Sample Collection Rate Research Articles

Feasibility of Home Collection for Urogenital Microbiome Samples.

Feasibility of home urogenital microbiome specimen collection is unknown. This study aimed to evaluate successful sample collection rates from home and clinical research centers. Adult women participants enrolled in a multicentered cohort study were recruited to an in-person research center evaluation, including self-collected urogenital samples. A nested feasibility substudy evaluated home biospecimen collection prior to the scheduled in-person evaluation using a home collection kit with written instructions, sample collection supplies, and a Peezy™ urine collection device. Participants self-collected samples at home and shipped them to a central laboratory 1 day prior to and the day of the in-person evaluation. We defined successful collection as receipt of at least one urine specimen that was visibly viable for sequencing. Of 156 participants invited to the feasibility substudy, 134 were enrolled and sent collection kits with 89% (119/134) returning at least 1 home urine specimen; the laboratory determined that 79% (106/134) of these urine samples were visually viable for analysis. The laboratory received self-collected urine from the research center visit in 97% (115/119); 76% (91/119) were visually viable for sequencing. Among 401 women who did not participate in the feasibility home collection substudy, 98% (394/401) self-collected urine at the research center with 80% (321/401) returned and visibly viable for sequencing. Home collection of urogenital microbiome samples for research is feasible, with comparable success to clinical research center collection. Sample size adjustment should plan for technical and logistical difficulties, regardless of specimen collection site.

Human biomonitoring without in-person interaction: public health engagements during the COVID-19 pandemic and future implications

BackgroundPublic health initiatives, including human biomonitoring, have been impacted by unique challenges since the onset of the COVID-19 pandemic, compounding a decades-long trend of declining public participation. To combat low public participation rates, public health professionals often employ extensive engagement approaches including in-person interactions related to enrollment and sampling, success of which is an essential component of a statistically defensible study. The onset of the COVID-19 pandemic challenged public health programs to diversify engagement and sampling approaches, limiting direct interactions for the health and safety of the population. This study explores biomonitoring recruitment strategies through non-contact mechanisms and evaluate the application feasibility for population-based studies.MethodsThe Iowa Biomonitoring Program at the State Hygienic Laboratory developed a human biomonitoring study that utilized a multifaceted, distance-based approach. Traditional techniques, such as mailed recruitment invitations and phone-based discussions, were coupled with internet-based surveys and self-collected, shipped urine and water samples. Participation rates were evaluated by employing different mailing methods, and the demographics of enrolled participants were examined.ResultsThis non-human contact approach achieved a nearly 14% participation rate among a rural population, well above our target rates. Our improved mailing strategy for targeting initially unresponsive participants yielded a significantly increase in the participation rates. The respondents were predominantly individuals with educational attainment of at least high school level. Among all the eligible participants, 83% submitted self-collected samples, a rate comparable to the National Health and Nutrition Examination Survey which involved in-person interviews.ConclusionsThe practice of engaging a rural population during the COVID-19 pandemic by transitioning from face-to-face interactions to a combination of mailing and internet-based approaches resulted in higher-than-expected participant recruitment and sample collection rates. Given the declining trend in the response rates for population-based survey studies, our results suggest conducting human biomonitoring without direct human interaction is feasible, which provides further opportunity to improve response rates and the relevance and reach of public health initiatives.

Sensitive SERS aptasensor for histamine detection based on Au/Ag nanorods and IRMOF-3@Au based flexible PDMS membrane

