Last data update: Sep 23, 2024. (Total: 47723 publications since 2009)
Records 1-30 (of 86 Records) |
Query Trace: Caldwell K [original query] |
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Efficacy of internet recruitment and HIV self-testing for diagnosing HIV infections among black and Hispanic/Latino MSM and transgender women in 11 US states, 2020-2021
MacGowan RJ , Chavez PR , Dana R , Hannah M , Raiford JL , Caldwell JA , Wall KM , Johnson JA , Sharma A , Hightow-Weidman L , Stephenson R , Sanchez T , Smith AJ , Sullivan S , Jones J , Sullivan PS . J Acquir Immune Defic Syndr 2024 97 (2) 133-141 INTRODUCTION: We evaluated internet platforms for distributing HIV self-tests (HIVSTs) to Black or African American (Black) and Hispanic or Latino men who have sex with men (MSM) and transgender women (TGW). METHODS: We recruited MSM and TGW from general interest, dating, and lesbian, gay, bisexual, and transgender platforms. Two HIVSTs were mailed to all MSM and TGW. Surveys (screening, baseline, 4-month, and results reporting) were completed online. After 4 months, participants were mailed another HIVST and a dried blood spot card. All HIVST interpretations and images of HIVST devices were reported online. RESULTS: Of 2093 MSM and 102 TGW, most were recruited through general interest and dating platforms. Over 50% were 18-29 years old, most identified as gay or bisexual. Overall, 45% had not tested for HIV in the past 12 months, and 9.1% of MSM reported a positive (reactive for HIV antibodies) HIVST result, with the highest percentage among Black MSM (11.5%). Dating platforms recruited higher percentages of MSM who recorded positive results compared with MSM from general interest platforms during the intervention period (11.9% vs 5.5% (P < 0.0001)), and MSM who had never tested for HIV reported a greater percentage of positive HIVST results compared with MSM who had been tested for HIV before enrollment (16.1% vs. 7.1%; P < 0.0001). MSM were able to correctly interpret and report HIVST results. Of TGW, 7% reported a positive HIVST result. CONCLUSIONS: Internet dating and general interest platforms can be key to increasing awareness of infection among BMSM, HMSM, and TGW persons, including those who do not use existing HIV services. TRIAL REGISTRATION: www.clinicaltrials.gov Identifier: NCT04219878. |
Naegleria fowleri detected in Grand Teton National Park Hot Springs
Barnhart EP , Kinsey SM , Wright PR , Caldwell SL , Hill V , Kahler A , Mattioli M , Cornman RS , Iwanowicz D , Eddy Z , Halonen S , Mueller R , Peyton BM , Puzon GJ . ACS ES and T Water 2023 The free-living thermophilic amoeba Naegleria fowleri (N. fowleri) causes the highly fatal disease primary amoebic meningoencephalitis. The environmental conditions that are favorable to the growth and proliferation of N. fowleri are not well-defined, especially in northern regions of the United States. In this study, we used culture-based methods and multiple molecular approaches to detect and analyzeN. fowleri and other Naegleria spp. in water, sediment, and biofilm samples from five hot spring sites in Grand Teton National Park, Wyoming, U.S.A. These results provide the first detections of N. fowleri in Grand Teton National Park and provide new insights into the distribution of pathogenic N. fowleri and other nonpathogenic Naegleria spp. in natural thermal water systems in northern latitudes. © 2024 The Authors. Published by American Chemical Society. |
A systematic review of the data, methods and environmental covariates used to map Aedes-borne arbovirus transmission risk
Lim AY , Jafari Y , Caldwell JM , Clapham HE , Gaythorpe KAM , Hussain-Alkhateeb L , Johansson MA , Kraemer MUG , Maude RJ , McCormack CP , Messina JP , Mordecai EA , Rabe IB , Reiner RC Jr , Ryan SJ , Salje H , Semenza JC , Rojas DP , Brady OJ . BMC Infect Dis 2023 23 (1) 708 BACKGROUND: Aedes (Stegomyia)-borne diseases are an expanding global threat, but gaps in surveillance make comprehensive and comparable risk assessments challenging. Geostatistical models combine data from multiple locations and use links with environmental and socioeconomic factors to make predictive risk maps. Here we systematically review past approaches to map risk for different Aedes-borne arboviruses from local to global scales, identifying differences and similarities in the data types, covariates, and modelling approaches used. METHODS: We searched on-line databases for predictive risk mapping studies for dengue, Zika, chikungunya, and yellow fever with no geographical or date restrictions. We included studies that needed to parameterise or fit their model to real-world epidemiological data and make predictions to new spatial locations of some measure of population-level risk of viral transmission (e.g. incidence, occurrence, suitability, etc.). RESULTS: We found a growing number of arbovirus risk mapping studies across all endemic regions and arboviral diseases, with a total of 176 papers published 2002-2022 with the largest increases shortly following major epidemics. Three dominant use cases emerged: (i) global maps to identify limits of transmission, estimate burden and assess impacts of future global change, (ii) regional models used to predict the spread of major epidemics between countries and (iii) national and sub-national models that use local datasets to better understand transmission dynamics to improve outbreak detection and response. Temperature and rainfall were the most popular choice of covariates (included in 50% and 40% of studies respectively) but variables such as human mobility are increasingly being included. Surprisingly, few studies (22%, 31/144) robustly tested combinations of covariates from different domains (e.g. climatic, sociodemographic, ecological, etc.) and only 49% of studies assessed predictive performance via out-of-sample validation procedures. CONCLUSIONS: Here we show that approaches to map risk for different arboviruses have diversified in response to changing use cases, epidemiology and data availability. We identify key differences in mapping approaches between different arboviral diseases, discuss future research needs and outline specific recommendations for future arbovirus mapping. |
How did the 2022 global mpox outbreak happen? A travel-associated case 6 months earlier may provide important clues
Kreuze MA , Minhaj FS , Duwell M , Gigante CM , Kim AM , Crum D , Perlmutter R , Rubin JH , Myers R , Lukula SL , Ravi-Caldwell N , Sockwell D , Chen TH , de Perio MA , Hughes CM , Davidson WB , Wilkins K , Baird N , Lowe D , Li Y , McCollum AM , Blythe D , Rao AK . Travel Med Infect Dis 2023 55 102618 Approximately 6 months before an unprecedented global mpox outbreak was first identified in the United Kingdom, an adult man was diagnosed with mpox in Maryland, USA [1]. At the time of the investigation, the case was only the eighth monkeypox virus (MPXV) infection diagnosed in a non-African country during the preceding 3 years, all of which were associated with recent travel to Nigeria [2]. One of these 8 imported cases occurred in Texas, USA four months earlier; that case exhibited features clinically consistent with those classically reported in Africa (i.e., large and diffuse lesions, high fever and prodromal symptoms, umbilicated lesions in the same stage of development on specific anatomic surfaces) [3]. In contrast, the Maryland case was milder in severity and had signs that, at the time, were considered unusual for mpox. Several aspects of the Maryland case are noteworthy and in retrospect may offer clues to the origins of the 2022 global mpox outbreak, as well as explain how mpox might have spread undetected before emerging as a global outbreak. |
A systematic review of the data, methods and environmental covariates used to map Aedes-borne arbovirus transmission risk (preprint)
