Johns Hopkins Bloomberg School of Public Health
Recent publications
Introduction People who use drugs (PWUD) face a multitude of barriers to accessing healthcare and other services. Mobile health clinics (MHC) are an innovative, cost-effective health care delivery approach that increases healthcare access to vulnerable populations and medically underserved areas. There is limited understanding, however, of how PWUD perceive and experience MHCs. Methods Semi-structured interviews were conducted with 31 PWUD – 16 who had received care (clients) on an MHC (The Spot) and 15 who had not (non-clients) – to explore their perceptions and utilization of an MHC partnered with a mobile syringe services program in Baltimore, Maryland. Data analysis of the text was conducted using an iterative thematic constant comparison process informed by grounded theory. Results Clients and non-clients, once aware of the MHC, had positive perceptions of The Spot and its benefits for their individual health as well as for the wellbeing of their community. These sentiments among clients were largely driven by access to low-barrier buprenorphine and service delivery without stigma around drug use. However, lack of general awareness of the spot and specific service offering were barriers to its use among non-clients. Discussion MHCs provide an important opportunity to engage PWUD in healthcare and to expand buprenorphine use; however, even with accessibility near where PWUD access injection equipment, barriers to its use remain. Peer dissemination may be able to facilitate program information sharing and recruitment. • KEY MESSAGES • People who use drugs perceive a mobile health clinic in their neighbourhood as a benefit to their communities and themselves by improving access to healthcare services, providing access to low-threshold buprenorphine dispensation, and offering services without drug use stigma. • People who use drugs learned about a mobile health clinic in their neighbourhood largely through word-of-mouth. As a result, people received limited information about the mobile health clinic services creating a barrier to its use.
A global rise in antimicrobial resistance among pathogenic bacteria has proved to be a major public health threat, with the rate of multidrug-resistant bacterial infections increasing over time. The gut microbiome has been studied as a reservoir of antibiotic resistance genes (ARGs) that can be transferred to bacterial pathogens via horizontal gene transfer (HGT) of conjugative plasmids and mobile genetic elements (the gut resistome). Advances in metagenomic sequencing have facilitated the identification of resistome modulators, including live microbial therapeutics such as probiotics and fecal microbiome transplantation that can either expand or reduce the abundances of ARG-carrying bacteria in the gut. While many different gut microbes encode for ARGs, they are not uniformly distributed across, or transmitted by, various members of the microbiome, and not all are of equal clinical relevance. Both experimental and theoretical approaches in microbial ecology have been applied to understand differing frequencies of ARG horizontal transfer between commensal microbes as well as between commensals and pathogens. In this commentary, we assess the evidence for the role of commensal gut microbes in encoding antimicrobial resistance genes, the degree to which they are shared both with other commensals and with pathogens, and the host and environmental factors that can impact resistome dynamics. We further discuss novel sequencing-based approaches for identifying ARGs and predicting future transfer events of clinically relevant ARGs from commensals to pathogens.
Background Genome-wide association studies (GWAS) have identified multiple common breast cancer susceptibility variants. Many of these variants have differential associations by estrogen receptor (ER) status, but how these variants relate with other tumor features and intrinsic molecular subtypes is unclear. Methods Among 106,571 invasive breast cancer cases and 95,762 controls of European ancestry with data on 173 breast cancer variants identified in previous GWAS, we used novel two-stage polytomous logistic regression models to evaluate variants in relation to multiple tumor features (ER, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and grade) adjusting for each other, and to intrinsic-like subtypes. Results Eighty-five of 173 variants were associated with at least one tumor feature (false discovery rate < 5%), most commonly ER and grade, followed by PR and HER2. Models for intrinsic-like subtypes found nearly all of these variants (83 of 85) associated at p < 0.05 with risk for at least one luminal-like subtype, and approximately half (41 of 85) of the variants were associated with risk of at least one non-luminal subtype, including 32 variants associated with triple-negative (TN) disease. Ten variants were associated with risk of all subtypes in different magnitude. Five variants were associated with risk of luminal A-like and TN subtypes in opposite directions. Conclusion This report demonstrates a high level of complexity in the etiology heterogeneity of breast cancer susceptibility variants and can inform investigations of subtype-specific risk prediction.
