Last data update: May 20, 2024. (Total: 46824 publications since 2009)
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Notes from the field: Campylobacteriosis outbreak associated with consumption of raw water - Montana, 2022
Hinnenkamp R , Sorenson S , Evanson E , Yoder J , Mattioli M . MMWR Morb Mortal Wkly Rep 2023 72 (15) 411-412 Consumption of raw water (water that has not been disinfected or filtered) has become an emerging trend in the United States and could pose serious health consequences (1). Drinking water collected directly from outdoor freshwater sources such as lakes, rivers, and streams that has not been adequately treated (i.e., to remove pathogens) can cause disease and outbreaks (2). This report describes how a community in Western Montana responded to an outbreak of 19 cases of diarrheal illness associated with consuming untreated surface water. | | On May 9, 2022, Sanders County, Montana, reported to the state health department six active cases of Campylobacter infection in their community; this case count represented a substantial increase above the 5-year average of six reported cases annually during 2017–2021. All infected persons reported drinking water from watering point A, an outlet of surface water from a creek near Paradise, Montana (Figure), before their onset of symptoms, which began on or after May 4. During the next 6 weeks, 13 additional cases of Campylobacter jejuni infection among persons exposed to the same water source were identified through laboratory testing (two by culture-independent confirmation and four by culture confirmation) or epidemiologic linkage (seven). One person was hospitalized, and no deaths were reported. |
Persistence of Human Norovirus (GII) in Surface Water: Decay Rate Constants and Inactivation Mechanisms.
Kennedy LC , Costantini VP , Huynh KA , Loeb SK , Jennings WC , Lowry S , Mattioli MC , Vinjé J , Boehm AB . Environ Sci Technol 2023 57 (9) 3671-3679 Human norovirus (HuNoV) is an important cause of acute gastroenteritis and can be transmitted by water exposures, but its persistence in water is not well understood. Loss of HuNoV infectivity in surface water was compared with persistence of intact HuNoV capsids and genome segments. Surface water from a freshwater creek was filter-sterilized, inoculated with HuNoV (GII.4) purified from stool, and incubated at 15 or 20 °C. We measured HuNoV infectivity via the human intestinal enteroid system and HuNoV persistence via reverse transcription-quantitative polymerase chain reaction assays without (genome segment persistence) or with (intact viral capsid persistence) enzymatic pretreatment to digest naked RNA. For infectious HuNoV, results ranged from no significant decay to a decay rate constant ("k") of 2.2 day(-1). In one creek water sample, genome damage was likely a dominant inactivation mechanism. In other samples from the same creek, loss of HuNoV infectivity could not be attributed to genome damage or capsid cleavage. The range in k and the difference in the inactivation mechanism observed in water from the same site could not be explained, but variable constituents in the environmental matrix could have contributed. Thus, a single k may be insufficient for modeling virus inactivation in surface waters. |
Cyanobacteria growth in nitrogen- & phosphorus-spiked water from a hypereutrophic reservoir in Kentucky, USA
Hughes SE , Marion JW . J Environ Prot 2021 12 (2) 75-89 Cyanobacteria may adversely impact aquatic ecosystems through oxygen depletion and cyanotoxin production. These cyanotoxins can also harm human health and livestock. In recent years, cyanobacterial blooms have been observed in several drinking water reservoirs in Kentucky, United States. In Kentucky, the paradigm is that phosphorous is the limiting nutrient for cyanobacteria growth. To explore this paradigm, an indoor microcosm study was conducted using hypereutrophic Guist Creek Lake water. Samples were collected and spiked with various combinations of locally used agricultural grade fertilizers, including ammonium nitrate, urea, and triple phosphate (calcium dihydrogen phosphate). Samples were incubated indoors for the photoperiod-specific to the time of the year. Cyanobacteria density, measured by phycocyanin, did not demonstrate increased growth with the addition of phosphate fertilizer alone. Cyanobacteria growth was enhanced in these conditions by the combined addition of ammonium nitrate, urea, and phosphorus fertilizer. Growth also occurred when using either ammonium nitrate or urea fertilizer with no additional phosphorus input, suggesting that phosphorus was not limiting the cyanobacteria at the time of sample collection. The addition of both nitrogen fertilizers (ammonium nitrate and urea) at the concentrations used in this study, in the absence of phosphorus, was deleterious to both the Chlorophyta and cyanobacteria. The results suggest further studies using more robust experimental designs are needed to explore lake-specific dual nutrient management strategies for preventing cyanobacterial blooms in this phosphorus-rich hypereutrophic lake and possibly other hypereutrophic lakes. |
Detection of Cyclospora cayetanensis in produce irrigation and wash water using large-volume sampling techniques
Kahler AM , Mattioli MC , da Silva AJ , Hill V . Food Waterborne Parisitol 2021 22 e00110 The recent increase of reported cyclosporiasis outbreaks associated with fresh produce has highlighted the need for understanding environmental transmission of Cyclospora cayetanensis in agricultural settings and facilities. Conducting such environmental investigations necessitates robust sample collection and analytical methods to detect C. cayetanensis in water samples. This study evaluated three sample collection methods for recovery of C. cayetanensis oocysts from water samples during seeded recovery experiments. Two filtration-based methods, dead-end ultrafiltration (DEUF) and USEPA Method 1623.1, were evaluated for oocyst recovery from irrigation water. A non-filter-based method, continuous flow centrifugation (CFC), was evaluated separately for recovery from creek water and spent produce wash water. Median C. cayetanensis recovery efficiencies were 17% for DEUF and 16–22% for Method 1623.1. The DEUF method proved to be more robust than Method 1623.1, as the recovery efficiencies were less variable and the DEUF ultrafilters were capable of filtering larger volumes of high-turbidity water without clogging. Median C. cayetanensis recovery efficiencies for CFC were 28% for wash water and 63% for creek water, making it a viable option for processing water with high turbidity or organic matter. The data from this study demonstrate the capability of DEUF and CFC as filter-based and non-filter-based options, respectively, for the recovery of C. cayetanensis oocysts from environmental and agricultural waters. |
