Search

Breakthrough invasive fungal infections (IFI) have emerged as a significant problem in patients receiving systemic antifungals; however, consensus criteria for defining breakthrough IFI are missing. This position paper establishes broadly applicable definitions of breakthrough IFI for clinical research. Representatives of the Mycoses Study Group Education and Research Consortium (MSG-ERC) and the European Confederation of Medical Mycology (ECMM) reviewed the relevant English literature for definitions applied and published through 2018. A draft proposal for definitions was developed, and circulated to all members of the two organizations for comment and suggestions. The authors addressed comments received, and circulated the updated document for approval. Breakthrough IFI was defined as any IFI occurring during exposure to an antifungal drug, including fungi outside the spectrum of activity of an antifungal. The time of breakthrough IFI was defined as the first attributable clinical sign or symptom, mycological finding or radiological feature. The period defining breakthrough IFI depends on pharmacokinetic properties and extends at least until one dosing interval after drug discontinuation. Persistent IFI describes IFI that is unchanged/stable since treatment initiation with ongoing need for antifungal therapy. It is distinct from refractory IFI, defined as progression of disease and therefore similar to non-response to treatment. Relapsed IFI occurs after treatment, and is caused by the same pathogen at the same site, although dissemination can occur. These proposed definitions are intended to support the design of future clinical trials and epidemiological research in clinical mycology, with the ultimate goal of increasing the comparability of clinical trial results.

The widespread availability of antiretroviral therapy (ART) for HIV infection in Sub-Saharan Africa (SSA) has resulted in decreased morbidity, mortality, and transmission of HIV. This region, however, still represents the majority of the global burden of HIV. Furthermore, levels of retention in care and medication adherence, critical determinants of ART effectiveness, are currently suboptimal, and, thus, continue to be the target of many interventions. This dissertation is comprised of three chapters related to understanding ART adherence and interventions to improve it.Chapter 1 quantitatively describes and examines the distribution of poor adherence to antiretroviral therapy in a study of HIV-positive patients in Zambia. In a novel application of the Lorenz curve, a tool used commonly in economics, this analysis characterized the concentration of medication non-possession in a network of clinics in order to identify “hotspots” and predictors of poor adherence. Results extend previous studies by revealing that even though average adherence is high, lapses in adherence are common and concentrated among a minority of patients, and also in certain clinics. This concentration and variability varies with time on ART. Furthermore, a small fraction of patients accounts for the majority of days of medication non-possession, with the size of this group increasing with time on ART. This suggests that targeted interventions may represent a preferable overall strategy as compared to those targeting all patients to improve adherence. Furthermore, there was high variability across clinics suggesting that interventions targeting clinic “hotspots” may also represent an efficient use of resources to improve ART adherence. Chapter 2 presents the results of the first qualitative study to examine conditional incentives for ART adherence and their potential pathways of action among people living with HIV. This study was conducted within a study of conditional food and cash transfers to increase retention in care and adherence to ART among HIV-positive food insecure recent adults in Shinyanga, Tanzania. Although financial and in-kind incentives have been shown to improve outcomes along the HIV care cascade, results are mixed, and there is little evidence about the pathways through which incentives work. Results of this qualitative study and analysis revealed that incentives acted through three primary pathways to potentially increase retention in care and adherence to ART: 1) addressing competing needs and offsetting opportunity costs associated with clinic attendance, 2) increasing motivation and 3) alleviating stress associated with attending clinic, worry about providing for oneself and one’s family, and providing hope for a better future. The first pathway was the strongest, which was consistent with field observations and discussions with local clinic staff, research staff, and Ministry of Health officials. Participants did not report any harmful events associated with the incentives, and reported a variety of beneficial spillover effects on household welfare. Understanding these pathways can help improve design and targeting of future food or cash incentive interventions. Chapter 3 focused on intrinsic motivation within the aforementioned study of food and cash transfers for ART adherence in Tanzania. Some critical of incentives argue that incentives can ‘crowd out’ intrinsic motivation, making the individual less likely to engage in the desired behavior after the incentive is removed, potentially leading to limited durability of effect and causing harm in the long term. This hypothesis was examined among recent antiretroviral treatment initiates in Tanzania by comparing participants’ level of intrinsic motivation before receiving transfers to the level once the transfer period ended. The analysis revealed that, not only did intrinsic motivation not decrease after the transfer period ended, but that the level of intrinsic motivation increased overall and within study arms. Furthermore, the change in motivation did not differ by study arms. As the first study to empirically examine the crowding out hypothesis regarding incentives in a real-world, resource-limited setting, these results suggest that incentive interventions in such settings should not be impeded by concerns of crowding out intrinsic motivation.Together these chapters contribute to improving our understanding of antiretroviral adherence and intervention response. The Lorenz curve and medication possession analysis provides a more comprehensive and detailed measurement and illustration of adherence and its variability across individuals and clinics in Zambia. Such information is critical to targeting and designing future interventions. Next, by examining an ongoing intervention to improve adherence in Tanzania, we were able to elucidate and examine the potential pathways of action of food and cash transfers. Furthermore, we found no evidence that these incentives decreased intrinsic motivation. Knowledge gleaned from this deep exploration of the incentives’ mechanism of action in a real-world setting not only informs refinement of the intervention, but also helps to fill the gap in understanding how and when these interventions may work.

Worldwide, women struggle to control the timing and spacing of childbearing, resulting in a high number of pregnancies that are unintended. In order to achieve many of the United Nations Millennium Development goals related to maternal and child health, gender equality and HIV prevention, the incidence of unintended pregnancy and its consequences must be significantly reduced. The three papers comprising this dissertation represent distinct analyses related to the general theme of unintended pregnancy among disadvantaged women, with a particular focus on research that is responsive to and can directly inform pressing policy questions. Paper 1 synthesizes the observational evidence on the relationship between use of hormonal contraception (HC) and women's risk of HIV acquisition using quantitative meta-analysis. Given the central role of HC in preventing unintended pregnancy, policymakers and practitioners are struggling to translate an inconsistent body of observational evidence on this question into balanced contraceptive guidance for women, in particular in high prevalence HIV settings such as sub Saharan Africa. Pooled effect estimates from studies that use a comparable approach to identify the effect of use of various forms of HC on risk of HIV acquisition, and adequately address confounding and selection bias, suggest that use of certain forms of HC is associated with an elevated risk of HIV acquisition, but not of the magnitude that would merit complete withdrawal of these methods.Paper 2 capitalizes on a unique study design to examine the role of an unintended birth on women's educational attainment in the United States. Despite over three decades of research, there remains debate over the extent to which reduced educational attainment among women with an unintended pregnancy is a function of childbearing itself, or a consequence of common selection factors that predispose women to both early childbearing and poor socioeconomic outcomes. By exploiting a discontinuity in the timing of presentation for abortion care, this paper compares the incidence of graduation or drop out from school among exchangeable groups of women, half of whom had an unintended birth and half of whom received an abortion. Unlike previous research, this analysis finds no difference in the educational achievements of women who experience an unintended birth and those that experience an unintended pregnancy that they do not carry to term.Finally, paper 3 explores the extent to which minors seeking abortion in the U.S. involve parents and other important individuals in their decision-making process, and how these relationships influence their confidence in and projected coping with their abortion decision. Despite the fact that a majority of states require parental involvement in minors' abortion, little is known about the effect of involving a parent on minors' abortion decision-making and anticipated coping after abortion. This analysis reveals that in the absence of a law mandating involvement, a majority of minors involve parents, primarily mothers, and male partners in their abortion decisions. For a minority of minors, experiencing pressure or lack of support from mothers reduces confidence in their decision and increases their likelihood of anticipating poor coping after an abortion.