The COVID-19 pandemic has underscored the changing role of scientists, clinicians, ethicists, and educators in advocacy as they rapidly translate their findings to inform practice and policy. Critical efforts have been directed towards understanding child well-being, especially with pandemic-related educational disruptions. While school closures were part of early widespread public health measures to curb the spread of COVID-19, they have not been without consequences for all children, and especially for children from disadvantaged backgrounds. In a recent Isr J Health Policy Res perspective, Paltiel and colleagues demonstrate the integral role of academic activism to promote child well-being during the pandemic by highlighting work of the multidisciplinary academic group on children and coronavirus (MACC). In this commentary, we explore parallels to MACC’s work in an international context by describing the efforts of a multidisciplinary team at Johns Hopkins University in Baltimore, Maryland, United States, to aggregate data, conduct analyses, and offer training tools intended to minimize health and educational inequities for children throughout the COVID-19 pandemic. As both MACC and our work collectively demonstrates, multidisciplinary partnerships and public-facing data-driven initiatives are crucial to advocating for children's equitable access to quality health and education. This will likely not be the last pandemic that children experience in their lifetime. As such, efforts should be made to apply the lessons learned during the current pandemic to strengthen multidisciplinary academic-public partnerships which will continue to play a critical role in the future.
Background Spinal cord motor neurons (MNs) from human iPS cells (iPSCs) have wide applications in disease modeling and therapeutic development for amyotrophic lateral sclerosis (ALS) and other MN-associated neurodegenerative diseases. We need highly efficient MN differentiation strategies for generating iPSC-derived disease models that closely recapitulate the genetic and phenotypic complexity of ALS. An important application of these models is to understand molecular mechanisms of action of FDA-approved ALS drugs that only show modest clinical efficacy. Novel mechanistic insights will help us design optimal therapeutic strategies together with predictive biomarkers to achieve better efficacy. Methods We induce efficient MN differentiation from iPSCs in 4 days using synthetic mRNAs coding two transcription factors (Ngn2 and Olig2) with phosphosite modification. These MNs after extensive characterization were applied in electrophysiological and neurotoxicity assays as well as transcriptomic analysis, to study the neuroprotective effect and molecular mechanisms of edaravone, an FDA-approved drug for ALS, for improving its clinical efficacy. Results We generate highly pure and functional mRNA-induced MNs (miMNs) from control and ALS iPSCs, as well as embryonic stem cells. Edaravone alleviates H 2 O 2 -induced neurotoxicity and electrophysiological dysfunction in miMNs, demonstrating its neuroprotective effect that was also found in the glutamate-induced miMN neurotoxicity model. Guided by the transcriptomic analysis, we show a previously unrecognized effect of edaravone to induce the GDNF receptor RET and the GDNF/RET neurotrophic signaling in vitro and in vivo, suggesting a clinically translatable strategy to activate this key neuroprotective signaling. Notably, edaravone can replace required neurotrophic factors (BDNF and GDNF) to support long-term miMN survival and maturation, further supporting the neurotrophic function of edaravone-activated signaling. Furthermore, we show that edaravone and GDNF combined treatment more effectively protects miMNs from H 2 O 2 -induced neurotoxicity than single treatment, suggesting a potential combination strategy for ALS treatment. Conclusions This study provides methodology to facilitate iPSC differentiation and disease modeling. Our discoveries will facilitate the development of optimal edaravone-based therapies for ALS and potentially other neurodegenerative diseases. Graphical abstract
Background Male partner’s approval is a key determinant of contraceptive use for women living in Sub-Saharan Africa and improving men’s support and couple communication is a cornerstone of family planning programs. However, approval is often only measured through the women’s perception of their partner’s opinion. Methods This study conducted in Kinshasa compares contraceptive approval variables from matched male and female partners (n = 252 couples) to establish the frequency of (in)accurate perceptions by the woman, then test their association with modern contraceptive use. Additional regressions estimate individual and couple variables associated with (in)correct perceptions. Results Results confirm women are poorly aware of their partner’s opinion but indicate that perceived approval or disapproval by the woman is a much stronger determinant of modern contraceptive use than her partner’s actual opinion. Higher educational achievement from the woman is the strongest driver of misunderstanding her partner’s approval. Conclusions Women’s perceptions of partner’s approval are much stronger determinant of contraceptive use than the latter’s actual opinion, and stereotyping men’s opinion of family planning is a common error of appreciation. However, findings also suggest these misunderstandings might serve women’s capacity to negotiate contraceptive use.