BackgroundHistamine is a kind of biogenic amine with strong toxicity and potential carcinogenicity. Many traditional methods of detecting histamine have the disadvantages of cumbersome detection steps, expensive equipment, and high professional requirements for staff. In contrast, SERS has become the preferred method for quantitative analysis of histamine because of rich fingerprint information, rapidity and economy. However, most of SERS substrates still have technical problems, such as poor stability, low sample collection rate, and detection efficiency. Therefore, there is a great need for new strategies to develop high-performance SERS substrates based sensors. ResultsIn our study, a sensitive SERS aptasensor for the detection of histamine was synthesized. The assembly was formed between IRMOF-3@Au/PDMS (flexible SERS substrate) and AuNR-DTNB@Ag-HA apt (Raman signal probe with both the target capture ability) via π-π stacking interaction from HA aptamer and IRMOF-3. Consequently, the SERS signal of the assembly derived from DTNB reached highest due to the synergistic enhancement effect by AuNR@Ag and IRMOF-3@Au. Meanwhile, HA aptamer can specifically capture histamine, therefore histamine addition competitively bound to the probe, leading to a corresponding decrease in the DTNB signal value on the SERS substrate. The SERS intensity at 1331 cm−1 presented a good linear relationship towards the logarithmic value of histamine concentrations ranging from 0.0001 mg/L to 400 mg/L (R2 = 0.990) with the LOD of 3.6 × 10−5 mg/L. Furthermore, the application in wine samples demonstrated the accuracy and applicability of the developed sensor. SignificanceThis method effectively improves substrate stability, detection sensitivity and signal response immediacy to amplify the SERS sensor, thus satisfying the histamine detection requirements of various systems. According to this aptasensor design, our strategy can be extended to create other MOF-based SERS substrates for accurately detecting relative targets to ensure food safety.

Enhancing Bone Marrow Biopsy Sample Quality: A Comprehensive Quality Improvement Study at UNM Cancer Center

Introduction Adequate samples from bone marrow biopsies are required for pathologists to diagnose and monitor hematologic conditions accurately. These biopsies involve the extraction of bone marrow samples in two main forms: an aspirate and a core biopsy. In some cases, additional molecular testing may be conducted for the purposes of diagnosis and classification. The journey of a bone marrow sample from the patient's bedside to the laboratory is a complex process that involves the collaboration of numerous participants and interconnected systems to ensure the integrity and accuracy of the results. At our cancer center, we initiated a quality improvement (QI) project to assess the baseline success rate of bone marrow sample collection, identify areas for improvement in collection, form and implement targeted interventions, and then measure the project's success. Methods In this QI study, we utilized an A3 model which included 1) assessing the current state of bone marrow biopsy samples at our institution 2) reviewing the current process of collection 3) analysis to identify the root causes affecting quality 4) Identifying our goal state 5) implementing interventions to improve the quality and 6) follow up to evaluate the effectiveness of our interventions against the stated goal. To identify the current state, we assessed the quality of 101 bone marrow biopsy samples collected from May to October 2022, focusing on the aspirate, clot, and biopsy sections. Two pathologists reviewed 20 of these samples at random to re-read them and defined inadequate aspirate and clots as those which were ‘aspicular’ or ‘paucispicular’ and inadequate trephine biopsies as those that were reported as ‘limited’ or ‘inadequate’ for interpretation. This limited analysis was hypothesis generating and we relied on descriptions of aspirate quality and core length in the biopsy reports for the remaining samples. We observed different providers and technicians performing bone marrow biopsies to understand the current process of collection across our institution. Our system analysis identified the following issues: Non-standardized collection technique, communication errors between technicians and providers in terms of core length and aspirate adequacy, and technician proficiency in identifying spicules and core length To address these issues, we wrote a guideline outlining the recommended standard technique and performed a training for all providers. This guideline included a standard communication guideline between technicians and providers. Technicians underwent additional training in terms of identifying spicules and measuring core length. We set a pre-defined goal of success as 70% adequacy for bone marrow biopsy aspirates and 90% adequacy for core biopsies. Following our interventions, we started collecting post-intervention bone marrow biopsies in May 2023 and plan to evaluate the adequacy of 100 bone marrow samples Results Samples were categorized as those performed by interventional radiology (IR) providers and non-IR providers (advanced practice providers, attendings, and fellows).At baseline, the adequacy rates for aspirate, clot, and biopsy sections were 35%, 36%, and 87%, respectively, for IR providers, and 63%, 70%, and 67%, respectively, for non-IR providers. (Table 1)We plan to evaluate 100 samples post-intervention and to date, we have evaluated 20 samples. Among IR cases, adequacy rates for aspirate, clot, and biopsy sections were 69%, 85%, and 92%, respectively. For non-IR cases, adequacy rates were 86%, 100%, and 86%, respectively. (Table 2) Although additional samples are needed to confirm our results, there is thus far a noticeable improvement in the rate of adequate sample collection for both IR and non-IR providers. While not included in the current analysis, we plan to add patient factors that may affect sample collection such as Body Mass Index or use of sedation in our final analysis to address potential confounders. Conclusion Through our QI study, we aimed to enhance the quality of bone marrow biopsy samples at our institution. Preliminary results demonstrate improvements in the rate of adequate sample collection for aspirate and core biopsies following our quality interventions. Future studies will explore the impact of patient and disease factors on sample quality and also assess whether the improved outcomes are sustained at a later point in time with additional follow up.