Biomonitoring of populations in Western New York at risk for exposure to Great Lakes contaminants
Savadatti SS , Liu M , Caglayan C , Reuther J , Lewis-Michl EL , Aldous KM , Parsons PJ , Kannan K , Rej R , Wang W , Palmer CD , Steuerwald AJ , Wattigney WA , Irvin-Barnwell E , Hwang SA . Environ Res 2019 179 108690 The New York State Department of Health conducted the Healthy Fishing Communities Program in collaboration with the Agency for Toxic Substances and Disease Registry to assess human exposure to contaminants common to Lake Ontario, Lake Erie and surrounding rivers and waterways among populations in western New York State who eat locally caught fish. The program enrolled licensed anglers and Burmese refugees and immigrants, living near four designated Great Lakes Areas of Concern: Buffalo River, Niagara River, Eighteenmile Creek, and the Rochester Embayment. These target populations were sampled and enrolled independently into the program between February and October of 2013. A core set of contaminants were measured in blood and urine of 409 licensed anglers and 206 Burmese refugees and immigrants which included lead, cadmium, mercury, PCBs, PBDEs, organochlorine pesticides (hexachlorobenzene, mirex, DDT, DDE, and chlordane and its metabolites oxychlordane and trans-Nonachlor), and PFOS and PFOA. Biomonitoring results showed that both groups had higher geometric means for blood lead, total blood mercury, and serum PFOS compared to the 2013-2014 NHANES reference levels. The Burmese refugee group also showed higher geometric means for creatinine-adjusted urine mercury and lipid-adjusted serum DDE compared to national levels. Licensed angler participants reported eating a median of 16 locally caught fish meals in the past year. Burmese participants consumed local fish throughout the year, and most frequently in the summer (median 39 fish meals or 3 times a week). The study results provide valuable information on populations at high risk of exposure to contaminants in the Great Lakes Basin of western New York. The results provide the foundation for developing and implementing public health actions to reduce potential exposures to Great Lakes pollutants. |
Salmonella enterica serotype Newport infections in the United States, 2004-2013: Increased incidence investigated through four surveillance systems
Crim SM , Chai SJ , Karp BE , Judd MC , Reynolds J , Swanson KC , Nisler A , McCullough A , Gould LH . Foodborne Pathog Dis 2018 15 (10) 612-620 Newport is the third most common Salmonella enterica serotype identified among the estimated 1.2 million human salmonellosis infections occurring annually in the United States. Risk factors for infection and food items implicated in outbreaks vary by antimicrobial resistance pattern. We conducted a descriptive analysis of data from four enteric disease surveillance systems capturing information on incidence, demographics, seasonality, geographic distribution, outbreaks, and antimicrobial resistance of Newport infections over a 10-year period from 2004 through 2013. Incidence increased through 2010, then declined to rates similar to those in the early years of the study. Incidence was highest in the South and among children <5 years old. Among isolates submitted for antimicrobial susceptibility testing, 88% were susceptible to all antimicrobials tested (pansusceptible) and 8% were resistant to at least seven agents, including ceftriaxone. Rates of pansusceptible isolates were also highest in the South and among young children, particularly in 2010. Pansusceptible strains of Newport have been associated with produce items and environmental sources, such as creek water and sediment. However, the role of environmental transmission of Newport in human illness is unclear. Efforts to reduce produce contamination through targeted legislation, as well as collaborative efforts to identify sources of contamination in agricultural regions, are underway. |
Prevalence and diversity of tick-borne pathogens in nymphal Ixodes scapularis (Acari: Ixodidae) in eastern National Parks
Johnson TL , Graham CB , Boegler KA , Cherry CC , Maes SE , Pilgard MA , Hojgaard A , Buttke DE , Eisen RJ . J Med Entomol 2016 54 (3) 742-751 Tick-borne pathogens transmitted by Ixodes scapularis Say (Acari: Ixodidae), also known as the deer tick or blacklegged tick, are increasing in incidence and geographic distribution in the United States. We examined the risk of tick-borne disease exposure in 9 national parks across six Northeastern and Mid-Atlantic States and the District of Columbia in 2014 and 2015. To assess the recreational risk to park visitors, we sampled for ticks along frequently used trails and calculated the density of I. scapularis nymphs (DON) and the density of infected nymphs (DIN). We determined the nymphal infection prevalence of I. scapularis with a suite of tick-borne pathogens including Borrelia burgdorferi, Borrelia miyamotoi, Anaplasma phagocytophilum, and Babesia microti Ixodes scapularis nymphs were found in all national park units; DON ranged from 0.40 to 13.73 nymphs per 100 m2 Borrelia burgdorferi, the causative agent of Lyme disease, was found at all sites where I. scapularis was documented; DIN with B. burgdorferi ranged from 0.06 to 5.71 nymphs per 100 m2 Borrelia miyamotoi and A. phagocytophilum were documented at 60% and 70% of the parks, respectively, while Ba. microti occurred at just 20% of the parks. Ixodes scapularis is well established across much of the Northeastern and Mid-Atlantic States, and our results are generally consistent with previous studies conducted near the areas we sampled. Newly established I. scapularis populations were documented in two locations: Washington, D.C. (Rock Creek Park) and Greene County, Virginia (Shenandoah National Park). This research demonstrates the potential risk of tick-borne pathogen exposure in national parks and can be used to educate park visitors about the importance of preventative actions to minimize tick exposure. |
Population pharmacokinetics and pharmacodynamics of lumefantrine in young Ugandan children treated with artemether-lumefantrine for uncomplicated malaria