Background: Travel distance to medication treatment for opioid use disorder (OUD) is a challenge for many patients, but little is known about how distance is associated with medication treatment utilization. This study examines the association between distance to the nearest physician waivered to prescribe buprenorphine and patient-level buprenorphine treatment among West Virginia Medicaid expansion enrollees with diagnosed OUD. Methods: We conducted a cross-sectional spatial analysis with 2016 Medicaid claims data, separately examining individuals living in metropolitan and non-metropolitan areas. We calculated the driving distance from the centroid of patients' residential ZIP codes to the street address of the nearest waivered physician derived from the 2015 Drug Enforcement Administration listing. Regression models examined the association between distance and initiation and duration of buprenorphine (among those initiating). Results: We focused on 8,008 individuals with OUD in 2016. The nearest waivered prescriber in metropolitan areas was an average of 7.13 miles away from patients' residential ZIP codes and 14.54 miles in non-metropolitan areas. The providers they actually visited were a mean of 33.63 miles away in metro areas and 46.36 in non-metropolitan areas. In multivariable analyses, compared to those living <10 miles from a waivered physician, living >20 miles from a waivered physician was associated with -32.13 fewer days of treatment (95% CI: -57.86, -6.40) in metro areas and -16.70 fewer days in non-metro areas (95% CI: -32.32, -1.08). Conclusions: Longer travel distance to buprenorphine treatment is associated with a shorter duration of care that is likely to be clinically meaningful.
Intimate partner violence (IPV) can impact the mental health of survivors; however, little is known about the role of state-level restorative justice policies. Restorative justice policies are survivor-centered justice approaches focused on repairing harm between the survivor and perpetrator, which may buffer mental health outcomes among IPV survivors. Furthermore, the impact of restorative justice policies on mental health may be influenced by the degree of state-level support for policy implementation. This study examined the relationship between (1) IPV exposure and mental health and whether restorative justice policies moderate the relationship; and (2) whether restorative justice policy implementation support moderates the relationship between IPV and mental health among women. Data on state restorative justice policies were drawn from a U.S. restorative justice legislation database. Individual-level data on 5104 adult women were collected from the 2010 National Intimate Partner and Sexual Violence Survey (NISVS), a nationally representative study of noninstitutionalized adult women and men. Generalized estimating equation (GEE) models were conducted to examine associations between IPV, state-level restorative justice policies, restorative justice policy implementation support, and perceived mental health (N = 5104). Women who experienced IPV had worse perceived mental health compared to women without IPV (b [95% CI] = −0.13 [−0.15, −0.11], p < 0.001). The inverse relationship between IPV and survivor mental health was attenuated in states with a restorative justice policy vs. states without (b [95% CI] = 0.05 [0.00, 0.09], p = 0.038). The relationship between IPV and worse survivor mental health was weakest in states with high restorative justice policy implementation support (b [95% CI] = 0.03 [0.00, 0.05], p = 0.032). Restorative justice policies may serve as a scalable tool to reduce negative mental health sequelae related to IPV and strengthen current justice responses for IPV survivors.
Background The era of big data has enabled sophisticated models to predict air pollution concentrations over space and time. Historically these models have been evaluated using overall metrics that measure how close predictions are to monitoring data. However, overall methods are not designed to distinguish error at timescales most relevant for epidemiologic studies, such as day-to-day errors that impact studies of short-term health associations. Methods We introduce frequency band model performance, which quantifies health estimation capacity of air quality prediction models for time series studies of air pollution and health. Frequency band model performance uses a discrete Fourier transform to evaluate prediction models at timescales of interest. We simulated fine particulate matter (PM 2.5 ), with errors at timescales varying from acute to seasonal, and health time series data. To compare evaluation approaches, we use correlations and root mean squared error (RMSE). Additionally, we assess health estimation capacity through bias and RMSE in estimated health associations. We apply frequency band model performance to PM 2.5 predictions at 17 monitors in 8 US cities. Results In simulations, frequency band model performance rates predictions better (lower RMSE, higher correlation) when there is no error at a particular timescale (e.g., acute) and worse when error is added to that timescale, compared to overall approaches. Further, frequency band model performance is more strongly associated ( R ² = 0.95) with health association bias compared to overall approaches ( R ² = 0.57). For PM 2.5 predictions in Salt Lake City, UT, frequency band model performance better identifies acute error that may impact estimated short-term health associations. Conclusions For epidemiologic studies, frequency band model performance provides an improvement over existing approaches because it evaluates models at the timescale of interest and is more strongly associated with bias in estimated health associations. Evaluating prediction models at timescales relevant for health studies is critical to determining whether model error will impact estimated health associations.
