Last data update: Apr 29, 2024. (Total: 46658 publications since 2009)
Records 1-30 (of 30 Records) |
Query Trace: Potts C[original query] |
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Outcomes up to age 36 months after congenital Zika virus infection-U.S. states
Neelam V , Woodworth KR , Chang DJ , Roth NM , Reynolds MR , Akosa A , Carr CP , Anderson KN , Mulkey SB , DeBiasi RL , Biddle C , Lee EH , Elmore AL , Scotland SJ , Sowunmi S , Longcore ND , Ahmed M , Langlois PH , Khuwaja S , Browne SE , Lind L , Shim K , Gosciminski M , Blumenfeld R , Khuntia S , Halai UA , Locklear A , Chan M , Willabus T , Tonzel J , Marzec NS , Barreto NA , Sanchez C , Fornoff J , Hale S , Nance A , Iguchi L , Adibhatla SN , Potts E , Schiffman E , Raman D , McDonald MF , Stricklin B , Ludwig E , Denson L , Contreras D , Romitti PA , Ferrell E , Marx M , Signs K , Cook A , Leedom VO , Beauregard S , Orantes LC , Cronquist L , Roush L , Godfred-Cato S , Gilboa SM , Meaney-Delman D , Honein MA , Moore CA , Tong VT . Pediatr Res 2023 BACKGROUND: To characterize neurodevelopmental abnormalities in children up to 36 months of age with congenital Zika virus exposure. METHODS: From the U.S. Zika Pregnancy and Infant Registry, a national surveillance system to monitor pregnancies with laboratory evidence of Zika virus infection, pregnancy outcomes and presence of Zika associated birth defects (ZBD) were reported among infants with available information. Neurologic sequelae and developmental delay were reported among children with ≥1 follow-up exam after 14 days of age or with ≥1 visit with development reported, respectively. RESULTS: Among 2248 infants, 10.1% were born preterm, and 10.5% were small-for-gestational age. Overall, 122 (5.4%) had any ZBD; 91.8% of infants had brain abnormalities or microcephaly, 23.0% had eye abnormalities, and 14.8% had both. Of 1881 children ≥1 follow-up exam reported, neurologic sequelae were more common among children with ZBD (44.6%) vs. without ZBD (1.5%). Of children with ≥1 visit with development reported, 46.8% (51/109) of children with ZBD and 7.4% (129/1739) of children without ZBD had confirmed or possible developmental delay. CONCLUSION: Understanding the prevalence of developmental delays and healthcare needs of children with congenital Zika virus exposure can inform health systems and planning to ensure services are available for affected families. IMPACT: We characterize pregnancy and infant outcomes and describe neurodevelopmental abnormalities up to 36 months of age by presence of Zika associated birth defects (ZBD). Neurologic sequelae and developmental delays were common among children with ZBD. Children with ZBD had increased frequency of neurologic sequelae and developmental delay compared to children without ZBD. Longitudinal follow-up of infants with Zika virus exposure in utero is important to characterize neurodevelopmental delay not apparent in early infancy, but logistically challenging in surveillance models. |
Design of different shapes of drill shroud to reduce dust deposit using computational fluid dynamics method
Zheng Y , Reed WR , Potts JD . CIM J 2023 11-20 Effective dust control using drill shroud air-blocking shelves was confirmed previously through laboratory tests, field studies, and computational fluid dynamics (CFD) simulations. However, when the drilling machine moves to different locations, deposits on these shelves can produce a large dust cloud. To minimize the dust exposure hazard, this study modified the drill shroud air-blocking shelves by using the concept of angle of repose to eliminate the deposits while at the same time, confining the dust inside the drill shroud. Two types of drill shroud inner shapes were evaluated using CFD models: U-shaped and V-shaped. In addition, a drill shroud with 45 blocking shelves was built to examine its dust control capacity. The angle of repose used to minimize dust problems during mast lowering was shown to be effective in reducing the dust problems during drilling. However, care must be taken to use a properly designed shroud because the V-shaped drill shroud can potentially exacerbate dust leakage. |
Comparison of an ID NOW COVID-19 assay used at the point of care to laboratory-based nucleic acid amplification tests
Payne D , Williams C , Jacob J , Chastain-Potts S , Adjei M , Taye B , Montalvo S , Short L , Tran A . J Clin Microbiol 2023 61 (7) e0041323 The emergence of a novel coronavirus, namely, SARS-CoV-2, necessitated the use of rapid, accurate diagnostics to quickly diagnose COVID-19. This need has increased with the emergence of new variants and continued waves of COVID-19 cases. The ID NOW COVID-19 assay is a rapid nucleic acid amplification test (NAAT) that is used by hospitals, urgent care facilities, medical clinics, and public health laboratories for rapid molecular SARS-CoV-2 testing at the point of care. The District of Columbia Department of Forensic Sciences Public Health Laboratory Division (DC DFS PHL) implemented ID NOW COVID-19 testing in nontraditional laboratory settings, including a mobile testing unit, health clinic, and emergency department, to assist with rapid identification and isolation for populations at high risk of SARS-CoV-2 transmission in the District of Columbia. The DC DFS PHL provided these nontraditional laboratories with safety risk assessment, assay training, competency assessment, and quality control monitoring as parts of a comprehensive quality management system (QMS). We assessed the accuracy of the ID NOW COVID-19 assay when operated in the context of these trainings and systems. This was done by comparing results from 9,518 paired tests, and strong agreement (κ = 0.88, OPA = 98.3%) was found between the ID NOW COVID-19 assay and laboratory-based NAATs. These findings indicate that the ID NOW COVID-19 assay can be used to detect SARS-CoV-2 in nontraditional laboratory settings when used within the context of a comprehensive QMS. |
Adeno-associated virus type 2 in US children with acute severe hepatitis.