Tchaparian E , Sambol NC , Arinaitwe E , McCormack SA , Bigira V , Wanzira H , Muhindo M , Creek DJ , Sukumar N , Blessborn D , Tappero JW , Kakuru A , Bergqvist Y , Aweeka FT , Parikh S . J Infect Dis 2016 214 (8) 1243-51 BACKGROUND: The pharmacokinetics and pharmacodynamics of lumefantrine, a component of the most widely-used treatment for malaria, artemether-lumefantrine, has not been adequately characterized in young children. METHODS: Capillary whole blood was collected in 105 Ugandan children, ages 6 months to 2 years, treated for 249 episodes of Plasmodium falciparum malaria with artemether-lumefantrine. RESULTS: Population pharmacokinetics for lumefantrine employed a 2-compartment open model with first-order absorption. Age had a significant positive correlation with bioavailability in a model that included allometric scaling. Children not on trimethoprim-sulfamethoxazole with concentrations below 200 ng/mL had a 3-fold higher hazard of 28-day recurrent parasitemia compared to those above 200 ng/mL(p=0.0007). However, for children on trimethoprim-sulfamethoxazole, the risk of recurrent parasitemia did not differ significantly based on this threshold. Day 3 concentrations were a stronger predictor of 28-day recurrence than day 7 concentrations. CONCLUSIONS: We demonstrate that age, in addition to weight, is a determinant of lumefantrine exposure, and in the absence of TS, lumefantrine exposure is a determinant of recurrent parasitemia. Exposure in children 6 months to 2 years was generally lower than those published for older children and adults. Further refinement of artemether-lumefantrine dosing to improve exposure in infants and very young children may be warranted. |
Population Pharmacokinetics of Piperaquine in Young Ugandan Children Treated With Dihydroartemisinin-Piperaquine for Uncomplicated Malaria
Sambol NC , Yan L , Creek DJ , McCormack SA , Arinaitwe E , Bigira V , Wanzira H , Kakuru A , Tappero JW , Lindegardh N , Tarning J , Nosten F , Aweeka FT , Parikh S . Clin Pharmacol Ther 2015 98 (1) 87-95 This prospective trial investigated the population pharmacokinetics of piperaquine given with dihydroartemisinin to treat uncomplicated malaria in 107 Ugandan children 6 months to 2 years old, an age group previously unstudied. Current weight-based dosing does not adequately address physiological changes in early childhood. Patients were administered standard 3-day oral doses and provided 1,282 capillary plasma concentrations from 218 malaria episodes. Less than 30% of treatments achieved 57 ng/mL on day 7. A three-compartment model with first-order absorption described the data well. Age had a statistically significant effect (P < 0.005) on clearance/bioavailability in a model that accounts for allometric scaling. Simulations demonstrated that higher doses in all children, but especially in those with lower weight for age, are required for adequate piperaquine exposure, although safety and tolerance will need to be established. These findings support other evidence that both weight- and age-specific guidelines for piperaquine dosing in children are urgently needed. |
Analysis of gob gas venthole production performances for strata gas control in longwall mining
Karacan CO . Int J Rock Mech Min Sci 2015 79 9-18 Longwall mining of coal seams affects a large area of overburden by deforming it and creating stress-relief fractures, as well as bedding plane separations, as the mining face progresses. Stress-relief fractures and bedding plane separations are recognized as major pathways for gas migration from gas-bearing strata into sealed and active areas of the mines. In order for strata gas not to enter and inundate the ventilation system of a mine, gob gas ventholes (GGVs) can be used as a methane control measure. The aim of this paper is to analyze production performances of GGVs drilled over a longwall panel. These boreholes were drilled to control methane emissions from the Pratt group of coals due to stress-relief fracturing and bedding plane separations into a longwall mine operating in the Mary Lee/Blue Creek coal seam of the Upper Pottsville Formation in the Black Warrior Basin, Alabama. During the course of the study, Pratt coal's reservoir properties were integrated with production data of the GGVs. These data were analyzed by using material balance techniques to estimate radius of influence of GGVs, gas-in-place and coal pressures, as well as their variations during mining.The results show that the GGVs drilled to extract gas from the stress-relief zone of the Pratt coal interval is highly effective in removing gas from the Upper Pottsville Formation. The radii of influence of the GGVs were in the order of 330-380. m, exceeding the widths of the panels, due to bedding plane separations and stress relieved by fracturing. Material balance analyses indicated that the initial pressure of the Pratt coals, which was around 648. KPa when longwall mining started, decreased to approximately 150. KPa as the result of strata fracturing and production of released gas. Approximately 70% of the initial gas-in-place within the area of influence of the GGVs was captured during a period of one year. |
Assessment of emergency responders after a vinyl chloride release from a train derailment - New Jersey, 2012
Brinker K , Lumia M , Markiewicz KV , Duncan MA , Dowell C , Rey A , Wilken J , Shumate A , Taylor J , Funk R . MMWR Morb Mortal Wkly Rep 2015 63 (53) 1233-7 On November 30, 2012, at approximately 7:00 am, a freight train derailed near a small town in New Jersey. Four tank cars, including a breached tank car carrying vinyl chloride, landed in a tidal creek. Vinyl chloride, a colorless gas with a mild, sweet odor, is used in plastics manufacture. Acute exposure can cause respiratory irritation and headache, drowsiness, and dizziness; chronic occupational exposure can result in liver damage, accumulation of fat in the liver, and tumors (including angiosarcoma of the liver). Because health effects associated with acute exposures have not been well studied, the New Jersey Department of Health requested assistance from the Agency for Toxic Substances and Disease Registry (ATSDR) and CDC. On December 11, teams from these agencies deployed to assist the New Jersey Department of Health in conducting an assessment of exposures in the community as well as the occupational health and safety of emergency personnel who responded to the incident. This report describes the results of the investigation of emergency personnel. A survey of 93 emergency responders found that 26% of respondents experienced headache and upper respiratory symptoms during the response. A minority (22%) reported using respiratory protection during the incident. Twenty-one (23%) of 92 respondents sought medical evaluation. Based on these findings, CDC recommended that response agencies 1) implement the Emergency Responder Health Monitoring and Surveillance (ERHMS) system for ongoing health monitoring of the emergency responders involved in the train derailment response and 2) ensure that in future incidents, respiratory protection is used when exposure levels are unknown or above the established occupational exposure limits. |
