Last data update: Sep 30, 2024. (Total: 47785 publications since 2009)
Records 1-30 (of 53 Records) |
Query Trace: Ansari U[original query] |
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Carbapenem-resistant and extended-spectrum β-Lactamase-producing enterobacterales in children, United States, 2016-2020
Grome HN , Grass JE , Duffy N , Bulens SN , Ansari U , Campbell D , Lutgring JD , Gargis AS , Masters T , Kent AG , McKay SL , Smith G , Wilson LE , Vaeth E , Evenson B , Dumyati G , Tsay R , Phipps E , Flores K , Wilson CD , Czaja CA , Johnston H , Janelle SJ , Lynfield R , O'Malley S , Vagnone PS , Maloney M , Nadle J , Guh AY . Emerg Infect Dis 2024 30 (6) 1104-1114 |
An interactive modeling tool for projecting the health and direct medical cost impact of changes in the sexually transmitted diseases prevention program budgets
Martin EG , Ansari B , Gift TL , Johnson BL , Collins D , Williams AM , Chesson HW . J Public Health Manag Pract 2024 30 (2) 221-230 CONTEXT: Estimating the return on investment for public health services, tailored to the state level, is critical for demonstrating their value and making resource allocation decisions. However, many health departments have limited staff capacity and expertise to conduct economic analyses in-house. PROGRAM: We developed a user-friendly, interactive Excel-based spreadsheet model that health departments can use to estimate the impact of increases or decreases in sexually transmitted infection (STI) prevention funding on the incidence and direct medical costs of chlamydia, gonorrhea, syphilis, and STI-attributable HIV infections. Users tailor results to their jurisdictions by entering the size of their population served; the number of annual STI diagnoses; their prior annual funding amount; and their anticipated new funding amount. The interface was developed using human-centered design principles, including focus groups with 15 model users to collect feedback on an earlier model version and a usability study on the prototype with 6 model users to finalize the interface. IMPLEMENTATION: The STI Prevention Allocation Consequences Estimator ("SPACE Monkey 2.0") model will be publicly available as a free downloadable tool. EVALUATION: In the usability testing of the prototype, participants provided overall positive feedback. They appreciated the clear interpretations, outcomes expressed as direct medical costs, functionalities to interact with the output and copy charts into external applications, visualization designs, and accessible information about the model's assumptions and limitations. Participants provided positive responses to a 10-item usability evaluation survey regarding their experiences with the prototype. DISCUSSION: Modeling tools that synthesize literature-based estimates and are developed with human-centered design principles have the potential to make evidence-based estimates of budget changes widely accessible to health departments. |
Proposed priorities for low-dose radiation research and their relevance to the practice of radiology
Mahesh M , Frush DP , Gros S , Dauer L , Barreto I , Ansari AJ . Radiology 2023 309 (2) e222590 Because ionizing radiation is widely used in medical imaging and in military, industry, and commercial applications, programmatic management and advancement in knowledge is needed, especially related to the health effects of low-dose radiation. The U.S. Congress in partnership with the U.S. Department of Energy called on the National Academies of Sciences, Engineering, and Medicine (NASEM) to develop a long-term strategic and prioritized agenda for low-dose radiation research. Low doses were defined as dose amounts less than 100 mGy or low-dose rates less than 5 mGy per hour. The 2022 NASEM report was divided into sections detailing the low-dose radiation exposure and health effects, scientific basis for radiation protection, status of low-dose radiation research, a prioritized radiation research agenda, and essential components of a low-dose radiation research program, including resources needed and recommendations for financial recourse. The purpose of this review is to summarize this report and examine the recommendations to assess how these pertain to the practice of radiology and medicine. |
Centers for Disease Control and Prevention participation in Cobalt Magnet National-Level Radiological Exercise
Ansari A , Salame-Alfie A , Dopson SA . Disaster Med Public Health Prep 2023 17 e472 Since September 11, 2001, the Centers for Disease Control and Prevention (CDC) has increased efforts to prepare the agency and public health partners for response to potential nuclear/radiological disasters. During the week of May 16-20, 2022, the CDC participated in a national-level radiological emergency exercise, Cobalt Magnet 22 (CM22). The exercise scenario consisted of a notional, failed search mission for a radiological dispersal device (RDD, "dirty bomb"), followed by its explosion during a public event in a large US city. Testing radioanalytical laboratory capabilities during a nuclear/radiological incident was an exercise objective, and developing clear messaging on low-dose exposure and long-term health concerns was a primary output of the exercise. The CDC practiced its activation protocols, exercised the establishment of its updated Incident Management System structure for radiation emergencies, and identified critical staffing needs for this type of response. |
A methodology for calculating inhalation dose to public health personnel exposed to material resuspended from evacuees following the detonation of a fission device
Anspaugh LR , Mauro J , Briggs N , Porrovecchio J , Amann W , Salame-Alfie A , Ansari A . Health Phys 2023 125 (4) 289-304 Following a nuclear fission event, there likely would be a large number of contaminated persons who would seek assistance at community reception centers to be established outside the affected area. This paper provides a methodology for calculating inhalation doses to public health and other response personnel at such facilities who would be receiving and assisting potentially contaminated persons from whom particles can be resuspended. Three hypothetical facilities were considered: the Base Case is a rather small room with no forced air ventilation. The Preferred Case, which is more realistic, is a mid-sized room with an operating HVAC system with air being recirculated through a filter. The Gymnasium Case has only fresh air intake. Initial bounding calculations for the Base Case indicated the need for pre-screening of arrivals to avoid unacceptable doses to staff. The screening criterion selected was 1.67 × 106 Bq m-2. Calculations are presented for radionuclide concentrations in air, dose to staff from inhalation, and how exposures and the resulting doses can be altered by air-turnover rates and the use of filters with varying efficiency. Doses are presented for various arrival times and for both plutonium- and uranium-fueled detonations. The highest calculated dose via inhalation with no respiratory protection was 0.23 mSv for the Base Case. The more important radionuclides contributing to dose with exposure starting at day D + 1 were 239Np and 133I. At day D + 30, 131I and 140Ba were the more important dosimetrically. The variable creating the highest uncertainty was the slough-off factor for resuspension of contamination from people arriving at the reception center. |