Servellita V , Gonzalez AS , Lamson DM , Foresythe A , Huh HJ , Bazinet AL , Bergman NH , Bull RL , Garcia KY , Goodrich JS , Lovett SP , Parker K , Radune D , Hatada A , Pan CY , Rizzo K , Bertumen JB , Morales C , Oluniyi PE , Nguyen J , Tan J , Stryke D , Jaber R , Leslie MT , Lyons Z , Hedman HD , Parashar U , Sullivan M , Wroblewski K , Oberste MS , Tate JE , Baker JM , Sugerman D , Potts C , Lu X , Chhabra P , Pediatric Hepatitis of Unknown Etiology Working Group , Ingram LA , Shiau H , Britt W , Sanchez LHG , Ciric C , Rostad CA , Vinjé J , Kirking HL , Wadford DA , Raborn RT , St George K , Chiu CY . Nature 2023 As of August 2022, clusters of acute severe hepatitis of unknown etiology in children have been reported from 35 countries, including the United States(1,2). Previous studies have found human adenoviruses (HAdVs) in the blood from cases in Europe and the United States(3-7), although it is unclear whether this virus is causative. Here we used PCR testing, viral enrichment based sequencing, and agnostic metagenomic sequencing to analyze samples from 16 HAdV-positive cases from October 1, 2021 to May 22, 2022, in parallel with 113 controls. In blood from 14 cases, adeno-associated virus 2 (AAV2) sequences were detected in 93% (13 of 14), compared to 4 (3.5%) of 113 controls (P<0.001) and to 0 of 30 patients with hepatitis of defined etiology (P<0.001). In controls, HAdV-41 was detected in blood from 9 (39.1%) of the 23 patients with acute gastroenteritis (without hepatitis), including 8 of 9 patients with positive stool HAdV testing, but co-infection with AAV2 was observed in only 3 (13.0%) of these 23 patients versus 93% of cases (P<0.001). Co-infections by Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), and/or enterovirus A71 (EV-A71) were also detected in 12 (85.7%) of 14 cases, with higher herpesvirus detection in cases versus controls (P<0.001). Our findings suggest that the severity of the disease is related to co-infections involving AAV2 and one or more helper viruses. |
Interim Analysis of Acute Hepatitis of Unknown Etiology in Children Aged <10 Years - United States, October 2021-June 2022.
Cates J , Baker JM , Almendares O , Kambhampati AK , Burke RM , Balachandran N , Burnett E , Potts CC , Reagan-Steiner S , Kirking HL , Sugerman D , Parashar UD , Tate JE . MMWR Morb Mortal Wkly Rep 2022 71 (26) 852-858 On April 21, 2022, CDC issued a health advisory(†) encouraging U.S. clinicians to report all patients aged <10 years with hepatitis of unknown etiology to public health authorities, after identification of similar cases in both the United States (1) and Europe.(§) A high proportion of initially reported patients had adenovirus detected in whole blood specimens, thus the health advisory encouraged clinicians to consider requesting adenovirus testing, preferentially on whole blood specimens. For patients meeting the criteria in the health advisory (patients under investigation [PUIs]), jurisdictional public health authorities abstracted medical charts and interviewed patient caregivers. As of June 15, 2022, a total of 296 PUIs with hepatitis onset on or after October 1, 2021, were reported from 42 U.S. jurisdictions. The median age of PUIs was 2 years, 2 months. Most PUIs were hospitalized (89.9%); 18 (6.1%) required a liver transplant, and 11 (3.7%) died. Adenovirus was detected in a respiratory, blood, or stool specimen of 100 (44.6%) of 224 patients.(¶) Current or past infection with SARS-CoV-2 (the virus that causes COVID-19) was reported in 10 of 98 (10.2%) and 32 of 123 (26.0%) patients, respectively. No common exposures (e.g., travel, food, or toxicants) were identified. This nationwide investigation is ongoing. Further clinical data are needed to understand the cause of hepatitis in these patients and to assess the potential association with adenovirus. |
Invasive meningococcal disease among people experiencing homelessness-United States, 2016-2019
Rudmann KC , Brown NE , Blain A , Burns M , Ramsey A , Las Nueces D , Martin T , Barnes M , Davizon ES , Retchless AC , Potts C , Wang X , Hariri S , McNamara LA . J Infect Dis 2022 226 S322-S326 BACKGROUND: Recently, several invasive meningococcal disease (IMD) outbreaks caused by Neisseria meningitidis have occurred among people experiencing homelessness (PEH). However, overall IMD risk among PEH is not well described. We compared incidence and characteristics of IMD among PEH and persons not known to be experiencing homelessness (non-PEH) in the United States. METHODS: We analyzed 2016-2019 IMD data from the National Notifiable Diseases Surveillance System (NNDSS) and enhanced meningococcal disease surveillance. Incidence was calculated using U.S. census data and Point-in-Time counts from the U.S. Department of Housing and Urban Development. RESULTS: Of cases from states participating in enhanced surveillance during 2016-2019 (n = 1409), 45 (3.2%) cases occurred among PEH. Annual incidence was higher among PEH (2.12 cases/100,000) than non-PEH (0.11 cases/100,000; relative risk: 19.8, 95% CI: 14.8-26.7). Excluding outbreak-associated cases (PEH n = 18, 40%; non-PEH n = 98, 7.2%), incidence among PEH remained elevated compared to incidence in non-PEH (relative risk: 12.8, 95% CI: 8.8-18.8). Serogroup C was identified in 68.2% of PEH cases compared to 26.4% in non-PEH (p < 0.0001). CONCLUSIONS: PEH are at increased risk for IMD. Further assessment is needed to determine the feasibility and potential impact of meningococcal vaccination for PEH in the United States. |
Trends in Acute Hepatitis of Unspecified Etiology and Adenovirus Stool Testing Results in Children - United States, 2017-2022.
Kambhampati AK , Burke RM , Dietz S , Sheppard M , Almendares O , Baker JM , Cates J , Stein Z , Johns D , Smith AR , Bull-Otterson L , Hofmeister MG , Cobb S , Dale SE , Soetebier KA , Potts CC , Adjemian J , Kite-Powell A , Hartnett KP , Kirking HL , Sugerman D , Parashar UD , Tate JE . MMWR Morb Mortal Wkly Rep 2022 71 (24) 797-802 In November 2021, CDC was notified of a cluster of previously healthy children with hepatitis of unknown etiology evaluated at a single U.S. hospital (1). On April 21, 2022, following an investigation of this cluster and reports of similar cases in Europe (2,3), a health advisory* was issued requesting U.S. providers to report pediatric cases(†) of hepatitis of unknown etiology to public health authorities. In the United States and Europe, many of these patients have also received positive adenovirus test results (1,3). Typed specimens have indicated adenovirus type 41, which typically causes gastroenteritis (1,3). Although adenovirus hepatitis has been reported in immunocompromised persons, adenovirus is not a recognized cause of hepatitis in healthy children (4). Because neither acute hepatitis of unknown etiology nor adenovirus type 41 is reportable in the United States, it is unclear whether either has recently increased above historical levels. Data from four sources were analyzed to assess trends in hepatitis-associated emergency department (ED) visits and hospitalizations, liver transplants, and adenovirus stool testing results among children in the United States. Because of potential changes in health care-seeking behavior during 2020-2021, data from October 2021-March 2022 were compared with a pre-COVID-19 pandemic baseline. These data do not suggest an increase in pediatric hepatitis or adenovirus types 40/41 above baseline levels. Pediatric hepatitis is rare, and the relatively low weekly and monthly counts of associated outcomes limit the ability to interpret small changes in incidence. Ongoing assessment of trends, in addition to enhanced epidemiologic investigations, will help contextualize reported cases of acute hepatitis of unknown etiology in U.S. children. |
Antimicrobial Susceptibility Survey of Invasive Haemophilus influenzae in the United States in 2016.