Latino day laborers in the United States are socially and economically vulnerable due to exclusionary immigration policies. Using data from a multi-mode survey, we examine the relationship between immigration policy legal vulnerability and mental health outcomes among 138 Latino, male day laborers (mean age = 45.65, SD = 12.05). Multivariable linear and logistic regression models separately estimated the effect of legal vulnerability, as measured by the Perceived Immigration Policy Effects Scale, on anxiety and depression symptoms and a positive depression and anxiety screening, respectively. Approximately 26.1% and 27.9% of day laborers reported depression and anxiety symptoms, respectively. In each adjusted model, we find a positive relationship between legal vulnerability and adverse mental health. Immigration policy legal vulnerability is associated with more depression and anxiety symptoms among Latino day laborers. Policies to reduce legal vulnerability, such as pathways to citizenship and employment authorization, may support Latino day laborers' mental health outcomes.

Poor sleep is common among older adults, affecting a wide range of health outcomes. However, little is known about sleep issues among older Korean immigrants, the fastest growing Asian American subgroup in the United States. We aimed to explore multiple factors associated with sleep among this group. We analyzed cross-sectional survey data from 43 older immigrants living in two large Korean communities in Southern California. Perceived sleep quality was significantly associated with gender, living arrangement, employment status, mental health, and sleep-related beliefs (all p-values

COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to examine the underlying vulnerabilities of Mexican immigrants in New York City (NYC) and Los Angeles (LA), its correspondence with area-level COVID-19 morbidity and mortality, and to document the role of trusted and culturally sensitive services offered during the pandemic through the Ventanillas de Salud (i.e. VDS, Health Windows) program. The study uses a mixed-methods approach including a cross-sectional survey of Mexican immigrants in LA and NYC collected in the Mexican Consulates at the onset of the pandemic, complemented with a georeferencing analysis and key informant interviews. Data suggested an increased vulnerability to COVID-19 given participants reported health status, health care profile and place of residence, which coincided with the georeferencing analysis. The key informant interviews confirmed the vulnerability of this population and the supporting role of VDS in helping immigrants navigate health systems and disseminate health information. Mexican immigrants had an increased vulnerability to COVID-19 at the individual, geographic and systemic levels. Trusted and culturally sensitive services are needed to overcome some of the barriers and risk factors that increase the vulnerability of URM and immigrant populations to COVID-19. Supplementary Information The online version contains supplementary material available at 10.1007/s10903-021-01283-8.

Purpose We examined prostate cancer patients’ participation in research and associated factors by race/ethnicity in a multiethnic sample. Methods Men with a new diagnosis of prostate cancer were identified through the California Cancer Registry. Patients completed a cross-sectional telephone interview in English, Spanish, Cantonese or Mandarin. Multivariable logistic regression models, stratified by race/ethnicity, estimated the associations of patient demographic and health characteristics with participation in (1) any research, (2) behavioral research, and (3) biological/clinical research. Results We included 855 prostate cancer patients: African American (19%), Asian American (15%), Latino (24%), and White (42%). In the overall model of participation in any research, African American men (Odds Ratio (OR) = 2.54, 95% CI 1.63–3.94), and those with two or more comorbidities (OR = 2.20, 95% CI 1.27–3.80) were more likely to report participation. Men 65 years old and older (OR = 0.65, 95% CI 0.47–0.91), those who were married or living with a partner (OR = 0.67, 95% CI 0.45–0.98), and those who completed the interview in Spanish (OR = 0.36, 95% CI 0.15–0.85) were less likely to report participating in any research. Stratified analyses identified racial/ethnic-specific sociodemographic characteristics associated with lower research participation, including Spanish or Chinese language, older age, and lower education. Conclusion African American prostate cancer patients reported higher research participation than all other groups. However, recruitment efforts are still needed to overcome barriers to participation for Spanish and Chinese speakers, and barriers among older adults and those with lower education levels.

Latinxs continue to be overrepresented in the U.S. HIV epidemic. We examined the transnational practices, family relationships, and realities of life of Mexicans and Puerto Ricans living with HIV in the continental U.S. We conducted qualitative interviews with 44 persons of Mexican and Puerto Rican origin participating in HIV care engagement interventions. Framework Analysis guided our data analysis. Among participants, a strong connection to the family was intertwined with transnational practices: communication, travel to their place of origin to maintain family ties, and material and/or emotional support. Separation from their family contributed to social isolation. Many participants lacked emotional support regarding living with HIV. Transnational practices and family relationships were intrinsic to the experiences of Mexicans and Puerto Ricans living with HIV in the continental U.S.; and may help understand the points of reference, health-seeking behaviors, and support sources that influence their health, well-being and engagement in HIV care.

