and is a significant cause of mortality and morbidity in immune-compromised individuals. Dectin-2, a C-type lectin receptor, is required for recognition of C. albicans by innate immune cells and is required for initiation of the anti-fungal immune response. We set out to identify components of the intracellular signaling cascade downstream of Dectin-2 activation in macrophages and to understand their importance in mediating the immune response to C. albicans in vivo. Using macrophages derived from Phospholipase-C-gamma 1 and 2 (PLCγ1and PLCγ2) knockout mice, we demonstrate that PLCγ2, but not PLCγ1, is required for activation of NF-κB and MAPK signaling pathways after C. albicans stimulation, resulting in impaired production of pro-inflammatory cytokines and reactive oxygen species. PLCγ2-deficient mice are highly susceptible to infections with C. albicans, indicating the importance of this pathway to the anti-fungal immune response. TAK1 and TRAF6 are critical nodes in NF-κB and MAPK activation downstream of immune surveillance and may be critical to the signaling cascade initiated by C-type lectin receptors in response to C. albicans. Macrophages derived from both TAK1 and TRAF6-deficient mice were unable to activate NF-κB and MAPK and consequently failed to produce inflammatory cytokines characteristic of the response to C. albicans. In this work we have identified PLCγ2, TAK1 and TRAF6 as components of a signaling cascade downstream of C. albicans recognition by C-type lectin receptors and as critical mediators of the anti-fungal immune response. A mechanistic understanding of the host immune response to C. albicans is important for the development of anti-fungal therapeutics and in understanding risk-factors determining susceptibility to C. albicans infection.

Dengue transmission risk maps of the continental United States

Dengue fever is a strictly human and non-human primate disease characterized by a high fever, thrombocytopenia, retro-orbital pain, and severe joint and muscle pain. Over 40% of the world population is at risk. Recent re-emergence of dengue outbreaks in Texas and Florida following the re-introduction of competent Aedes mosquito vectors in the United States have raised growing concerns about the potential for increased occurrences of dengue fever outbreaks throughout the southern United States. Current deficiencies in vector control, active surveillance and awareness among medical practitioners may contribute to a delay in recognizing and controlling a dengue virus outbreak. Previous studies have shown links between low-income census tracts, high population density, and dengue fever within the United States. Areas of low-income and high population density that correlate with the distribution of Aedes mosquitoes result in higher potential for outbreaks. In this retrospective ecologic study, nine maps were generated to model U.S. census tracts’ potential to sustain dengue virus transmission if the virus was introduced into the area. Variables in the model included presence of a competent vector in the county and census tract percent poverty and population density. Thirty states, 1,188 counties, and 34,705 census tracts were included in the analysis. Among counties with Aedes mosquito infestation, the census tracts were ranked high, medium, and low risk potential for sustained transmission of the virus. High risk census tracts were identified as areas having the vector, ≥20% poverty, and ≥500 persons per square mile. Census tracts with either ≥20% poverty or ≥500 persons per square mile and have the vector present are considered moderate risk. Census tracts that have the vector present but have <20% poverty and <500 persons per square mile are considered low risk. Furthermore, counties were characterized as moderate risk if 50% or more of the census tracts in that county were rated high or moderate risk, and high risk if 25% or greater were rated high risk. Extreme risk counties, which were primarily concentrated in Texas and Mississippi, were considered having 50% or greater of the census tracts ranked as high risk. Mapping of geographic areas with potential to sustain dengue virus transmission will support surveillance efforts and assist medical personnel in recognizing potential cases. ^

Developing the follow-up schedules for women with breast cancer

Background: The follow-up care for women with breast cancer requires an understanding of disease recurrence patterns and the follow-up visit schedule should be determined according to the times when the recurrence are most likely to occur, so that preventive measure can be taken to avoid or minimize the recurrence. Objective: To model breast cancer recurrence through stochastic process with an aim to generate a hazard function for determining a follow-up schedule. Methods: We modeled the process of disease progression as the time transformed Weiner process and the first-hitting-time was used as an approximation of the true failure time. The women's "recurrence-free survival time" or a "not having the recurrence event" is modeled by the time it takes Weiner process to cross a threshold value which represents a woman experiences breast cancer recurrence event. We explored threshold regression model which takes account of covariates that contributed to the prognosis of breast cancer following development of the first-hitting time model. Using real data from SEER-Medicare, we proposed models of follow-up visits schedule on the basis of constant probability of disease recurrence between consecutive visits. Results: We demonstrated that the threshold regression based on first-hitting-time modeling approach can provide useful predictive information about breast cancer recurrence. Our results suggest the surveillance and follow-up schedule can be determined for women based on their prognostic factors such as tumor stage and others. Women with early stage of disease may be seen less frequently for follow-up visits than those women with locally advanced stages. Our results from SEER-Medicare data support the idea of risk-controlled follow-up strategies for groups of women. Conclusion: The methodology we proposed in this study allows one to determine individual follow-up scheduling based on a parametric hazard function that incorporates known prognostic factors.^

Surveillance of antimicrobial resistance of Streptococcus pneumoniae and Haemophilus influenzae in children with pneumonia

