Last data update: Apr 18, 2025. (Total: 49119 publications since 2009)
Records 1-19 (of 19 Records) |
Query Trace: Houghton K[original query] |
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Evaluating reception center models for radiation response screening capacity and throughput predictions
Finklea L , Goff R , Houghton E . Health Phys 2024 Introduction: The current fleet of nuclear reactors in the United States is mandated to provide evidence that surrounding jurisdictions can screen their populations should an incident occur. Capacity can be measured as throughput in reception centers used for screening. Due to the significant staffing and resources required to exercise screening capacity, most jurisdictions typically perform smaller exercises and use models to estimate their overall throughput. Objective: To evaluate the applicability and realism of current throughput models and practices. Methods: Throughput capacity for radiation screening is estimated with a mathematical model derived by the Federal Emergency Management Agency (FEMA). The Centers for Disease Control and Prevention developed a discrete event simulation model as a tool, SimPLER, to evaluate capacity and make throughput predictions. Model estimates will be compared and evaluated using timing data collected at a large-scale exercise. Results: The FEMA model estimated a throughput 41.2% higher than the actual radiation screening throughput, while the SimPLER model provided identical values. The FEMA and SimPLER models' predicted throughputs were 50% and 3.8%, respectively, higher than total exercise throughput. Applying each model to the throughput projections for a 12-hour shift, the FEMA model estimates ranged from 665 to 6,646 people and the SimPLER model yielded an estimated throughput of 1,809 people with a standard deviation of 74.6. Conclusion: Discrete event simulation models, such as SimPLER, may provide more realistic and accurate predictions of radiation screening and throughput capacity of reception centers than mathematical models such as the FEMA model. |
Comparison of two novel one-tube nested real-time qPCR assays to detect human-infecting Cyclospora spp
Richins T , Houghton K , Barratt J , HSapp SG , Peterson A , Qvarnstrom Y . Microbiol Spectr 2023 11 (6) e0138823 ![]() Human-infecting Cyclospora spp. currently include three coccidian parasites that cause the gastrointestinal disease cyclosporiasis in humans. They are often spread through contaminated produce, including leafy greens and berries. The increased availability of sensitive molecular tests for the diagnosis of cyclosporiasis is an important advancement, allowing public health agencies to better understand the scope and source of cyclosporiasis outbreaks. To improve the diagnosis of infected patients, rapidly detect outbreaks, and keep the food supply safe, it is important to continue to develop sensitive, reliable, and inexpensive tests to detect human-infecting Cyclospora spp. In this report, we describe the development and evaluation of two novel one-tube nested qPCR assays for the detection of human-infecting Cyclospora spp. in clinical stool samples, one targeting cytb and the other targeting coxI. Of these, the assay targeting the cytb mitochondrial locus possessed strong performance characteristics compared to a routinely used 18S assay, including a markedly improved (approximately 10-fold lower) relative detection limit of 0.613 oocysts per gram of feces. This is compared to coxI that has a relative detection limit equal to that of the 18S assay. Given the strong performance characteristics of the cytb assay, we propose that it may be useful to diagnostic laboratories wishing to screen clinical fecal specimens suspected of containing human-infecting Cyclospora spp.IMPORTANCEHuman-infecting Cyclospora spp. cause gastrointestinal distress among healthy individuals contributing to morbidity and putting stress on the economics of countries and companies in the form of produce recalls. Accessible and easy-to-use diagnostic tools available to a wide variety of laboratories would aid in the early detection of possible outbreaks of cyclosporiasis. This, in turn, will assist in the timely traceback investigation to the suspected source of an outbreak by informing the smallest possible recall and protecting consumers from contaminated produce. This manuscript describes two novel detection methods with improved performance for the causative agents of cyclosporiasis when compared to the currently used 18S assay. |