Author(s): Bialous, Stella A; Nohavova, Iveta; Kralikova, Eva; Wells, Marjorie J; Brook, Jenny; Sarna, Linda | Abstract: IntroductionProperly educated nurses delivering evidence-based tobacco dependence treatment could contribute to improving health and reducing regional disparities in tobacco-related disease and death in Central and Eastern Europe. The aims of this study are to describe development of the Eastern European Nurses' Centre of Excellence for Tobacco Control (COE) and evaluate its online educational program on tobacco dependence treatment using the 5As framework.MethodsThe online education evaluation followed a prospective, single group, pre- and post-assessment of changes in nurses' self-reported tobacco cessation interventions. Leaders from five Eastern European countries (Hungary, Czech Republic, Romania, Slovakia, Slovenia) developed protocols for in-country tobacco control education. Nurses responded to a baseline survey, accessed an online nursing educational program, and completed a follow-up survey at 3 months, in the period December 2015 to June 2016. A total of 695 nurses from five countries answered questions on cessation interventions at baseline and of these 507 (73%) completed a follow-up survey at 3 months.ResultsAt the follow-up at 3 months, the 507 nurses self-reported a significant increase in providing all 5A components, i.e. nurses were significantly (pl0.0001) more likely to always /usually advise a patient to quit, assess interest in quitting (p=0.002), assist with a quit plan, review barriers to quitting and recommend a smoke-free home post-discharge (all pl0.0001). They were also significantly more likely (p=0.01) to agree or strongly agree that nurses have an obligation to advise patients on the risks of smoking. There was a significant increase (pl0.0001) in nurses' estimate of the number of patients they provided a cessation intervention the previous week. Nurses who smoked were 60% more likely to assist and arrange compared to nurses who never smoked.ConclusionsCoordinating multi-country activities through a COE was successful in engaging a network of nurses to use an online educational program and participate in other tobacco control activities.

Skilled nursing home facilities (SNFs) house a vulnerable population frequently exposed to respiratory pathogens. Our study aims to gain a better understanding of the transmission of nursing home-acquired viral respiratory infections in non-epidemic settings. Symptomatic surveillance was performed in three SNFs for residents exhibiting acute respiratory symptoms. Environmental surveillance of five high-touch areas was performed to assess possible transmission. All resident and environmental samples were screened using a commercial multiplex polymerase chain reaction platform. Bayesian methods were used to evaluate environmental contamination. Among nursing home residents with respiratory symptoms, 19% had a detectable viral pathogen (parainfluenza-3, rhinovirus/enterovirus, RSV, or influenza B). Environmental contamination was found in 20% of total room surface swabs of symptomatic residents. Environmental and resident results were all concordant. Target period prevalence among symptomatic residents ranged from 5.5 to 13.3% depending on target. Bayesian analysis quantifies the probability of environmental shedding due to parainfluenza-3 as 92.4% (95% CI: 86.8–95.8%) and due to rhinovirus/enterovirus as 65.6% (95% CI: 57.9–72.5%). Our findings confirm that non-epidemic viral infections are common among SNF residents exhibiting acute respiratory symptoms and that environmental contamination may facilitate further spread with considerable epidemiological implications. Findings further emphasise the importance of environmental infection control for viral respiratory pathogens in long-term care facilities.

// Hanan Goldberg 1 , Zachary Klaassen 1 , Thenappan Chandrasekar 1 , Rashid Sayyid 1 , Girish S. Kulkarni 1 , Robert J. Hamilton 1 and Neil E. Fleshner 1 1 Division of Urology, Department of Surgical Oncology, Princess Margaret Cancer Centre, University Health Network and the University of Toronto, Toronto, Ontario, Canada Correspondence to: Hanan Goldberg, email: gohanan@gmail.com Keywords: upper tract urothelial carcinoma; chemotherapy; cancer specific mortality; other cause mortality Received: August 15, 2017 Accepted: February 24, 2018 Published: April 10, 2018 ABSTRACT Objectives: To evaluate the utilization and outcomes of perioperative chemotherapy in non-metastatic UTUC patients over the past decade using a large national database. Methods: All patients aged 18 and older diagnosed with non-metastatic UTUC between 2004 and 2013 were identified within the Surveillance, Epidemiology and End Results (SEER) database. Relevant clinical data was collected and predictors of cancer specific mortality (CSM) and other cause mortality (OCM) were analyzed. Results: The total cohort included 8,762 patients. Of these, 1,402 (16%) patients received chemotherapy, including only 35% of high-risk patients ( > pT2 or N1). Treated patients had higher CSM (21.3% vs. 13.1%, p

Regardless of their area of specialization, adult psychiatrists are likely to encounter gender-variant patients; however, medical school curricula and psychiatric residency training programs devote little attention to their care. This article aims to assist adult psychiatrists who are not gender specialists in the delivery of respectful, clinically competent, and culturally attuned care to gender-variant patients, including those who identify as transgender or transsexual or meet criteria for the diagnosis of Gender Dysphoria (GD) as defined by The Diagnostic and Statistical Manual of Mental Disorders (5th edition). The article will also be helpful for other mental health professionals. The following areas are addressed: evolution of diagnostic nosology, epidemiology, gender development, and mental health assessment, differential diagnosis, treatment, and referral for gender-affirming somatic treatments of adults with GD.

SUMMARYWe compared the cost-effectiveness (CE) of an active case-finding (ACF) programme for household contacts of tuberculosis (TB) cases enrolled in first-line treatment to routine passive case-finding (PCF) within an established national TB programme in Peru. Decision analysis was used to model detection of TB in household contacts through: (1) self-report of symptomatic cases for evaluation (PCF), (2) a provider-initiated ACF programme, (3) addition of an Xpert MTB/RIF diagnostic test for a single sputum sample from household contacts, and (4) all strategies combined. CE was calculated as the incremental cost-effectiveness ratio (ICER) in terms of US dollars per disability-adjusted life years (DALYs) averted. Compared to PCF alone, ACF for household contacts resulted in an ICER of $2155 per DALY averted. The addition of the Xpert MTB/RIF diagnostic test resulted in an ICER of $3275 per DALY averted within a PCF programme and $3399 per DALY averted when an ACF programme was included. Provider-initiated ACF of household contacts in an urban setting of Lima, Peru can be highly cost-effective, even including costs to seek out contacts and perform an Xpert/MTB RIF test. ACF including Xpert MTB/RIF was not cost-effective if TB cases detected had high rates of default from treatment or poor outcomes.

SUMMARYWe assessed evidence of exposure to viruses and bacteria in an unmanaged and long-isolated population of Soay sheep (Ovis aries) inhabiting Hirta, in the St Kilda archipelago, 65 km west of Benbecula in the Outer Hebrides of Scotland. The sheep harbour many metazoan and protozoan parasites but their exposure to viral and bacterial pathogens is unknown. We tested for herpes viral DNA in leucocytes and found that 21 of 42 tested sheep were infected with ovine herpesvirus 2 (OHV-2). We also tested 750 plasma samples collected between 1997 and 2010 for evidence of exposure to seven other viral and bacterial agents common in domestic Scottish sheep. We found evidence of exposure toLeptospiraspp., with overall seroprevalence of 6·5%. However, serological evidence indicated that the population had not been exposed to border disease, parainfluenza, maedi-visna, or orf viruses, nor toChlamydia abortus. Some sheep tested positive for antibodies againstMycobacterium aviumsubsp.paratuberculosis(MAP) but, in the absence of retrospective faecal samples, the presence of this infection could not be confirmed. The roles of importation, the pathogen–host interaction, nematode co-infection and local transmission warrant future investigation, to elucidate the transmission ecology and fitness effects of the few viral and bacterial pathogens on Hirta.