Clinical and genomic epidemiology of mcr-9-carrying carbapenem-resistant Enterobacterales isolates in Metropolitan Atlanta, 2012-2017 (preprint)
Babiker A , Bower C , Lutgring JD , Howard-Anderson J , Ansari U , McAllister G , Adamczyk M , Breaker E , Satola SW , Jacob JT , Woodworth MH . medRxiv 2021 2021.10.13.21264308 Colistin is a last-resort antibiotic for multidrug-resistant gram-negative infections. Recently, the ninth allele of the mobile colistin resistance (mcr) gene family, designated mcr-9, was reported. However, its clinical and public health significance remains unclear. We queried genomes of carbapenem-resistant Enterobacterales (CRE) for mcr-9 from a convenience sample of clinical isolates collected between 2012-2017 through the Georgia Emerging Infections Program, a population- and laboratory-based surveillance program. Isolates underwent phenotypic characterization and whole genome sequencing. Phenotypic characteristics, genomic features, and clinical outcomes of mcr-9 positive and negative CRE cases were then compared. Among 235 sequenced CRE genomes, thirteen (6%) were found to harbor mcr-9, all of which were Enterobacter cloacae complex. The median MIC, rates of heteroresistance and inducible resistance to colistin were similar between mcr-9 positive and negative isolates. However, rates of resistance were higher among mcr-9 positive isolates across most antibiotic classes. All cases had significant healthcare exposures. The 90-day mortality was similarly high in both mcr-9 positive (31%) and negative (7%) CRE cases. Nucleotide identity and phylogenetic analysis did not reveal geo-temporal clustering. mcr-9 positive isolates had a significantly higher number of median [range] AMR genes (16 [4-22] vs. 6 [2-15]; p <0.001) compared to mcr-9 negative isolates. Pan genome tests confirmed a significant association of mcr-9 detection with mobile genetic element and heavy metal resistance genes. Overall, the presence of mcr-9 was not associated with significant changes in colistin resistance or clinical outcomes but continued genomic surveillance to monitor for emergence of AMR genes is warranted.Competing Interest StatementThe authors have declared no competing interest.Funding StatementEIP Surveillance of the Multi-site Gram-Negative Surveillance Initiative (MuGSI) was funded through the Centers for Disease Control and Preventions Emerging Infections Program [U50CK000485].Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:Georgia EIP surveillance activities are reviewed and approved by the Emory University Institutional Review Board.I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesAll data produced in the present study are available upon reasonable request to the authors |
Measurable radiation levels around individuals externally contaminated by nuclear fallout
Samuels C , Ansari A , Finklea L , Hertel N . Radiat Prot Dosimetry 2023 199 (12) 1310-1323 During the early response to large-scale radioactive contamination events, people who are potentially affected need to be screened for radioactive contamination and public health staff need to triage individuals who may need immediate decontamination. This is typically done by screening individuals for external contamination using ionising radiation detection equipment. In this study, spatially and temporally dependent isotopic compositions from a simulated nuclear detonation and Monte Carlo methods were used to relate contamination activity levels to the measurable radiation levels at select distances away from an individual with whole-body contamination. Radionuclide-specific air kerma rate coefficients and Geiger-Mueller instrument response coefficients at five select distances from contaminated individuals are presented for 662 radionuclides. Temporally and spatially dependent incident-specific coefficients are presented for a hypothetical surface detonation of a 235U-fueled device. |
Patient exposure from radiologic and nuclear medicine procedures in the United States and Worldwide: 2009-2018
Mahesh M , Ansari AJ , Mettler FA Jr . Radiology 2023 307 (1) e221263 The U.S. National Council on Radiation Protection and Measurements (NCRP) conducted a retrospective assessment of the U.S. data, and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) performed a similar worldwide assessment for 2009-2018 (with most data from 2014 to 2017). Using the data from those reports, the frequency of radiologic and nuclear medicine studies, annual collective, and per capita effective dose in the United States for 2016 were compared with worldwide estimates from 2009 to 2018. There were an estimated 691 million radiologic, CT, dental, and nuclear medicine studies performed in the United States in 2016, which represented 16.5% of the 4.2 billion performed worldwide. The United States also accounted for 74 million CT procedures (18% of the world's estimated total), 275 million conventional radiology procedures (11% of the world's total), 8.1 million interventional radiologic procedures (34% of the world's total), 320 million dental radiography procedures (29% of the world's total), and 13.5 million nuclear medicine procedures (34% of the world's total). The U.S. collective effective dose was 717 000 person-sieverts (17.6% of the world's total). The average annual individual effective dose in the United States was 2.2 mSv compared with 0.56 mSv worldwide. The United States accounts for a large and disproportionate share of global medical radiation procedures and collective effective dose, but use of CT has increased more in other countries compared with the United States. |
Time motion studies for conduct of population monitoring during functional radiological exercises at community reception centers
Finklea L , Salame-Alfie A , Ansari A . Disaster Med Public Health Prep 2022 17 1-8 OBJECTIVE: The objectives of this study were to: validate current capacity estimates for radiological emergency response by collecting time motion observations from stations that would be used for screening and decontaminating populations, and use collected times to evaluate potential impact on current throughput calculations. METHODS: Time observations were collected at 11 functional radiation exercises across the country and aggregated for analysis for population monitoring activities, including contamination screening, decontamination, and registration. Collected times were compared to published estimates in current planning guidance, and evaluated to determine the suitability of using exercise observations to estimate throughput capacity. RESULTS: 2532-time observations were collected from 11 functional exercises. Of those, 2380 were validated and used for analysis. Contamination screening times varied greatly from current guidance, ranging from 19% below to 267% above existing estimates. Measurements indicate that capacity to perform contamination screening is significantly overestimated when using current estimates of service times and calculations when compared to observed aggregate service times. CONCLUSION: Aggregate service time data presented in this study can be used to yield a more realistic estimate of capacity to respond to a radiation event. |
Carbapenem-Resistant enterobacterales in individuals with and without health care risk factors -Emerging infections program, United States, 2012-2015.
