Meningococcal Vaccination Rates Among People With a New Diagnosis of HIV Infection in the US.

Importance: In the United States, individuals with HIV infection have been recommended to receive a 2-dose series of the meningococcal A, C, W, Y (MenACWY) vaccine since 2016 owing to their increased risk of meningococcal disease. Objective: To examine uptake and time to receipt of the MenACWY vaccine among people with a new diagnosis of HIV. Design, Setting, and Participants: This cohort study used health insurance data from the US Optum Research Database from January 1, 2016, through March 31, 2018, to retrospectively identify 1208 individuals aged 2 years or older with 1 or more inpatient claim or 2 or more outpatient claims evidencing a new diagnosis of HIV infection and with continuous insurance enrollment for 12 or more months before and 6 or more months after diagnosis. Follow-up was 6 to 33 months. Statistical analysis was conducted from March 7, 2019, to January 5, 2022. Exposure: Receipt of the MenACWY vaccine. Main Outcomes and Measures: The coprimary outcomes were uptake and time to receipt of 1 or more doses of the MenACWY vaccine after a new HIV diagnosis. Secondary outcomes included uptake and time to receipt of 2 or more doses of the MenACWY vaccine. Vaccination uptake and receipt were estimated by Kaplan-Meier analysis; factors associated with receipt of 1 or more doses of the MenACWY vaccine were identified with multivariable Cox proportional hazards regression analysis. Results: Of 1208 individuals eligible for vaccination (1024 male patients [84.8%]; mean [SD] age, 38.8 [12.5] years; 35 [2.9%] Asian; 273 [22.6%] Black; 204 [16.9%] Hispanic; 442 [36.6%] White), 16.3% were estimated to have received a first dose of the MenACWY vaccine in the 2 years after a new HIV diagnosis. Among individuals who received a first dose, at 1 year or more of enrollment after the first dose, 66.2% were estimated to have received a second dose within 1 year of the first dose. Factors statistically significantly associated with uptake of the MenACWY vaccine included receipt of a pneumococcal vaccine (hazard ratio [HR], 23.03; 95% CI, 13.93-38.09), attendance at a well-care visit (HR, 3.67; 95% CI, 1.11-12.12), West or Midwest geographic region (West: HR, 2.24; 95% CI, 1.44-3.47; Midwest: HR, 1.78; 95% CI, 1.16-2.71), and male sex (HR, 2.72; 95% CI, 1.18-6.26), whereas age of 56 years or older was significantly associated with reduced uptake of the MenACWY vaccine (HR, 0.42; 95% CI, 0.18-0.97). Conclusions and Relevance: This cohort study suggests that MenACWY vaccine uptake among people with a new diagnosis of HIV was low, highlighting the need to educate patients and clinicians about the recommendations for conditions such as HIV infection that increase the risk of meningococcal disease among high-risk populations.

Low Meningococcal Vaccination Rates Among Patients With Newly Diagnosed Complement Component Deficiencies in the United States.

Meningococcal vaccination is recommended for patients with complement component deficiencies (CDs) in the United States. In this retrospective database study, only 4.6% and 2.2% of patients received MenACWY and MenB vaccination, respectively, within 3 years of CD diagnosis. Thus, meningococcal vaccination rates among patients with CDs need to be improved.

Meningococcal vaccination in patients with newly diagnosed asplenia in the United States.

BACKGROUND: Patients with asplenia are recommended to receive meningococcal ACWY (MenACWY) and B (MenB) vaccines in the United States (US). OBJECTIVES: To examine uptake and time to receipt of meningococcal vaccines in newly diagnosed asplenia patients, and identify factors associated with vaccination. METHODS: For this retrospective database analysis, patients were identified from 1/1/2010 (MenACWY) or 1/1/2015 (MenB) through 3/31/2018 from an administrative claims database including commercially insured US patients with ≥1 inpatient or ≥2 outpatient claims with evidence of a new asplenia diagnosis (sickle cell disease was excluded); continuous enrollment for ≥12 months before and ≥6 months after the index date; and age ≥2 (MenACWY) or ≥10 (MenB) years. Co-primary outcomes were uptake and time to receipt of ≥1 dose, separately for MenACWY and MenB, by Kaplan-Meier analysis. Cox proportional hazards regression models were used to identify characteristics associated with vaccination. RESULTS: Among 2,273 and 741 patients eligible for the MenACWY and MenB analyses, respectively, 28.1% and 9.7% received MenACWY and MenB in the first 3 years after a new asplenia diagnosis. Patients were more likely to receive meningococcal vaccines if they had received pneumococcal vaccines (MenACWY: hazard ratio [HR] 26.02; 95% confidence interval [CI] 21.01-32.22; MenB: HR 3.89; 95% CI 2.07-7.29) or attended ≥1 well-care visit (MenACWY: HR 6.63; 95% CI 4.84-9.09; MenB: HR 11.17; 95% CI 3.02-41.26). CONCLUSIONS: Meningococcal vaccination rates among newly diagnosed asplenia patients were low, highlighting the need to educate providers about the recommendations for high-risk conditions and ensure healthcare access for vulnerable patients.