Applying the R = MC2 implementation science heuristic to assess the impact of readiness on reach and implementation of a population-wide genomic screening program.

Population-wide genomic screening for genes that have high penetrance and clinical actionability enhances the opportunity to identify individuals at risk for developing hereditary conditions. Organizational readiness has been shown to influence the likelihood of successful implementation of complex initiatives such as the integration of population-wide genomic screening in clinical settings. We use the organizational readiness heuristic R = MC2 to better understand three factors that influence readiness for implementation of In Our DNA SC, a population-wide genomic screening program: motivation to implement, general capacity of an organization, and innovation-specific capacities. We then assessed the influence of these readiness factors on implementation outcomes of reach (measured through enrollment rate) and implementation (measured through the number of DNA samples collected). Data were collected pre-implementation and captured during the three-month pilot phase of the In Our DNA SC program. We collected administrative data from the electronic health record and quantitatively captured elements of readiness through surveys distributed to provider champions and clinical administrative champions at the 10 sites implementing the population-wide genomic screening program. We facilitated innovation-specific capacity through training offered at each site, as well as technical assistance through weekly meetings with other implementing sites, and resources available to all staff. Forty percent of provider champions attended training and 80% of administrative champions attended training. An average of 3.7 additional staff were trained at each implementing site. Satisfaction with training positively influenced reach (β = 0.0121, p = 0.0271) but did not impact implementation. Provider engagement (innovation capabilities) was associated with reach (β = 0.0020, p = 0.0251) and clinical administrator engagement was associated with sample collection rate (β = 0.2599, β = 0.038). Readiness to change is considered one of the most important factors in understanding the potential opportunity for implementation. We found that motivation to adopt a population-wide genomic screening program positively impacted the program's reach. The type of champion influenced discrete outcomes, with provider champions positively impacting reach and administrative champions influencing implementation (assessed through sample collection rate). As genomics continues to be integrated into clinical practice, it will be important to understand the contextual factors that influence readiness for implementation and design support throughout the life-course of implementation to ensure the success of large-scale, complex initiatives.

Faecal sampling using detection dogs to study reproduction and health in North Atlantic right whales (Eubalaena glacialis)

Conservation and management of many cetaceans is hindered by the difficulty of acquiring samples from free-swimming individuals to obtain essential data on health, diet, reproduction and physiological impacts of environmental and anthropogenic stressors. This is particularly true for large whales, which are logistically difficult to live-capture for sampling. In North Atlantic right whales (Eubalaena glacialis), a significant decline in reproduction and health in the 1990s led to the application of faecal-based analyses to study stress and reproductive endocrinology, marine biotoxin exposure and prevalence of disease-causing protozoa. However, this approach was limited by low sample acquisition rates with opportunistic faecal (scat) collection methods. The work presented here evaluates the relative sampling efficiency of scent detection dogs trained to locate North Atlantic right whale scat versus opportunistic scat collection during photoidentification surveys. Three years of sample collection using both detection dogs and opportunistic methods are summarised. Faecal sample collection rates using detection dogs were over four times higher than opportunistic methods. The use of detection dogs for scat collection from free-swimming right whales has for the first time provided adequate numbers of samples for statistical analyses. The endocrine, disease, genetic and biotoxin studies currently being performed on these samples markedly improve the ability to address fundamental questions vital to effective conservation and management of highly endangered right whales.