Potts CC , Rodriguez-Rivera LD , Retchless AC , Buono SA , Chen AT , Marjuki H , Blain AE , Wang X . Microbiol Spectr 2022 10 (3) e0257921 Antibiotics are important for the treatment and prevention of invasive Haemophilus influenzae disease. Reduced susceptibility to clinically relevant drugs, except ampicillin, has been uncommon in the United States. Susceptibility of 700 invasive H. influenzae isolates, collected through population-based surveillance during 2016, was assessed for 15 antibiotics using broth microdilution, according to the CLSI guidelines; a subset of 104 isolates were also assessed for rifampin susceptibility using Etest. Genomes were sequenced to identify genes and mutations known to be associated with reduced susceptibility to clinically relevant drugs. A total of 508 (72.6%) had reduced susceptibility to at least one antibiotic and more than half of the isolates exhibited reduced susceptibility to only one (33.6%) or two (21.6%) antibiotic classes. All tested isolates were susceptible to rifampin, a chemoprophylaxis agent, and <1% (n=3) of isolates had reduced susceptibility to third generation cephalosporins, which are recommended for invasive disease treatment. In contrast, ampicillin resistance was more common (28.1%) and predominantly associated with the detection of a -lactamase gene; 26.2% of isolates in the collection contained either a TEM-1 or ROB-1 -lactamase gene, including 88.8% of ampicillin-resistant isolates. -lactamase negative ampicillin-resistant (BLNAR) isolates were less common and associated with ftsI mutations; resistance to amoxicillin-clavulanate was detected in <2% (n=13) of isolates. The proportion of reduced susceptibility observed was higher among nontypeable H. influenzae and serotype e than other serotypes. US invasive H. influenzae isolates remain predominantly susceptible to clinically relevant antibiotics except ampicillin, and BLNAR isolates remain uncommon. IMPORTANCE Antibiotics play an important role for the treatment and prevention of invasive Haemophilus influenzae disease. Antimicrobial resistance survey of invasive H. influenzae isolates collected in 2016 showed that the US H. influenzae population remained susceptible to clinically relevant antibiotics, except for ampicillin. Detection of approximately a quarter ampicillin-resistant and -lactamase containing strains demonstrates that resistance mechanisms can be acquired and sustained within the H. influenzae population, highlighting the continued importance of antimicrobial resistance surveillance for H. influenzae to monitor susceptibility trends and mechanisms of resistance. |
Antimicrobial Susceptibility Survey of Invasive Neisseria meningitidis, United States 2012-2016.
Potts CC , Rodriguez-Rivera LD , Retchless AC , Hu F , Marjuki H , Blain AE , McNamara LA , Wang X . J Infect Dis 2022 225 (11) 1871-1875 BACKGROUND: Historically, antimicrobial resistance has been rare in US invasive meningococcal disease cases. METHODS: Meningococcal isolates (n=695) were collected through population-based surveillance, 2012-2016, and national surveillance, 2015-2016. Antimicrobial susceptibility was assessed by broth microdilution. Resistance mechanisms were characterized using whole genome sequencing. RESULTS: All isolates were susceptible to six antibiotics (cefotaxime, ceftriaxone, meropenem, rifampin, minocycline, and azithromycin). Approximately 25% were penicillin- or ampicillin-intermediate; among these, 79% contained mosaic penA gene mutations. Less than 1% of isolates were penicillin-, ampicillin-, ciprofloxacin-, or levofloxacin-resistant. CONCLUSION: Penicillin- and ampicillin-intermediate isolates were common, but resistance to clinically relevant antibiotics remained rare. |
Zika-associated birth defects reported in pregnancies with laboratory evidence of confirmed or possible Zika virus infection - U.S. Zika Pregnancy and Infant Registry, December 1, 2015-March 31, 2018
Roth NM , Reynolds MR , Lewis EL , Woodworth KR , Godfred-Cato S , Delaney A , Akosa A , Valencia-Prado M , Lash M , Elmore A , Langlois P , Khuwaja S , Tufa A , Ellis EM , Nestoridi E , Lyu C , Longcore ND , Piccardi M , Lind L , Starr S , Johnson L , Browne SE , Gosciminski M , Velasco PE , Johnson-Clarke F , Locklear A , Chan M , Fornoff J , Toews KE , Tonzel J , Marzec NS , Hale S , Nance AE , Willabus T , Contreras D , Adibhatla SN , Iguchi L , Potts E , Schiffman E , Lolley K , Stricklin B , Ludwig E , Garstang H , Marx M , Ferrell E , Moreno-Gorrin C , Signs K , Romitti P , Leedom V , Martin B , Castrodale L , Cook A , Fredette C , Denson L , Cronquist L , Nahabedian JF3rd , Shinde N , Polen K , Gilboa SM , Martin SW , Cragan JD , Meaney-Delman D , Honein MA , Tong VT , Moore CA . MMWR Morb Mortal Wkly Rep 2022 71 (3) 73-79 Zika virus infection during pregnancy can cause serious birth defects of the brain and eyes, including intracranial calcifications, cerebral or cortical atrophy, chorioretinal abnormalities, and optic nerve abnormalities (1,2). The frequency of these Zika-associated brain and eye defects, based on data from the U.S. Zika Pregnancy and Infant Registry (USZPIR), has been previously reported in aggregate (3,4). This report describes the frequency of individual Zika-associated brain and eye defects among infants from pregnancies with laboratory evidence of confirmed or possible Zika virus infection. Among 6,799 live-born infants in USZPIR born during December 1, 2015-March 31, 2018, 4.6% had any Zika-associated birth defect; in a subgroup of pregnancies with a positive nucleic acid amplification test (NAAT) for Zika virus infection, the percentage was 6.1% of live-born infants. The brain and eye defects most frequently reported included microcephaly, corpus callosum abnormalities, intracranial calcification, abnormal cortical gyral patterns, ventriculomegaly, cerebral or cortical atrophy, chorioretinal abnormalities, and optic nerve abnormalities. Among infants with any Zika-associated birth defect, one third had more than one defect reported. Certain brain and eye defects in an infant might prompt suspicion of prenatal Zika virus infection. These findings can help target surveillance efforts to the most common brain and eye defects associated with Zika virus infection during pregnancy should a Zika virus outbreak reemerge, and might provide a signal to the reemergence of Zika virus, particularly in geographic regions without ongoing comprehensive Zika virus surveillance. |
Acquisition of ciprofloxacin resistance among an expanding clade of β-lactamase positive, serogroup Y Neisseria meningitidis in the United States.