The limit of detection of the BioFire FilmArray gastrointestinal panel for the foodborne parasite Cyclospora cayetanensis
Peterson A , Richins T , Houghton K , Mishina M , Sharma S , Sambhara S , Jacobson D , Qvarnstrom Y , Cama V . Diagn Microbiol Infect Dis 2023 107 (2) 116030 ![]() ![]() Cyclosporiasis is a foodborne diarrheal illness caused by the parasite Cyclospora cayetanensis. The BioFire® FilmArray® gastrointestinal (FilmArray GI) panel is a common method for diagnosing cyclosporiasis from clinical stool samples. The currently published limit of detection (LOD) of this panel is in genome equivalents; however, it is unclear how this relates to the number of C. cayetanensis oocysts in a clinical sample. In this study, we developed a technique to determine the LOD in terms of oocysts, using a cell sorter to sort 1 to 50 C. cayetanensis oocyst(s) previously purified from three human stool sources. We found the FilmArray GI panel detected samples with ≥20 C. cayetanensis oocysts in 100% of replicates, with varying detection among samples with 1, 5, or 10 C. cayetanensis oocysts. This method provides a parasitologically relevant LOD that should enable comparison among C. cayetanensis detection techniques, including the FilmArray GI panel. |
Notes from the field: Outbreak of cryptosporidiosis among collegiate swimmers and evidence of secondary transmission - Massachusetts and Rhode Island, 2023
Chiumento G , Osinski A , DeVoe K , Houghton A , Joshi A , Ivanof C , Creegan E , Gosciminski M , Newman AP , Madison-Antenucci S , Hlavsa MC , Imada E , Lysen C , Miko S , Schultz J , Harvey E , Vostok J , Brown CM . MMWR Morb Mortal Wkly Rep 2023 72 (26) 734-735 Inadvertent ingestion of recreational waters contaminated with feces containing Cryptosporidium spp., an extremely chlorine-tolerant parasite, can result in gastrointestinal illness. In early 2023, a Massachusetts college notified the Massachusetts Department of Public Health (MDPH) that 19 of 50 (38%) members of the men’s and women’s swim teams had experienced diarrhea beginning 3 days after their return from a weeklong training trip to Puerto Rico. One ill swimmer reported receiving a positive ova and parasite test result for Cryptosporidium. On days 5 and 6 after return from Puerto Rico, symptomatic Massachusetts swimmers competed in two meets against New York and Rhode Island collegiate teams (meet 1 and meet 2, respectively), raising concern about the potential for secondary transmission. |
Cyclospora cayetanensis comprises at least three species that cause human cyclosporiasis
Barratt JLN , Shen J , Houghton K , Richins T , Sapp SGH , Cama V , Arrowood MJ , Straily A , Qvarnstrom Y . Parasitology 2023 150 (3) 269-285 ![]() The apicomplexan parasite Cyclospora cayetanensis causes seasonal foodborne outbreaks of the gastrointestinal illness cyclosporiasis. Prior to the coronavirus disease-2019 pandemic, annually reported cases were increasing in the USA, leading the US Centers for Disease Control and Prevention to develop a genotyping tool to complement cyclosporiasis outbreak investigations. Thousands of US isolates and 1 from China (strain CHN_HEN01) were genotyped by Illumina amplicon sequencing, revealing 2 lineages (A and B). The allelic composition of isolates was examined at each locus. Two nuclear loci (CDS3 and 360i2) distinguished lineages A and B. CDS3 had 2 major alleles: 1 almost exclusive to lineage A and the other to lineage B. Six 360i2 alleles were observed 2 exclusive to lineage A (alleles A1 and A2), 2 to lineage B (B1 and B2) and 1 (B4) was exclusive