Lim AY , Jafari Y , Caldwell JM , Clapham HE , Gaythorpe KAM , Hussain-Alkhateeb L , Johansson MA , Kraemer MUG , Maude RJ , McCormack CP , Messina JP , Mordecai EA , Rabe IB , Reiner RC , Ryan SJ , Salje H , Semenza JC , Rojas DP , Brady OJ . medRxiv 2023 20 Background Aedes (Stegomyia)-borne diseases are an expanding global threat, but gaps in surveillance make comprehensive and comparable risk assessments challenging. Geostatistical models combine data from multiple locations and use links with environmental and socioeconomic factors to make predictive risk maps. Here we systematically review past approaches to map risk for different Aedesborne arboviruses from local to global scales, identifying differences and similarities in the data types, covariates, and modelling approaches used. Methods We searched on-line databases for predictive risk mapping studies for dengue, Zika, chikungunya, and yellow fever with no geographical or date restrictions. We included studies that needed to parameterise or fit their model to real-world epidemiological data and make predictions to new spatial locations of some measure of population-level risk of viral transmission (e.g. incidence, occurrence, suitability, etc). Results We found a growing number of arbovirus risk mapping studies across all endemic regions and arboviral diseases, with a total of 183 papers published 2002-2022 with the largest increases shortly following major epidemics. Three dominant use cases emerged: i) global maps to identify limits of transmission, estimate burden and assess impacts of future global change, ii) regional models used to predict the spread of major epidemics between countries and iii) national and sub-national models that use local datasets to better understand transmission dynamics to improve outbreak detection and response. Temperature and rainfall were the most popular choice of covariates (included in 50% and 40% of studies respectively) but variables such as human mobility are increasingly being included. Surprisingly, few studies (22%, 33/148) robustly tested combinations of covariates from different domains (e.g. climatic, sociodemographic, ecological, etc) and only 48% of studies assessed predictive performance via out-of-sample validation procedures. Conclusions Here we show that approaches to map risk for different arboviruses have diversified in response to changing use cases, epidemiology and data availability. We outline specific recommendations for future studies regarding aims and data choice, covariate selection, model formulation and evaluation. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
Salmonella outbreaks associated with not ready-to-eat breaded, stuffed chicken products - United States, 1998-2022
Ford L , Buuck S , Eisenstein T , Cote A , McCormic ZD , Kremer-Caldwell S , Kissler B , Forstner M , Sorenson A , Wise ME , Smith K , Medus C , Griffin PM , Robyn M . MMWR Morb Mortal Wkly Rep 2023 72 (18) 484-487 Not ready-to-eat (NRTE) breaded, stuffed chicken products (e.g., chicken stuffed with broccoli and cheese) typically have a crispy, browned exterior that can make them appear cooked. These products have been repeatedly linked to U.S. salmonellosis outbreaks, despite changes to packaging initiated in 2006 to identify the products as raw and warn against preparing them in a microwave oven (microwave) (1-4). On April 28, 2023, the U.S. Department of Agriculture proposed to declare Salmonella an adulterant* at levels of one colony forming unit per gram or higher in these products (5). Salmonella outbreaks associated with NRTE breaded, stuffed chicken products during 1998-2022 were summarized using reports in CDC's Foodborne Disease Outbreak Surveillance System (FDOSS), outbreak questionnaires, web postings, and data from the Minnesota Department of Health (MDH)(†) and the U.S. Department of Agriculture's Food Safety and Inspection Service (FSIS). Eleven outbreaks were identified in FDOSS. Among cultured samples from products obtained from patients' homes and from retail stores during 10 outbreaks, a median of 57% of cultures per outbreak yielded Salmonella. The NRTE breaded, stuffed chicken products were produced in at least three establishments.(§) In the seven most recent outbreaks, 0%-75% of ill respondents reported cooking the product in a microwave and reported that they thought the product was sold fully cooked or did not know whether it was sold raw or fully cooked. Outbreaks associated with these products have occurred despite changes to product labels that better inform consumers that the products are raw and provide instructions on safe preparation, indicating that consumer-targeted interventions are not sufficient. Additional Salmonella controls at the manufacturer level to reduce contamination in ingredients might reduce illnesses attributable to NRTE breaded, stuffed chicken products. |
Engaging Black or African American and Hispanic or Latino men who have sex with men for HIV testing and prevention services through technology: Protocol for the iSTAMP comparative effectiveness trial
Dana R , Sullivan S , MacGowan RJ , Chavez PR , Wall KM , Sanchez TH , Stephenson R , Hightow-Weidman L , Johnson JA , Smith A , Sharma A , Jones J , Hannah M , Trigg M , Luo W , Caldwell J , Sullivan PS . JMIR Res Protoc 2023 12 e43414 BACKGROUND: Gay, bisexual, and other men who have sex with men (MSM), particularly Black or African American MSM (BMSM) and Hispanic or Latino MSM (HLMSM), continue to be disproportionately affected by the HIV epidemic in the United States. Previous HIV self-testing programs have yielded high testing rates, although these studies predominantly enrolled White, non-Hispanic MSM. Mobile health tools can support HIV prevention, testing, and treatment. This protocol details an implementation study of mailing free HIV self-tests (HIVSTs) nested within a randomized controlled trial designed to assess the benefit of a mobile phone app for increasing the uptake of HIV prevention and other social services. OBJECTIVE: This study was a comparative effectiveness trial of innovative recruitment and testing promotion strategies intended to effectively reach cisgender BMSM and HLMSM. We evaluated the use of a mobile app for increasing access to care. METHODS: Study development began with individual and group consultations that elicited feedback from 3 core groups: HIV care practitioners and researchers, HIV service organization leaders from study states, and BMSM and HLMSM living in the study states. Upon completion of the formative qualitative work, participants from 11 states, based on the observed areas of highest rate of new HIV diagnoses among Black and Hispanic MSM, were recruited through social networking websites and smartphone apps. After eligibility was verified, participants consented and were randomized to the intervention arm (access to the Know@Home mobile app) or the control arm (referral to web resources). We provided all participants with HIVSTs. The evaluation of the efficacy of a mobile phone app to support linkage to posttest prevention services that included sexually transmitted infection testing, pre-exposure prophylaxis initiation, antiretroviral treatment, and acquisition of condoms and compatible lubricants has been planned. Data on these outcomes were obtained from several sources, including HIVST-reporting surveys, the 4-month follow-up survey, laboratory analyses of dried blood spot cards returned by the participant, and data obtained from the state health department surveillance systems. Where possible, relevant subgroup analyses were performed. RESULTS: During the formative development phase, 9 consultations were conducted: 6 in-depth individual discussions and 3 group consultations. From February 2020 through February 2021, we enrolled 2093 MSM in the randomized controlled trial from 11 states, 1149 BMSM and 944 HLMSM. CONCLUSIONS: This study was designed and implemented to evaluate the effectiveness of recruitment strategies to reach BMSM and HMSM and of a mobile app with regard to linkage to HIV prevention or treatment services. Data were also obtained to allow for the analyses of cost and cost-effectiveness related to study enrollment, HIV testing uptake, identification of previously undiagnosed HIV, sexually transmitted infection testing and treatment, and linkage to HIV prevention or treatment services. TRIAL REGISTRATION: ClinicalTrials.gov (NCT04219878); https://clinicaltrials.gov/ct2/show/NCT04219878. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/43414. |