Potts CC , Retchless AC , McNamara LA , Marasini D , Reese N , Swint S , Hu F , Sharma S , Blain AE , Lonsway D , Karlsson M , Hariri S , Fox LM , Wang X . Clin Infect Dis 2021 73 (7) 1185-1193 BACKGROUND: Penicillin and ciprofloxacin are important for invasive meningococcal disease (IMD) management and prevention. IMD cases caused by penicillin- and ciprofloxacin-resistant Neisseria meningitidis containing a ROB-1 β-lactamase gene (blaROB-1) and a mutated DNA gyrase gene (gyrA), have been recently reported in the USA. METHODS: We examined 2097 meningococcal genomes collected through US population-based surveillance from January 2011-February 2020 to identify IMD cases caused by strains with blaROB-1 or gyrA-mediated resistance. Antimicrobial resistance was confirmed phenotypically. The US isolate genomes were compared to non-US isolate genomes containing blaROB-1. Interspecies transfer of ciprofloxacin resistance was assessed by comparing gyrA among Neisseria species. RESULTS: Eleven penicillin- and ciprofloxacin-resistant isolates were identified after December 2018; all were serogroup Y, sequence type 3587, clonal complex (CC) 23, and contained blaROB-1 and a T91I-containing gyrA allele. An additional 22 penicillin-resistant, blaROB-1-containing US isolates with wild-type gyrA were identified from 2013-2020. All 33 blaROB-1-containing isolates formed a single clade, along with 12 blaROB-1-containing isolates from six other countries. Two-thirds of blaROB-1-containing US isolates were from Hispanic individuals. Twelve additional ciprofloxacin-resistant isolates with gyrA T91 mutations were identified. Ciprofloxacin-resistant isolates belonged to six CCs and contained 10 unique gyrA alleles; seven were similar or identical to alleles from N. lactamica or N. gonorrhoeae. CONCLUSIONS: Recent IMD cases caused by a dual resistant serogroup Y suggest changing antimicrobial resistance patterns in the USA. The emerging dual-resistance is due to acquisition of ciprofloxacin resistance by β-lactamase-containing N. meningitidis. Routine antimicrobial resistance surveillance will effectively monitor resistance changes and spread. |
Incidence of meningococcal disease before and after implementation of quadrivalent meningococcal conjugate vaccine in the United States
Mbaeyi S , Pondo T , Blain A , Yankey D , Potts C , Cohn A , Hariri S , Shang N , MacNeil JR . JAMA Pediatr 2020 174 (9) 843-851 IMPORTANCE: In 2005, the US Advisory Committee on Immunization Practices recommended routine quadrivalent meningococcal conjugate (MenACWY) vaccine for all adolescents aged 11 to 12 years, and in 2010, a booster dose for adolescents aged 16 years. Measuring the association between MenACWY vaccination and the incidence of meningococcal disease in adolescents is critical for evaluating the adolescent vaccination program and informing future vaccine policy. OBJECTIVE: To describe the association between MenACWY vaccination and the incidence of meningococcal disease in US adolescents. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, analysis of surveillance data included all confirmed and probable cases of Neisseria meningitidis reported to the National Notifiable Diseases Surveillance System from January 1, 2000, to December 31, 2017. Statistical analysis was conducted from October 1, 2018, to August 31, 2019. EXPOSURES: Routine MenACWY vaccination among US adolescents. MAIN OUTCOMES AND MEASURES: Poisson segmented regression analysis was used to model the annual incidence of meningococcal disease among adolescents aged 11 to 15 years and 16 to 22 years before the introduction of the MenACWY vaccine (2000-2005), after the primary dose recommendation (2006-2010), and after the booster dose recommendation (2011-2017); 95% CIs were used to determine significant differences between time periods. RESULTS: The national incidence of meningococcal disease declined from 0.61 cases per 100 000 population during the prevaccine period (2000-2005) to 0.15 cases per 100 000 population during the post-booster dose period (2011-2017). The greatest percentage decline was observed for serogroup C, W, and Y combined (CWY) among adolescents aged 11 to 15 years and 16 to 22 years in the periods after vaccine introduction. Incidence of serogroup CWY meningococcal disease among adolescents aged 11 to 15 years decreased by 16.3% (95% CI, 12.1%-20.3%) annually during the prevaccine period and 27.8% (95% CI, 20.6%-34.4%) during the post-primary dose period (P = .02); among adolescents aged 16 to 22 years, the incidence decreased by 10.6% (95% CI, 6.8%-14.3%) annually in the post-primary dose period and 35.6% (95% CI, 29.3%-41.0%) annually in the post-booster dose period (P < .001). An estimated 222 cases of meningococcal disease due to serogroup CWY among adolescents were averted through vaccination during the evaluation period. CONCLUSIONS AND RELEVANCE: After introduction of a primary and booster MenACWY dose, the rates of decline in incidence of meningococcal disease due to serogroup C, W, or Y accelerated nearly 2-fold to 3-fold in vaccinated adolescent age groups. Although the MenACWY vaccine alone cannot explain the decline of meningococcal disease in the United States, these data suggest that MenACWY vaccination is associated with reduced disease rates in adolescents. |
Detection of Ciprofloxacin-Resistant, β-Lactamase-Producing Neisseria meningitidis Serogroup Y Isolates - United States, 2019-2020.