to CHN_HEN01 which shared allele B3 with lineage B. Examination of heterozygous genotypes revealed that mixtures of A- and B-type 360i2 alleles occurred rarely, suggesting a lack of gene flow between lineages. Phylogenetic analysis of loci from whole-genome shotgun sequences, mitochondrial and apicoplast genomes, revealed that CHN_HEN01 represents a distinct lineage (C). Retrospective examination of epidemiologic data revealed associations between lineage and the geographical distribution of US infections plus strong temporal associations. Given the multiple lines of evidence for speciation within human-infecting Cyclospora, we provide an updated taxonomic description of C. cayetanensis, and describe 2 novel species as aetiological agents of human cyclosporiasis: Cyclospora ashfordi sp. nov. and Cyclospora henanensis sp. nov. (Apicomplexa: Eimeriidae). |
In situ differences in nitrogen cycling related to presence of submerged aquatic vegetation in a Gulf of Mexico estuary
Fulford RS , Houghton K , James J , Russell M . Ecosphere 2022 13 (12) e4290 Abstract Estuaries provide a suite of ecosystem services to people but are also under heavy stress from human development including excess nutrient loading and alterations in benthic habitat that affect nutrient cycling. Here we examine the interaction of two important and common ecosystem management priorities in estuaries: limiting eutrophication and restoration of submerged aquatic vegetation (SAV). Rates of benthic nitrogen processing can vary by habitat type and there is need for more complete data on the contribution of SAV to overall nitrogen cycling in estuaries, as well as a need to examine nitrogen cycling in situ to better characterize the role of SAV areal coverage in mediating estuarine eutrophication. We compare nitrogen cycling between two common and adjacent habitat types (SAV and adjacent bare sediment [BS]) in an index coastal estuary using an in situ chamber-based approach to better capture realized habitat differences. We also examined genomic community structure of sediment bacteria and archaea to identify biological indicators of nitrogen exchange. Both mean sediment–water exchange of dissolved N2 and microbial functional community structure differed between SAV and BS. Habitat differences were more consistent with lower variability at locations with low salinity and when sediment organic content was highest, which aligns with findings in other studies. Habitat types differed significantly in microbial composition, including functional groups and genes, like nifH, that may contribute to observed differences in nitrogen cycling. Overall, habitat type appeared most important to nitrogen cycling near the river mouth where sediment nitrogen was higher, and this information has implications for integrated management of habitat restoration/conservation and nutrient loading. |
Genotyping Cyclospora cayetanensis from multiple outbreak clusters with an emphasis on a cluster linked to bagged salad mix - United States, 2020.
Barratt J , Ahart L , Rice M , Houghton K , Richins T , Cama V , Arrowood M , Qvarnstrom Y , Straily A . J Infect Dis 2021 225 (12) 2176-2180 ![]() ![]() Cyclosporiasis is a diarrheal illness caused by the food-borne parasite Cyclospora cayetanensis. Annually reported cases have been increasing in the United States prompting development of genotyping tools to aid cluster detection. A recently developed Cyclospora genotyping system based on eight genetic markers was applied to clinical samples collected during the cyclosporiasis peak-period of 2020, facilitating assessment of its epidemiologic utility. While the system performed well and helped inform epidemiological investigations, inclusion of additional markers to improve cluster detection was supported. Consequently, investigations have commenced to identify additional markers to enhance performance. |
Investigation of US Cyclospora cayetanensis outbreaks in 2019 and evaluation of an improved Cyclospora genotyping system against 2019 cyclosporiasis outbreak clusters.