Preexposure prophylaxis implementation in a reproductive health setting: Perspectives From Planned Parenthood providers and leaders
Wilbourn B , Ogburn DF , Safon CB , Galvao RW , Kershaw TS , Willie TC , Taggart T , Caldwell A , Kaplan C , Phillips N , Calabrese SK . Health Promot Pract 2022 15248399221086616 Integrating pregnancy and HIV prevention services would make reproductive health care settings an optimal venue for the promotion and delivery of preexposure prophylaxis (PrEP) to cisgender women. However, these settings have been slow to adopt PrEP. Planned parenthood clinicians and leaders possess critical insight that can help accelerate PrEP implementation in reproductive health care settings and elements of the Consolidated Framework for Implementation Research (i.e., relative priority of the intervention to staff, implementation climate, available resources to implement the intervention, and staff access to knowledge and information about the intervention) can shed light on elements of Planned Parenthood's inner setting that can facilitate PrEP implementation. In this study, individual 60-min interviews were conducted with clinical care team members (n = 10), leadership team members (n = 6), and center managers (n = 2) to explore their perspectives on PrEP implementation and associated training needs. Transcripts were transcribed verbatim and thematically analyzed. Despite having variable PrEP knowledge, participants (100% women, 61% non-Hispanic White) expressed positive attitudes toward implementing PrEP. Barriers and facilitators toward providing PrEP were reported at the structural, provider, and patient levels. Participants desired PrEP training that incorporated culturally competent patient-provider communication. Although participants identified ways that Planned Parenthood uniquely enabled PrEP implementation, barriers must be overcome to optimize promotion and delivery of PrEP to cisgender women. |
Mapping nurse practitioners' scope of practice laws: A resource for evaluating pre-exposure prophylaxis prescriptions
Salvant Valentine S , Carnes N , Caldwell J , Gelaude D , Taylor R . Health Equity 2022 6 (1) 27-31 Context: Reducing the number of new HIV infections will require addressing barriers to HIV pre-exposure prophylaxis (PrEP) access and uptake. Nurse practitioners (NPs) may help increase PrEP access and uptake. State scope of practice laws determines NPs' ability to work independently and their authority to prescribe PrEP, a legend nonscheduled medication. Methods: This analysis applied legal epidemiology methods to analyze the laws of the 50 states and the District of Columbia that govern NPs' scope of practice as they may apply to prescribing legend nonscheduled medications. These laws were extracted from Westlaw Next between April and June 2019. Results: As of June 8, 2019, 17 states had laws that allowed NPs to both practice independently and prescribe legend nonscheduled drugs without restriction. Conclusion: The role that state scope of practice laws plays in potentially limiting NPs' ability to prescribe PrEP should be considered. Increasing PrEP access and uptake is essential in reaching national HIV prevention goals. This analysis can inform further studies and polices on barriers to PrEP access and uptake. |
LET's CONNECT Community Mentorship Program for Adolescents with Peer Social Problems: A Randomized Intervention Trial
King CA , Gipson PY , Arango A , Lernihan D , Clark M , Ewell Foster C , Caldwell C , Ghaziuddin N , Stone D . Am J Community Psychol 2021 68 310-322 This study examined the effectiveness of LET's CONNECT (LC), a community mentorship program based on the positive youth development model. Participants were 218 youth (66.5% girls), ages 12 to 15, who reported peer victimization, bullying perpetration, and/or low social connectedness. These youth were randomized to LC or the control group (community resource information). The LC program linked youth to community mentors who connected with youth and facilitated their involvement in social growth activities across a 16-month period. Outcomes were assessed at 6 and 16 months with self-report measures of social and community connectedness, thwarted belongingness, depression, self-esteem, and suicidal ideation and behavior. In intent-to-treat analyses, LC was associated with modest positive effects for social connectedness, self-esteem, and depression. It had no effects on suicidal ideation or behavior. Results suggest that LC has the potential to positively impact the developmental trajectories of youth dealing with the interpersonal challenges of victimization, bullying perpetration, or low social connectedness. LC implementation challenges and directions for further research are also discussed. |
Electronic dissemination of a web-based video promotes PrEP contemplation and conversation among US women engaged in care at Planned Parenthood
Calabrese SK , Lane SB , Caldwell A , Kaplan C , Dovidio JF , Galvao RW , Ogburn DF , Safon CB , Tekeste M , Taggart T , Modrakovic D , Wilbourn BC , Blackstock O , Kershaw TS . AIDS Behav 2021 25 (8) 2483-2500 We evaluated the acceptability and impact of a web-based PrEP educational video among women (n = 126) by comparing two Planned Parenthood centers: one assigned to a Web Video Condition and one to a Standard Condition. Most women reported the video helped them better understand what PrEP is (92%), how PrEP works (93%), and how to take PrEP (92%). One month post-intervention, more women in the Web Video Condition reported a high level of comfort discussing PrEP with a provider (82% vs. 48%) and commonly thinking about PrEP (36% vs. 4%). No women with linked medical records initiated PrEP during 1-year follow-up. |
Effect of CDC 2006 Revised HIV Testing Recommendations for Adults, Adolescents, Pregnant Women, and Newborns on state laws, 2018
Salvant Valentine S , Caldwell J , Tailor A . Public Health Rep 2020 135 189s-196s In 2006, the Centers for Disease Control and Prevention updated its recommendations for HIV testing of 4 population groups in health care settings: adults, adolescents, pregnant women, and newborns. Important components of the revised recommendations included opt-out routine HIV screening; eliminating prevention counseling for opt-out routine HIV screening; repeat HIV testing in the third trimester for all women at high risk for acquiring HIV and for women receiving health care in facilities and/or jurisdictions with high HIV burden; testing during labor and delivery for women with undocumented HIV status; and testing the newborn when the mother's HIV status is unknown. To assess the integration of these testing recommendations into state laws and to inform future recommendations, we researched and assessed statutes and regulations that addressed HIV testing in the 4 population groups in all 50 states and the District of Columbia in 2018. We then classified the laws, based on their consistency with the recommendations for each of the 4 population groups. Of 31 states and the District of Columbia that had relevant laws, all addressed at least 1 component of the recommendations. Although no state had laws that incorporated all the recommendations for all the population groups, 5 states (Delaware, Illinois, Louisiana, Maryland, and New Hampshire) had incorporated all the recommendations for adults and adolescents, and 4 states (Connecticut, Nevada, North Carolina, and West Virginia) had incorporated all the recommendations for pregnant women and newborns. |