McNamara LA , Potts C , Blain AE , Retchless AC , Reese N , Swint S , Lonsway D , Karlsson M , Lunquest K , Sweitzer JJ , Wang X , Hariri S , Fox LM . MMWR Morb Mortal Wkly Rep 2020 69 (24) 735-739 Meningococcal disease is a sudden-onset, life-threatening illness caused by the bacterium Neisseria meningitidis. Prompt empiric antibiotic treatment can reduce morbidity and mortality among patients, and antibiotic prophylaxis can prevent secondary disease in close contacts. Historically, N. meningitidis isolates in the United States have largely been susceptible to the antibiotics recommended for treatment and prophylaxis, including penicillin and ciprofloxacin. This report describes detection of penicillin-resistant and ciprofloxacin-resistant N. meningitidis serogroup Y (NmY) isolates in the United States. NmY isolates containing a blaROB-1 beta-lactamase enzyme gene conferring resistance to penicillins (1) were recovered from 33 cases reported during 2013-2020. Isolates from 11 of these cases, reported during 2019-2020, harbored a ciprofloxacin resistance-associated mutation in a chromosomal gene (gyrA). Cases were reported from 12 geographically disparate states; a majority of cases (22 of 33, 67%) occurred in Hispanic persons. These cases represent a substantial increase in penicillin-resistant and ciprofloxacin-resistant meningococci in the United States since 2013. Ceftriaxone and cefotaxime, the recommended first-line agents for empiric bacterial meningitis treatment, can continue to be used for treatment, but health care providers should ascertain susceptibility of meningococcal isolates to penicillin before switching to penicillin or ampicillin. Ongoing monitoring for antimicrobial resistance among meningococcal isolates and prophylaxis failures will be important to inform treatment and prophylaxis recommendations. |
Epidemiology of Bacterial Meningitis in the Nine Years Since Meningococcal Serogroup A Conjugate Vaccine Introduction, Niger, 2010-2018.
Sidikou F , Potts CC , Zaneidou M , Mbaeyi S , Kadade G , Paye MF , Ousmane S , Issaka B , Chen A , Chang HY , Issifou D , Lingani C , Sakande S , Bienvenu B , Mahamane AE , Diallo AO , Moussa A , Seidou I , Abdou M , Sidiki A , Garba O , Haladou S , Testa J , Obama Nse R , Mainassara HB , Wang X . J Infect Dis 2019 220 S206-s215 BACKGROUND: In 2010, Niger and other meningitis belt countries introduced a meningococcal serogroup A conjugate vaccine (MACV). We describe the epidemiology of bacterial meningitis in Niger from 2010 to 2018. METHODS: Suspected and confirmed meningitis cases from January 1, 2010 to July 15, 2018 were obtained from national aggregate and laboratory surveillance. Cerebrospinal fluid specimens were analyzed by culture and/or polymerase chain reaction. Annual incidence was calculated as cases per 100 000 population. Selected isolates obtained during 2016-2017 were characterized by whole-genome sequencing. RESULTS: Of the 21 142 suspected cases of meningitis, 5590 were confirmed: Neisseria meningitidis ([Nm] 85%), Streptococcus pneumoniae ([Sp] 13%), and Haemophilus influenzae ([Hi] 2%). No NmA cases occurred after 2011. Annual incidence per 100 000 population was more dynamic for Nm (0.06-7.71) than for Sp (0.18-0.70) and Hi (0.01-0.23). The predominant Nm serogroups varied over time (NmW in 2010-2011, NmC in 2015-2018, and both NmC and NmX in 2017-2018). Meningococcal meningitis incidence was highest in the regions of Niamey, Tillabery, Dosso, Tahoua, and Maradi. The NmW isolates were clonal complex (CC)11, NmX were CC181, and NmC were CC10217. CONCLUSIONS: After MACV introduction, we observed an absence of NmA, the emergence and continuing burden of NmC, and an increase in NmX. Niger's dynamic Nm serogroup distribution highlights the need for strong surveillance programs to inform vaccine policy. |
Genomic characterization of Haemophilus influenzae: a focus on the capsule locus.
Potts CC , Topaz N , Rodriguez-Rivera LD , Hu F , Chang HY , Whaley MJ , Schmink S , Retchless AC , Chen A , Ramos E , Doho GH , Wang X . BMC Genomics 2019 20 (1) 733 BACKGROUND: Haemophilus influenzae (Hi) can cause invasive diseases such as meningitis, pneumonia, or sepsis. Typeable Hi includes six serotypes (a through f), each expressing a unique capsular polysaccharide. The capsule, encoded by the genes within the capsule locus, is a major virulence factor of typeable Hi. Non-typeable (NTHi) does not express capsule and is associated with invasive and non-invasive diseases. METHODS: A total of 395 typeable and 293 NTHi isolates were characterized by whole genome sequencing (WGS). Phylogenetic analysis and multilocus sequence typing were used to characterize the overall genetic diversity. Pair-wise comparisons were used to evaluate the capsule loci. A WGS serotyping method was developed to predict the Hi serotype. WGS serotyping results were compared to slide agglutination (SAST) or real-time PCR (rt-PCR) serotyping. RESULTS: Isolates of each Hi serotype clustered into one or two subclades, with each subclade being associated with a distinct sequence type (ST). NTHi isolates were genetically diverse, with seven subclades and 125 STs being detected. Regions I and III of the capsule locus were conserved among the six serotypes (>/=82% nucleotide identity). In contrast, genes in Region II were less conserved, with only six gene pairs from all serotypes showing >/=56% nucleotide identity. The WGS serotyping method was 99.9% concordant with SAST and 100% concordant with rt-PCR in determining the Hi serotype. CONCLUSIONS: Genomic analysis revealed a higher degree of genetic diversity among NTHi compared to typeable Hi. The WGS serotyping method accurately predicted the Hi capsule type and can serve as an alternative method for Hi serotyping. |
Mouth level nicotine in a clinical setting versus non-clinical setting
Watson CV , Richter P , Yao L , Phillips T , Pickworth WB , deCastro BR , Potts J , Watson C . Am J Health Behav 2019 43 (3) 229-241 Objective: Our objective was to improve understanding of the differences in cigarette use behavior and exposure for participants smoking their own brand of cigarettes in a clinical setting versus smoking under natural conditions. Methods: Adult daily smokers (N = 163) attended 2 clinic visits where they smoked through a CReSS topography device. Participants collected cigarette butts smoked without a CReSS device and completed a diary of location, mood, and activity for each cigarette smoked. Cigarette butts were used to determine mouth level nicotine (MLN). Least square means (LSMs) were estimated from mixed effects models. Results: The LSM for MLN was higher among participants who smoked cigarettes in the clinical setting. LSM MLN was 1.589 [95% CI: 1.312, 1.924] mg/cig for cigarettes smoked in the clinic and 1.087 [95% CI: 0.902, 1.310] mg/cig for cigarettes smoked outside of the clinic; we found differences between race and sex. Conclusions: Our results show nicotine intake and some smoking behavior are significantly biased upwards when studied in a clinical setting. Therefore, tobacco smoke exposure determinations in a clinical setting may not be completely generalizable to smoke exposure determinations in naturalistic settings. |
Invasive meningococcal disease due to nongroupable Neisseria meningitidis - Active Bacterial Core Surveillance Sites, 2011-2016
McNamara LA , Potts CC , Blain A , Topaz N , Apostol M , Alden NB , Petit S , Farley MM , Harrison LH , Triden L , Muse A , Poissant T , Wang X , MacNeil JR . Open Forum Infect Dis 2019 6 (5) ofz190 We characterized 22 meningococcal disease cases due to nongroupable Neisseria meningitidis, a rare cause of invasive disease. Disease presentation and severity were similar to those for serogroupable meningococcal disease. However, 7 (32%) patients had complement deficiency or abnormal complement testing results, highlighting the importance of complement testing for nongroupable cases. |