Barratt J , Houghton K , Richins T , Straily A , Threlkel R , Bera B , Kenneally J , Clemons B , Madison-Antenucci S , Cebelinski E , Whitney BM , Kreil KR , Cama V , Arrowood MJ , Qvarnstrom Y . Epidemiol Infect 2021 149 1-39 ![]() ![]() ![]() Cyclosporiasis is an illness characterised by watery diarrhoea caused by the food-borne parasite Cyclospora cayetanensis. The increase in annual US cyclosporiasis cases led public health agencies to develop genotyping tools that aid outbreak investigations. A team at the Centers for Disease Control and Prevention (CDC) developed a system based on deep amplicon sequencing and machine learning, for detecting genetically-related clusters of cyclosporiasis to aid epidemiologic investigations. An evaluation of this system during 2018 supported its robustness, indicating that it possessed sufficient utility to warrant further evaluation. However, the earliest version of CDC's system had some limitations from a bioinformatics standpoint. Namely, reliance on proprietary software, the inability to detect novel haplotypes and absence of a strategy to select an appropriate number of discrete genetic clusters would limit the system's future deployment potential. We recently introduced several improvements that address these limitations and the aim of this study was to reassess the system's performance to ensure that the changes introduced had no observable negative impacts. Comparison of epidemiologically-defined cyclosporiasis clusters from 2019 to analogous genetic clusters detected using CDC's improved system reaffirmed its excellent sensitivity (90%) and specificity (99%), and confirmed its high discriminatory power. This C. cayetanensis genotyping system is robust and with ongoing improvement will form the basis of a US-wide C. cayetanensis genotyping network for clinical specimens. |
Associations between zinc and hemoglobin concentrations in preschool children and women of reproductive age: An analysis of representative survey data from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project
Greffeuille V , Fortin S , Gibson R , Rohner F , Williams A , Young MF , Houghton L , Ou J , Dijkhuizen MA , Wirth JP , Lander RL , McDonald CM , Suchdev PS , Berger J , Wieringa FT . J Nutr 2021 151 (5) 1277-1285 BACKGROUND: Anemia is a worldwide concern. Nutritional deficiencies and inflammation are considered main contributors, but zinc deficiency has only recently been associated with anemia. OBJECTIVES: In this study we assessed associations between zinc status and hemoglobin (Hb) concentrations and anemia in preschool children 6-59 mo old (PSC) and nonpregnant women of reproductive age 15-49 y old (WRA) in population-based nutrition surveys. METHODS: Cross-sectional data from 13 (PSC) and 12 (WRA) countries within the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project were used. Multivariable linear models were constructed that included zinc status (plasma/serum zinc concentrations), Hb concentrations and anemia, iron status, age, sex, and inflammation (C-reactive protein and α-1-acid glycoprotein). Zinc was adjusted for inflammation in PSC according to the BRINDA algorithm. RESULTS: Data were available for 18,658 PSC and 22,633 WRA. Prevalence of anemia ranged from 7.5% to 73.7% and from 11.5% to 94.7% in PSC and WRA, respectively. Prevalence of zinc deficiency ranged from 9.2% to 78.4% in PSC and from 9.8% to 84.7% in WRA, with prevalence of zinc deficiency >20% in all countries except Azerbaijan (PSC), Ecuador (PSC), and the United Kingdom (WRA). Multivariable linear regression models showed that zinc concentrations were independently and positively associated with Hb concentrations in 7 of 13 countries for PSC and 5 of 12 countries for WRA. In the same models, ferritin concentration was also significantly associated with Hb among PSC and WRA in 9 and 10 countries, respectively. Zinc deficiency was significantly associated with anemia in PSC and WRA in 5 and 4 countries respectively. CONCLUSIONS: Zinc deficiency was prevalent in most countries and associations between zinc and Hb in roughly half of the countries examined suggesting that strategies to combat zinc deficiency may help reduce anemia prevalence. More research on mechanisms by which zinc deficiency is associated with anemia and the reasons for the heterogeneity among countries is warranted. |
Evaluation of an ensemble-based distance statistic for clustering MLST datasets using epidemiologically defined clusters of cyclosporiasis.