Inference of strata separation and gas emission paths in longwall overburden using continuous wavelet transform of well logs and geostatistical simulation
Karacan CO , Olea RA . J Appl Geophy 2014 105 147-158 Prediction of potential methane emission pathways from various sources into active mine workings or sealed gobs from longwall overburden is important for controlling methane and for improving mining safety. The aim of this paper is to infer strata separation intervals and thus gas emission pathways from standard well log data. The proposed technique was applied to well logs acquired through the Mary Lee/Blue Creek coal seam of the Upper Pottsville Formation in the Black Warrior Basin, Alabama, using well logs from a series of boreholes aligned along a nearly linear profile.For this purpose, continuous wavelet transform (CWT) of digitized gamma well logs was performed by using Mexican hat and Morlet, as the mother wavelets, to identify potential discontinuities in the signal. Pointwise Holder exponents (PHE) of gamma logs were also computed using the generalized quadratic variations (GQV) method to identify the location and strength of singularities of well log signals as a complementary analysis. PHEs and wavelet coefficients were analyzed to find the locations of singularities along the logs.Using the well logs in this study, locations of predicted singularities were used as indicators in single normal equation simulation (SNESIM) to generate equi-probable realizations of potential strata separation intervals. Horizontal and vertical variograms of realizations were then analyzed and compared with those of indicator data and training image (TI) data using the Kruskal-Wallis test. A sum of squared differences was employed to select the most probable realization representing the locations of potential strata separations and methane flow paths.Results indicated that singularities located in well log signals reliably correlated with strata transitions or discontinuities within the strata. Geostatistical simulation of these discontinuities provided information about the location and extents of the continuous channels that may form during mining. If there is a gas source within their zone of influence, paths may develop and allow methane movement towards sealed or active gobs under pressure differentials. Knowledge gained from this research will better prepare mine operations for potential methane inflows, thus improving mine safety. |
Twenty-year summary of surveillance for human hantavirus infections, United States
Knust B , Rollin PE . Emerg Infect Dis 2013 19 (12) 1934-7 In the past 20 years of surveillance for hantavirus in humans in the United States, 624 cases of hantavirus pulmonary syndrome (HPS) have been reported, 96% of which occurred in states west of the Mississippi River. Most hantavirus infections are caused by Sin Nombre virus, but cases of HPS caused by Bayou, Black Creek Canal, Monongahela, and New York viruses have been reported, and cases of domestically acquired hemorrhagic fever and renal syndrome caused by Seoul virus have also occurred. Rarely, hantavirus infections result in mild illness that does not progress to HPS. Continued testing and surveillance of clinical cases in humans will improve our understanding of the etiologic agents involved and the spectrum of diseases. |
Time-lapse analysis of methane quantity in the Mary Lee group of coal seams using filter-based multiple-point geostatistical simulation
Karacan OC , Olea RA . Math Geosci 2013 1-24 Coal seam degasification and its success are important for controlling methane, and thus for the health and safety of coal miners. During the course of degasification, properties of coal seams change. Thus, the changes in coal reservoir conditions and in-place gas content as well as methane emission potential into mines should be evaluated by examining time-dependent changes and the presence of major heterogeneities and geological discontinuities in the field. In this work, time-lapsed reservoir and fluid storage properties of the New Castle coal seam, Mary Lee/Blue Creek seam, and Jagger seam of Black Warrior Basin, Alabama, were determined from gas and water production history matching and production forecasting of vertical degasification wellbores. These properties were combined with isotherm and other important data to compute gas-in-place (GIP) and its change with time at borehole locations. Time-lapsed training images (TIs) of GIP and GIP difference corresponding to each coal and date were generated by using these point-wise data and Voronoi decomposition on the TI grid, which included faults as discontinuities for expansion of Voronoi regions. Filter-based multiple-point geostatistical simulations, which were preferred in this study due to anisotropies and discontinuities in the area, were used to predict time-lapsed GIP distributions within the study area. Performed simulations were used for mapping spatial time-lapsed methane quantities as well as their uncertainties within the study area. | The systematic approach presented in this paper is the first time in literature that history matching, TIs of GIPs and filter simulations are used for degasification performance evaluation and for assessing GIP for mining safety. Results from this study showed that using production history matching of coalbed methane wells to determine time-lapsed reservoir data could be used to compute spatial GIP and representative GIP TIs generated through Voronoi decomposition. Furthermore, performing filter simulations using point-wise data and TIs could be used to predict methane quantity in coal seams subjected to degasification. During the course of the study, it was shown that the material balance of gas produced by wellbores and the GIP reductions in coal seams predicted using filter simulations compared very well, showing the success of filter simulations for continuous variables in this case study. Quantitative results from filter simulations of GIP within the studied area briefly showed that GIP was reduced from an initial ∼73 Bcf (median) to ∼46 Bcf (2011), representing a 37 % decrease and varying spatially through degasification. It is forecasted that there will be an additional 2 Bcf reduction in methane quantity between 2011 and 2015. This study and presented results showed that the applied methodology and utilized techniques can be used to map GIP and its change within coal seams after degasification, which can further be used for ventilation design for methane control in coal mines. |