Racial and ethnic differences in women's HIV risk and attitudes towards pre-exposure prophylaxis (PrEP) in the context of the substance use, violence, and depression syndemic
Willie TC , Kershaw TS , Blackstock O , Galvao RW , Safon CB , Tekeste M , Ogburn DF , Wilbourn B , Modrakovic D , Taggart T , Kaplan C , Caldwell A , Calabrese SK . AIDS Care 2020 33 (2) 1-10 Women with syndemic conditions, i.e., two or more co-occurring epidemics, are at elevated risk for HIV acquisition and are therefore prime candidates for pre-exposure prophylaxis (PrEP). However, PrEP uptake remains low among women, especially among Black and Hispanic women. This study examined associations of syndemic conditions with PrEP attitudes and HIV risk among women, and the moderating effect of race and ethnicity. In 2017, 271 non-Hispanic Black, non-Hispanic White, and Hispanic, PrEP-eligible women engaged in care at Planned Parenthood in the northeastern region of the U.S. completed an online survey. Participants reported syndemic conditions (i.e., intimate partner violence, depression, substance use), PrEP attitudes (e.g., PrEP interest), HIV sexual risk (e.g., multiple male sexual partners), and sociodemographics. Structural equation modeling was used to examine the effects of syndemic conditions on PrEP attitudes and HIV risk, and the moderating effect of race and ethnicity. Women with more syndemic conditions had a higher odds of reporting multiple male sexual partners. Syndemic conditions were positively associated with PrEP attitudes for Hispanic women than non-Hispanic Black and White women. Women with syndemic conditions, particularly Hispanic women, may be receptive to interventions promoting PrEP. |
Concordance between sites of tumor development in humans and in experimental animals for 111 agents that are carcinogenic to humans
Krewski D , Rice JM , Bird M , Milton B , Collins B , Lajoie P , Billard M , Grosse Y , Cogliano VJ , Caldwell JC , Rusyn II , Portier CJ , Melnick RL , Baan RA , Little J , Zielinski JM . J Toxicol Environ Health B Crit Rev 2019 22 203-236 Since the inception of the IARC Monographs Programme in the early 1970s, this Programme has developed 119 Monograph Volumes on more than 1000 agents for which there exists some evidence of cancer risk to humans. Of these, 120 agents were found to meet the criteria for classification as carcinogenic to humans (Group 1). Volume 100 of the IARC Monographs, compiled in 2008-2009 and published in 2012, provided a review and update of the 107 Group 1 agents identified as of 2009. These agents were divided into six broad categories: (I) pharmaceuticals; (II) biological agents; (III) arsenic, metals, fibers and dusts; (IV) radiation; (V) personal habits and indoor combustions; and (VI) chemical agents and related occupations. The Group I agents reviewed in Volume 100, as well as five additional Group 1 agents defined in subsequent Volumes of the Monographs, were used to assess the degree of concordance between sites where tumors originate in humans and experimental animals including mice, rats, hamsters, dogs, and non-human primates using an anatomically based tumor nomenclature system, representing 39 tumor sites and 14 organ and tissue systems. This evaluation identified 91 Group 1 agents with sufficient evidence (82 agents) or limited evidence (9 agents) of carcinogenicity in animals. The most common tumors observed in both humans and animals were those of the respiratory system including larynx, lung, and lower respiratory tract. In humans, respiratory system tumors were noted for 31 of the 111 distinct Group 1 carcinogens identified up to and including Volume 109 of the IARC Monographs, comprising predominantly 14 chemical agents and related occupations in category VI; seven arsenic, metals, fibers, and dusts in category III, and five personal habits and indoor combustions in category V. Subsequent to respiratory system tumors, those in lymphoid and hematopoietic tissues (26 agents), the urothelium (18 agents), and the upper aerodigestive tract (16 agents) were most often seen in humans, while tumors in digestive organs (19 agents), skin (18 agents), and connective tissues (17 agents) were frequently seen in animals. Exposures to radiation, particularly X- and gamma-radiation, and tobacco smoke were associated with tumors at multiple sites in humans. Although the IARC Monographs did not emphasize tumor site concordance between animals and humans, substantial concordance was detected for several organ and tissue systems, even under the stringent criteria for sufficient evidence of carcinogenicity used by IARC. Of the 60 agents for which at least one tumor site was identified in both humans and animals, 52 (87%) exhibited tumors in at least one of the same organ and tissue systems in humans and animals. It should be noted that some caution is needed in interpreting concordance at sites where sample size is particularly small. Although perfect (100%) concordance was noted for agents that induce tumors of the mesothelium, only two Group 1 agents that met the criteria for inclusion in the concordance analysis caused tumors at this site. Although the present analysis demonstrates good concordance between animals and humans for many, but not all, tumor sites, limitations of available data may result in underestimation of concordance. |
Determination of iodine content in dairy products by inductively coupled plasma mass spectrometry
Vance KA , Makhmudov A , Shakirova G , Roenfanz H , Jones RL , Caldwell KL . At Spectrosc 2018 39 (3) 95-99 A probing study to establish a reliable and robust method for determining the iodine concentration using the ELAN DRC II ICP-MS was performed in combination with a sample digestion and filtration step. Dairy products from locally available sources were evaluated to help determine the possibility and need for further evaluations in relation to the U.S. population’s iodine intake. Prior to analysis, the samples were aliquoted and digested for 3 hours at 90+/-3 C. Dilution and filtration were performed, following the digestion. The sample extract was analyzed, and the results were confirmed with NIST SRM 1549a Whole Milk Powder. Further experimentation will need to be performed to optimize the method for projected sample concentration and throughput. |
Trace metals screening process of devices used for the collection, analysis, and storage of biological specimens
Ward CD , Williams RJ , Mullenix K , Syhapanha K , Jones RL , Caldwell K . At Spectrosc 2018 39 (6) 219-228 The Centers for Disease Control and Prevention’s (CDC) Environmental Health Laboratory uses modified versions of inductively coupled plasma mass spectrometry (ICP-MS) analytical methods to quantify metals contamination present in items that will come into contact with patient samples during the preanalytical, analytical, and postanalytical stages. This lot screening process allows us to reduce the likelihood of introducing contamination which can lead to falsely elevated results. This is particularly important when looking at biomonitoring levels in humans which tend to be near the limit of detection of many methods. The fundamental requirements for a lot screening program in terms of facilities and processes are presented along with a discussion of sample preparation techniques used for lot screening. The criteria used to evaluate the lot screening data to determine the acceptability of a particular manufacturing lot is presented as well. As a result of lot testing, unsuitable manufactured lots are identified and excluded from use. |