Nascimento FS , Barratt J , Houghton K , Plucinski M , Kelley J , Casillas S , Bennett CC , Snider C , Tuladhar R , Zhang J , Clemons B , Madison-Antenucci S , Russell A , Cebelinski E , Haan J , Robinson T , Arrowood MJ , Talundzic E , Bradbury RS , Qvarnstrom Y . Epidemiol Infect 2020 148 e172 ![]() ![]() Outbreaks of cyclosporiasis, a food-borne illness caused by the coccidian parasite Cyclospora cayetanensis have increased in the USA in recent years, with approximately 2300 laboratory-confirmed cases reported in 2018. Genotyping tools are needed to inform epidemiological investigations, yet genotyping Cyclospora has proven challenging due to its sexual reproductive cycle which produces complex infections characterized by high genetic heterogeneity. We used targeted amplicon deep sequencing and a recently described ensemble-based distance statistic that accommodates heterogeneous (mixed) genotypes and specimens with partial genotyping data, to genotype and cluster 648 C. cayetanensis samples submitted to CDC in 2018. The performance of the ensemble was assessed by comparing ensemble-identified genetic clusters to analogous clusters identified independently based on common food exposures. Using these epidemiologic clusters as a gold standard, the ensemble facilitated genetic clustering with 93.8% sensitivity and 99.7% specificity. Hence, we anticipate that this procedure will greatly complement epidemiologic investigations of cyclosporiasis. |
Development of a workflow for identification of nuclear genotyping markers for Cyclospora cayetanensis.
Houghton KA , Lomsadze A , Park S , Nascimento FS , Barratt J , Arrowood MJ , VanRoey E , Talundzic E , Borodovsky M , Qvarnstrom Y . Parasite 2020 27 24 ![]() ![]() Cyclospora cayetanensis is an intestinal parasite responsible for the diarrheal illness, cyclosporiasis. Molecular genotyping, using targeted amplicon sequencing, provides a complementary tool for outbreak investigations, especially when epidemiological data are insufficient for linking cases and identifying clusters. The goal of this study was to identify candidate genotyping markers using a novel workflow for detection of segregating single nucleotide polymorphisms (SNPs) in C. cayetanensis genomes. Four whole C. cayetanensis genomes were compared using this workflow and four candidate markers were selected for evaluation of their genotyping utility by PCR and Sanger sequencing. These four markers covered 13 SNPs and resolved parasites from 57 stool specimens, differentiating C. cayetanensis into 19 new unique genotypes. |
Molecular detection and genotyping of pathogenic protozoan parasites in raw and treated water samples from southwest Colombia.
Sanchez C , Lopez MC , Galeano LA , Qvarnstrom Y , Houghton K , Ramirez JD . Parasit Vectors 2018 11 (1) 563 ![]() ![]() BACKGROUND: Protozoan parasites such as Giardia duodenalis, Cryptosporidium spp., Cyclospora cayetanensis, Toxoplasma gondii and Entamoeba histolytica represent a great challenge to the systems producing water for human consumption because their cystic forms are persistent in the environment and resist to the disinfection methods conventionally used for their control. In this study, we investigated the presence of these protozoan pathogens in both raw and treated water samples used for the production of drinking water in Narino Department, southwest Colombia. We collected 110 water samples (10 lof each sample) and analyzed them with real-time PCR (qPCR). qPCR-positive samples were genotyped with PCR and DNA sequencing. RESULTS: Giardia duodenalis was detected in 35/110 (31.8%) of the samples and Cryptosporidium spp. in 9/110 (8.2%) of the samples; no sample was positive for T. gondii, E. histolytica or C. cayetanensis. Giardia duodenalis was detected in samples of both raw water (Drinking Water Treatment Plants (DWTP): 47.83%;Drinking Water Rural Plants (DWRP): 18.42%) and water collected either after conventional physicochemical treatment (26.09%) or after disinfection by chlorine (50%), whereas Cryptosporidium spp. were only detected in raw waters (DWTP: 17.39%; DWRP: 13.16%). The two pathogens were detected in both types of treatment plants supplying water to urban areas and to rural zones. Analysis of gdh and tpi markers identified assemblages AI, AII and H of G. duodenalis, while analysis of the small subunit rRNA and gp60 markers of Cryptosporidium-positive samples identified C. parvum (Subtype IIcA5G3c), C. galli, C. molnari, Cryptosporidium sp. genotype II of bats and Cryptosporidium sp. genotype VIII of birds. CONCLUSIONS: The results obtained demonstrate the presence of protozoan parasites in the water of the study region, and the need to improve the surveillance systems for these pathogens and identify the corresponding sources of contamination. |