Pharmacokinetic predictors for recurrent malaria after dihydroartemisinin-piperaquine treatment of uncomplicated malaria in Ugandan infants
Creek DJ , Bigira V , McCormack S , Arinaitwe E , Wanzira H , Kakuru A , Tappero JW , Sandison TG , Lindegardh N , Nosten F , Aweeka FT , Parikh S . J Infect Dis 2013 207 (11) 1646-54 BACKGROUND: Although dihydroartemisinin-piperaquine (DP) is used primarily in children, pharmacokinetic/pharmacodynamic (PK/PD) data on DP use in young children are lacking. METHODS: We conducted a prospective PK/PD study of piperaquine in 107 young children in Uganda. Samples were collected up to 28 days after 218 episodes of malaria treatment, which occurred during follow-up periods of up to 5 months. Malaria follow-up was conducted actively to day 28 and passively to day 63. RESULTS: The median capillary piperaquine concentration on day 7 after treatment was 41.9 ng/mL. Low piperaquine concentrations were associated with an increased risk of recurrent malaria for up to 42 days, primarily in those receiving trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis. In children not receiving TMP-SMX, low piperaquine concentrations were only modestly associated with an increased risk of recurrent malaria. However, for children receiving TMP-SMX, associations were strong and evident for all sampling days, with PQ concentrations of ≤27.3 ng/mL on day 7 associated with a greatly increased risk of recurrent malaria. Notably, of 132 cases of recurrent malaria, 119 had detectable piperaquine concentrations at the time of presentation with recurrent malaria. CONCLUSIONS: These piperaquine PK/PD data represent the first in children <2 years of age. Piperaquine exposure on day 7 correlated with an increased risk of recurrent malaria after DP treatment in children receiving TMP-SMX prophylaxis. Interestingly, despite strong associations, infants remained at risk for malaria, even if they had residual levels of piperaquine. |
Integration of vertical and in-seam horizontal well production analyses with stochastic geostatistical algorithms to estimate pre-mining methane drainage efficiency from coal seams: Blue Creek seam, Alabama
Karacan CO . Int J Coal Geol 2013 114 96-113 Coal seam degasification and its efficiency are directly related to the safety of coal mining. Degasification activities in the Black Warrior basin started in the early 1980s by using vertical boreholes. Although the Blue Creek seam, which is part of the Mary Lee coal group, has been the main seam of interest for coal mining, vertical wellbores have also been completed in the Pratt, Mary Lee, and Black Creek coal groups of the Upper Pottsville formation to degasify multiple seams. Currently, the Blue Creek seam is further degasified 2-3 years in advance of mining using in-seam horizontal boreholes to ensure safe mining. The studied location in this work is located between Tuscaloosa and Jefferson counties in Alabama and was degasified using 81 vertical boreholes, some of which are still active. When the current longwall mine expanded its operation into this area in 2009, horizontal boreholes were also drilled in advance of mining for further degasification of only the Blue Creek seam to ensure a safe and a productive operation. This paper presents an integrated study and a methodology to combine history matching results from vertical boreholes with production modeling of horizontal boreholes using geostatistical simulation to evaluate spatial effectiveness of in-seam boreholes in reducing gas-in-place (GIP). Results in this study showed that in-seam wells' boreholes had an estimated effective drainage area of 2050 acres with cumulative production of 604 MMscf methane during ~ 2 years of operation. With horizontal borehole production, GIP in the Blue Creek seam decreased from an average of 1.52 MMscf to 1.23 MMscf per acre. It was also shown that effective gas flow capacity, which was independently modeled using vertical borehole data, affected horizontal borehole production. GIP and effective gas flow capacity of coal seam gas were also used to predict remaining gas potential for the Blue Creek seam. |
Highly active antiretroviral therapy and adverse birth outcomes among HIV-infected women in Botswana
Chen JY , Ribaudo HJ , Souda S , Parekh N , Ogwu A , Lockman S , Powis K , Dryden-Peterson S , Creek T , Jimbo W , Madidimalo T , Makhema J , Essex M , Shapiro RL . J Infect Dis 2012 206 (11) 1695-705 BACKGROUND: It is unknown whether adverse birth outcomes are associated with maternal highly active antiretroviral therapy (HAART) in pregnancy, particularly in resource-limited settings. METHODS: We abstracted obstetrical records at 6 sites in Botswana for 24 months. Outcomes included stillbirths (SBs), preterm delivery (PTD), small for gestational age (SGA), and neonatal death (NND). Among human immunodeficiency virus (HIV)-infected women, comparisons were limited to HAART exposure status at conception, and those with similar opportunities for outcomes. Comparisons were adjusted for CD4(+) lymphocyte cell count. RESULTS: Of 33,148 women, 32,113 (97%) were tested for HIV, of whom 9504 (30%) were HIV infected. Maternal HIV was significantly associated with SB, PTD, SGA, and NND. Compared with all other HIV-infected women, those continuing HAART from before pregnancy had higher odds of PTD (adjusted odds ratio [AOR], 1.2; 95% confidence interval [CI], 1.1, 1.4), SGA (AOR, 1.8; 95% CI, 1.6, 2.1) and SB (AOR, 1.5; 95% CI, 1.2, 1.8). Among women initiating antiretroviral therapy in pregnancy, HAART use (vs zidovudine) was associated with higher odds of PTD (AOR, 1.4; 95% CI, 1.2, 1.8), SGA (AOR, 1.5; 95% CI, 1.2, 1.9), and SB (AOR, 2.5; 95% CI, 1.6, 3.9). Low CD4(+) was independently associated with SB and SGA, and maternal hypertension during pregnancy with PTD, SGA, and SB. CONCLUSIONS: HAART receipt during pregnancy was associated with increased PTD, SGA, and SB. |