Impact of population aging on the burden of vaccine-preventable diseases among older adults in the United States.

Despite vaccination recommendations, the burden of vaccine-preventable diseases remains high in older adults in the United States (US), contributing to substantial morbidity, mortality, and health care resource use and costs. To adequately plan for health care resource needs and to help inform vaccination policies, burden of disease projections that account for population aging over the coming decades are needed. As a first step, this exploratory study projects the burden of influenza, pertussis, herpes zoster, and pneumococcal disease in adults aged 50 y and older in the US, using a population-based modeling framework with separate decision trees for each vaccine-preventable disease. The model uses projected population estimates from the US Census Bureau to account for changes in the US population over time and then calculates expected numbers of cases and associated costs for each disease, keeping current estimates of age-specific disease incidence, vaccine coverage, and efficacy constant over time. This approach was used to focus the exploratory analysis on the burden of disease that may be expected due to population changes alone, assuming that all else remains unchanged. Due to population growth and the shifting age distribution over the next 30 y, the annual societal economic burden for the four vaccine-preventable diseases is projected to increase from approximately $35 billion to $49 billion, resulting in cumulative costs of approximately $1.3 trillion, as well as more than 1 million disease-related deaths. Given such notable burden, further efforts to increase vaccination coverage and effectiveness in older adults are needed.

Determinants of Meningococcal ACWY vaccination in adolescents in the US: completion and compliance with the CDC recommendations.

Since 2011, the Advisory Committee on Immunization Practices (ACIP) guidelines for routine MenACWY vaccination in the US include a primary dose before age 16 y, preferably at ages 11-12 y, with a booster dose at age 16 y. Data on rates and drivers of meningococcal vaccination completion (receipt of both doses) and compliance with recommendations (receipt of primary dose at ages 11-12 y followed by booster at 16 y) down to state-level are limited.This study evaluated rates and determinants of MenACWY vaccination completion and compliance in adolescents aged 17 y based on data from the annual National Immunization Survey-Teen between 2011 and 2016. Individual- and state-level determinants of completion and compliance were assessed using uni-level and multi-level multivariable regression models. Average national rates were 23.2% and 12.1% for completion and compliance, respectively, with large inter-state variation observed (completion: 8.7-39.7%; compliance: 3.1-26.2%). Beyond the state of residence, factors significantly associated with a higher likelihood of both completion and compliance included being male, up-to-date on other routine vaccines, having private or hospital-based vaccine providers (vs. public) and having >1 child in the household. Factors specifically associated with completion included having >1 annual health-care visit and presence of a booster-dose vaccine mandate, while a history of asthma and high-risk health conditions had a positive association with compliance. State-level determinants of completion and compliance included pediatricians-to-children ratio and the proportion of Immunization Information System use among adolescents, respectively. Outcomes of this study may help guide clinical, policy and educational interventions to further increase MenACWY completion rates and reduce disparities in vaccination.

Increasing role of Staphylococcus aureus and community-acquired methicillin-resistant Staphylococcus aureus infections in the United States: a 10-year trend of replacement and expansion.

BACKGROUND: There is the need to properly characterize the temporal trend of U.S. Staphylococcus aureus infections, including methicillin-resistant S. aureus (MRSA) and community-acquired (CA) MRSA in inpatient and outpatient settings. METHODS: The study used the Surveillance Network(®) surveillance database (Eurofins Medinet) and the National Hospitalization Discharge Survey for the period 1998-2007. CA-MRSA phenotype was defined by a resistance profile that includes susceptibility to gentamicin and cotrimoxazole, and coresistance to ciprofloxacin/clindamycin. Adjusted rates, rate ratios, and 95% confidence intervals (CIs) were computed using multivariate logistic regression. RESULTS: The study consisted of 1,761,991 S. aureus isolates. Annual MRSA prevalence continuously increased over the 10-year period from 32.7% in 1998 to 53.8% in 2007 (odds ratio 2.4, 95% CI 2.3-2.5). CA-MRSA replaced competing strains by increasing its share of MRSA from 22.3% in 1998 to 66.1% in 2007 (odds ratio 6.7, 95% CI 6.5-6.9). MRSA-related hospitalization rate per 1,000 discharges doubled from 3.5 ± 0.9 in 1998 to 7.6 ± 1.5 in 2007 (RR 2.2, 95% CI 1.8-3.1), whereas CA-MRSA increased from 0.4 ± 0.14 hospitalizations per 1,000 discharges in 1998 to 3.1 ± 0.5 in 2007 (RR 8.1, 95% CI 5.2-14.1), By 2007, 81.5% of all MRSA isolates were categorized as CA-MRSA among children, whereas CA-MRSA represented 48.9% of MRSA isolates from the elderly. CONCLUSION: MRSA not only replaced methicillin susceptible S. aureus (MSSA) isolates as a percentage of all S. aureus isolates, but its hospitalization rates increased over and above the replacement process. This trend also applies to CA-MRSA over hospital-acquired (HA) MRSA.