LAMP: A CDC program to ensure the quality of blood-lead laboratory measurements
Caldwell KL , Cheng PY , Vance KA , Makhmudov A , Jarrett JM , Caudill SP , Ho DP , Jones RL . J Public Health Manag Pract 2019 25 S23-s30 CONTEXT: The Lead and Multielement Proficiency (LAMP) program is an external quality assurance program promoting high-quality blood-lead measurements. OBJECTIVES: To investigate the ability of US laboratories, participating in the Centers for Disease Control and Prevention (CDC) LAMP program to accurately measure blood-lead levels (BLL) 0.70 to 47.5 mug/dL using evaluation criteria of +/-2 mug/dL or 10%, whichever is greater. METHODS: The CDC distributes bovine blood specimens to participating laboratories 4 times per year. We evaluated participant performance over 5 challenges on samples with BLL between 0.70 and 47.5 mug/dL. The CDC sent 15 pooled samples (3 samples shipped in 5 rounds) to US laboratories. The LAMP laboratories used 3 primary technologies to analyze lead in blood: inductively coupled plasma mass spectrometry, graphite furnace atomic absorption spectroscopy, and LeadCare technologies based on anodic stripping voltammetry. Laboratories reported their BLL analytical results to the CDC. The LAMP uses these results to provide performance feedback to the laboratories. SETTING: The CDC sent blood samples to approximately 50 US laboratories for lead analysis. PARTICIPANTS: Of the approximately 200 laboratories enrolled in LAMP, 38 to 46 US laboratories provided data used in this report (January 2017 to March 2018). RESULTS: Laboratory precision ranged from 0.26 mug/dL for inductively coupled plasma mass spectrometry to 1.50 mug/dL for LeadCare instruments. All participating US LAMP laboratories reported accurate BLL for 89% of challenge samples, using the +/-2 mug/dL or 10% evaluation criteria. CONCLUSIONS: Laboratories participating in the CDC's LAMP program can accurately measure blood lead using the current Clinical Laboratory Improvement Amendments of 1988 guidance of +/-4 mug/dL or +/-10%, with a success rate of 96%. However, when we apply limits of +/-2 mug/dL or +/-10%, the success rate drops to 89%. When challenged with samples that have target values between 3 and 5 mug/dL, nearly 100% of reported results fall within +/-4 mug/dL, while 5% of the results fall outside of the acceptability criteria used by the CDC's LAMP program. As public health focuses on lower blood lead levels, laboratories must evaluate their ability to successfully meet these analytical challenges surrounding successfully measuring blood lead. In addition proposed CLIA guidelines (+/-2 mug/dL or 10%) would be achievable performance by a majority of US laboratories participating in the LAMP program. |
Comparison of nicotine and toxicant exposure in users of electronic cigarettes and combustible cigarettes
Goniewicz ML , Smith DM , Edwards KC , Blount BC , Caldwell KL , Feng J , Wang L , Christensen C , Ambrose B , Borek N , van Bemmel D , Konkel K , Erives G , Stanton CA , Lambert E , Kimmel HL , Hatsukami D , Hecht SS , Niaura RS , Travers M , Lawrence C , Hyland AJ . JAMA Netw Open 2018 1 (8) e185937 Importance: Use of electronic cigarettes (e-cigarettes) is increasing. Measures of exposure to known tobacco-related toxicants among e-cigarette users will inform potential health risks to individual product users. Objectives: To estimate concentrations of tobacco-related toxicants among e-cigarette users and compare these biomarker concentrations with those observed in combustible cigarette users, dual users, and never tobacco users. Design, Setting, and Participants: A population-based, longitudinal cohort study was conducted in the United States in 2013-2014. Cross-sectional analysis was performed between November 4, 2016, and October 5, 2017, of biomarkers of exposure to tobacco-related toxicants collected by the Population Assessment of Tobacco and Health Study. Participants included adults who provided a urine sample and data on tobacco use (N = 5105). Exposures: The primary exposure was tobacco use, including current exclusive e-cigarette users (n = 247), current exclusive cigarette smokers (n = 2411), and users of both products (dual users) (n = 792) compared with never tobacco users (n = 1655). Main Outcomes and Measures: Geometric mean concentrations of 50 individual biomarkers from 5 major classes of tobacco product constituents were measured: nicotine, tobacco-specific nitrosamines (TSNAs), metals, polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs). Results: Of the 5105 participants, most were aged 35 to 54 years (weighted percentage, 38%; 95% CI, 35%-40%), women (60%; 95% CI, 59%-62%), and non-Hispanic white (61%; 95% CI, 58%-64%). Compared with exclusive e-cigarette users, never users had 19% to 81% significantly lower concentrations of biomarkers of exposure to nicotine, TSNAs, some metals (eg, cadmium and lead), and some VOCs (including acrylonitrile). Exclusive e-cigarette users showed 10% to 98% significantly lower concentrations of biomarkers of exposure, including TSNAs, PAHs, most VOCs, and nicotine, compared with exclusive cigarette smokers; concentrations were comparable for metals and 3 VOCs. Exclusive cigarette users showed 10% to 36% lower concentrations of several biomarkers than dual users. Frequency of cigarette use among dual users was positively correlated with nicotine and toxicant exposure. Conclusions and Relevance: Exclusive use of e-cigarettes appears to result in measurable exposure to known tobacco-related toxicants, generally at lower levels than cigarette smoking. Toxicant exposure is greatest among dual users, and frequency of combustible cigarette use is positively correlated with tobacco toxicant concentration. These findings provide evidence that using combusted tobacco cigarettes alone or in combination with e-cigarettes is associated with higher concentrations of potentially harmful tobacco constituents in comparison with using e-cigarettes alone. |
Waterpipe tobacco smoke: Characterization of toxicants and exposure biomarkers in a cross-sectional study of waterpipe employees
Kaplan B , Sussan T , Rule A , Moon K , Grau-Perez M , Olmedo P , Chen R , Carkoglu A , Levshin V , Wang L , Watson C , Blount B , Calafat AM , Jarrett J , Caldwell K , Wang Y , Breysse P , Strickland P , Cohen J , Biswal S , Navas-Acien A . Environ Int 2019 127 495-502 INTRODUCTION: Few studies have comprehensively characterized toxic chemicals related to waterpipe use and secondhand waterpipe exposure. This cross-sectional study investigated biomarkers of toxicants associated with waterpipe use and passive waterpipe exposure among employees at waterpipe venues. METHOD: We collected urine specimens from employees in waterpipe venues from Istanbul, Turkey and Moscow, Russia, and identified waterpipe and cigarette smoking status based on self-report. The final sample included 110 employees. Biomarkers of exposure to sixty chemicals (metals, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), nicotine, and heterocyclic aromatic amines (HCAAs)) were quantified in the participants' urine. RESULTS: Participants who reported using waterpipe had higher urinary manganese (geometric mean ratio (GMR): 2.42, 95% confidence interval (CI): 1.16, 5.07) than never/former waterpipe or cigarette smokers. Being exposed to more hours of secondhand smoke from waterpipes was associated with higher concentrations of cobalt (GMR: 1.38, 95% CI: 1.10, 1.75). Participants involved in lighting waterpipes had higher urinary cobalt (GMR: 1.43, 95% CI: 1.10, 1.86), cesium (GMR: 1.21, 95% CI: 1.00, 1.48), molybdenum (GMR: 1.45, 95% CI: 1.08, 1.93), 1-hydroxypyrene (GMR: 1.36, 95% CI: 1.03, 1.80), and several VOC metabolites. CONCLUSION: Waterpipe tobacco users and nonsmoking employees of waterpipe venues had higher urinary concentrations of several toxic metals including manganese and cobalt as well as of VOCs, in a distinct signature compared to cigarette smoke. Employees involved in lighting waterpipes may have higher exposure to multiple toxic chemicals compared to other employees. |