Diagnostic yield of liquid-based cytology in serial pancreatic juice aspiration cytological examination.

ObjectivesSerial pancreatic juice aspiration cytological examination (SPACE) via endoscopic retrograde cholangiopancreatography is a useful diagnostic method for early‐stage pancreatic cancer, such as carcinoma in situ that are difficult to diagnose by endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA). However, the diagnostic accuracy of SPACE is low, which is attributed to problems regarding specimen treatment. Hence, we evaluated the diagnostic efficacy of liquid‐based cytology (LBC) in pancreatic juice cytology for pancreatic cancer.MethodsWe retrospectively analyzed 24 patients with suspected pancreatic cancer that was difficult to diagnose by endoscopic ultrasound‐guided fine needle aspiration who underwent SPACE using LBC between April 2017 and April 2021.ResultsThe most common reason for performing SPACE was localized stenosis of the main pancreatic duct without a mass. Eleven patients were diagnosed with malignancy after surgical resection, nine of whom had pancreatic ductal adenocarcinoma. Ten patients were diagnosed as benign after a follow‐up of more than 1 year. The nine cases of malignancy were diagnosed before surgical resection by SPACE using LBC, with a sensitivity of 81.8% and specificity of 100%. The overall diagnostic accuracy was 91.7%. A total of 152 LBC examinations were performed via SPACE, with an adequate sample collection rate of 88.9%. No adverse events, including acute pancreatitis, occurred after endoscopic retrograde cholangiopancreatography.ConclusionSPACE with LBC offers good diagnostic efficacy in patients with pancreatic cancer that is difficult to diagnose by endoscopic ultrasound‐guided fine needle aspiration.

Lessons Learned from the Pilot Phase of a Population-Wide Genomic Screening Program: Building the Base to Reach a Diverse Cohort of 100,000 Participants.

Background and Objectives: Genomic information is increasingly relevant for disease prevention and risk management at the individual and population levels. Screening healthy adults for Tier 1 conditions of hereditary breast and ovarian cancer, Lynch syndrome, and familial hypercholesterolemia using a population-based approach can help identify the 1–2% of the US population at increased risk of developing diseases associated with these conditions and tailor prevention strategies. Our objective is to report findings from an implementation science study that evaluates multi-level facilitators and barriers to implementation of the In Our DNA SC population-wide genomic screening initiative. Methods: We established an IMPACTeam (IMPlementAtion sCience for In Our DNA SC Team) to evaluate the pilot phase using principles of implementation science. We used a parallel convergent mixed methods approach to assess the Reach, Implementation, and Effectiveness outcomes from the RE-AIM implementation science framework during the pilot phase of In Our DNA SC. Quantitative assessment included the examination of frequencies and response rates across demographic categories using chi-square tests. Qualitative data were audio-recorded and transcribed, with codes developed by the study team based on the semi-structured interview guide. Results: The pilot phase (8 November 2021, to 7 March 2022) included recruitment from ten clinics throughout South Carolina. Reach indicators included enrollment rate and representativeness. A total of 23,269 potential participants were contacted via Epic’s MyChart patient portal with 1976 (8.49%) enrolled. Black individuals were the least likely to view the program invitation (28.9%) and take study-related action. As a result, there were significantly higher enrollment rates among White (10.5%) participants than Asian (8.71%) and Black (3.46%) individuals (p < 0.0001). Common concerns limiting reach and participation included privacy and security of results and the impact participation would have on health or life insurance. Facilitators included family or personal history of a Tier 1 condition, prior involvement in genetic testing, self-interest, and altruism. Assessment of implementation (i.e., adherence to protocols/fidelity to protocols) included sample collection rate (n = 1104, 55.9%) and proportion of samples needing recollection (n = 19, 1.7%). There were no significant differences in sample collection based on demographic characteristics. Implementation facilitators included efficient collection processes and enthusiastic clinical staff. Finally, we assessed the effectiveness of the program, finding low dropout rates (n = 7, 0.35%), the identification of eight individuals with Tier 1 conditions (0.72% positive), and high rates of follow-up genetic counseling (87.5% completion). Conclusion: Overall, Asian and Black individuals were less engaged, with few taking any study-related actions. Strategies to identify barriers and promoters for the engagement of diverse populations are needed to support participation. Once enrolled, individuals had high rates of completing the study and follow-up engagement with genetic counselors. Findings from the pilot phase of In Our DNA SC offer opportunities for improvement as we expand the program and can provide guidance to organizations seeking to begin efforts to integrate population-wide genomic screening.