Lessons learned during tuberculosis screening in public medical clinics in Francistown, Botswana
Bloss E , Makombe R , Kip E , Smit M , Chirenda J , Gammino VM , Creek T , Oeltmann JE . Int J Tuberc Lung Dis 2012 16 (8) 1030-2 In Botswana, where one quarter of the adult population is infected with the human immunodeficiency virus and the annual tuberculosis (TB) incidence is among the highest globally, intensified TB case finding is needed in health care facilities to detect and treat TB cases early and prevent transmission. During August-December 2009, TB screening was implemented among adults at patient intake in five clinics in Francistown. Among 11,779 TB screenings at intake, 926 were positive. Nineteen patients were diagnosed with TB. Routine TB screening at intake was operationally feasible, but had low yield. Innovative case-finding strategies are needed in Botswana. |
High prevalence of hypertension and placental insufficiency, but no in utero HIV transmission, among women on HAART with stillbirths in Botswana
Shapiro RL , Souda S , Parekh N , Binda K , Kayembe M , Lockman S , Svab P , Babitseng O , Powis K , Jimbo W , Creek T , Makhema J , Essex M , Roberts DJ . PLoS One 2012 7 (2) e31580 BACKGROUND: Increased stillbirth rates occur among HIV-infected women, but no studies have evaluated the pathological basis for this increase, or whether highly active antiretroviral therapy (HAART) influences the etiology of stillbirths. It is also unknown whether HIV infection of the fetus is associated with stillbirth. METHODS: HIV-infected women and a comparator group of HIV-uninfected women who delivered stillbirths were enrolled at the largest referral hospital in Botswana between January and November 2010. Obstetrical records, including antiretroviral use in pregnancy, were extracted at enrollment. Verbal autopsies; maternal HIV, CD4 and HIV RNA testing; stillbirth HIV PCR testing; and placental pathology (blinded to HIV and treatment status) were performed. RESULTS: Ninety-nine stillbirths were evaluated, including 62 from HIV-infected women (34% on HAART from conception, 8% on HAART started in pregnancy, 23% on zidovudine started in pregnancy, and 35% on no antiretrovirals) and 37 from a comparator group of HIV-uninfected women. Only 2 (3.7%) of 53 tested stillbirths from HIV-infected women were HIV PCR positive, and both were born to women not receiving HAART. Placental insufficiency associated with hypertension accounted for most stillbirths. Placental findings consistent with chronic hypertension were common among HIV-infected women who received HAART and among HIV-uninfected women (65% vs. 54%, p = 0.37), but less common among HIV-infected women not receiving HAART (28%, p = 0.003 vs. women on HAART). CONCLUSIONS: In utero HIV infection was rarely associated with stillbirths, and did not occur among women receiving HAART. Hypertension and placental insufficiency were associated with most stillbirths in this tertiary care setting. |
Health facility characteristics and their relationship to coverage of PMTCT of HIV services across four African countries: the PEARL Study
Ekouevi DK , Stringer E , Coetzee D , Tih P , Creek T , Stinson K , Westfall AO , Welty T , Chintu N , Chi BH , Wilfert C , Shaffer N , Stringer J , Dabis F . PLoS One 2012 7 (1) e29823 BACKGROUND: Health facility characteristics associated with effective prevention of mother-to-child transmission of HIV (PMTCT) coverage in sub-Saharan are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We conducted surveys in health facilities with active PMTCT services in Cameroon, Cote d'Ivoire, South Africa, and Zambia. Data was compiled via direct observation and exit interviews. We constructed composite scores to describe provision of PMTCT services across seven topical areas: antenatal quality, PMTCT quality, supplies available, patient satisfaction, patient understanding of medication, and infrastructure quality. Pearson correlations and Generalized Estimating Equations (GEE) to account for clustering of facilities within countries were used to evaluate the relationship between the composite scores, total time of visit and select individual variables with PMTCT coverage among women delivering. Between July 2008 and May 2009, we collected data from 32 facilities; 78% were managed by the government health system. An opt-out approach for HIV testing was used in 100% of facilities in Zambia, 63% in Cameroon, and none in Cote d'Ivoire or South Africa. Using Pearson correlations, PMTCT coverage (median of 55%, (IQR: 33-68) was correlated with PMTCT quality score (rho = 0.51; p = 0.003); infrastructure quality score (rho = 0.43; p = 0.017); time spent at clinic (rho = 0.47; p = 0.013); patient understanding of medications score (rho = 0.51; p = 0.006); and patient satisfaction quality score (rho = 0.38; p = 0.031). PMTCT coverage was marginally correlated with the antenatal quality score (rho = 0.304; p = 0.091). Using GEE adjustment for clustering, the, antenatal quality score became more strongly associated with PMTCT coverage (p<0.001) and the PMTCT quality score and patient understanding of medications remained marginally significant. CONCLUSIONS/RESULTS: We observed a positive relationship between an antenatal quality score and PMTCT coverage but did not identify a consistent set of variables that predicted PMTCT coverage. |
Case-control study to determine risk factors for diarrhea among children during a large outbreak in a country with a high prevalence of HIV infection