SUMMARYWe conducted prospective, community-wide surveillance for acute respiratory illnesses (ARIs) in Rochester, NY and Marshfield, WI during a 3-month period in winter 2011. We estimated the incidence of ARIs in each community, tested for viruses, and determined the proportion of ARIs associated with healthcare visits. We used a rolling cross-sectional design to sample participants, conducted telephone interviews to assess ARI symptoms (defined as a current illness with feverishness or cough within the past 7 days), collected nasal/throat swabs to identify viruses, and extracted healthcare utilization from outpatient/inpatient records. Of 6492 individuals, 321 reported an ARI within 7 days (4·9% total, 5·7% in Rochester, 4·4% in Marshfield); swabs were collected from 208 subjects. The cumulative ARI incidence for the entire 3-month period was 52% in Rochester [95% confidence interval (CI) 42–63] and 35% in Marshfield (95% CI 28–42). A specific virus was identified in 39% of specimens: human coronavirus (13% of samples), rhinovirus (12%), RSV (7%), influenza virus (4%), human metapneumovirus (4%), and adenovirus (1%). Only 39/200 (20%) had a healthcare visit (2/9 individuals with influenza). ARI incidence was ~5% per week during winter.

Phylodynamics has become an increasingly popular statistical framework to extract evolutionary and epidemiological information from pathogen genomes. By harnessing such information, epidemiologists aim to shed light on the spatio-temporal patterns of spread and to test hypotheses about the underlying interaction of evolutionary and ecological dynamics in pathogen populations. Although the field has witnessed a rich development of statistical inference tools with increasing levels of sophistication, these tools initially focused on sequences as their sole primary data source. Integrating various sources of information, however, promises to deliver more precise insights in infectious diseases and to increase opportunities for statistical hypothesis testing. Here, we review how the emerging concept of data integration is stimulating new advances in Bayesian evolutionary inference methodology which formalize a marriage of statistical thinking and evolutionary biology. These approaches include connecting sequence to trait evolution, such as for host, phenotypic and geographic sampling information, but also the incorporation of covariates of evolutionary and epidemic processes in the reconstruction procedures. We highlight how a full Bayesian approach to covariate modeling and testing can generate further insights into sequence evolution, trait evolution, and population dynamics in pathogen populations. Specific examples demonstrate how such approaches can be used to test the impact of host on rabies and HIV evolutionary rates, to identify the drivers of influenza dispersal as well as the determinants of rabies cross-species transmissions, and to quantify the evolutionary dynamics of influenza antigenicity. Finally, we briefly discuss how data integration is now also permeating through the inference of transmission dynamics, leading to novel insights into tree-generative processes and detailed reconstructions of transmission trees. [Bayesian inference; birth–death models; coalescent models; continuous trait evolution; covariates; data integration; discrete trait evolution; pathogen phylodynamics.

Purpose: To investigate the association between social isolation and loneliness, how they relate to depression, and whether these associations are explained by genetic influences. Methods: We used data from the age-18 wave of the Environmental Risk (E-Risk) Longitudinal Twin Study, a birth cohort of 1,116 same-sex twin pairs born in England and Wales in 1994 and 1995. Participants reported on their levels of social isolation, loneliness and depressive symptoms. We conducted regression analyses to test the differential associations of isolation and loneliness with depression. Using the twin study design, we estimated the proportion of variance in each construct and their covariance that was accounted for by genetic and environmental factors. Results: Social isolation and loneliness were moderately correlated (r = .39), reflecting the separateness of these constructs, and both were associated with depression. When entered simultaneously in a regression analysis, loneliness was more robustly associated with depression. We observed similar degrees of genetic influence on social isolation (40%) and loneliness (38%), and a smaller genetic influence on depressive symptoms (29%), with the remaining variance accounted for by the non-shared environment. Genetic correlations of .65 between isolation and loneliness and .63 between loneliness and depression indicated a strong role of genetic influences in the co-occurrence of these phenotypes. Conclusions: Socially isolated young adults do not necessarily experience loneliness. However, those who are lonely are often depressed, partly because the same genes influence loneliness and depression. Interventions should not only aim at increasing social connections but also focus on subjective feelings of loneliness.

Although considered a disease of the elderly, a subset of patients with mesothelioma are young (

Epidemiol. Infect. (2015), 143, 949–950. © Cambridge University Press 2014 doi:10.1017/S0950268814001794 COMMENTARY Mycobacterium tuberculosis and the search for the impossible truth T. F. BREWER* University of California, Los Angeles, CA, USA Received 11 June 2014; Accepted 25 June 2014; first published online 27 August 2014 The ability of accidentally inoculated Mycobacterium tuberculosis to cause skin and soft tissue infections has been known for almost two centuries, yet it was, and remains, a rare form of tuberculosis (TB) [1]. Because M. tuberculosis is assumed to have very limited survival outside the host, environmental reservoirs are not felt to have any role in TB transmission [2]. When inoculation TB cases are reported, they tend to be iso- lated or to include a limited number of cases over a short period of time [3]. In contrast, non-tuberculous mycobacteria (NTM) are ubiquitous in the environment, and are readily iden- tified from water, soil, instruments and other sources [4]. They can be resistant to disinfection, and have been responsible for a range of skin and soft tissue infec- tion outbreaks through a variety of inoculation proce- dures including tattoos, surgical procedures, injections and acupuncture among others [5]. In one epidemic associated with video-assisted surgical instruments, 1051 possible cases of Mycobacterium massiliense wound infection were identified across 38 Brazilian hos- pitals over an 11-month period [6]. Among mycobac- teria, the members of the M. tuberculosis complex and NTM are presumed to inhabit two different worlds. What then is one to make of the recent report by Wang and colleagues in this Journal reporting 13 cases of acupuncture-associated inoculation TB occur- ring over a 4-month period in patients attending a southeastern China clinic? [7]. The epidemiological evi- dence supports a point source for the outbreak, and the microbiological evidence supports M. tuberculosis as * Address for correspondence: T. F. Brewer, MD, MPH, University of California, Los Angeles, Box 951405, Los Angeles, CA 90095, USA. (Email: tbrewer@conet.ucla.edu) the causative agent. But given conventional wisdom that M. tuberculosis should not exist in the environment for any meaningful length of time, one must consider alternative explanations. The first would be that these cases were unrelated; however, the cases all attended the same clinic, developed infections at the site of known injections, had – when tested – the same strain of M. tuberculosis and new cases stopped occurring when the clinic switched to disposable needles. The conclusion that these cases were unrelated seems improbable. Another possibility was that NTM were misiden- tified as M. tuberculosis. All 13 patients were M. tu- berculosis culture positive, and the 10 patients who underwent interferon-gamma release assay testing using the T-SPOT.TB test were also positive. Five iso- lates were genotyped at the Disease Control Centre of Zhejiang Province and found to be M. tuberculosis, Beijing type. Misdiagnosis of NTM also seems im- probable. Another possibility is laboratory cross- contamination. Twelve patients had positive stains for acid-fast bacilli at aspiration or surgical drainage, and granulomatous reactions were found on histopatho- logical examination of biopsies from all patients. The cases also were spread over a 4-month time period, further making laboratory cross-contamination unlikely. To paraphrase the great fictional detective Sherlock Holmes, once the improbable has been ruled out, one must consider the impossible, i.e. that M. tuberculosis can survive in the environment for extended periods of time and remain capable of causing disease. Mycobacterium bovis, another member of the M. tu- berculosis complex, has previously been shown to be able to survive in the environment for extended peri- ods of time, and soil-contaminated M. bovis may be responsible for ongoing outbreaks of disease in cattle in the UK, for example [8, 9]. Mycobacterium canettii