Assessing climate change and health vulnerability at the local level: Travis County, Texas
Prudent N , Houghton A , Luber G . Disasters 2016 40 (4) 740-52 We created a measure to help comprehend population vulnerability to potential flooding and excessive heat events using health, built environment and social factors. Through principal component analysis (PCA), we created non-weighted sum index scores of literature-reviewed social and built environment characteristics. We created baseline poor health measures using 1999-2005 age-adjusted cardiovascular and combined diabetes and hypertension mortality rates to correspond with social-built environment indices. We mapped US Census block groups by linked age-adjusted mortality and a PCA-created social-built environment index. The goal was to measure flooding and excessive heat event vulnerability as proxies for population vulnerability to climate change for Travis County, Texas. This assessment identified communities where baseline poor health, social marginalisation and built environmental impediments intersected. Such assessments may assist targeted interventions and improve emergency preparedness in identified vulnerable communities, while fostering resilience through the focus of climate change adaptation policies at the local level. |
Community rabies knowledge and pet vaccination practices after a skunk rabies outbreak in Eddy County, New Mexico
McNeil CS , Nagy S , Moonan C , Wallace RM , Vora NM , Dyer JL , Blanton JD , Dorado T , Heinrich ML , Sankey R , Uhrig S , Cary A , Houghton W , Ettestad P . J Am Vet Med Assoc 2015 246 (11) 1242-7 OBJECTIVE: To determine percentages of domestic cats and dogs vaccinated against rabies, identify barriers to vaccination, and assess knowledge about rabies in a semirural New Mexico community after a skunk rabies outbreak. DESIGN: Cross-sectional, door-to-door, bilingual, community-based participatory survey. Sample-366 residential properties in Eddy County, NM. PROCEDURES: The New Mexico Department of Health and CDC administered surveys and analyzed data. RESULTS: Individuals at 247 of the 366 residential properties participated in the survey. One hundred eighty of the 247 (73%) households owned a dog (n = 292) or cat (163). Cats were more likely than dogs to not have an up-to-date rabies vaccination status (prevalence ratio, 3.2; 95% confidence interval, 2.3 to 4.4). Cost and time or scheduling were the most frequently identified barriers to vaccination. One hundred sixty (65%) respondents did not know livestock can transmit rabies, 78 (32%) did not know rabies is fatal, and 89 (36%) did not know a bat scratching a person can be an exposure. Only 187 (76%) respondents indicated they would contact animal control if they saw a sick skunk, and only 166 (67%) indicated they would contact animal control if bitten by a dog they did not own. CONCLUSIONS AND CLINICAL RELEVANCE: Findings indicated that rabies vaccination prevalence among pet dogs and cats was low, despite the fact that the region had experienced a skunk rabies outbreak during the previous 2 years. In addition, substantial percentages of respondents did not have correct knowledge of rabies or rabies exposure. |
Melioidosis Diagnostic Workshop, 2013
Hoffmaster AR , AuCoin D , Baccam P , Baggett HC , Baird R , Bhengsri S , Blaney DD , Brett PJ , Brooks TJ , Brown KA , Chantratita N , Cheng AC , Dance DA , Decuypere S , Defenbaugh D , Gee JE , Houghton R , Jorakate P , Lertmemongkolchai G , Limmathurotsakul D , Merlin TL , Mukhopadhyay C , Norton R , Peacock SJ , Rolim DB , Simpson AJ , Steinmetz I , Stoddard RA , Stokes MM , Sue D , Tuanyok A , Whistler T , Wuthiekanun V , Walke HT . Emerg Infect Dis 2015 21 (2) Melioidosis is a severe disease that can be difficult to diagnose because of its diverse clinical manifestations and a lack of adequate diagnostic capabilities for suspected cases. There is broad interest in improving detection and diagnosis of this disease not only in melioidosis-endemic regions but also outside these regions because melioidosis may be underreported and poses a potential bioterrorism challenge for public health authorities. Therefore, a workshop of academic, government, and private sector personnel from around the world was convened to discuss the current state of melioidosis diagnostics, diagnostic needs, and future directions. |