Bulens SN , Reses HE , Ansari UA , Grass JE , Carmon C , Albrecht V , Lawsin A , McAllister G , Daniels J , Lee YK , Yi S , See I , Jacob JT , Bower CW , Wilson L , Vaeth E , Lynfield R , Vagnone PS , Shaw KM , Dumyati G , Tsay R , Phipps EC , Bamberg W , Janelle SJ , Beldavs ZG , Cassidy PM , Kainer M , Muleta D , Mounsey JT , Laufer-Halpin A , Karlsson M , Lutgring JD , Walters MS . Am J Infect Control 2022 51 (1) 70-77 BACKGROUND: Carbapenem-resistant Enterobacterales (CRE) are usually healthcare-associated but are also emerging in the community. METHODS: Active, population-based surveillance was conducted to identify case-patients with cultures positive for Enterobacterales not susceptible to a carbapenem (excluding ertapenem) and resistant to all third-generation cephalosporins tested at 8 US sites from January 2012 to December 2015. Medical records were used to classify cases as health care-associated, or as community-associated (CA) if a patient had no known health care risk factors and a culture was collected <3 days after hospital admission. Enterobacterales isolates from selected cases were submitted to CDC for whole genome sequencing. RESULTS: We identified 1499 CRE cases in 1194 case-patients; 149 cases (10%) in 139 case-patients were CA. The incidence of CRE cases per 100,000 population was 2.96 (95% CI: 2.81, 3.11) overall and 0.29 (95% CI: 0.25, 0.35) for CA-CRE. Most CA-CRE cases were in White persons (73%), females (84%) and identified from urine cultures (98%). Among the 12 sequenced CA-CRE isolates, 5 (42%) harbored a carbapenemase gene. CONCLUSIONS: Ten percent of CRE cases were CA; some isolates from CA-CRE cases harbored carbapenemase genes. Continued CRE surveillance in the community is critical to monitor emergence outside of traditional health care settings. |
Clinical and Genomic Epidemiology of mcr-9-Carrying Carbapenem-Resistant Enterobacterales Isolates in Metropolitan Atlanta, 2012 to 2017.
Babiker A , Bower C , Lutgring JD , Petit RA3rd , Howard-Anderson J , Ansari U , McAllister G , Adamczyk M , Breaker E , Satola SW , Jacob JT , Woodworth MH . Microbiol Spectr 2022 10 (4) e0252221 Colistin is a last-resort antibiotic for multidrug-resistant Gram-negative infections. Recently, the ninth allele of the mobile colistin resistance (mcr) gene family, designated mcr-9, was reported. However, its clinical and public health significance remains unclear. We queried genomes of carbapenem-resistant Enterobacterales (CRE) for mcr-9 from a convenience sample of clinical isolates collected between 2012 and 2017 through the Georgia Emerging Infections Program, a population- and laboratory-based surveillance program. Isolates underwent phenotypic characterization and whole-genome sequencing. Phenotypic characteristics, genomic features, and clinical outcomes of mcr-9-positive and -negative CRE cases were then compared. Among 235 sequenced CRE genomes, 13 (6%) were found to harbor mcr-9, all of which were Enterobacter cloacae complex. The median MIC and rates of heteroresistance and inducible resistance to colistin were similar between mcr-9-positive and -negative isolates. However, rates of resistance were higher among mcr-9-positive isolates across most antibiotic classes. All cases had significant health care exposures. The 90-day mortality was similarly high in both mcr-9-positive (31%) and -negative (7%) CRE cases. Nucleotide identity and phylogenetic analysis did not reveal geotemporal clustering. mcr-9-positive isolates had a significantly higher number of median [range] antimicrobial resistance (AMR) genes (16 [4 to 22] versus 6 [2 to 15]; P < 0.001) than did mcr-9-negative isolates. Pangenome tests confirmed a significant association of mcr-9 detection with mobile genetic element and heavy metal resistance genes. Overall, the presence of mcr-9 was not associated with significant changes in colistin resistance or clinical outcomes, but continued genomic surveillance to monitor for emergence of AMR genes is warranted. IMPORTANCE Colistin is a last-resort antibiotic for multidrug-resistant Gram-negative infections. A recently described allele of the mobile colistin resistance (mcr) gene family, designated mcr-9, has been widely reported among Enterobacterales species. However, its clinical and public health significance remains unclear. We compared characteristics and outcomes of mcr-9-positive and -negative CRE cases. All cases were acquired in the health care setting and associated with a high rate of mortality. The presence of mcr-9 was not associated with significant changes in colistin resistance, heteroresistance, or inducible resistance but was associated with resistance to other antimicrobials and antimicrobial resistance (AMR), virulence, and heavy metal resistance (HMR) genes. Overall, the presence of mcr-9 was not associated with significant phenotypic changes or clinical outcomes. However, given the increase in AMR and HMR gene content and potential clinical impact, continued genomic surveillance of multidrug-resistant organisms to monitor for emergence of AMR genes is warranted. |
Public health response and medical management of internal contamination in past radiological or nuclear incidents: A narrative review
Li C , Alves Dos Reis A , Ansari A , Bertelli L , Carr Z , Dainiak N , Degteva M , Efimov A , Kalinich J , Kryuchkov V , Kukhta B , Kurihara O , Antonia Lopez M , Port M , Riddell T , Rump A , Sun Q , Tuo F , Youngman M , Zhang J . Environ Int 2022 163 107222 Following a radiological or nuclear emergency, workers, responders and the public may be internally contaminated with radionuclides. Screening, monitoring and assessing any internal contamination and providing necessary medical treatment, especially when a large number of individuals are involved, is challenging. Experience gained and lessons learned from the management of previous incidents would help to identify gaps in knowledge and capabilities on preparedness for and response to radiation emergencies. In this paper, eight large-scale and five workplace radiological and nuclear incidents are reviewed cross 14 technical areas, under the broader topics of emergency preparedness, emergency response and recovery processes. The review findings suggest that 1) new strategies, algorithms and technologies are explored for rapid screening of large populations; 2) exposure assessment and dose estimation in emergency response and dose reconstruction in recovery process are supported by complementary sources of information, including 'citizen science'; 3) surge capacity for monitoring and dose assessment is coordinated through national and international laboratory networks; 4) evidence-based guidelines for medical management and follow-up of internal contamination are urgently needed; 5) mechanisms for international and regional access to medical countermeasures are investigated and implemented; 6) long-term health and medical follow up programs are designed and justified; and 7) capabilities and capacity developed for emergency response are sustained through adequate resource allocation, routine non-emergency use of technical skills in regular exercises, training, and continuous improvement. |
Molecular Characterization of Carbapenem-Resistant Enterobacterales Collected in the United States.