Postnatally acquired Zika virus disease among children, United States, 2016-2017
Lindsey NP , Porse CC , Potts E , Hyun J , Sandhu K , Schiffman E , Cervantes KB , White JL , Mason K , Owens K , Holsinger C , Fischer M , Staples JE . Clin Infect Dis 2019 70 (2) 227-231 BACKGROUND: The clinical findings among children with postnatally acquired Zika virus disease are not well characterized. We describe and compare clinical signs and symptoms for children aged <18 years. METHODS: Zika virus disease cases were included if they met the national surveillance case definition, had illness onset in 2016 or 2017, resided in a participating state, and were reported to CDC. Pediatric cases were aged <18 years; congenital and perinatal infections were excluded. Pediatric cases were matched to adult cases (1849 years). Clinical information was compared between younger and older pediatric cases and between children and adults. RESULTS: A total of 141 pediatric Zika virus disease cases were identified; none experienced neurologic disease. Overall, 28 (20%) were treated in an emergency department, 1 (<1%) was hospitalized; none died. Of the four primary clinical signs and symptoms associated with Zika virus disease, 133 (94%) children had rash, 104 (74%) fever, 67 (48%) arthralgia, and 51 (36%) conjunctivitis. Fever, arthralgia, and myalgia were more common in older children (1217 years) than younger children (111 years). Arthralgia, arthritis, edema, and myalgia were more common in adults compared to children. CONCLUSIONS: This report supports previous findings that Zika virus disease is generally mild in children. The most common symptoms are similar to other childhood infections, and clinical findings and outcomes are similar to those in adults. Healthcare providers should consider a diagnosis of Zika virus infection in children with fever, rash, arthralgia, or conjunctivitis, who reside in or have traveled to an area where Zika virus transmission is occurring. |
Whole genome sequencing to characterize capsule locus and predict serogroup of invasive meningococcal isolates.
Marjuki H , Topaz N , Rodriguez-Rivera LD , Ramos E , Potts CC , Chen A , Retchless AC , Doho GH , Wang X . J Clin Microbiol 2018 57 (3) Invasive meningococcal disease is mainly caused by Neisseria meningitidis (Nm) serogroups A, B, C, X, W and Y. Serogroup is typically determined by slide agglutination serogrouping (SASG) and real-time PCR (rt-PCR). We describe a whole-genome sequencing (WGS)-based method to characterize the capsule polysaccharide synthesis (cps) locus, classify Nm serogroups, and identify mechanisms for nongroupability using 453 isolates from a global strain collection. We identified novel genomic organizations within functional cps loci, consisting of insertion-sequence (IS) elements in unique positions that did not disrupt the coding sequence. Genetic mutations (partial gene deletion, missing genes, IS insertion, internal stop, and phase variable off) that led to nongroupability were identified. WGS and SASG were in 91-100% agreement for all serogroups, while WGS and rt-PCR showed 99-100% agreement. Among isolates determined nongroupable by WGS (31 of 453), all three methods agreed 100% for those without a capsule polymerase gene. However, 61% (WGS vs. SASG) and 36% (WGS vs. rt-PCR) agreements were observed for isolates particularly with phase variations or internal stops in cps loci, which warrant further characterization by additional tests. Our WGS-based serogrouping method provides comprehensive characterization of the Nm capsule, which is critical for meningococcal surveillance and outbreak investigations. |
Outbreak of Neisseria meningitidis serogroup C outside the meningitis belt-Liberia, 2017: an epidemiological and laboratory investigation.
Bozio CH , Vuong J , Dokubo EK , Fallah MP , McNamara LA , Potts CC , Doedeh J , Gbanya M , Retchless AC , Patel JC , Clark TA , Kohar H , Nagbe T , Clement P , Katawera V , Mahmoud N , Djingarey HM , Perrocheau A , Naidoo D , Stone M , George RN , Williams D , Gasasira A , Nyenswah T , Wang X , Fox LM . Lancet Infect Dis 2018 18 (12) 1360-1367 BACKGROUND: On April 25, 2017, a cluster of unexplained illnesses and deaths associated with a funeral was reported in Sinoe County, Liberia. Molecular testing identified Neisseria meningitidis serogroup C (NmC) in specimens from patients. We describe the epidemiological investigation of this cluster and metagenomic characterisation of the outbreak strain. METHODS: We collected epidemiological data from the field investigation and medical records review. Confirmed, probable, and suspected cases were defined on the basis of molecular testing and signs or symptoms of meningococcal disease. Metagenomic sequences from patient specimens were compared with 141 meningococcal isolate genomes to determine strain lineage. FINDINGS: 28 meningococcal disease cases were identified, with dates of symptom onset from April 21 to April 30, 2017: 13 confirmed, three probable, and 12 suspected. 13 patients died. Six (21%) patients reported fever and 23 (82%) reported gastrointestinal symptoms. The attack rate for confirmed and probable cases among funeral attendees was 10%. Metagenomic sequences from six patient specimens were similar to a sequence type (ST) 10217 (clonal complex [CC] 10217) isolate genome from Niger, 2015. Multilocus sequencing identified five of seven alleles from one specimen that matched ST-9367, which is represented in the PubMLST database by one carriage isolate from Burkina Faso, in 2011, and belongs to CC10217. INTERPRETATION: This outbreak featured high attack and case fatality rates. Clinical presentation was broadly consistent with previous meningococcal disease outbreaks, but predominance of gastrointestinal symptoms was unusual compared with previous African meningitis epidemics. The outbreak strain was genetically similar to NmC CC10217, which caused meningococcal disease outbreaks in Niger and Nigeria. CC10217 had previously been identified only in the African meningitis belt. FUNDING: US Global Health Security. |
Work practices and respiratory health status of Appalachian coal miners with progressive massive fibrosis
Reynolds LE , Blackley DJ , Colinet JF , Potts JD , Storey E , Short C , Carson R , Clark KA , Laney AS , Halldin CN . J Occup Environ Med 2018 60 (11) e575-e581 OBJECTIVE: To characterize workplace practices and respiratory health among coal miners with large opacities consistent with progressive massive fibrosis (PMF) who received care at a federally-funded black lung clinic network in Virginia. METHODS: Participants were interviewed about their workplace practices and respiratory health. Medical records were reviewed. RESULTS: Nineteen former coal miners were included. Miners reported cutting rock, working downwind of dust-generating equipment, non-adherence to mine ventilation plans (including dust controls), improper sampling of respirable coal mine dust exposures, working after developing respiratory illness, and suffering from debilitating respiratory symptoms. CONCLUSIONS: Consistent themes of suboptimal workplace practices contributing to development of PMF emerged during the interviews. Some of the practices reported were unsafe and unacceptable. Further research is needed to determine the prevalence of these factors and how best to address them. |
Population structure of invasive Neisseria meningitidis in the United States, 2011-15.