Acute kidney injury associated with smoking synthetic cannabinoid
Buser GL , Gerona RR , Horowitz BZ , Vian KP , Troxell ML , Hendrickson RG , Houghton DC , Rozansky D , Su SW , Leman RF . Clin Toxicol (Phila) 2014 52 (7) 664-73 CONTEXT AND OBJECTIVES: Synthetic cannabinoids are illegal drugs of abuse known to cause adverse neurologic and sympathomimetic effects. They are an emerging health risk: 11% of high school seniors reported smoking them during the previous 12 months. We describe the epidemiology of a toxicologic syndrome of acute kidney injury associated with synthetic cannabinoids, review the toxicologic and public health investigation of the cluster, and describe clinical implications of the cluster investigation. MATERIALS AND METHODS: Case series of nine patients affected by the toxicologic syndrome in Oregon and southwestern Washington during May-October 2012. Cases were defined as acute kidney injury (creatinine > 1.3 mg/dL) among persons aged 13-40 years without known renal disease who reported smoking synthetic cannabinoids. Toxicology laboratories used liquid chromatography and time-of-flight mass spectrometry to test clinical and product specimens for synthetic cannabinoids, their metabolites, and known nephrotoxins. Public health alerts informed clinicians, law enforcement, and the community about the cluster and the need to be alert for toxidromes associated with emerging drugs of abuse. RESULTS: Patients were males aged 15-27 years (median, 18 years), with intense nausea and flank or abdominal pain, and included two sets of siblings. Peak creatinine levels were 2.6-17.7 mg/dL (median, 6.6 mg/dL). All patients were hospitalized; one required dialysis; none died. No alternate causes of acute kidney injury or nephrotoxins were identified. Patients reported easily purchasing synthetic cannabinoids at convenience, tobacco, and adult bookstores. One clinical and 2 product samples contained evidence of a novel synthetic cannabinoid, XLR-11 ([1-(5-fluoropentyl)-1H-indol-3-yl](2,2,3,3-tetramethylcyclopropyl)methanone). DISCUSSION AND CONCLUSION: Whether caused by direct toxicity, genetic predisposition, or an as-yet unidentified nephrotoxin, this association between synthetic cannabinoid exposure and acute kidney injury reinforces the need for vigilance to detect new toxicologic syndromes associated with emerging drugs of abuse. Liquid chromatography and time-of-flight mass spectrometry are useful tools in determining the active ingredients in these evolving products and evaluating them for toxic contaminants. |
Development of a prototype lateral flow immunoassay (LFI) for the rapid diagnosis of melioidosis
Houghton RL , Reed DE , Hubbard MA , Dillon MJ , Chen H , Currie BJ , Mayo M , Sarovich DS , Theobald V , Limmathurotsakul D , Wongsuvan G , Chantratita N , Peacock SJ , Hoffmaster AR , Duval B , Brett PJ , Burtnick MN , Aucoin DP . PLoS Negl Trop Dis 2014 8 (3) e2727 Burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. Isolation of B. pseudomallei from clinical samples is the "gold standard" for the diagnosis of melioidosis; results can take 3-7 days to produce. Alternatively, antibody-based tests have low specificity due to a high percentage of seropositive individuals in endemic areas. There is a clear need to develop a rapid point-of-care antigen detection assay for the diagnosis of melioidosis. Previously, we employed In vivo Microbial Antigen Discovery (InMAD) to identify potential B. pseudomallei diagnostic biomarkers. The B. pseudomallei capsular polysaccharide (CPS) and numerous protein antigens were identified as potential candidates. Here, we describe the development of a diagnostic immunoassay based on the detection of CPS. Following production of a CPS-specific monoclonal antibody (mAb), an antigen-capture immunoassay was developed to determine the concentration of CPS within a panel of melioidosis patient serum and urine samples. The same mAb was used to produce a prototype Active Melioidosis Detect Lateral Flow Immunoassay (AMD LFI); the limit of detection of the LFI for CPS is comparable to the antigen-capture immunoassay ( approximately 0.2 ng/ml). The analytical reactivity (inclusivity) of the AMD LFI was 98.7% (76/77) when tested against a large panel of B. pseudomallei isolates. Analytical specificity (cross-reactivity) testing determined that 97.2% of B. pseudomallei near neighbor species (35/36) were not reactive. The non-reactive B. pseudomallei strain and the reactive near neighbor strain can be explained through genetic sequence analysis. Importantly, we show the AMD LFI is capable of detecting CPS in a variety of patient samples. The LFI is currently being evaluated in Thailand and Australia; the focus is to optimize and validate testing procedures on melioidosis patient samples prior to initiation of a large, multisite pre-clinical evaluation. |