Karlsson M , Lutgring JD , Ansari U , Lawsin A , Albrecht V , McAllister G , Daniels J , Lonsway D , McKay S , Beldavs Z , Bower C , Dumyati G , Gross A , Jacob J , Janelle S , Kainer MA , Lynfield R , Phipps EC , Schutz K , Wilson L , Witwer ML , Bulens SN , Walters MS , Duffy N , Kallen AJ , Elkins CA , Rasheed JK . Microb Drug Resist 2022 28 (4) 389-397 Carbapenem-resistant Enterobacterales (CRE) are a growing public health concern due to resistance to multiple antibiotics and potential to cause health care-associated infections with high mortality. Carbapenemase-producing CRE are of particular concern given that carbapenemase-encoding genes often are located on mobile genetic elements that may spread between different organisms and species. In this study, we performed phenotypic and genotypic characterization of CRE collected at eight U.S. sites participating in active population- and laboratory-based surveillance of carbapenem-resistant organisms. Among 421 CRE tested, the majority were isolated from urine (n = 349, 83%). Klebsiella pneumoniae was the most common organism (n = 265, 63%), followed by Enterobacter cloacae complex (n = 77, 18%) and Escherichia coli (n = 50, 12%). Of 419 isolates analyzed by whole genome sequencing, 307 (73%) harbored a carbapenemase gene; variants of bla(KPC) predominated (n = 299, 97%). The occurrence of carbapenemase-producing K. pneumoniae, E. cloacae complex, and E. coli varied by region; the predominant sequence type within each genus was ST258, ST171, and ST131, respectively. None of the carbapenemase-producing CRE isolates displayed resistance to all antimicrobials tested; susceptibility to amikacin and tigecycline was generally retained. |
Variation in patterns of racial and ethnic disparities in primary and secondary syphilis diagnosis rates among heterosexually active women by region and age group in the United States
Martin EG , Ansari B , Rosenberg ES , Hart-Malloy R , Smith D , Bernstein KT , Chesson HW , Delaney K , Trigg M , Gift TL . Sex Transm Dis 2022 49 (5) 330-337 BACKGROUND: Syphilis rates have increased substantially over the past decade. Women are an important population due to negative sequalae and adverse maternal outcomes including congenital syphilis. We assessed whether racial and ethnic disparities in primary and secondary (P&S) syphilis among heterosexually active women differ by region and age group. METHODS: We synthesized four national surveys to estimate numbers of heterosexually active women in the United States from 2014 through 2018 by region, race and ethnicity, and age group (18-24, 25-29, 30-44, and ≥ 45 years). We calculated annual P&S syphilis diagnosis rates, assessing disparities with rate differences and rate ratios comparing White, Hispanic, and Black heterosexually active women. RESULTS: Nationally, annual rates were 6.42 and 2.20 times as high among Black and Hispanic than among White heterosexually active women (10.99, 3.77, and 1.71 per 100,000, respectively). Younger women experienced a disproportionate burden of P&S syphilis and the highest disparities. Regionally, the Northeast had the highest Black-White and Hispanic-White disparities using a relative disparity measure (relative rate) and the West had the highest disparities using an absolute disparity measure (rate difference). CONCLUSIONS: To meet the racial and ethnic disparities goals of the Sexually Transmitted Infections National Strategic Plan, tailored local interventions that address the social and structural factors associated with disparities are needed for different age groups. |
Distinctive Features of Ertapenem-Mono-Resistant Carbapenem-Resistant Enterobacterales in the United States: A Cohort Study.