Plasmodium knowlesi malaria infection in humans has been reported throughout southeast Asia. The communities at risk are those living in areas where Macaque monkeys and Anopheles mosquito are present. Zoonotic malaria control is challenging due to the presence of the reservoir host and the possibility of human-vector-human transmission. Current control measures, including insecticide-treated nets (ITNs) and indoor residual spraying (IRS), are insufficient to address this threat due to gaps in protection associated with outdoor and early evening vector biting and social and economic activities, such as agricultural and forest work. Understanding the challenges faced by affected communities in preventing mosquito bites is important for reducing disease transmission. This opinion paper discusses opportunities to improve P. knowlesi malaria control through understanding the challenges faced by communities at risk and increasing community engagement and ownership of control measures. The paper highlights this issue by describing how the concept of reimagining malaria can be adapted to zoonotic malaria control measures including identifying current gaps in vector control, understanding interactions between environmental, economic, and human behavioral factors, and increasing community participation in and ownership of control measures.
Background: Alcohol consumption in the U.S. is a public health problem that has been exacerbated by the COVID-19 pandemic. Relatedly, many states have responded to COVID-19 by relaxing their alcohol laws, making it possible for adults to have alcohol delivered to their homes. This study sought to understand the impact of allowing alcohol home delivery on self-reported adult alcohol consumption in the US. Methods: In May 2020, we surveyed a convenience sample of U.S. adults over 21 years of age recruited through social media and listservs. Eight hundred and thirty-two participants completed the online survey: 84% were female, 85% were White, and 72% were between the ages of 26 and 49. Results: Twenty-one percent of participants who consumed alcohol in the past month had at least some alcohol delivered, with 60% having it delivered from liquor stores, restaurants, or bars. The remainder of the participants purchased the alcohol in-person or owned it pre-COVID-19. Participants who reported having alcohol delivered also reported consuming more drinks (β = 13.3; 95% CI [8.2, 18.4]; p < .000) and drinking on more days (β = 5.0; 95% CI [2.9, 7.0]; p < .000) over the past month than participants who obtained alcohol through other methods. Participants who had alcohol delivered were nearly two times more likely to report engaging in binge drinking than those who obtained alcohol through other methods (OR = 1.96; 95% CI [1.3, 3.1]; p = .003). Conclusions: Obtaining alcohol through home delivery was associated with greater alcohol consumption including binge drinking. As states consider permanently allowing alcohol home delivery, it is important to consider the potential public health implications.
Research integrity, an essential precept of scientific inquiry and discovery, comprises norms such as Rigor, Reproducibility, and Responsibility (the 3R’s). Over the past decades, numerous issues have arisen that challenge the reliability of scientific studies, including irreproducibility crises, lack of good scientific principles, and erroneous communications, which have impacted the public’s trust in science and its findings. Here, we highlight one important component of research integrity that is often overlooked in the discussion of proposals for improving research quality and promoting robust research; one that spans from the lab bench to the dissemination of scientific work: responsible science communication. We briefly outline the role of education and institutions of higher education in teaching the tenets of good scientific practice and within that, the importance of adequate communications training. In that context, we present our framework of responsible science communication that we live by and teach to our students in courses and workshops that are part of the Johns Hopkins Bloomberg School of Public Health R ³ Center for Innovation in Science Education.