Non-diffeomorphic registration of brain tumor images by simulating tissue loss and tumor growth.

Although a variety of diffeomorphic deformable registration methods exist in the literature, application of these methods in the presence of space-occupying lesions is not straightforward. The motivation of this work is spatial normalization of MR images from patients with brain tumors in a common stereotaxic space, aiming to pool data from different patients into a common space in order to perform group analyses. Additionally, transfer of structural and functional information from neuroanatomical brain atlases into the individual patient's space can be achieved via the inverse mapping, for the purpose of segmenting brains and facilitating surgical or radiotherapy treatment planning. A method that estimates the brain tissue loss and replacement by tumor is applied for achieving equivalent image content between an atlas and a patient's scan, based on a biomechanical model of tumor growth. Automated estimation of the parameters modeling brain tissue loss and displacement is performed via optimization of an objective function reflecting feature-based similarity and elastic stretching energy, which is optimized in parallel via APPSPACK (Asynchronous Parallel Pattern Search). The results of the method, applied to 21 brain tumor patients, indicate that the registration accuracy is relatively high in areas around the tumor, as well as in the healthy portion of the brain. Also, the calculated deformation in the vicinity of the tumor is shown to correlate highly with expert-defined visual scores indicating the tumor mass effect, thereby potentially leading to an objective approach to quantification of mass effect, which is commonly used in diagnosis.

A comparative study of biomechanical simulators in deformable registration of brain tumor images.

Simulating the brain tissue deformation caused by tumor growth has been found to aid the deformable registration of brain tumor images. In this paper, we evaluate the impact that different biomechanical simulators have on the accuracy of deformable registration. We use two alternative frameworks for biomechanical simulations of mass effect in 3-D magnetic resonance (MR) brain images. The first one is based on a finite-element model of nonlinear elasticity and unstructured meshes using the commercial software package ABAQUS. The second one employs incremental linear elasticity and regular grids in a fictitious domain method. In practice, biomechanical simulations via the second approach may be at least ten times faster. Landmarks error and visual examination of the coregistered images indicate that the two alternative frameworks for biomechanical simulations lead to comparable results of deformable registration. Thus, the computationally less expensive biomechanical simulator offers a practical alternative for registration purposes.

Simulating complex tumor dynamics from avascular to vascular growth using a general level-set method.

A comprehensive continuum model of solid tumor evolution and development is investigated in detail numerically, both under the assumption of spherical symmetry and for arbitrary two-dimensional growth. The level set approach is used to obtain solutions for a recently developed multi-cell transport model formulated as a moving boundary problem for the evolution of the tumor. The model represents both the avascular and the vascular phase of growth, and is able to simulate when the transition occurs; progressive formation of a necrotic core and a rim structure in the tumor during the avascular phase are also captured. In terms of transport processes, the interaction of the tumor with the surrounding tissue is realistically incorporated. The two-dimensional simulation results are presented for different initial configurations. The computational framework, based on a Cartesian mesh/narrow band level-set method, can be applied to similar models that require the solution of coupled advection-diffusion equations with a moving boundary inside a fixed domain. The solution algorithm is designed so that extension to three-dimensional simulations is straightforward.

The time-dependent magneto-visco-elastic behavior of a magnetostrictive fiber actuated viscoelastic polymer matrix composite.

The paper develops a one-dimensional magneto-elastic model of a magnetostrictive fiber actuated polymer matrix composite material which accounts for a strong viscoelastic response in the polymer matrix. The viscoelastic behavior of the composite polymer matrix is modeled with a three parallel Maxwell element viscoelastic model, the magnetoelastic behavior of the composite fibers is modeled with an anhysteric directional potential based domain occupation theory. Example calculations are performed to identify and explain the dynamical behavior of the composite. These calculations assume that a constant stress and the oscillating magnetic field are applied in the fiber longitudinal direction. The inclusion of matrix viscosity results in an apparent hysteresis loop in the magnetization and magnetostriction curves even though the model does not include magnetoelastic hysteresis in the fibers. The apparent hysteresis is a consequence of the interaction of the time varying fiber stress caused by matrix viscosity with a multidomain state in the fiber. The small increase in fiber longitudinal compressive stress due to matrix viscosity under increasing field inhibits the occupation of domains with magnetization orientations near the fiber longitudinal [112] direction. As a consequence, the summed longitudinal magnetization and magnetostriction is reduced as compared to the decreasing field limb.