Lead exposure during childhood and subsequent anthropometry through adolescence in girls
Deierlein AL , Teitelbaum SL , Windham GC , Pinney SM , Galvez MP , Caldwell KL , Jarrett JM , Gajek R , Kushi LH , Biro F , Wolff MS . Environ Int 2018 122 310-315 INTRODUCTION: Cross-sectional studies suggest that postnatal blood lead (PbB) concentrations are negatively associated with child growth. Few studies prospectively examined this association in populations with lower PbB concentrations. We investigated longitudinal associations of childhood PbB concentrations and subsequent anthropometric measurements in a multi-ethnic cohort of girls. METHODS: Data were from The Breast Cancer and the Environment Research Program at three sites in the United States (U.S.): New York City, Cincinnati, and San Francisco Bay Area. Girls were enrolled at ages 6-8years in 2004-2007. Girls with PbB concentrations collected at </=10years old (mean 7.8years, standard deviation (SD) 0.82) and anthropometry collected at >/=3 follow-up visits were included (n=683). The median PbB concentration was 0.99mug/d (10th percentile=0.59mug/dL and 90th percentile=2.00mug/dL) and the geometric mean was 1.03mug/dL (95% Confidence Interval (CI): 0.99, 1.06). For analyses, PbB concentrations were dichotomized as <1mug/dL (n=342) and >/=1mug/dL (n=341). Anthropometric measurements of height, body mass index (BMI), waist circumference (WC), and percent body fat (%BF) were collected at enrollment and follow-up visits through 2015. Linear mixed effects regression estimated how PbB concentrations related to changes in girls' measurements from ages 7-14years. RESULTS: At 7years, mean difference in height was -2.0cm (95% CI: -3.0, -1.0) for girls with >/=1mug/dL versus <1mug/dL PbB concentrations; differences persisted, but were attenuated, with age to -1.5cm (95% CI: -2.5, -0.4) at 14years. Mean differences for BMI, WC, and BF% at 7years between girls with >/=1mug/dL versus <1mug/dL PbB concentrations were -0.7kg/m(2) (95% CI: -1.2, -0.2), -2.2cm (95% CI: -3.8, -0.6), and -1.8% (95% CI: -3.2, -0.4), respectively. Overall, these differences generally persisted with advancing age and at 14years, differences were -0.8kg/m(2) (95% CI: -1.5, -0.02), -2.9cm (95% CI: -4.8, -0.9), and -1.7% (95% CI: -3.1, -0.4) for BMI, WC, and BF%, respectively. CONCLUSIONS: These findings suggest that higher concentrations of PbB during childhood, even though relatively low by screening standards, may be inversely associated with anthropometric measurements in girls. |
Iodine status of pregnant women and women of reproductive age in the United States
Perrine CG , Herrick KA , Gupta PM , Caldwell K . Thyroid 2018 29 (1) 153-154 In the United States, the iodine status of populations is determined from the median urinary iodine concentration (UIC) of spot urine samples collected in the National Health and Nutrition Examination Survey (NHANES). Because of the critical role of iodine in fetal growth and development, pregnant women and women who may enter pregnancy are key groups for ensuring adequate iodine nutrition (1). The World Health Organization (WHO) categorizes population median UIC <150 μg/L and <100 μg/L as iodine insufficiency for pregnant and nonpregnant women, respectively (1). In NHANES 2001–2006, the median UIC was 153 μg/L [confidence interval (CI) 105–196] for pregnant women and 130 μg/L [CI 117–140] for nonpregnant women (2). In NHANES 2005–2010, these estimates were 129 μg/L [CI 101–173] and 129 μg/L [CI 119–136], respectively (3). We used NHANES 2007–2014 data to provide an update of the iodine status of pregnant and nonpregnant women, aged 15–44 years, in the United States. |
Iodine status and consumption of key iodine sources in the U.S. population with special attention to reproductive age women
Herrick KA , Perrine CG , Aoki Y , Caldwell KL . Nutrients 2018 10 (7) We estimated iodine status (median urinary iodine concentration (mUIC (µg/L))) for the US population (6 years and over; n = 4613) and women of reproductive age (WRA) (15(-)44 years; n = 901). We estimated mean intake of key iodine sources by race and Hispanic origin. We present the first national estimates of mUIC for non-Hispanic Asian persons and examine the intake of soy products, a potential source of goitrogens. One-third of National Health and Nutrition Examination Survey (NHANES) participants in 2011(-)2014 provided casual urine samples; UIC was measured in these samples. We assessed dietary intake with one 24-h recall and created food groups using the USDA’s food/beverage coding scheme. For WRA, mUIC was 110 µg/L. For both non-Hispanic white (106 µg/L) and non-Hispanic Asian (81 µg/L) WRA mUIC was significantly lower than mUIC among Hispanic WRA (133 µg/L). Non-Hispanic black WRA had a mUIC of 124 µg/L. Dairy consumption was significantly higher among non-Hispanic white (162 g) compared to non-Hispanic black WRA (113 g). Soy consumption was also higher among non-Hispanic Asian WRA (18 g compared to non-Hispanic black WRA (1 g). Differences in the consumption pattern of key sources of iodine and goitrogens may put subgroups of individuals at risk of mild iodine deficiency. Continued monitoring of iodine status and variations in consumption patterns is needed. |
Assessing the stability of Cd, Mn, Pb, Se, and total Hg in whole human blood by ICP-DRC-MS as a function of temperature and time
Tevis DS , Jarrett JM , Jones DR , Cheng PY , Franklin M , Mullinex N , Caldwell KL , Jones RL . Clin Chim Acta 2018 485 1-6 BACKGROUND: Comprehensive information on the effect of time and temperature storage on the measurement of elements in human, whole blood (WB) by inductively coupled plasma-dynamic reaction cell-mass spectrometry (ICP-DRC-MS) is lacking, particularly for Mn and Se. METHODS: Human WB was spiked at 3 concentration levels, dispensed, and then stored at 5 different temperatures: -70 degrees C, -20 degrees C, 4 degrees C, 23 degrees C, and 37 degrees C. At 3 and 5weeks, and at 2, 4, 6, 8, 10, 12, 36months, samples were analyzed for Pb, Cd, Mn, Se and total Hg, using ICP-DRC-MS. We used a multiple linear regression model including time and temperature as covariates to fit the data with the measurement value as the outcome. We used an equivalence test using ratios to determine if results from the test storage conditions, warmer temperature and longer time, were comparable to the reference storage condition of 3weeks storage time at -70 degrees C. RESULTS: Model estimates for all elements in human WB samples stored in polypropylene cryovials at -70 degrees C were equivalent to estimates from samples stored at 37 degrees C for up to 2months, 23 degrees C up to 10months, and -20 degrees C and 4 degrees C for up to 36months. Model estimates for samples stored for 3weeks at -70 degrees C were equivalent to estimates from samples stored for 2months at -20 degrees C, 4 degrees C, 23 degrees C and 37 degrees C; 10months at -20 degrees C, 4 degrees C, and 23 degrees C; and 36months at -20 degrees C and 4 degrees C. This equivalence was true for all elements and pools except for the low concentration blood pool for Cd. CONCLUSIONS: Storage temperatures of -20 degrees C and 4 degrees C are equivalent to -70 degrees C for stability of Cd, Mn, Pb, Se, and Hg in human whole blood for at least 36months when blood is stored in sealed polypropylene vials. Increasing the sample storage temperature from -70 degrees C to -20 degrees C or 4 degrees C can lead to large energy savings. The best analytical results are obtained when storage time at higher temperature conditions (e.g. 23 degrees C and 37 degrees C) is minimized because recovery of Se and Hg is reduced. Blood samples stored in polypropylene vials also lose volume over time and develop clots at higher temperature conditions (e.g., 23 degrees C and 37 degrees C), making them unacceptable for elemental testing after 10months and 2months, respectively. |