Chemical and Isotopic Evaluation of a Microsampling Method using Laser Ablation and Membrane Filter

Microscale isotopic measurements in geological materials are becoming of significant importance in geochemistry. This study evaluated the potential of a new microsampling method called laser ablation coupled with filter (LAF) for precise isotopic measurements of small‐sized geological materials, compared with conventional micromilling techniques. We optimised the system to maximise the sample collection rate and minimise the extent of the contamination. Isotope ratios (87Sr/86Sr, 142Nd/144Nd, 143Nd/144Nd, 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb) of the glass reference material NIST SRM 610 collected using LAF were measured by thermal ionisation mass spectrometry, and no isotopic fractionation or blank effect was observed. This indicates that LAF can be applied for high‐precision isotope ratio measurement of these elements. Considering the total procedural blanks in LAF sampling, the minimum amounts required for high‐precision isotope measurement were 50, 2 and 20 ng for Sr, Nd and Pb, respectively. The LAF method has advantages over the conventional method. It also causes less damage in the test sample’s depth direction and can be applied to samples with complex shapes. It is expected therefore that the LAF sampling method will be applied to geology and other research fields that require microsampling.

Noninvasive sampling of mountain lion hair using modified foothold traps

AbstractAlthough genetic analysis is an increasingly affordable option for wildlife studies, obtaining high‐quality samples from cryptic carnivores remains difficult. To address this, we modified and tested 20.3‐cm (8‐inch) foot snares in unbaited trail sets for noninvasive collection of hair samples from mountain lions (Puma concolor). We deployed 22 hair traps in the Black Range in southern New Mexico from May to November 2017, monitored by remote cameras, at 66 locations for 1,618 trap nights ( = 24.5 nights, SD = 7.2 nights). Photos indicated 20 instances of mountain lions passing within 2 m of a hair trap and we collected 7 mountain lion hair samples, which averaged &gt;20 hairs/sample. All samples contained hair with visible roots and were identifiable to species; 6 of the 7 (85.7%) yielded sufficient DNA for individual identification. We attributed failure to obtain samples to 3 primary causes: individual trap saturation (2 instances), trap failure (2 instances), and non‐trigger events (9 instances). Black bears (Ursus americanus) and heavy rains were the primary sources of disturbance to hair trap sets, contributing to individual trap saturation and trap failure. We speculate that low trigger rates were associated with pan tension having been set too high in the first month of the study, as well as disturbance of hair traps or leading foot placements by nontarget species. We discuss strategies to increase hair sample collection rates, including seasonal use of hair traps, more selective placement on the landscape, and altering physical attributes of the hair traps. The quality of hair samples we collected and subsequent amplification rates indicated that, along with proper deployment strategies, hair traps are a viable tool for noninvasively collecting genetic material for individual identification of mountain lions and other elusive species.