Adelman MW , Bower CW , Grass JE , Ansari UA , Soda EA , See I , Lutgring JD , Jacob JT . Open Forum Infect Dis 2022 9 (1) ofab643 BACKGROUND: Carbapenem-resistant Enterobacterales (CRE) are highly antibiotic-resistant bacteria. Whether CRE resistant only to ertapenem among carbapenems (ertapenem "mono-resistant") represent a unique CRE subset with regards to risk factors, carbapenemase genes, and outcomes is unknown. METHODS: We analyzed surveillance data from 9 CDC Emerging Infections Program (EIP) sites. A case was the first isolation of a carbapenem-resistant Enterobacter cloacae complex, Escherichia coli, Klebsiella aerogenes, K. oxytoca, K. pneumoniae, or K. variicola from a normally sterile site or urine in an EIP catchment area resident in 2016-2017. We compared risk factors, carbapenemase genes, antibiotic susceptibility, and mortality of ertapenem "mono-resistant" cases to "other" CRE cases (resistant to1 carbapenem other than ertapenem) and analyzed risk factors for mortality. RESULTS: Of 2009 cases, 1249 (62.2%) were ertapenem-mono-resistant and 760 (37.8%) were other CRE. Ertapenem-mono-resistant CRE cases were more frequently80 years old (29.1% vs 19.5%; P<.0001) and female (67.9% vs 59.0%; P<.0001). Ertapenem-mono-resistant isolates were more likely to be Enterobacter cloacae complex (48.4% vs 15.4%; P<.0001) but less likely to be isolated from a normally sterile site (7.1% vs 11.7%; P<.01) or to have a carbapenemase gene (2.4% vs 47.4%; P<.0001). Ertapenem-mono-resistance was not associated with 90-day mortality in logistic regression models. Carbapenemase-positive isolates were associated with mortality (odds ratio, 1.93; 95% CI, 1.30-2.86). CONCLUSIONS: Ertapenem-mono-resistant CRE rarely have carbapenemase genes and have distinct clinical and microbiologic characteristics from other CRE. These findings may inform antibiotic choice and infection prevention practices, particularly when carbapenemase testing is not available. |
A Million Persons, A Million Dreams: A Vision For A National Center Of Radiation Epidemiology And Biology
Boice JD Jr , Quinn B , Al-Nabulsi I , Ansari A , Blake PK , Blattnig SR , Caffrey EA , Cohen SS , Golden AP , Held KD , Jokisch DW , Leggett RW , Mumma MT , Samuels C , Till JE , Tolmachev SY , Yoder RC , Zhou JY , Dauer LT . Int J Radiat Biol 2021 98 (4) 1-50 BACKGROUND: Epidemiologic studies of radiation-exposed populations form the basis for human safety standards. They also help shape public health policy and evidence-based health practices by identifying and quantifying health risks of exposure in defined populations. For more than a century, epidemiologists have studied the consequences of radiation exposures, yet the health effects of low levels delivered at a low-dose rate remain equivocal. MATERIALS AND METHODS: The Million Person Study (MPS) of U.S. Radiation Workers and Veterans was designed to examine health effects following chronic exposures in contrast with brief exposures as experienced by the Japanese atomic bomb survivors. Radiation associations for rare cancers, intakes of radionuclides, and differences between men and women are being evaluated, as well as noncancers such as cardiovascular disease and conditions such as dementia and cognitive function. The first international symposium, held November 6, 2020, provided a broad overview of the MPS. Representatives from four U.S. government agencies addressed the importance of this research for their respective missions: U.S. Department of Energy (DOE), the Centers for Disease Control and Prevention (CDC), the U.S. Department of Defense (DOD), and the National Aeronautical Space Agency (NASA). The major components of the MPS were discussed and recent findings summarized. The importance of radiation dosimetry, an essential feature of each MPS investigation, was emphasized. RESULTS: The seven components of the MPS are DOE workers, nuclear weapons test participants, nuclear power plant workers, industrial radiographers, medical radiation workers, nuclear submariners, other U.S. Navy personnel, and radium dial painters. The MPS cohorts include tens of thousands of workers with elevated intakes of alpha particle emitters for which organ-specific doses are determined. Findings to date for chronic radiation exposure suggest that leukemia risk is lower than after acute exposure; lung cancer risk is much lower and there is little difference in risks between men and women; an increase in ischemic heart disease is yet to be seen; esophageal cancer is frequently elevated but not myelodysplastic syndrome; and Parkinson's disease may be associated with radiation exposure. CONCLUSIONS: The MPS has provided provocative insights into the possible range of health effects following low-level chronic radiation exposure. When the 34 MPS cohorts are completed and combined, a powerful evaluation of radiation-effects will be possible. This final article in the MPS special issue summarizes the findings to date and the possibilities for the future. A National Center for Radiation Epidemiology and Biology is envisioned. |
Racial and ethnic disparities in HIV diagnoses among heterosexually active persons in the United States nationally and by state, 2018
Martin EG , Ansari B , Hart-Malloy R , Smith DK , Delaney KP , Gift TL , Berruti AA , Trigg M , Rosenberg ES . PLoS One 2021 16 (9) e0257583 BACKGROUND: Despite declining HIV infection rates, persistent racial and ethnic disparities remain. Appropriate calculations of diagnosis rates by HIV transmission category, race and ethnicity, and geography are needed to monitor progress towards reducing systematic disparities in health outcomes. We estimated the number of heterosexually active adults (HAAs) by sex and state to calculate appropriate HIV diagnosis rates and disparity measures within subnational regions. METHODS: The analysis included all HIV diagnoses attributed to heterosexual transmission in 2018 in the United States, in 50 states and the District of Columbia. Logistic regression models estimated the probability of past-year heterosexual activity among adults in three national health surveys, by sex, age group, race and ethnicity, education category, and marital status. Model-based probabilities were applied to estimated counts of HAAs by state, which were synthesized through meta-analysis. HIV diagnoses were overlaid to calculate racial- and ethnic-specific rates, rate differences (RDs), and rate ratios (RRs) among HAAs by sex and state. RESULTS: Nationally, HAA women have a two-fold higher HIV diagnosis rate than HAA men (rate per 100,000 HAAs, women: 6.57; men: 3.09). Compared to White non-Hispanic HAAs, Black HAAs have a 20-fold higher HIV diagnosis rate (RR, men: 21.28, women: 19.55; RD, men: 15.40, women: 31.78) and Hispanic HAAs have a 4-fold higher HIV diagnosis rate (RR, men: 4.68, RD, women: 4.15; RD, men: 2.79, RD, women: 5.39). Disparities were ubiquitous across regions, with >75% of states in each region having Black-to-White RR ≥10. CONCLUSION: The racial and ethnic disparities across regions suggests a system-wide failure particularly with respect to preventing HIV among Black and Hispanic women. Pervasive disparities emphasize the role for coordinated federal responses such as the current Ending the HIV Epidemic (EHE) initiative. |