Measurement challenges at low blood lead levels
Caldwell KL , Cheng PY , Jarrett JM , Makhmudov A , Vance K , Ward CD , Jones RL , Mortensen ME . Pediatrics 2017 140 (2) In 2012, the Centers for Disease Control and Prevention (CDC) adopted its Advisory Committee on Childhood Lead Poisoning Prevention recommendation to use a population-based reference value to identify children and environments associated with lead hazards. The current reference value of 5 mug/dL is calculated as the 97.5th percentile of the distribution of blood lead levels (BLLs) in children 1 to 5 years old from 2007 to 2010 NHANES data. We calculated and updated selected percentiles, including the 97.5th percentile, by using NHANES 2011 to 2014 blood lead data and examined demographic characteristics of children whose blood lead was ≥90th percentile value. The 97.5th percentile BLL of 3.48 microg/dL highlighted analytical laboratory and clinical interpretation challenges of blood lead measurements ≤5 mug/dL. Review of 5 years of results for target blood lead values <11 microg/dL for US clinical laboratories participating in the CDC's voluntary Lead and Multi-Element Proficiency quality assurance program showed 40% unable to quantify and reported a nondetectable result at a target blood lead value of 1.48 microg/dL, compared with 5.5% at a target BLL of 4.60 microg/dL. We describe actions taken at the CDC's Environmental Health Laboratory in the National Center for Environmental Health, which measures blood lead for NHANES, to improve analytical accuracy and precision and to reduce external lead contamination during blood collection and analysis. |
Biomonitoring method for the analysis of chromium and cobalt in human whole blood using inductively coupled plasma-kinetic energy discrimination-mass spectrometry (ICP-KED-MS)
Georgi JC , Sommer YL , Ward CD , Cheng P , Jones RL , Caldwell KL . Anal Methods 2017 9 (23) 3464-3476 The Centers for Disease Control and Prevention developed a biomonitoring method to rapidly and accurately quantify chromium and cobalt in human whole blood by ICP-MS. Many metal-on-metal hip implants which contain significant amounts of chromium and cobalt are susceptible to metal degradation. This method is used to gather population data about chromium and cobalt exposure of the U.S. population that does not include people that have metal-on-metal hip implants so that reference value can be established for a baseline level in blood. We evaluated parameters such as; helium gas flow rate, choice and composition of the diluent solution for sample preparation, and sample rinse time to determine the optimal conditions for analysis. The limits of detection for chromium and cobalt in blood were determined to be 0.41 and 0.06 g L-1, respectively. Method precision, accuracy, and recovery for this method were determined using quality control material created in-house and historical proficiency testing samples. We conducted experiments to determine if quantitative changes in the method parameters affect the results obtained by changing four parameters while analyzing human whole blood spiked with National Institute of Standard and Technology traceable materials: the dilution factor used during sample preparation, sample rinse time, diluent composition, and kinetic energy discrimination gas flow rate. The results at the increased and decreased levels for each parameter were statistically compared to the results obtained at the optimized parameters. We assessed the degree of reproducibility obtained under a variety of conditions and evaluated the method's robustness by analyzing the same set of proficiency testing samples by different analysts, on different instruments, with different reagents, and on different days. The short-term stability of chromium and cobalt in human blood samples stored at room temperature was monitored over a time period of 64 hours by diluting and analyzing samples at different time intervals. The stability of chromium and cobalt post-dilution was also evaluated over a period of 48 hours and at two storage temperatures (room temperature and refrigerated at 4 C). The results obtained during the stability studies showed that chromium and cobalt are stable in human blood for a period of 64 hours. The Royal Society of Chemistry 2017. |
Reply: Iodine content in milk alternatives
Vance K , Makhmudov A , Jones RL , Caldwell K . Thyroid 2017 Response to "Iodine in Milk Alternatives". |
Association of acute toxic encephalopathy with litchi consumption in an outbreak in Muzaffarpur, India, 2014: a case-control study
Shrivastava A , Kumar A , Thomas JD , Laserson KF , Bhushan G , Carter MD , Chhabra M , Mittal V , Khare S , Sejvar JJ , Dwivedi M , Isenberg SL , Johnson R , Pirkle JL , Sharer JD , Hall PL , Yadav R , Velayudhan A , Papanna M , Singh P , Somashekar D , Pradhan A , Goel K , Pandey R , Kumar M , Kumar S , Chakrabarti A , Sivaperumal P , Kumar AR , Schier JG , Chang A , Graham LA , Mathews TP , Johnson D , Valentin L , Caldwell KL , Jarrett JM , Harden LA , Takeoka GR , Tong S , Queen K , Paden C , Whitney A , Haberling DL , Singh R , Singh RS , Earhart KC , Dhariwal AC , Chauhan LS , Venkatesh S , Srikantiah P . Lancet Glob Health 2017 5 (4) e458-e466 BACKGROUND: Outbreaks of unexplained illness frequently remain under-investigated. In India, outbreaks of an acute neurological illness with high mortality among children occur annually in Muzaffarpur, the country's largest litchi cultivation region. In 2014, we aimed to investigate the cause and risk factors for this illness. METHODS: In this hospital-based surveillance and nested age-matched case-control study, we did laboratory investigations to assess potential infectious and non-infectious causes of this acute neurological illness. Cases were children aged 15 years or younger who were admitted to two hospitals in Muzaffarpur with new-onset seizures or altered sensorium. Age-matched controls were residents of Muzaffarpur who were admitted to the same two hospitals for a non-neurologic illness within seven days of the date of admission of the case. Clinical specimens (blood, cerebrospinal fluid, and urine) and environmental specimens (litchis) were tested for evidence of infectious pathogens, pesticides, toxic metals, and other non-infectious causes, including presence of hypoglycin A or methylenecyclopropylglycine (MCPG), naturally-occurring fruit-based toxins that cause hypoglycaemia and metabolic derangement. Matched and unmatched (controlling for age) bivariate analyses were done and risk factors for illness were expressed as matched odds ratios and odds ratios (unmatched analyses). FINDINGS: Between May 26, and July 17, 2014, 390 patients meeting the case definition were admitted to the two referral hospitals in Muzaffarpur, of whom 122 (31%) died. On admission, 204 (62%) of 327 had blood glucose concentration of 70 mg/dL or less. 104 cases were compared with 104 age-matched hospital controls. Litchi consumption (matched odds ratio [mOR] 9.6 [95% CI 3.6 - 24]) and absence of an evening meal (2.2 [1.2-4.3]) in the 24 h preceding illness onset were associated with illness. The absence of an evening meal significantly modified the effect of eating litchis on illness (odds ratio [OR] 7.8 [95% CI 3.3-18.8], without evening meal; OR 3.6 [1.1-11.1] with an evening meal). Tests for infectious agents and pesticides were negative. Metabolites of hypoglycin A, MCPG, or both were detected in 48 [66%] of 73 urine specimens from case-patients and none from 15 controls; 72 (90%) of 80 case-patient specimens had abnormal plasma acylcarnitine profiles, consistent with severe disruption of fatty acid metabolism. In 36 litchi arils tested from Muzaffarpur, hypoglycin A concentrations ranged from 12.4 mug/g to 152.0 mug/g and MCPG ranged from 44.9 mug/g to 220.0 mug/g. INTERPRETATION: Our investigation suggests an outbreak of acute encephalopathy in Muzaffarpur associated with both hypoglycin A and MCPG toxicity. To prevent illness and reduce mortality in the region, we recommended minimising litchi consumption, ensuring receipt of an evening meal and implementing rapid glucose correction for suspected illness. A comprehensive investigative approach in Muzaffarpur led to timely public health recommendations, underscoring the importance of using systematic methods in other unexplained illness outbreaks. FUNDING: US Centers for Disease Control and Prevention. |