Evaluation of Contacts of the Patients with Negative COVID RT-PCR and Thorax CT findings compatible with Covid-19 Pneumonia

Objectives: This study aimed to evaluate the test results of patients whose RT-PCR test result was negative, but thorax CT findings were compatible with COVID-19 and their infectiousness in terms of contacts. Materials and Methods: The study was designed as cross-sectional, descriptive research. In the first group, thorax CT revealed findings compatible with COVID-19 pneumonia, and the RT-PCR test result was negative. In the second group, thorax CT revealed findings compatible with COVID-19 pneumonia, and the RT-PCR test result was positive. Data collected were assessed with SPSS 21.0 software program. The significance level was accepted as 5%. Results: Of the participants, 54.41% were male, and 45.59% were female. There was no significant difference between the two groups in terms of contact environment and status of being a healthcare worker and exitus. There was no difference between the first and second groups in terms of the number of contacts. The rate of sample collection was higher in the second group. The number of people who had contact with the patients and positive RT-PCR test results was higher in the first group. Conclusion: Even if patients have negative RT-PCR test results for COVID-19, they are still infectious. © 2021 Ankara Yildirim Beyazit University. All rights reserved.

Standardized sputum collection increases sputum sample collection rate for novel coronavirus nucleic acid detection

To evaluate the effect of standardized health education on the sputum specimen collection rate for nucleic acid detection of coronavirus disease 2019 (COVID-19). Two hundred and twenty-seven patients in fever clinics and isolation wards of Sir Run Run Shaw Hospital of Zhejiang University and 307 migrant workers returning to 5 enterprises in Shanghai from February 3 to March 14, 2020 were enrolled in the study. Through clarifying the procedures of collecting sputum specimens, making graphic/video health education materials, standardizing the contents and methods of health education, we conducted education to the subjects. The subject expectorated spontaneously or with medical assistance. For patients, the number of sampling attempts and sputum acquisition times were documented before and after the implementation of the standardized expectoration method; for the returning migrant employees in the enterprises, only the number of collected samples after the implementation of the standardized expectoration method were recorded. A total of 378 sputum samples were collected from 227 patients. The sputum sampling rates before and after the implementation of health education were 40.9%and 58.4%, respectively (P<0.01). A total of 304 sputum samples were obtained from 307 enterprise returnees, with a sample collection rate of 99.0%. The education for standardized sputum sample collection method can effectively increase the sputum collection rate.

Trends of human influenza infection in Chhattisgarh: a retrospective observational study

Background: Human influenza virus was recognized as a pandemic in 2009 by the World Health Organization (WHO). Since then many newer incidences was recognized in India, but there was no sufficient data from all state of India. This study will provide data from the Chhattisgarh state of India.Methods: It was a retrospective observational study from December 2015 to November 2017. All patient samples with suspected influenza infection were collected and analysed by Real-time reverse polymerase chain reaction (RT-PCR).Results: 341 patients’ sample was collected and analysed; among these samples, 07.9% of patients have all three serotype of influenza positive. Raipur district has the highest incidence of influenza A followed by Durg and Raigarh district of Chhattisgarh. There was no significant difference between male and female who was affected by the influenza virus.Conclusions: The incidence of Human influenza virus is lesser in Chhattisgarh as compare to the average states of India and the state capital has a higher rate of sample collection as well as positive influenza infection.

Platelet Detection in Unaltered Whole Blood

Abstract Platelets are non-nucleated cellular fragments circulating in the peripheral blood, derived from megakaryocytes. They are critical in the maintenance of hemostasis. Alterations in their function are associated with a range of clinical conditions. Using flow cytometry, light scatter signals from platelets typically overlap signals from red blood cells (RBC). Since RBC outnumber platelets by more than an order of magnitude in whole blood, platelets are typically studied by depleting samples of RBCs by centrifugation methods or selective RBC cell lysis. These sample preparation procedures require manipulations that may affect platelet health and function, and result in loss of cells. Additionally, lysed samples require labeling of the platelets with a fluorescent marker to adequately resolve the platelets from debris/noise. We present a novel technique for resolving leukocytes and platelets from RBC in whole blood using orthogonal light scatter from 2 lasers. This method exploits the differences in light-scattering properties between RBCs and platelets and white blood cells (WBC). Hemoglobin readily absorbs 405 nm laser light, reducing the scatter signal from RBC relative to WBCs and platelets, resulting in a reproducible scatter pattern when analyzing human whole blood with both blue (488 nm) and violet (405 nm) side scatter. Using this approach, a distinct platelet population can be discerned in unaltered whole blood, requiring only dilution of whole blood in buffer. Combining this approach with acoustic cytometry allows great flexibility in determining optimal dilution and sample collection rates for minimal coincidence and rapid analysis. For research use only. Not for use in diagnostic procedures.