Background Until recently, few carceral facilities offered medications for opioid use disorder (MOUD). Although more facilities are adopting MOUD, much remains to be learned about addressing implementation challenges related to expansion of MOUD in carceral settings and linkage to care upon re-entry. This is particularly important in jails, where individuals cycle rapidly in and out of these facilities, especially in jurisdictions beginning to implement bail reform laws (i.e., laws that remove the requirement to pay bail for most individuals). Increasing access to MOUD in these settings is a key unexplored challenge. Methods In this qualitative study, we interviewed staff from county jails across New Jersey, a state that has implemented state-wide efforts to increase capacity for MOUD treatment in jails. We analyzed themes related to current practices used to engage individuals in MOUD while in jail and upon re-entry; major challenges to delivering MOUD and re-entry services, particularly under bail reform conditions; and innovative strategies to facilitate delivery of these services. Results Jail staff from 11 New Jersey county jails participated in a baseline survey and an in-depth qualitative interview from January–September 2020. Responses revealed that practices for delivering MOUD varied substantially across jails. Primary challenges included jails’ limited resources and highly regulated operations, the chaotic nature of short jail stays, and concerns regarding limited MOUD and resources in the community. Still, jail staff identified multiple facilitators and creative solutions for delivering MOUD in the face of these obstacles, including opportunities brought on by the COVID-19 pandemic. Conclusions Despite challenges to the delivery of MOUD, states can make concerted and sustained efforts to support opioid addiction treatment in jails. Increased use of evidence-based clinical guidelines, greater investment in resources, and increased partnerships with health and social service providers can greatly improve reach of treatment and save lives.
Background The Nigerian health care system is weak due to lack of coordination, fragmentation of services by donor funding of vertical services, dearth and poor distribution of resources, and inadequate infrastructures. The Global Polio Eradication Initiative has supported the country’s health system and provided strategies and skills which need to be documented for use by other health programs attempting disease control or eradication. This study, therefore, explored the contributions of the Polio Eradication Initiative (PEI) activities to the operations of other health programs within the Nigerian health system from the perspectives of frontline workers and managers. Methods This cross-sectional qualitative study used key informant interviews (KIIs) and inductive thematic analysis. Twenty-nine KIIs were conducted with individuals who have been involved continuously in PEI activities for at least 12 months since the program's inception. This research was part of a more extensive study, the Synthesis and Translation of Research and Innovations from Polio Eradication (STRIPE), conducted in 2018. The KII tool focused on four major themes: work experience in other health programs, similarities and differences between polio programs and other health programs, contributions of polio programs, and missed opportunities for implementing polio lessons. All interviews were transcribed verbatim and analyzed using a thematic framework. Results The implementation of the PEI has increased health promotion activities and coverage of maternal and child health interventions through the development of tangible and intangible resources, building the capacities of health workers and discovering innovations. The presence of a robust PEI program within a weakened health system of similar programs lacking such extensive support led to a shift in health workers' primary roles. This was perceived to reduce human resources efforts in rural areas with a limited workforce, and to affect other programs' service delivery. Conclusion The PEI has made a notable impact on the Nigerian health system. There should be hastened efforts to transition these resources from the PEI into other programs where there are missed opportunities and future control programs. The primary health care managers should continue integration efforts to ensure that programs leverage opportunities within successful programs to improve the health of the community members.
Objective Adolescents and youth constitute a significant proportion of the population in developing nations. Conventional survey methods risk missing adolescents/youth because their family planning/contraception (FP/C) behavior is hidden. Respondent-driven sampling (RDS), a modified chain-referral recruitment sampling approach, was used to reach unmarried adolescents/youth aged 15–24 in Nairobi, Kenya to measure key FP/C indicators. Seeds were selected and issued with three coupons which they used to invite their peers, male or female, to participate in the study. Referred participants were also given coupons to invite others till sample size was achieved. We report on key implementation parameters following standard RDS reporting recommendations. Results A total of 1674 coupons were issued to generate a sample size of 1354. Coupon return rate was 82.7%. Study participants self-administered most survey questions and missing data was low. Differential enrolment by gender was seen with 56.0% of females recruiting females while 44.0% of males recruited males. In about two months, it was possible to reach the desired sample size using RDS methodology. Implementation challenges included presentation of expired coupons, recruitment of ineligible participants and difficulty recruiting seeds and recruits from affluent neighborhoods. Challenges were consistent with RDS implementation in other settings and populations. RDS can complement standard surveillance/survey approaches, particularly for mobile populations like adolescents/youth.
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2,096 members
Radames JB Cordero
  • W. Harry Feinstone Department of Molecular Microbiology and Immunology
Ron Goetzel
  • Department of Health, Behavior and Society
Andres Ignacio Vecino Ortiz
  • Department of International Health
Luke C Mullany
  • Department of International Health
Masoumeh Dejman
  • Department of Mental Health
Baltimore, MD, United States