Recent genome-wide studies conducted in European Whites have identified novel susceptibility genes for childhood acute lymphoblastic leukemia (ALL). We sought to examine whether these loci are susceptibility genes among Hispanics, whose reported incidence of childhood ALL is the highest of all ethnic groups in California, and whether their effects differ between Hispanics and non-Hispanic Whites (NHWs). We genotyped 13 variants in these genes among 706 Hispanic (300 cases, 406 controls) and 594 NHW (225 cases, 369 controls) participants in a matched population-based case-control study in California. We found significant associations for the five studied ARID5B variants in both Hispanics (p values of 1.0 × 10(-9) to 0.004) and NHWs (p values of 2.2 × 10(-6) to 0.018). Risk estimates were in the same direction in both groups (ORs of 1.53-1.99 and 1.37-1.84, respectively) and strengthened when restricted to B-cell precursor high-hyperdiploid ALL (>50 chromosomes; ORs of 2.21-3.22 and 1.67-2.71, respectively). Similar results were observed for the single CEBPE variant. Hispanics and NHWs exhibited different susceptibility loci at CDKN2A. Although IKZF1 loci showed significant susceptibility effects among NHWs (p < 1 × 10(-5)), their effects among Hispanics were in the same direction but nonsignificant, despite similar minor allele frequencies. Future studies should examine whether the observed effects vary by environmental, immunological, or lifestyle factors.

Asian subgroup-specific information on type 2 diabetes mellitus (DM) is scarce. Using the California Health Interview Survey 2007 data, we examined Chinese, Korean, Japanese, Filipinos, and Vietnamese adults (n = 3,688) and Caucasian adults (n = 33,981) for the prevalence of DM and risk factors. The age-adjusted prevalence of DM was the highest among Filipinos (8.05%) followed by Japanese (7.07%), Vietnamese (7.03%), and Koreans (6.3%). Chinese (5.93%) was the only Asian group studied whose prevalence was lower than Caucasians (5.94%). From multiple logistic regression, after adjusting for risk factors, Japanese had the highest likelihood of DM (OR = 1.75, CI = [1.12-2.73], P

Immigration status is a likely deterrent of mental health care utilization in the United States. Using the Medical Expenditure Panel Survey and National Health Interview survey from 2002 to 2006, multivariable logistic regressions were used to estimate the effects of immigration status on mental health care utilization among patients with depression or anxiety disorders. Multivariate regressions showed that immigrants were significantly less likely to take any prescription drugs, but not significantly less likely to have any physician visits compared to US-born citizens. Results also showed that improving immigrants’ health care access and health insurance coverage could potentially reduce disparities between US-born citizens and immigrants by 14–29% and 9–28% respectively. Policy makers should focus on expanding the availability of regular sources of health care and immigrant health coverage to reduce disparities on mental health care utilization. Targeted interventions should also focus on addressing immigrants’ language barriers, and providing culturally appropriate services.

The prevalence of childhood obesity is high among young children of Mexican origin in the United States, however, the determinants are poorly understood. We conducted a binational study with a sample from California (CA) and Mexico (MX), to identify and compare the most important factors associated with overweight and obesity among children of Mexican descent. Significantly more children were classified as overweight or obese in CA compared to MX (53.3 vs. 14.9%, P < 0.01). In CA and MX, having an obese mother was significantly associated with being overweight or obese. In MX, male gender, high socioeconomic status and very low food insecurity were associated with being overweight or obese. These data offer hypotheses for how migration may influence the high prevalence of overweight among the Mexican children in California. © 2010 The Author(s).

Introduction The study compared anxiety and depression prevalence between parents and non-parents in a society with family- and parenthood-friendly social politics, controlling for family status and family history, age, gender, education and social class. Methods All participants aged 30–49 (N = 24,040) in the large, non-sampled Norwegian HUNT2 community health study completed the Hospital Anxiety and Depression Scales. Results The slightly elevated anxiety and depression among non-parents compared to parents in the complete sample was not confirmed as statistically significant within any subgroups. Married parents and (previously unmarried) cohabiting parents did not differ in portraying low anxiety and depression prevalence. Anxiety was associated with single parenthood, living alone or being divorced, while elevated depression was found only among those living alone. Discussion Burdening selection and cultural/political context are suggested as interpretative perspectives on the contextual and personal influences on the complex relationship between parenthood and mental health.

Purpose The opposing carcinogenic and antiestrogenic properties of tobacco smoke may explain why epidemiologic studies have not consistently reported positive associations for active smoking and breast cancer risk. A negative relation between mammographic density, a strong breast cancer risk factor, and active smoking would lend support for an antiestrogenic mechanism. Methods We used multivariable linear regression to assess the associations of active smoking and secondhand smoke (SHS) exposure with mammographic density in 799 pre- and early perimenopausal women in the Study of Women’s Health Across the Nation (SWAN). Results We observed that current active smoking was associated with 7.2% lower mammographic density, compared to never active smoking and no SHS exposure (p = 0.02). Starting to smoke before 18 years of age and having smoked ≥20 cigarettes/day were also associated with statistically significantly lower percent densities. Among nulliparous women having smoked ≥20 cigarettes/day was associated with 23.8% lower density, compared to having smoked ≤9 cigarettes/day (p

Acute/early HIV infection plays a critical role in onward HIV transmission. Detection of HIV infections during this period provides an important early opportunity to offer interventions which may prevent further transmission. In six US cities, persons with acute/early HIV infection were identified using either HIV RNA testing of pooled sera from persons screened HIV antibody negative or through clinical referral of persons with acute or early infections. Fifty-one cases were identified and 34 (68%) were enrolled into the study; 28 (82%) were acute infections and 6 (18%) were early infections. Of those enrolled, 13 (38%) were identified through HIV pooled testing of 7,633 HIV antibody negative sera and 21 (62%) through referral. Both strategies identified cases that would have been missed under current HIV testing and counseling protocols. Efforts to identify newly infected persons should target specific populations and geographic areas based on knowledge of the local epidemiology of incident infections.