Faster clean catch urine collection (Quick-Wee method) from infants: randomised controlled trial

Objective To determine if a simple stimulation method increases the rate of infant voiding for clean catch urine within five minutes.Design Randomised controlled trial.Setting Emergency department of a tertiary paediatric...

System Design and Development of a Robotic Device for Automated Venipuncture and Diagnostic Blood Cell Analysis.

Diagnostic blood testing is the most prevalent medical procedure performed in the world and forms the cornerstone of modern health care delivery. Yet blood tests are still predominantly carried out in centralized labs using large-volume samples acquired by manual venipuncture, and no end-to-end solution from blood draw to sample analysis exists today. Our group is developing a platform device that merges robotic phlebotomy with automated diagnostics to rapidly deliver patient information at the site of the blood draw. The system couples an image-guided venipuncture robot, designed to address the challenges of routine venous access, with a centrifuge-based blood analyzer to obtain quantitative measurements of hematology. In this paper, we first present the system design and architecture of the integrated device. We then perform a series of in vitro experiments to evaluate the cannulation accuracy of the system on blood vessel phantoms. Next, we assess the effects of vessel diameter, needle gauge, flow rate, and viscosity on the rate of sample collection. Finally, we demonstrate proof-of-concept of a white cell assay on the blood analyzer using in vitro human samples spiked with fluorescently labeled microbeads.

Newborn Screening for Sickle Cell Disease: Jamaican Experience.

To review the history of newborn screening for sickle cell disease with especial reference to Jamaica. A summary was done of the history, the development of associated laboratory technology and the implementation of newborn screening for sickle cell disease in Jamaica. Screening was initiated at Victoria Jubilee Hospital, Kingston from 1973-1981, reactivated in 1995 and extended to the University Hospital of the West Indies in 1997 and to Spanish Town Hospital in 1998. From August 2008, there was a progressive recruitment of 12 hospitals in the south and west of Jamaica which has raised the frequency of islandwide newborn coverage from 25% in 1973 to 81%. The results of this extended programme in southwest Jamaica are presented. Dried blood spots collected from the umbilical cord proved stable, cheap and efficient; mean sample collection rates were 98%, maternal contamination occurred in < 1% and caused diagnostic confusion in < 0.1%. By March 31, 2015, a total of 54 566 births have been screened, detecting 161 with homozygous sickle cell (SS) disease, 125 with sickle cell-haemoglobin C (SC) disease and 36 with sickle cell-beta thalassaemia. Of the 327 babies with clinically significant sickle cell syndromes, all except five who died within seven days of birth were confirmed by four to six weeks and recruited to local sickle cell clinics. Early detection of sickle cell disease and recruitment to clinics is known to reduce its morbidity and mortality. The methods currently detailed provide an effective and economic model of newborn screening which may be of value elsewhere.

Feasibility and informative value of environmental sample collection in the National Children's Vanguard Study

BackgroundBirth cohort studies provide the opportunity to advance understanding of the impact of environmental factors on childhood health and development through prospective collection of environmental samples. MethodsWe evaluated the feasibility and informative value of the environmental sample collection methodology in the initial pilot phase of the National Children's Study, a planned U.S. environmental birth cohort study. Environmental samples were collected from January 2009–September 2010 at up to three home visits: pre-pregnancy (n=306), pregnancy (n=807), and 6-months postnatal (n=117). Collections included air for particulate matter ≤2.5µm (PM2.5), nitrogen dioxide, ozone, volatile organic compounds (VOCs), and carbonyls; vacuum dust for allergens/endotoxin; water for VOCs, trihalomethanes (THMs), and haloacetic acids (HAAs); and wipe samples for pesticides, semi-volatile organics, and metals. We characterized feasibility using sample collection rates and times and informative value using analyte detection frequencies (DF). ResultsAmong the 1230 home visits, environmental sample collection rates were high across all sample types (mean=89%); all samples except the air PM2.5 samples had collection times <30min. Informative value was low for water VOCs (median DF=0%) and pesticide floor wipes (median DF=5%). Informative value was moderate for air samples (median DF=35%) and high for water THMs and HAAs (median DF=91% and 75%, respectively). ConclusionsThough collection of environmental samples was feasible, some samples (e.g., wipe pesticides and water VOCs) yielded limited information. These results can be used in conjunction with other study design considerations, such as target population size and hypotheses of interest, to inform the method selection of future environmental health birth cohort studies.