Geospatial analysis in responding to a nuclear detonation scenario in NYC: The Gotham Shield Exercise
Lowe L , Salame-Alfie A , Neurath B , Quinn C , Ansari A , Whitcomb R , Dopson S . J Homel Secur Emerg Manag 2020 17 (3) In April 2017, the Centers for Disease Control and Prevention (CDC) participated in the Gotham Shield Exercise, led by the Federal Emergency Management Agency (FEMA) and in collaboration with other federal agencies to test the federal, state and local government's ability to respond to an improvised nuclear device (IND). With active engagement from CDC leadership, 266 scientific and support staff from across the agency participated in the Gotham Shield exercise. The scenario involved a 10-kiloton detonation near the Lincoln Tunnel in New Jersey. This nuclear detonation scenario provided CDC with the opportunity to test some of the all-hazards tools the agency uses during response to other national or international emergencies, such as Geographic Information Systems (GIS) and mapping tools, and apply these tools to a nuclear emergency. Geospatial analysis associated with real time data can provide near real time information for individuals and entities associated with response and recovery activities. This type of analysis can provide timely data in regard to maps and information used to properly place staging areas for Community Reception Centers (CRC), mass care locations, and other medical care and countermeasure related services. Maps showing locations of power loss, such as locations of lost or inoperable main electrical grid and substations, combined with real time data on where power is available provides valuable information for first responders and emergency managers as well as responders engaged in communicating critical public messages to affected populations in these areas. By using real-time information, response officials can direct the response, allocate scarce resources, aid in coordination efforts, and provide a more efficient means of providing critical public health and medical services. The results of the exercise highlight the importance of using geospatial analysis for response planning and effect mitigation before, during, and after a public health event of this magnitude, and the value they represent in informed decision making. |
Antibiotic susceptibility of NDM-producing enterobacterales collected in the United States, 2017-2018
Lutgring JD , Balbuena R , Reese N , Gilbert SE , Ansari U , Bhatnagar A , Boyd S , Campbell D , Cochran J , Haynie J , Ilutsik J , Longo C , Swint S , Rasheed JK , Brown AC , Karlsson M . Antimicrob Agents Chemother 2020 64 (9) The treatment of infections caused by carbapenem-resistant Enterobacterales, especially New Delhi metallo-beta-lactamase (NDM)-producing bacteria, is challenging. Although less common in the United States than some other carbapenemase-producers, NDM-producing bacteria are a public health threat due to the limited treatment options available. Here we report on the antibiotic susceptibility of 275 contemporary NDM-producing Enterobacterales collected from 30 U.S. states through the Centers for Disease Control and Prevention's Antibiotic Resistance Laboratory Network. The aim of the study was to determine the susceptibility of these isolates against 32 currently available antibiotics using reference broth microdilution and explore the in vitro activity of 3 combination agents that are not yet available. Categorical interpretations were determined using Clinical and Laboratory Standards Institute (CLSI) interpretative criteria. For agents without CLSI criteria, Food and Drug Administration (FDA) interpretative criteria were used. The percentage of susceptible isolates did not exceed 90% for any of the FDA-approved antibiotics tested. The antibiotics with breakpoints that had the highest in vitro activity were tigecycline (86.5% susceptible), eravacycline (66.2% susceptible), and omadacycline (59.6% susceptible) 18.2% of isolates were susceptible to aztreonam. All NDM-producing isolates tested were multidrug-resistant, and 116 isolates were extensively drug-resistant (42.2%) 207 (75.3%) isolates displayed difficult-to-treat resistance. The difficulty in treating infections caused by NDM-producing Enterobacterales highlights the need for containment and prevention efforts to keep these infections from becoming more common. |
Patient exposure from radiologic and nuclear medicine procedures in the United States: Procedure volume and effective dose for the period 2006-2016
Mettler FA Jr , Mahesh M , Bhargavan-Chatfield M , Chambers CE , Elee JG , Frush DP , Miller DL , Royal HD , Milano MT , Spelic DC , Ansari AJ , Bolch WE , Guebert GM , Sherrier RH , Smith JM , Vetter RJ . Radiology 2020 295 (2) 192256 Background Comprehensive assessments of the frequency and associated doses from radiologic and nuclear medicine procedures are rarely conducted. The use of these procedures and the population-based radiation dose increased remarkably from 1980 to 2006. Purpose To determine the change in per capita radiation exposure in the United States from 2006 to 2016. Materials and Methods The U.S. National Council on Radiation Protection and Measurements conducted a retrospective assessment for 2016 and compared the results to previously published data for the year 2006. Effective dose values for procedures were obtained from the literature, and frequency data were obtained from commercial, governmental, and professional society data. Results In the United States in 2006, an estimated 377 million diagnostic and interventional radiologic examinations were performed. This value remained essentially the same for 2016 even though the U.S. population had increased by about 24 million people. The number of CT scans performed increased from 67 million to 84 million, but the number of other procedures (eg, diagnostic fluoroscopy) and nuclear medicine procedures decreased from 17 million to 13.5 million. The number of dental radiographic and dental CT examinations performed was estimated to be about 320 million in 2016. Using the tissue-weighting factors from Publication 60 of the International Commission on Radiological Protection, the U.S. annual individual (per capita) effective dose from diagnostic and interventional medical procedures was estimated to have been 2.9 mSv in 2006 and 2.3 mSv in 2016, with the collective doses being 885 000 and 755 000 person-sievert, respectively. Conclusion The trend from 1980 to 2006 of increasing dose from medical radiation has reversed. Estimated 2016 total collective effective dose and radiation dose per capita dose are lower than in 2006. (c) RSNA, 2020 See also the editorial by Einstein in this issue. |
Estimation of External Contamination and Exposure Rates Due to Fission Product Release.