In order to identify optimal therapy for children with bacterial pneumonia, Pakistan's ARI Program, in collaboration with the National Institute of Health (NIH), Islamabad, undertook a national surveillance of antimicrobial resistance in S. pneumoniae and H. influenzae. The project was carried out at selected urban and peripheral sites in 6 different regions of Pakistan, in 1991–92. Nasopharyngeal (NP) specimens and blood cultures were obtained from children with pneumonia diagnosed in the outpatient clinic of participating facilities. Organisms were isolated by local hospital laboratories and sent to NIH for confirmation, serotyping and antimicrobial susceptibility testing. Following were the aims of the study (i) to determine the antimicrobial resistance patterns of S. pneumoniae and H. influenzae in children aged 2–59 months; (ii) to determine the ability of selected laboratories to identify and effectively transport isolates of S. pneumoniae and H. influenzae cultured from nasopharyngeal and blood specimens; (iii) to validate the comparability of resistance patterns for nasopharyngeal and blood isolates of S. pneumoniae and H. influenzae from children with pneumonia; and (iv) to examine the effect of drug resistance and laboratory error on the cost of effectively treating children with ARI. ^ A total of 1293 children with ARI were included in the study: 969 (75%) from urban areas and 324 (25%) from rural parts of the country. Of 1293, there were 786 (61%) male and 507 (39%) female children. The resistance rate of S. pneumoniae to various antibiotics among the urban children with ARI was: TMP/SMX (62%); chloramphenicol (23%); penicillin (5%); tetracycline (16%); and ampicillin/amoxicillin (0%). The rates of resistance of H. influenzae were higher than S. pneumoniae: TMP/SMX (85%); chloramphenicol (62%); penicillin (59%); ampicillin/amoxicillin (46%); and tetracycline (100%). There were similar rates of resistance to each antimicrobial agent among isolates from the rural children. ^ Of a total 614 specimens that were tested for antimicrobial susceptibility, 432 (70.4%) were resistant to TMP/SMX and 93 (15.2%) were resistant to antimicrobial agents other than TMP/SMX viz. ampicillin/amoxicillin, chloramphenicol, penicillin, and tetracycline. ^ The sensitivity and positive predictive value of peripheral laboratories for H. influenzae were 99% and 65%, respectively. Similarly, the sensitivity and positive predictive value of peripheral laboratory tests compared to gold standard i.e. NIH laboratory, for S. pneumoniae were 99% and 54%, respectively. ^ The sensitivity and positive predictive value of nasopharyngeal specimens compared to blood cultures (gold standard), isolated by the peripheral laboratories, for H. influenzae were 88% and 11%, and for S. pneumoniae 92% and 39%, respectively. (Abstract shortened by UMI.)^

The normal range of the leukocyte count: Implications for surveillance of occupational and environmental exposure and the practice of preventive medicine

Leukopenia, the leukocyte count, and prognosis of disease are interrelated; a systematic search of the literature was undertaken to ascertain the strength of the evidence. One hundred seventy-one studies were found from 1953 onward pertaining to the predictive capabilities of the leukocyte count. Of those studies, 42 met inclusion criteria. An estimated range of 2,200cells/μL to 7,000cells/μL was determined as that which indicates good prognosis in disease and indicates the least amount of risk to an individual overall. Tables of the evidence are included indicating the disparate populations examined and the possible degree of association. ^

Prevalence and risk factors of methicillin-resistant Staphylococcus aureus in critically-ill hospitalized patients in a tertiary care center in Houston, Texas: An active surveillance pilot project

Objective. The objective of this study is to determine the prevalence of MRSA colonization in adult patients admitted to intensive care units at an urban tertiary care hospital in Houston, Texas and to evaluate the risk factors associated with colonization during a three month active-screening pilot project. Design. This study used secondary data from a small cross-sectional pilot project. Methods. All patients admitted to the seven specialty ICUs were screened for MRSA by nasal culture. Results were obtained utilizing the BD GeneOhm™ IDI-MRSA assay in vitro diagnostic test, for rapid MRSA detection. Statistical analysis was performed using the STATA 10, Epi Info, and JavaStat. Results . 1283/1531 (83.4%) adult ICU admissions were screened for nasal MRSA colonization. Of those screened, demographic and risk factor data was available for 1260/1283 (98.2%). Unresolved results were obtained for 73 patients. Therefore, a total of 1187/1531 (77.5%) of all ICU admissions during the three month study period are described in this analysis. Risk factors associated with colonization included the following: hospitalization within the last six months (odds ratio 2.48 [95% CI, 1.70-3.63], p=0.000), hospitalization within the last 12 months, (odds ratio 2.27 [95% CI, 1.57-3.80], p=0.000), and having diabetes mellitus (odds ratio 1.63 [95% CI, 1.14-2.32], p=0.007). Conclusion. Based on the literature, the prevalence of MRSA for this population is typical of other prevalence studies conducted in the United States and coincides with the continual increasing trend of MRSA colonization. Significant risk factors were similar to those found in previous studies. Overall, the active surveillance screening pilot project has provided valuable information on a population not widely addressed. These findings can aid in future interventions for the education, control, prevention, and treatment of MRSA. ^