Performanc of Meales Surveillance System in Zhuhai during 2009-2012

Objective To evaluate the running status of Measles Surveillance System(MSS) in Zhuhai during 2009-2012 and to provide some references for enhancing measles surveillance and eliminating measles in Zhuhai.Methods All the cases of measles-like illnesses(MLIs) reported during 2009 to 2012 were collected.The main indicators were analyzed to evaluate the quality.Results From year 2009 to 2012,there were 217 MLIs cases reported from the Measles Surveillance System.87 cases were finally diagnosed with Measles.The reporting rate of suspected cases were 0.94/100,000,1.54/100,000,3.01/100,000,1.92/10 0000 from 2009 to 2012,respectively.The investigation rate of suspected cases in 48 hours increased from 29.48％ to 100.00％.Blood sample collection rate of suspected cases also increased from 25.64％ to 97.62％.Conclusions In Zhuhai City,the quality of Measles Surveillance System got better year by year from 2009 to 2012. Key words: Measles; Measles Surveillance System; Measles surveillance quality

A modified sulphur hexafluoride tracer technique enables accurate determination of enteric methane emissions from ruminants

The sulphur hexafluoride (SF6) tracer technique enables determination of enteric methane emissions from large numbers of individual ruminant animals. The objective of this research was to identify and correct substantial errors within the SF6 technique. Six experiments were undertaken using respiration chamber, laboratory or SF6 techniques. Experiment 1 used respiration chambers to demonstrate that the daily pattern of methane emissions from dairy cows was related to their pattern of feed intake. In contrast, the daily emission of SF6 from these cows was constant and independent of the pattern of methane emission. This finding supports the contention that in order to accurately determine daily methane emissions using the SF6 technique, it is necessary that gases are collected continuously at a constant rate for 24h. Since development of the SF6 technique in 1993, it has been propounded that capillary-tube flow restrictors achieved a constant rate of sample collection into evacuated gas collection canisters. Laboratory experiments 2, 3, 4 and 5 demonstrated that, when capillary-tube flow restrictors are used, the rate of sample collection declined and caused a bias of up to 15.6% in calculated methane emissions. This error was caused by an interaction between the declining sample collection rate and the pattern of an animal's methane emission over 24h. In contrast, orifice plate flow restrictors maintained a constant sample collection rate at canister pressures <0.31atm and thereby minimised the decline in sample collection rate. Experiment 5 also demonstrated that sample collection using orifice plate flow restrictors, combined with initial (<0.03atm) and final (<0.49atm) canister pressures, substantially reduced measurement error. Accuracy of the modified SF6 technique, incorporating orifice plate flow restrictors for 24h sample collection, was validated in Experiment 6. The mean (S.D.) methane yield (g CH4/kg DMI) of eight cows did not differ (P=0.135) when determined using the modified SF6 technique 22.3 (1.44) or chambers 21.9 (1.65). In addition, the between-animal coefficient of variation for methane yield determined using the modified SF6 technique (6.5%) was similar to that determined using chambers (7.5%). Consequently the modified SF6 technique enables the statistical power of experiments to be increased or their size decreased. We conclude that the modified SF6 technique reduced error associated with SF6 release, sample collection and analysis. It is recommended that the modified SF6 technique should be used in preference to the original SF6 technique for determination of enteric methane emissions from ruminants.