Background The racial/ethnic disparities in prostate cancer rates are well documented, with the highest incidence and mortality rates observed among African-Americans followed by non-Hispanic Whites, Hispanics, and Asian/Pacific Islanders. Whether socioeconomic status (SES) can account for these differences in risk has been investigated in previous studies, but with conflicting results. Furthermore, previous studies have focused primarily on the differences between African-Americans and non-Hispanic Whites, and little is known for Hispanics and Asian/Pacific Islanders. Objective To further investigate the relationship between SES and prostate cancer among African-Americans, non-Hispanic Whites, Hispanics, and Asian/Pacific Islanders, we conducted a large population-based cross-sectional study of 98,484 incident prostate cancer cases and 8,997 prostate cancer deaths from California. Methods Data were abstracted from the California Cancer Registry, a population-based surveillance, epidemiology, and end results (SEER) registry. Each prostate cancer case and death was assigned a multidimensional neighborhood-SES index using the 2000 US Census data. SES quintile-specific prostate cancer incidence and mortality rates and rate ratios were estimated using SEER*Stat for each race/ethnicity categorized into 10-year age groups. Results For prostate cancer incidence, we observed higher levels of SES to be significantly associated with increased risk of disease [SES Q1 vs. Q5: relative risk (RR) = 1.28; 95% confidence interval (CI): 1.25–1.30]. Among younger men (45–64 years), African-Americans had the highest incidence rates followed by non-Hispanic Whites, Hispanics, and Asian/Pacific Islanders for all SES levels. Yet, among older men (75–84 years) Hispanics, following African-Americans, displayed the second highest incidence rates of prostate cancer. For prostate cancer deaths, higher levels of SES were associated with lower mortality rates of prostate cancer deaths (SES Q1 vs. Q5: RR = 0.88; 95% CI: 0.92–0.94). African-Americans had a twofold to fivefold increased risk of prostate cancer deaths in comparison to non-Hispanic Whites across all levels of SES. Conclusions Our findings suggest that SES alone cannot account for the greater burden of prostate cancer among African-American men. In addition, incidence and mortality rates of prostate cancer display different age and racial/ethnic patterns across gradients of SES. Electronic supplementary material The online version of this article (doi:10.1007/s10552-009-9369-0) contains supplementary material, which is available to authorized users.

Objective Blue-collar workers are difficult to reach and less likely to successfully quit smoking. The objective of this study was to test a training site-based smoking cessation intervention. Methods This study is a randomized-controlled trial of a smoking cessation intervention that integrated occupational health concerns and was delivered in collaboration with unions to apprentices at 10 sites (n = 1,213). We evaluated smoking cessation at 1 and 6 months post-intervention. Results The baseline prevalence of smoking was 41%. We observed significantly higher quit rates in the intervention versus control group (26% vs. 16.8%; p = 0.014) 1 month after the intervention. However, the effects diminished over time so that the difference in quit rate was not significant at 6 month post-intervention (9% vs. 7.2%; p = 0.48). Intervention group members nevertheless reported a significant decrease in smoking intensity (OR = 3.13; 95% CI: 1.55–6.31) at 6 months post-intervention, compared to controls. Conclusion The study demonstrates the feasibility of delivering an intervention through union apprentice programs. Furthermore, the notably better 1-month quit rate results among intervention members and the greater decrease in smoking intensity among intervention members who continued to smoke underscore the need to develop strategies to help reduce relapse among blue-collar workers who quit smoking.

Objective We examined the associations between sweets, sweetened and unsweetened beverages, and sugars and pancreatic cancer risk. Methods We conducted a population-based case–control study (532 cases, 1,701 controls) and used multivariate logistic regression models to calculate odds ratios (OR) and 95% confidence intervals (CI). Because associations were often different by sex, we present results for men and women combined and separately. Results Among men, greater intakes of total and specific sweets were associated with pancreatic cancer risk (total sweets: OR = 1.9, 95% CI: 1.0, 3.6; sweet condiments: OR = 1.9, 95% CI: 1.2, 3.1; chocolate candy: OR = 2.4, 95% CI: 1.1, 5.0; other mixed candy bars: OR = 3.3, 95% CI: 1.5, 7.3 for 1 + servings/day versus none/rarely). Sweets were not consistently associated with risk among women. Sweetened beverages were not associated with increased pancreatic cancer risk. In contrast, low-calorie soft drinks were associated with increased risk among men only; while other low-/non-caloric beverages (e.g., coffee, tea, and water) were unassociated with risk. Of the three sugars assessed (lactose, fructose, and sucrose), only the milk sugar lactose was associated with pancreatic cancer risk (OR = 2.0, 95% CI: 1.5, 2.7 comparing extreme quartiles). Conclusion These results provide limited support for the hypothesis that sweets or sugars increase pancreatic cancer risk.

Objective: Whether alcohol consumption influences ovarian cancer risk is unclear. Therefore, we investigated the association between alcohol intake at various ages and risk of ovarian cancer. Methods: Among 90,371 eligible members of the California Teachers Study cohort who completed a baseline alcohol assessment in 1995-1996, 253 women were diagnosed with epithelial ovarian cancer by the end of 2003. Multivariate Cox proportional hazards regression analysis was performed to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: Consumption of total alcohol, beer, or liquor in the year prior to baseline, at ages 30-35 years, or at ages 18-22 years was not associated with risk of ovarian cancer. Consumption of at least one glass per day of wine, compared to no wine, in the year before baseline was associated with increased risk of developing ovarian cancer: RR = 1.57 (95% CI 1.11-2.22), Ptrend= 0.01. The association with wine intake at baseline was particularly strong among peri-/post-menopausal women who used estrogen-only hormone therapy and women of high socioeconomic status. Conclusions: Alcohol intake does not appear to affect ovarian cancer risk. Constituents of wine other than alcohol or, more likely, unmeasured determinants of wine drinking were associated with increased risk of ovarian cancer. © 2006 Springer Science+Business Media B.V.