Potts CC , Joseph SJ , Chang HY , Chen A , Vuong J , Hu F , Jenkins LT , Schmink S , Blain A , MacNeil JR , Harrison LH , Wang X . J Infect 2018 77 (5) 427-434 OBJECTIVES: Meningococcal conjugate vaccines (MenACWY) were licensed in the United States in 2005. We assessed the population structure of invasive Neisseria meningitidis (Nm) ten years after recommended use of MenACWY among adolescents. METHODS: Meningococcal isolates obtained through Active Bacterial Core surveillance (ABCs) from 2000-05, 2006-10, and 2011-15 underwent whole genome or Sanger sequencing. Genome phylogenies were completed using maximum likelihood methods; and distribution of multilocus sequence typing (MLST) sequence type (ST) and clonal complex (CC), and PorA and FetA types were assessed. RESULTS: Prevalent serogroups (B, C, Y and W), CCs, and PorA and FetA types were detected in all three time periods, but dynamic changes were observed. The proportion of serogroup W CC11 isolates increased in 2011-15 and were most related to South American strains. Changes in CC distribution were also observed in serogroup C and serogroup Y. Phylogenetic analysis showed that U.S. serogroup W CC11s are closely related to a subset of U.S. serogroup C isolates; combined global analysis demonstrated that some CCs, including CC11, exhibit regional clustering. CONCLUSIONS: Overall, the Nm population structure has remained stable after MenACWY introduction. Dynamic changes in genotypes, unlikely related to vaccination, also occurred, highlighting the need for continued whole genome-based surveillance. |
Dust control by air-blocking shelves and dust collector-to-bailing airflow ratios for a surface mine drill shroud
Zheng Y , Reed WR , Potts JD , Li M , Rider JP . Min Eng 2018 70 (5) 69-74 The National Institute for Occupational Safety and Health (NIOSH) recently developed a series of validated models utilizing computational fluid dynamics (CFD) to study the effects of air-blocking shelves on airflows and respirable dust distribution associated with medium-sized surface blasthole drill shrouds as part of a dry dust collector system. Using validated CFD models, three different air-blocking shelves were included in the present study: a 15.2-cm (6-in.)-wide shelf; a 7.6-cm (3-in.)-wide shelf; and a 7.6-cm (3-in.)-wide shelf at four different shelf heights. In addition, the dust-collector-to-bailing airflow ratios of 1.75:1, 1.5:1, 1.25:1 and 1:1 were evaluated for the 15.2-cm (6-in.)-wide air-blocking shelf. This paper describes the methodology used to develop the CFD models. The effects of air-blocking shelves and dust collector-to-bailing airflow ratios were identified by the study, and problem regions were revealed under certain conditions. © 2018 Society for Mining, Metallurgy and Exploration. All rights reserved. |
Rapid laboratory identification of Neisseria meningitidis serogroup C as the cause of an outbreak - Liberia, 2017
Patel JC , George J , Vuong J , Potts CC , Bozio C , Clark TA , Thomas J , Schier J , Chang A , Waller JL , Diaz MH , Whaley M , Jenkins LT , Fuller S , Williams DE , Redd JT , Arthur RR , Taweh F , Vera Walker Y , Hardy P , Freeman M , Katawera V , Gwesa G , Gbanya MZ , Clement P , Kohar H , Stone M , Fallah M , Nyenswah T , Winchell JM , Wang X , McNamara LA , Dokubo EK , Fox LM . MMWR Morb Mortal Wkly Rep 2017 66 (42) 1144-1147 On April 25, 2017, a cluster of unexplained illness and deaths among persons who had attended a funeral during April 21-22 was reported in Sinoe County, Liberia (1). Using a broad initial case definition, 31 cases were identified, including 13 (42%) deaths. Twenty-seven cases were from Sinoe County (1), and two cases each were from Grand Bassa and Monsterrado counties, respectively. On May 5, 2017, initial multipathogen testing of specimens from four fatal cases using the Taqman Array Card (TAC) assay identified Neisseria meningitidis in all specimens. Subsequent testing using direct real-time polymerase chain reaction (PCR) confirmed N. meningitidis in 14 (58%) of 24 patients with available specimens and identified N. meningitidis serogroup C (NmC) in 13 (54%) patients. N. meningitidis was detected in specimens from 11 of the 13 patients who died; no specimens were available from the other two fatal cases. On May 16, 2017, the National Public Health Institute of Liberia and the Ministry of Health of Liberia issued a press release confirming serogroup C meningococcal disease as the cause of this outbreak in Liberia. |
Smoking behavior and exposure: Results of a menthol cigarette cross-over study
Watson CV , Richter P , de Castro BR , Sosnoff C , Potts J , Clark P , McCraw J , Yan X , Chambers D , Watson C . Am J Health Behav 2017 41 (3) 309-319 OBJECTIVE: Our objective was to improve understanding of the differences in use behavior and exposure when smoking menthol and non-menthol cigarettes using a 2-part cross-over design. METHODS: Adult daily smokers were assigned randomly to alternate between 2 weeks of exclusively smoking a menthol test cigarette or a non-menthol test cigarette. Urine and saliva were collected for biomarker measurements; carbon monoxide (CO) was measured, and participants smoked test cigarettes through a CreSS(R) smoking topography device during 3 clinic visits. Participants turned in their cigarette butts from the test periods for determination of mouth level nicotine and completed subjective questionnaires related to the test cigarettes. RESULTS: Regardless of cigarette preference, participants had higher salivary cotinine when smoking the non-menthol test cigarette, but there were no significant differences detected in urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol between the 2 test cigarettes. Mouth level nicotine, puff volume, and puff duration were significantly higher when smoking the menthol brand. Both menthol and non-menthol smokers reported significantly lower enjoyment and satisfaction scores for test cigarettes compared with their brand of choice. CONCLUSIONS: Our results suggest that mentholation has an effect on measures of smoking behavior and that mouth level nicotine is a useful indicator of between-brand smoke exposure. |
Influence of continuous mining arrangements on respirable dust exposures
Beck TW , Organiscak JA , Pollock DE , Potts JD , Reed WR . Trans Soc Min Metall Explor Inc 2016 340 (1) 1-10 In underground continuous mining operations, ventilation, water sprays and machine-mounted flooded-bed scrubbers are the primary means of controlling respirable dust exposures at the working face. Changes in mining arrangements - such as face ventilation configuration, orientation of crosscuts mined in relation to the section ventilation and equipment operator positioning - can have impacts on the ability of dust controls to reduce occupational respirable dust exposures. This study reports and analyzes dust concentrations measured by the Pittsburgh Mining Research Division for remote-controlled continuous mining machine operators as well as haulage operators at 10 U.S. underground mines. The results of these respirable dust surveys show that continuous miner exposures varied little with depth of cut but are significantly higher with exhaust ventilation. Haulage operators experienced elevated concentrations with blowing face ventilation. Elevated dust concentrations were observed for both continuous miner operators and haulage operators when working in crosscuts driven into or counter to the section airflow. Individual cuts are highlighted to demonstrate instances of minimal and excessive dust exposures attributable to particular mining configurations. These findings form the basis for recommendations for lowering face worker respirable dust exposures. |
What have we learned from collaborative partnerships to concomitantly improve both education and health?