Arvelo W , Kim A , Creek T , Legwaila K , Puhr N , Johnston S , Masunge J , Davis M , Mintz E , Bowen A . Int J Infect Dis 2010 14 (11) e1002-7 OBJECTIVES: Between January and March of 2006, over 35,000 diarrhea cases and 532 deaths were reported among children aged <5 years in Botswana. We conducted an investigation to characterize the outbreak, identify risk factors for diarrhea, and recommend control strategies. METHODS: We enrolled children <5 years of age presenting to the emergency department between March 2 and March 20, 2006. Cases had ≥3 loose stools per day and no antecedent diarrhea among household members. Controls had had no diarrhea since January 1, 2006. We conducted a multivariate logistic regression analysis controlling for socioeconomic status, age, and maternal HIV status. RESULTS: Forty-nine cases with median age of 12 months (range 0-45 months) and 61 controls with median age of 24 months (range 0-59 months) were enrolled; 33 (30%) were born to HIV-positive mothers. Case-parents were more likely to report storing household drinking water (adjusted odds ratios (AOR) 3.9, 95% confidence interval (CI) 1.2-15.7). Lack of hand washing after using the toilet or latrine (AOR 4.2, 95% CI 1.1-20.4) was more likely to be reported by case-parents. Case-children were less likely to be currently breastfeeding (AOR 30.3, 95% CI 2.0-1000.0). Five (10%) case-patients and no control-patients died. Multiple causal pathogens were identified. CONCLUSIONS: During this diarrhea outbreak in a country with a national program to prevent mother-to-child transmission of HIV, ill children were less likely to be breastfed and more likely to have been exposed to environmental factors associated with fecal contamination. These findings underscore the importance of adequate access to safe water, sanitation, hygiene, and nutrition education among populations using breast milk substitutes. |
Pathology of Black Creek Canal virus infection in juvenile hispid cotton rats (Sigmodon hispidus)
Billings AN , Rollin PE , Milazzo ML , Molina CP , Eyzaguirre EJ , Livingstone W , Ksiazek TG , Fulhorst CF . Vector Borne Zoonotic Dis 2010 10 (6) 621-8 The purpose of this study was to assess the effect of inoculum dose on the pathogenesis of Black Creek Canal virus (BCCV) infection in the hispid cotton rat (Sigmodon hispidus), the principal host of BCCV. No sign of illness was observed in any of the 52 juvenile hispid cotton rats inoculated with 3.1, 1.1, -0.9, or -2.9 log(10) median infectious doses(VeroE6) (ID(50-VeroE6)) of BCCV and euthanized on day 9, 18, 27, or 54 postinoculation (PI). Analysis of virus assay and serological data indicated that inoculum dose could significantly affect the pathogenesis of BCCV infection in juvenile hispid cotton rats. For example, the six animals inoculated with 3.1 or 1.1 log(10) ID(50-VeroE6) and euthanized on day 54 PI were virus positive and antibody positive, whereas the six animals inoculated with -0.9 or -2.9 log(10) ID(50-VeroE6) and euthanized on day 54 PI were virus positive but antibody negative. Microscopic examination of tissues from the animals inoculated with 3.1 or 1.1 log(10) ID(50-VeroE6) revealed diffuse, subacute pneumonitis in the lungs of all the animals euthanized on day 18 PI or thereafter, and indicated that the severity of pneumonitis was dependent upon inoculum dose as well as duration of infection (i.e., amount of time elapsed since inoculation). |
Coverage of nevirapine-based services to prevent mother-to-child HIV transmission in 4 African countries
Stringer EM , Ekouevi DK , Coetzee D , Tih PM , Creek TL , Stinson K , Giganti MJ , Welty TK , Chintu N , Chi BH , Wilfert CM , Shaffer N , Dabis F , Stringer JS . JAMA 2010 304 (3) 293-302 CONTEXT: Few studies have objectively evaluated the coverage of services to prevent transmission of human immunodeficiency virus (HIV) from mother to child. OBJECTIVE: To measure the coverage of services to prevent mother-to-child HIV transmission in 4 African countries. DESIGN, SETTING, AND PATIENTS: Cross-sectional surveillance study of mother-infant pairs using umbilical cord blood samples collected between June 10, 2007, and October 30, 2008, from 43 randomly selected facilities (grouped as 25 service clusters) providing delivery services in Cameroon, Cote d'Ivoire, South Africa, and Zambia. All sites used at least single-dose nevirapine to prevent mother-to-child HIV transmission and some sites used additional prophylaxis drugs. MAIN OUTCOME MEASURE: Population nevirapine coverage, defined as the proportion of HIV-exposed infants in the sample with both maternal nevirapine ingestion (confirmed by cord blood chromatography) and infant nevirapine ingestion (confirmed by direct observation). RESULTS: A total of 27,893 cord blood specimens were tested, of which 3324 were HIV seropositive (12%). Complete data for cord blood nevirapine results were available on 3196 HIV-seropositive mother-infant pairs. Nevirapine coverage varied significantly by site (range: 0%-82%). Adjusted for country, the overall coverage estimate was 51% (95% confidence interval [CI], 49%-53%). In multivariable analysis, failed coverage of nevirapine-based services was significantly associated with maternal age younger than 20 years (adjusted odds ratio [AOR], 1.44; 95% CI, 1.18-1.76) and maternal age between 20 and 25 years (AOR, 1.28; 95% CI, 1.07-1.54) vs maternal age of older than 30 years; 1 or fewer antenatal care visits (AOR, 2.91; 95% CI, 2.40-3.54), 2 or 3 antenatal care visits (AOR, 1.93; 95% CI, 1.60-2.33), and 4 or 5 antenatal care visits (AOR, 1.56; 95% CI, 1.34-1.80) vs 6 or more antenatal care visits; vaginal delivery (AOR, 1.22; 95% CI, 1.03-1.44) vs cesarean delivery; and infant birth weight of less than 2500 g (AOR, 1.34; 95% CI, 1.11-1.62) vs birth weight of 3500 g or greater. CONCLUSION: In this random sampling of sites with services to prevent mother-to-child HIV transmission, only 51% of HIV-exposed infants received the minimal regimen of single-dose nevirapine. |
Winter ecology of Buggy Creek virus (Togaviridae, Alphavirus) in the Central Great Plains
Brown CR , Strickler SA , Moore AT , Knutie SA , Padhi A , Brown MB , Young GR , O'Brien VA , Foster JE , Komar N . Vector Borne Zoonotic Dis 2010 10 (4) 355-63 A largely unanswered question in the study of arboviruses is the extent to which virus can overwinter in adult vectors during the cold winter months and resume the transmission cycle in summer. Buggy Creek virus (BCRV; Togaviridae, Alphavirus) is an unusual arbovirus that is vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) and amplified by the ectoparasitic bug's main avian hosts, the migratory cliff swallow (Petrochelidon pyrrhonota) and resident house sparrow (Passer domesticus). Bugs are sedentary and overwinter in the swallows' mud nests. We evaluated the prevalence of BCRV and extent of infection in swallow bugs collected at different times in winter (October-early April) in Nebraska and explored other ecological aspects of this virus's overwintering. BCRV was detected in 17% of bug pools sampled in winter. Virus prevalence in bugs in winter at a site was significantly correlated with virus prevalence at that site