Dewji SA , Bales K , Asano E , Veinot K , Eckerman K , Hart S , Finklea L , Ansari A . Health Phys 2020 119 (2) 163-175 In the event of a radiological incident, the release of fission products into the surrounding environment and the ensuing external contamination present a challenge for triage assessment by emergency response personnel. Reference exposure rate and skin dose rate calibration data for emergency response personnel are currently lacking for cases where receptors are externally contaminated with fission products. Simulations were conducted to compute reference exposure rate coefficients and skin dose rate coefficients from photon-emitting fission products of radiological concern. To accomplish this task, simplified mathematical skin phantoms were created using surface area and height specifications from International Commission on Radiological Protection Publication 89. Simulations were conducted using Monte Carlo radiation transport code using newborn, 1-y-old, 5-y-old, 10-y-old, 15-y-old, and adult phantoms for 22 photon-emitting radionuclides. Exposure rate coefficient data were employed in a case study simulating the radionuclide inventory for a 17 x 17 Westinghouse pressurized water reactor, following three burn-up cycles at 14,600 MWd per metric ton of uranium. The decay times following the final cycle represent the relative activity fractions over a period of 0.5-30 d. The resulting data can be used as calibration standards for triage efforts in emergency response protocols. |
Potential health effects of low dose radiation and what it means to the practice of radiation protection
Ansari A , Kleinhans K , Boice JD . J Radiol Prot 2019 39 (4) E9-e13 If we ask a group of intelligent and educated individuals not familiar with the science or practice of radiation protection to review published information on health effects of exposures to low levels of radiation and share their findings, they are likely to come away with an understanding that is as clear as mud. This is unfortunate. | | While the unfamiliar jargon, complex quantities and concepts, linguistic nuances, and inherent uncertainties provide a fertile ground for confusion, there is another contributing factor to this bewilderment, with potentially damaging long-term consequences: it is not unusual to find instances in scientific publications or conferences where the system of radiation protection or its scientific underpinnings are misrepresented or mischaracterised. The language used by some authors target the credibility and intentions of respected institutions and independent radiation protection commissions that for nearly a century have laid the foundation of radiation protection practice and are the regarded authoritative voices in this field. Eroding trust in those institutions, not only among young professionals entering the field but the public in general, can have devastating consequences. |
Carbapenem-resistant Pseudomonas aeruginosa at US Emerging Infections Program Sites, 2015
Walters MS , Grass JE , Bulens SN , Hancock EB , Phipps EC , Muleta D , Mounsey J , Kainer MA , Concannon C , Dumyati G , Bower C , Jacob J , Cassidy PM , Beldavs Z , Culbreath K , Phillips WEJr , Hardy DJ , Vargas RL , Oethinger M , Ansari U , Stanton R , Albrecht V , Halpin AL , Karlsson M , Rasheed JK , Kallen A . Emerg Infect Dis 2019 25 (7) 1281-1288 Pseudomonas aeruginosa is intrinsically resistant to many antimicrobial drugs, making carbapenems crucial in clinical management. During July-October 2015 in the United States, we piloted laboratory-based surveillance for carbapenem-resistant P. aeruginosa (CRPA) at sentinel facilities in Georgia, New Mexico, Oregon, and Tennessee, and population-based surveillance in Monroe County, NY. An incident case was the first P. aeruginosa isolate resistant to antipseudomonal carbapenems from a patient in a 30-day period from any source except the nares, rectum or perirectal area, or feces. We found 294 incident cases among 274 patients. Cases were most commonly identified from respiratory sites (120/294; 40.8%) and urine (111/294; 37.8%); most (223/280; 79.6%) occurred in patients with healthcare facility inpatient stays in the prior year. Genes encoding carbapenemases were identified in 3 (2.3%) of 129 isolates tested. The burden of CRPA was high at facilities under surveillance, but carbapenemase-producing CRPA were rare. |
Identification of a carbapenemase-producing hypervirulent Klebsiella pneumoniae isolate, United States
Karlsson M , Stanton RA , Ansari U , McAllister G , Chan MY , Sula E , Grass JE , Duffy N , Anacker ML , Witwer ML , Rasheed JK , Elkins CA , Halpin AL . Antimicrob Agents Chemother 2019 63 (7) We report on a carbapenemase-producing hypervirulent Klebsiella pneumoniae (CP-hvKP) collected from a U.S. patient at an outpatient clinic. The isolate was identified as K. pneumoniae serotype K1, sequence type 23 and included both a hypervirulence (with rmpA, rmpA2 iroBCDN, peg-344 and iucABCD-iutA genes) and a carbapenemase-encoding (bla KPC-2) plasmid. The emergence of CP-hvKP underscores the importance of clinical awareness of this pathotype and the need for continued monitoring of CP-hvKP in the United States. |
The role of radiation protection professionals in the landscape of low dose radiation
Ansari A . J Radiol Prot 2019 39 (4) 1117-1122 Radiation protection professionals benefit from using and applying a robust system of radiological protection that has evolved and matured through decades of research and experience. Nevertheless, uncertainties in potential health effects from low doses and low dose rates of radiation continue to remain. This uncertainty, coupled with complex jargon and nuances, has created an environment where the system of radiological protection can be misrepresented, even by radiation safety professionals, and by extension, misunderstood by the public. While it is universally agreed that the linear-no-threshold model cannot adequately explain or predict health effects of low dose radiation for all cancers, all individuals, or all exposure situations, the recommendation of authoritative scientific bodies to use this model for managing risks of radiation exposure is unequivocal. The role of individual radiation protection professionals in communicating radiation health and risk information is critical and consistent with the primary objective of professional organizations that represent them, mainly to promote best science and practice of radiation protection. If radiation protection professionals provide advice contrary to the recommendations and advice of regulatory and authoritative scientific bodies, it can erode public confidence in the system of radiological protection and harm the credibility of our profession. |
Development and Validation of a Clinical Laboratory Improvement Amendments-Compliant Multiplex Real-Time PCR Assay for Detection of mcr Genes.