Evaluation of a well-established task-shifting initiative: the lay counselor cadre in Botswana
Ledikwe JH , Kejelepula M , Maupo K , Sebetso S , Thekiso M , Smith M , Mbayi B , Houghton N , Thankane K , O'Malley G , Semo BW . PLoS One 2013 8 (4) e61601 BACKGROUND: Evidence supports the implementation of task shifting to address health worker shortages that are common in resource-limited settings. However, there is need to learn from established programs to identify ways to achieve the strongest, most sustainable impact. This study examined the Botswana lay counselor cadre, a task shifting initiative, to explore effectiveness and contribution to the health workforce. METHODS: This evaluation used multiple methods, including a desk review, a national lay counselor survey (n=385; response=94%), in-depth interviews (n=79), lay counselors focus group discussions (n=7), lay counselors observations (n=25), and client exit interviews (n=47). RESULTS: Interview and focus group data indicate that lay counselors contribute to essentially all HIV-related programs in Botswana and they conduct the majority of HIV tests and related counseling at public health facilities throughout the country. Interviews showed that the lay counselor cadre is making the workload of more skilled health workers more manageable and increasing HIV acceptance in communities. The average score on a work-related knowledge test was 74.5%. However for 3 questions, less than half answered correctly. During observations, lay counselors demonstrated average competence for most skills assessed and clients (97.9%) were satisfied with services received. From the survey, lay counselors generally reported being comfortable with their duties; however, some reported clinical duties that extended beyond their training and mandate. Multiple factors affecting the performance of the lay counselors were identified, including insufficient resources, such as private counseling space and HIV test kits; and technical, administrative, and supervisory support. CONCLUSION: Lay counselors are fulfilling an important role in Botswana's healthcare system, serving as the entry point into HIV care, support, and treatment services. RECOMMENDATION: For this and other similar task shifting initiatives, it is important that lay counselors' responsibilities are clear and that training and support are adequate to optimize their effectiveness. |
Minimum data elements for research reports on CFS
Jason LA , Unger ER , Dimitrakoff JD , Fagin AP , Houghton M , Cook DB , Marshall GD Jr , Klimas N , Snell C . Brain Behav Immun 2012 26 (3) 401-6 Chronic fatigue syndrome (CFS) is a debilitating condition that has received increasing attention from researchers in the past decade. However, it has become difficult to compare data collected in different laboratories due to the variability in basic information regarding descriptions of sampling methods, patient characteristics, and clinical assessments. The issue of variability in CFS research was recently highlighted at the NIH's 2011 State of the Knowledge of CFS meeting prompting researchers to consider the critical information that should be included in CFS research reports. To address this problem, we present our consensus on the minimum data elements that should be included in all CFS research reports, along with additional elements that are currently being evaluated in specific research studies that show promise as important patient descriptors for subgrouping of CFS. These recommendations are intended to improve the consistency of reported methods and the interpretability of reported results. Adherence to minimum standards and increased reporting consistency will allow for better comparisons among published CFS articles, provide guidance for future research and foster the generation of knowledge that can directly benefit the patient. |
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