Kolbe LJ , Allensworth DD , Potts-Datema W , White DR . J Sch Health 2015 85 (11) 766-74 BACKGROUND: Collaborative partnerships are an essential means to concomitantly improve both education outcomes and health outcomes among K-12 students. METHODS: We describe examples of contemporaneous, interactive, and evolving partnerships that have been implemented, respectively, by a national governmental health organization, national nongovernmental education and health organizations, a state governmental education organization, and a local nongovernmental health organization that serves partner schools. RESULTS: Each of these partnerships strategically built operational infrastructures that enabled partners to efficiently combine their resources to improve student education and health. CONCLUSIONS: To implement a Whole School, Whole Community, Whole Child Framework, we need to purposefully strengthen, expand, and interconnect national, state, and local collaborative partnerships and supporting infrastructures that concomitantly can improve both education and health. |
The Whole School, Whole Community, Whole Child model: a new approach for improving educational attainment and healthy development for students
Lewallen TC , Hunt H , Potts-Datema W , Zaza S , Giles W . J Sch Health 2015 85 (11) 729-39 BACKGROUND: The Whole Child approach and the coordinated school health (CSH) approach both address the physical and emotional needs of students. However, a unified approach acceptable to both the health and education communities is needed to assure that students are healthy and ready to learn. METHODS: During spring 2013, the ASCD (formerly known as the Association for Supervision and Curriculum Development) and the US Centers for Disease Control and Prevention (CDC) convened experts from the field of education and health to discuss lessons learned from implementation of the CSH and Whole Child approaches and to explore the development of a new model that would incorporate the knowledge gained through implementation to date. RESULTS: As a result of multiple discussions and review, the Whole School, Whole Community, Whole Child (WSCC) approach was developed. The WSCC approach builds upon the traditional CSH model and ASCD's Whole Child approach to learning and promotes greater alignment between health and educational outcomes. CONCLUSION: By focusing on children and youth as students, addressing critical education and health outcomes, organizing collaborative actions and initiatives that support students, and strongly engaging community resources, the WSCC approach offers important opportunities that will improve educational attainment and healthy development for students. |
Nicotine delivery and pharmacologic response from Verve, an oral nicotine delivery product
Koszowski B , Viray LC , Stanfill SB , Lisko JG , Rosenberry ZR , Potts JL , Pickworth WB . Pharmacol Biochem Behav 2015 136 1-6 Verve, an oral nicotine delivery product (ONDP), was introduced by Nu Mark (Altria Client Group, Richmond VA) for smokers to use in places where smoking is prohibited. This study assessed the effect of this ONDP on plasma nicotine levels, heart rate, product satisfaction, and ability to suppress smoking urge and cigarette cravings. Thirteen daily cigarette smokers [8 men and 5 women; average age 33.4years] attended two laboratory sessions, one occurred after overnight tobacco abstinence. Plasma samples were collected before and after ONDP use and measured for nicotine. In non-abstinent smokers, mean plasma nicotine levels increased from 18.3 to 21.0ng/mL. In abstinent smokers, average nicotine levels increased from 3.1 to 4.5ng/mL. After overnight tobacco abstinence, ONDP use significantly (p<0.01) increased heart rate from 69 beats per minute (bpm) to 75bpm; while urge to smoke decreased significantly (p<0.01) from a score of 8.6 to 4.9. Participants indicated moderate product satisfaction that was not changed by tobacco abstinence. Analysis of unused ONDP revealed total nicotine levels of 1.68+/-0.09mg/disc. Spent ONDP discs were also analyzed to determine % nicotine liberated during chewing; results were 80% in the non-abstinent and 82% in the abstinent conditions (ns). Our study results indicate ONDP use can increase plasma nicotine levels and heart rate and reduce cigarette cravings in abstinent smokers. |
Field evaluation of air-blocking shelf for dust control on blasthole drills
Potts JD , Reed WR . Int J Min Reclam Environ 2011 25 (1) 32-40 In previous studies, an air-blocking shelf has been shown to be successful in reducing respirable dust leakage from the drill shroud in a laboratory setting. Dust reductions of up to 81% were achieved with the shelf under operating conditions consisting of a 1.9:1 collector-to-bailing airflow ratio and a 5.1-cm gap between the shroud and ground. Recent research focused on evaluating the shelf on two actual operating blasthole drills, in much more severe environments. In the field, the shelf reduced dust levels in the areas surrounding one operating blasthole drill by 70%. Dust reductions measured in the immediate vicinity of the shroud were reduced by 66% at one mine and 81% at the other mine. These field tests confirm that the air-blocking shelf is useful for reducing respirable dust generation from blasthole drills. |
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