Daniels JB , Campbell D , Boyd S , Ansari U , Lutgring J , Rasheed JK , Halpin AL , Sjolund-Karlsson M . Microb Drug Resist 2019 25 (7) 991-996 Increased use of colistin in both human and veterinary medicine has led to the emergence of plasmid-mediated colistin resistance (mcr genes). In this study, we report the development of a real-time PCR assay using TaqMan probe-based chemistry for detection of mcr genes from bacterial isolates. Positive control isolates harboring mcr-1 and mcr-2 yielded exponential amplification curves with the assay, and the amplification efficiency was 98% and 96% for mcr-1 and mcr-2, respectively. Each target gene could be reproducibly detected from a sample containing 10(3) cfu/mL of mcr-harboring bacteria, and there was no cross-reactivity with DNA extracted from several multidrug-resistant bacteria harboring other resistance genes, but lacking mcr genes. Both sensitivity and specificity of the mcr real-time PCR assay were 100% in a method validation performed with a set of 25 previously well-characterized bacterial isolates containing mcr-positive and -negative bacteria. This newly developed assay is a rapid and sensitive tool for detecting emerging mcr genes in cultured bacterial isolates. The assay was successfully validated according to quality standards of the Clinical Laboratory Improvement Amendments (CLIA). |
Monitoring and Dose Assessment for Children Following a Radiation Emergency-Part II: Calibration Factors for Thyroid Monitoring.
Li C , Tremblay M , Capello K , Kurihara O , Youngman M , Etherington G , Ansari A , Lopez MA , Franck D , Dewji S . Health Phys 2019 117 (3) 283-290 Past radiological and nuclear accidents have demonstrated that monitoring a large number of children following a radiological and nuclear emergency can be challenging, in accommodating their needs as well as adapting monitoring protocols and applying age-specific biokinetics to account for various ages and body sizes. This paper presents the derived calibration factors for thyroid monitoring of children of all ages recommended by the International Commission on Radiological Protection using four selected detectors at given times following a short-term (acute) intake of I by inhalation. These calibration factors were derived by Monte Carlo simulations using the models of various detectors and pediatric voxel phantoms. A collection of lookup tables is presented in this paper which may be directly used as a quick reference by emergency response personnel or technical experts performing thyroid monitoring and assessment without doing time-consuming calculations. |
Radiation exposure of workers and volunteers in shelters and community reception centers in the aftermath of a nuclear detonation
Anderson JL , Failla G , Finklea LR , Charp P , Ansari AJ . Health Phys 2019 116 (5) 619-624 After a nuclear detonation, workers and volunteers providing first aid, decontamination, and population monitoring in public shelters and community reception centers will potentially be exposed to radiation from people they are assisting who may be contaminated with radioactive fallout. A state-of-the-art computer-aided design program and radiation transport modeling software were used to estimate external radiation dose to workers in three different exposure scenarios: performing radiation surveys/decontamination, first aid, and triage duties. Calculated dose rates were highest for workers performing radiation surveys due to the relative proximity to the contaminated individual. Estimated cumulative doses were nontrivial but below the occupational dose limit established for normal operations by the Occupational Safety and Health Administration. |
US Centers For Disease Control and Prevention experience in the joint external evaluation process - radiation emergencies technical area
Whitcomb RC Jr , Ansari AJ , Salame-Alfie A , McCurley MC , Buzzell J , Chang A , Jones RL . Radiat Prot Dosimetry 2018 182 (1) 9-13 In 2015-16, the US Department of Health and Human Services led 23 US Government (USG) agencies including the Centers for Disease Control and Prevention (CDC), and more than 120 subject matter experts in conducting an in-depth review of the US core public health capacities and evaluation of the country's compliance with the International Health Regulations using the Joint External Evaluation (JEE) methodology. This two-part process began with a detailed 'self-assessment' followed by a comprehensive independent, external evaluation conducted by 15 foreign assessors. In the Radiation Emergencies Technical Area, on a scale from 1-lowest to 5-highest, the assessors concurred with the USG self-assessed score of 3 in both of the relevant indicators. The report identified five priority actions recommended to improve the USG capacity to handle large-scale radiation emergencies. CDC is working to implement a post-JEE roadmap to address these priority actions in partnership with national and international partners. |
Assessment of national efforts in emergency preparedness for nuclear terrorism: Is there a need for realignment to close remaining gaps
Salame-Alfie A , Ansari A . Health Phys 2018 114 (2) 261-269 This summary of the 53rd Annual Meeting of the National Council on Radiation Protection and Measurements (NCRP) captures the highlights of the presentations including the Warren K. Sinclair Keynote Address and the five scientific sessions and wrap-up summary and panel discussion of "Assessment of National Efforts in Emergency Preparedness for Nuclear Terrorism: Is There a Need for Realignment to Close Remaining Gaps?" The issue of radiological emergency preparedness has evolved in the last 20 y from a primarily nuclear power plant focus to a wider, more comprehensive approach that includes response to all types of radiological and nuclear emergencies, including terrorism. The meeting took an introspective look at the advances in radiological emergency preparedness in the last 15 y and focused on four major topic areas: Plans and guidance, training and exercising for both the first responder and the first receiver communities, recovery and return, and communication. In each area, the speakers reflected on the current state of that specific area and provided three to five practicable priority actions/initiatives for future work. As a result of the meeting, NCRP has made a commitment to create a committee to write a commentary that will go into more detail in each of the proposed priority areas discussed in the meeting and provide a roadmap for future work. |
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