Background: Transgender women and transfeminine nonbinary adults may be at disproportionate risk of problematic substance use and the co-occurrence of problematic substance use and psychological distress due to a lack of access to economic/social resources and gender affirmation. This dissertation estimated associations between social determinants of health and substance use and co-occurrence with psychological distress, which can inform prevention efforts.Methods: Data from The LITE Study, a longitudinal cohort of transgender women and transfeminine nonbinary adults in the Southern and Eastern United States, were analyzed. Cohort participants (N~1,300) were adults not living with HIV at baseline. Paper one used the baseline sample to estimate latent classes of substance use behavior and examine cross-sectional associations between social determinants of health and latent class membership and between latent class membership and problematic drug use. Paper two assessed associations between baseline social determinants of health and 6-month co-occurrence of problematic drug use and psychological distress. Paper three assessed associations between baseline medical and legal gender affirmation with 12-month problematic drug use and problematic alcohol use.Results: Paper one: Four classes were identified (“low/moderate alcohol use,” “problematic alcohol and cannabis use,” “poly substance use,” and “opioid and cannabis use”). Legal and medical gender affirmation, food insecurity, homelessness, and arrest predicted class membership. The “problematic alcohol and cannabis use,” “poly substance use,” and “opioid and cannabis use” had greater odds of problematic drug use compared to the “low/moderate alcohol use” class. Paper two: More income, never homelessness, never arrested, more food security, and not experiencing health care discrimination was negatively associated with co-occurrence of problematic substance use and psychological distress. Paper 3: Those who successfully obtained medical gender affirmation had 0.68 times the risk (95% CI 0.47—0.98) of problematic drug use compared to those who unsuccessfully tried to obtain medical gender affirmation. Conclusions: Access to economic/social resources and gender affirmation was negatively associated with problematic substance use and the co-occurrence of problematic substance use and psychological distress. Increasing access to such resources may improve substance use outcomes. Community-based intervention work is needed to develop culturally sensitive interventions for transgender women and transfeminine nonbinary adults.

The introduction of Antiretroviral Therapy (ART) in the late 1980s has transformed HIV from a fatal disease into a manageable chronic condition, although challenges like adherence to treatment and broader socio-economic factors continue to impact viral suppression and overall health status among people living with HIV (PLWH). The objective of this dissertation is to examine social (community environments), biological (pain), and psychological (self-perceived quality of life) factors associated with viral suppression among PLWH.The first paper investigates the association between neighborhood and sociodemographic factors and viral suppression among PLWH in Southern California, focusing on areas served by Ryan White clinics. Contrary to expectations, higher walkability scores were associated with lower levels of viral suppression. In line with our hypotheses, longer commute times were negatively associated with viral suppression. Employment showed a positive association with viral suppression, while higher poverty levels and longer work hours negatively impacted viral suppression rates. Additionally, no significant relationships were found between education level, public transportation score, and viral suppression.Given that PLWH often report higher instances of pain and substance use compared to the general population, the second paper explores the association between pain and viral suppression and how substance use modifies this relationship. We found that there was no substantial association between pain and viral suppression among women living with HIV (WLWH) in our cohort. Furthermore, we saw no modification by any type of substance use.The third paper examines the role of quality of life (QoL) on viral suppression and any disparities in this association by race/ethnicity. QoL encompassing physical health, psychological well-being, and socioeconomic stability, has been consistently linked to viral suppression. We found a significant positive association between QoL and viral suppression (aOR: 1.17, 95% CI [1.10, 1.25]). However, the magnitude of this association was shown to vary by racial and ethnic group. The increase in odds of viral suppression per one-point rise in QoL score was greatest among White WLWH and least among Black WLWH.Understanding the individual impact of each factor examined allows for the development of targeted, effective interventions. These findings not only advance our knowledge of HIV management but also emphasize the need for a multi-faceted approach that addresses the specific needs and circumstances of individuals living with HIV.

Emerging adulthood is an ideal development period to target for substance use interventions, as it is a period of immense transition in which individuals confront heightened stressors in many domains, including education, career, and relationships, rendering them to be more susceptible to tobacco and alcohol use. Notably, those initiating substance use during this period often develop enduring usage patterns. Therefore, directing prevention efforts towards emerging adulthood holds significant promise in mitigating future substance use trends. Moreover, we recognize that tobacco and alcohol use patterns are not evenly distributed among different demographic groups. For instance, research indicates that lesbian, gay, and bisexual (LGB) individuals exhibit higher rates of cigarette smoking and binge drinking compared to their heterosexual counterparts, reflecting potential effects of structural discrimination. Theoretical frameworks such as Link and Phelan's fundamental cause theory, Meyer's minority stress model, and Hatzenbuehler's work on LGB structural stigma provide a conceptual basis for understanding how structural discrimination manifests in substance use behaviors. Structural discrimination, such as the absence of comprehensive nondiscrimination policies, creates legal and institutional barriers for LGB individuals, restricting their employment opportunities, housing access, and healthcare services. These structural constraints exacerbate economic burdens and contribute to heightened levels of stress and anxiety among LGB individuals. Consequently, many may resort to maladaptive coping mechanisms, including substance use, to manage these stressors. Recognizing the significance of emerging adulthood, my dissertation focuses on understanding substance use within this population. In my first paper, I explore whether exposure to LGB state policy protections during emerging adulthood constitutes a critical period of policy exposure. However, heterosexism is not the only form of structural discrimination and does not operate alone in society, I was interested in exploring how multiple forms of structural discrimination coalesce and shape substance use behaviors using quantitative intersectionality methods. So, in my second paper, I presented a systematic review of quantitative intersectionality methods that have been employed to investigate intersectional hypotheses. Finally, in my third paper, I applied quantitative intersectionality methods to examine the interplay between heterosexism, racism, and economic marginalization in shaping patterns in tobacco use and binge drinking.