Stable transmission of Borrelia burgdorferi sensu stricto on the Outer Banks of North Carolina
Levine JF , Apperson CS , Levin M , Kelly TR , Kakumanu ML , Ponnusamy L , Sutton H , Salger SA , Caldwell JM , Szempruch AJ . Zoonoses Public Health 2016 64 (5) 337-354 The spirochaete (Borrelia burgdorferi) associated with Lyme disease was detected in questing ticks and rodents during a period of 18 years, 1991-2009, at five locations on the Outer Banks of North Carolina. The black-legged tick (Ixodes scapularis) was collected at varied intervals between 1991 and 2009 and examined for B. burgdorferi. The white-footed mouse (Peromyscus leucopus), house mouse (Mus musculus) marsh rice rat (Oryzomys palustris), marsh rabbit (Sylvilagus palustris), eastern cottontail (Sylvilagus floridanus) and six-lined racerunner (Cnemidophorus sexlineatus) were live-trapped, and their tissues cultured to isolate spirochaetes. Borrelia burgdorferi isolates were obtained from questing adult I. scapularis and engorged I. scapularis removed from P. leucopus, O. palustris and S. floridanus. The prevalence of B. burgdorferi infection was variable at different times and sites ranging from 7 to 14% of examined questing I. scapularis. Mitochondrial (16S) rRNA gene phylogenetic analysis from 65 adult I. scapularis identified 12 haplotypes in two major clades. Nine haplotypes were associated with northern/Midwestern I. scapularis populations and three with southern I. scapularis populations. Sixteen isolates obtained from tick hosts in 2005 were confirmed to be B. burgdorferi by amplifying and sequencing of 16S rRNA and 5S-23S intergenic spacer fragments. The sequences had 98-99% identity to B. burgdorferi sensu stricto strains B31, JD1 and M11p. Taken together, these studies indicate that B. burgdorferi sensu stricto is endemic in questing I. scapularis and mammalian tick hosts on the Outer Banks of North Carolina. |
Mortality among military participants at the 1957 PLUMBBOB nuclear weapons test series and from leukemia among participants at the SMOKY test
Caldwell GG , Zack MM , Mumma MT , Falk H , Heath CW , Till JE , Chen H , Boice JD . J Radiol Prot 2016 36 (3) 474-489 Health effects following low doses of ionizing radiation are uncertain. Military veterans at the Nevada test site (NTS) during the SMOKY atmospheric nuclear weapons test in 1957 were reported to be at increased risk for leukemia in 1979, but this increase was not evaluated with respect to radiation dose. The SMOKY test was one of 30 tests in 1957 within the PLUMBBOB test series. These early studies led to public laws where atomic veterans could qualify for compensation for presumptive radiogenic diseases. A retrospective cohort study was conducted of 12219 veterans at the PLUMBBOB test series, including 3020 at the SMOKY nuclear test. Mortality follow-up was through 2010 and observed causes of death were compared with expected causes based on general population rates. Radiation dose to red bone marrow was based on individual dose reconstructions, and Cox proportional hazards models were used to evaluate dose response for all leukemias other than chronic lymphocytic leukemia (non-CLL leukemia). Vital status was determined for 95.3% of the 12 219 veterans. The dose to red bone marrow was low (mean 3.2 mGy, maximum 500 mGy). Military participants at the PLUMBBOB nuclear test series remained relatively healthy after 53 years and died at a lower rate than the general population. In contrast, and in comparison with national rates, the SMOKY participants showed significant increases in all causes of death, respiratory cancer, leukemia, nephritis and nephrosis, and accidents, possibly related in part to lifestyle factors common to enlisted men who made up 81% of the SMOKY cohort. Compared with national rates, a statistically significant excess of non-CLL leukemia was observed among SMOKY participants (Standardized Mortality Ratio = 1.89, 95% 1.24-2.75, n = 27) but not among PLUMBBOB participants after excluding SMOKY (SMR = 0.87, 95% 0.64-1.51, n = 47). Leukemia risk, initially reported to be significantly increased among SMOKY participants, remained elevated, but this risk diminished over time. Despite an intense dose reconstruction, the risk for leukemia was not found to increase with increasing levels of radiation dose to the red bone marrow. Based on a linear model, the estimated excess relative risk per mGy is -0.05 (95% CI -0.14, 0.04). An explanation for the observed excess of leukemia remains unresolved but conceivably could be related to chance due to small numbers, subtle biases in the study design and/or high tobacco use among enlisted men. Larger studies should elucidate further the possible relationship between fallout radiation, leukemia and cancer among atomic veterans. |
Analysis of whole human blood for Pb, Cd, Hg, Se, and Mn by ICP-DRC-MS for biomonitoring and acute exposures
Jones DR , Jarrett JM , Tevis DS , Franklin M , Mullinix NJ , Wallon KL , Derrick Quarles C Jr , Caldwell KL , Jones RL . Talanta 2017 162 114-122 We improved our inductively coupled plasma mass spectrometry (ICP-MS) whole blood method [1] for determination of lead (Pb), cadmium (Cd), and mercury (Hg) by including manganese (Mn) and selenium (Se), and expanding the calibration range of all analytes. The method is validated on a PerkinElmer (PE) ELAN® DRC II ICP-MS (ICP-DRC-MS) and uses the Dynamic Reaction Cell (DRC) technology to attenuate interfering background ion signals via ion-molecule reactions. Methane gas (CH4) eliminates background signal from 40Ar2 + to permit determination of 80Se+, and oxygen gas (O2) eliminates several polyatomic interferences (e.g. 40Ar15N+, 54Fe1H+) on 55Mn+. Hg sensitivity in DRC mode is a factor of two higher than vented mode when measured under the same DRC conditions as Mn due to collisional focusing of the ion beam. To compensate for the expanded method's longer analysis time (due to DRC mode pause delays), we implemented an SC4-FAST autosampler (ESI Scientific, Omaha, NE), which vacuum loads the sample onto a loop, to keep the sample-to-sample measurement time to less than 5 min, allowing for preparation and analysis of 60 samples in an 8-h work shift. The longer analysis time also resulted in faster breakdown of the hydrocarbon oil in the interface roughing pump. The replacement of the standard roughing pump with a pump using a fluorinated lubricant, Fomblin®, extended the time between pump maintenance. We optimized the diluent and rinse solution components to reduce carryover from high concentration samples and prevent the formation of precipitates. We performed a robust calculation to determine the following limits of detection (LOD) in whole blood: 0.07 µg dL−1 for Pb, 0.10 µg L−1 for Cd, 0.28 μg L−1 for Hg, 0.99 µg L−1 for Mn, and 24.5 µg L−1 for Se. © 2016 |
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