the previous summer, but winter prevalence did not predict BCRV prevalence there the following summer. Prevalence was higher in bugs taken from house sparrow nests in winter and (in April) at colony sites where sparrows had been present all winter. Virus detected by reverse transcription (RT)-polymerase chain reaction in winter was less cytopathic than in summer, but viral RNA concentrations of samples in winter were not significantly different from those in summer. Both of the BCRV lineages (A, B) overwintered successfully, with lineage A more common at sites with house sparrows and (in contrast to summer) generally more prevalent in winter than lineage B. BCRV's ability to overwinter in its adult vector probably reflects its adaptation to the sedentary, long-lived bug and the ecology of the cliff swallow and swallow bug host-parasite system. Its overwintering mechanisms may provide insight into those of other alphaviruses of public health significance for which such mechanisms are poorly known. |
Natural infection of vertebrate hosts by different lineages of Buggy Creek virus (family Togaviridae, genus Alphavirus)
Brown CR , Moore AT , O'Brien VA , Padhi A , Knutie SA , Young GR , Komar N . Arch Virol 2010 155 (5) 745-9 Buggy Creek virus (BCRV; family Togaviridae, genus Alphavirus) is an arbovirus transmitted by the ectoparasitic swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) to cliff swallows (Petrochelidon pyrrhonota) and house sparrows (Passer domesticus). BCRV occurs in two lineages (A and B) that are sympatric in bird nesting colonies in the central Great Plains, USA. Previous work on lineages isolated exclusively from swallow bugs suggested that lineage A relies on amplification by avian hosts, in contrast to lineage B, which is maintained mostly among bugs. We report the first data on the BCRV lineages isolated from vertebrate hosts under natural conditions. Lineage A was overrepresented among isolates from nestling house sparrows, relative to the proportions of the two lineages found in unfed bug vectors at the same site at the start of the summer transmission season. Haplotype diversity of each lineage was higher in bugs than in sparrows, indicating reduced genetic diversity of virus amplified in the vertebrate host. BCRV appears to have diverged into two lineages based on different modes of transmission. |
Ecological divergence of two sympatric lineages of Buggy Creek virus, an arbovirus associated with birds
Brown CR , Padhi A , Moore AT , Brown MB , Foster JE , Pfeffer M , O'Brien VA , Komar N . Ecology 2009 90 (11) 3168-79 Most arthropod-borne viruses (arboviruses) show distinct serological subtypes or evolutionary lineages, with the evolution of different strains often assumed to reflect differences in ecological selection pressures. Buggy Creek virus (BCRV) is an unusual RNA virus (Togaviridae, Alphavirus) that is associated primarily with a cimicid swallow bug (Oeciacus vicarius) as its vector and the Cliff Swallow (Petrochelidon pyrrhonota) and the introduced House Sparrow (Passer domesticus) as its amplifying hosts. There are two sympatric lineages of BCRV (lineages A and B) that differ from each other by > 6% at the nucleotide level. Analysis of 385 BCRV isolates all collected from bug vectors at a study site in southwestern Nebraska, USA, showed that the lineages differed in their peak times of seasonal occurrence within a summer. Lineage A was more likely to be found at recently established colonies, at those in culverts (rather than on highway bridges), and at those with invasive House Sparrows, and in bugs on the outsides of nests. Genetic diversity of lineage A increased with bird colony size and at sites with House Sparrows, while that of lineage B decreased with colony size and was unaffected by House Sparrows. Lineage A was more cytopathic on mammalian cells than was lineage B. These two lineages have apparently diverged in their transmission dynamics, with lineage A possibly more dependent on birds and lineage B perhaps more a bug virus. The long-standing association between Cliff Swallows and BCRV may have selected for immunological resistance to the virus by swallows and thus promoted the evolution of the more bug-adapted lineage B. In contrast, the recent arrival of the introduced House Sparrow and its high competence as a BCRV amplifying host may be favoring the more bird-dependent lineage A. |
Hospitalization and mortality among primarily non-breastfed children during a large outbreak of diarrhea and malnutrition in Botswana, 2006
Creek TL , Kim A , Lu L , Bowen A , Masunge J , Arvelo W , Smit M , Mach O , Legwaila K , Motswere C , Zaks L , Finkbeiner T , Povinelli L , Maruping M , Ngwaru G , Tebele G , Bopp C , Puhr N , Johnston SP , Dasilva AJ , Bern C , Beard RS , Davis MK . J Acquir Immune Defic Syndr 2009 53 (1) 14-9 BACKGROUND: In 2006, a pediatric diarrhea outbreak occurred in Botswana, coinciding with heavy rains. Surveillance recorded a 3 times increase in cases and a 25 fold increase in deaths between January and March. Botswana has high HIV prevalence among pregnant women (33.4% in 2005), and an estimated 35% of all infants under the age of 6 months are not breastfed. METHODS: We followed all children <5 years old with diarrhea in the country's second largest referral hospital at the peak of the outbreak by chart review, interviewed mothers, and conducted laboratory testing for HIV and enteric pathogens. RESULTS: Of 153 hospitalized children with diarrhea, 97% were <2 years old; 88% of these were not breastfeeding. HIV was diagnosed in 18% of children and 64% of mothers. Cryptosporidium and enteropathogenic Escherichia coli were common; many children had multiple pathogens. Severe acute malnutrition (kwashiorkor or marasmus) developed in 38 (25%) patients, and 33 (22%) died. Kwashiorkor increased risk for death (relative risk 2.0; P = 0.05); only one breastfeeding child died. Many children who died had been undersupplied with formula. CONCLUSIONS: Most of the severe morbidity and mortality in this outbreak occurred in children who were HIV negative and not breastfed. Feeding and nutritional factors were the most important determinants of severe illness and death. Breastfeeding is critical to infant survival in the developing world, and support for breastfeeding among HIV-negative women, and HIV-positive women who cannot formula feed safely, may prevent further high-mortality outbreaks. |
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