Chronic liver disease is increasingly prevalent with high rates of morbidity and mortality, yet it receives less attention than other similar chronic diseases such as cardiovascular disease and chronic obstructive pulmonary disease. Barriers to timely medical care may preclude diagnosis and management and thus, exacerbate potentially avoidable morbidity and mortality for persons with chronic liver disease. This dissertation explored the extent of health care barriers among adults with chronic liver disease compared to other chronic conditions and identified latent classes derived from different health care barriers to phenotype those at highest risk for recurrent acute care use within the adult population with chronic liver disease in the United States.The first paper, “Evaluation of the Extent of Health Care Barriers among Adults with Chronic Liver Disease vs. Other Chronic Diseases in the United States,” compared estimates of any and the number of health care barriers and the association of recurrent acute care use by prevalence of barriers to care among adults with chronic liver disease versus those with cardiovascular disease and/or chronic obstructive pulmonary disease. Using a multivariable hurdle model, the study found that adults with chronic liver disease were significantly more likely to have any barriers to care (incident rate ratio, 1.12), but such a significant difference did not exist for the frequency of health care barriers. There was a dose-dependent relationship between likelihood of recurrent acute care use and prevalence of barriers to care. Inclusion of chronic liver disease as a high-risk group in future health policies that aim to improve access to care may help reduce challenges that persons with chronic liver disease encounter when seeking timely medical care and potentially reduce preventable acute care use.The second paper, “Identification of Hidden Phenotypes Using Self-Reported Barriers to Care to Predict Risk of Recurrent Hospitalization or Emergency Department Visits among Adults with Chronic Liver Disease in the United States,” identified latent classes within the adult population with chronic liver disease using self-reported barriers to care and assessed each phenotype’s likelihood of recurrent acute care use. The best fitting model to the data included four latent classes or phenotypes: minimal barriers, unaffordability, care delays, and inability to establish care. The study used a multivariable multinomial logistic regression model to identify likelihood of class membership. The unaffordability phenotype was significantly associated with younger age, fair or poor health, functional limitation due to health, and uninsurance. Membership in the care delays class was significantly associated with Hispanics, fair or poor health, and functional limitation due to health. The inability to establish care phenotype was significantly associated with younger age, female sex, functional limitation due to health, and non-private insurance. The inability to establish care group had the highest odds of recurrent acute care use, followed by the care delays and unaffordability groups. An emphasis on risk stratification using health care barriers can potentially help improve interventions that aim to reduce recurrent acute care use among adults with chronic liver disease, particularly for those who struggle to establish care.In summary, both chapters highlighted the prevalence of health care barriers and its association with recurrent acute care use for adults with chronic liver disease. Findings from the second chapter showed the consistent disparity in health care barriers for adults with chronic liver disease versus other chronic diseases and aimed to capture the attention of health policy makers to include chronic liver disease in future iterations of existing health policies or new programs that strive to improve outpatient care access to reduce preventable hospitalizations. The third chapter identified novel phenotypes of persons with chronic liver disease with different associated sociodemographic, health, and insurance characteristics and risks of recurrent acute care use. The third chapter also introduced the concept of using self-reported barriers to care as a way to risk stratify and allocate resources to the most vulnerable individuals with chronic liver disease. Both chapters intend to help improve health care access, reduce preventable acute care use, and potentially improve the morbidity and mortality trends among adults with chronic liver disease in the United States.

Antimicrobial resistance (AMR) is a growing global concern that poses significant risks to human, animal, and environmental health. AMR describes organisms, including bacteria, viruses, and fungi, that have become resistant to the drugs used to kill or control them through evolutionary, environmental, or social pressures. The emergence and spread of AMR threaten decades of advancement in reducing morbidity and mortality from many infectious diseases and is one of the most pressing clinical and public health threats. In the United States alone, more than 2.8 million AMR infections occur annually, resulting in over 35,000 deaths and costing the healthcare system over $4.6 billion.Community-acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are a significant financial burden on healthcare systems and vary across populations. Several studies have documented infection disparities across racial-ethnic categories, economic indicators, and geography. Evidence suggests that differential infection rates are related to social determinants of health such as income, housing, and educational attainment. However, few studies connect infection disparities to the key mechanisms underlying the role of racial-ethnic category, income, or geography in shaping population health. The role of area-based determinants of infection has yet to be thoroughly examined, and addressing the challenges of AMR more broadly will require understanding the social, environmental, and economic processes that shape differential infection incidence. This dissertation explores the systems and determinants associated with disparities in CA-MRSA infection presenting in California emergency departments (ED). The first paper examines the epidemiology of CA-MRSA skin and soft tissue infections (SSTIs) across California from 2016-2019, examining the spatial distribution of infections in a unique neighborhood boundary. CA-MRSA infections are historically associated with densely populated urban areas, but statewide ED data revealed that more rural and mountainous regions of California are experiencing a higher burden of CA-MRSA SSTIs. This highlights a potential change in the epidemiology of CA-MRSA SSTIs and warrants further investigation into identifying at-risk populations and possible infection pathways.Electronic health records (EHR) are an increasingly utilized data source in public health, including throughout this dissertation. However, biases may exist when using EHR data for research, primarily due to the processes that drive whether someone is captured in the EHR. The second paper of this dissertation examines whether small-area inequalities in CA-MRSA infection that are observed in the EHR can be explained by selection bias. Using an agent-based model (ABM) to simulate the dynamics of healthcare-seeking behavior for CA-MRSA infection, we compared the spatial patterns of agents seeking care for their infection in the ED to empirical data. The ABM reproduced the observed infection prevalence for nine of the 21 geographies. The differences in prevalence across geographies did not reach the magnitude in the observed data, and the overall spatial patterns between the two had weak agreement. The results suggest that geographic disparities identified in the observed ED data are due to factors beyond selection bias and healthcare-seeking behaviors. Relative importance analyses point to environmental degradation, percent non-Hispanic white residents, and percent of residents living below the federal poverty level as potentially important determinants.Finally, poverty is an often-cited driver of health disparities, and associations between poverty and CA-MRSA infection are well documented. However, the pathways through which poverty influences infection have yet to be thoroughly examined. The third paper aims to identify mediating variables explaining why area-level poverty is associated with CA-MRSA infection in Californians. Mediation analyses using Bayesian multilevel spatial regression revealed that the association between area-level poverty and CA-MRSA infection could be partially explained by spatial autocorrelation, living in a primary care shortage area, and environmental degradation in the neighborhood. Combined, the mediators explain approximately 6% of the odds of CA-MRSA infection for individuals living in neighborhoods with high poverty rates and 50% of the statistical association between area-level poverty and CA-MRSA infection. The statistical association between area-level poverty and infection was entirely explained by the mediators for individuals living in neighborhoods with low poverty rates. Overall, this dissertation provides insight into the changing epidemiology of CA-MRSA infections in California, the accuracy of using EHR data in public health disparities research, and the mediating variables that explain the association between poverty and infection. Expanding our understanding of the determinants and mechanisms driving AMR and differential CA-MRSA infection incidence is essential for developing effective public health policies and interventions to reduce the burden of these infections. Addressing the challenges of AMR, including health disparities, will require multi-level approaches encompassing upstream facilitators, individual behavior, and social and environmental contexts.