BACKGROUND: In previous publications, the Task Force on Reference Measurement System Implementation proposed a procedural approach combining a critical review of entries available in the Joint Committee on Traceability in Laboratory Medicine (JCTLM) database with a comparison of this information against analytical performance specifications for measurement uncertainty (MU) and applied it to a group of 13 measurands. CONTENT: Here we applied this approach to 17 additional measurands, of which measurements are frequently requested. The aims of the study were (a) to describe the main characteristics for implementing traceability and the potential to fulfill the maximum allowable MU (MAU) at the clinical sample level of certified reference materials and reference measurement procedures listed in the JCTLM database; (b) to discuss limitations and obstacles, if any, to the achievement of the required quality of laboratory measurements; and (c) to provide a gap analysis by highlighting what is still missing in the database. Results were integrated with those obtained in the previous study, therefore offering an overview of where we are and what is still missing in the practical application of the metrological traceability concept to 30 common biochemical tests employed in laboratory medicine. SUMMARY: Our analysis shows that for 28 out of 30 measurands, conditions exist to correctly implement metrological traceability to the International System of units and fulfill at least the MAU of the minimum quality level derived according to internationally recommended models. For 2 measurands (serum albumin and chloride), further improvements in MU of higher-order references would be necessary.

BACKGROUND: National Malaria Programmes (NMPs) monitor the durability of insecticide-treated nets (ITNs) to inform procurement and replacement decisions. This is crucial for new dual active ingredients (AI) ITNs, for which less data is available. Pyrethroid-only ITN (Interceptor(®)) and dual AI (Interceptor® G2, and PermaNet(®) 3.0) ITNs were assessed across three health districts over 36 months in southern Burkina Faso to estimate median ITN survival, insecticidal efficacy, and to identify factors contributing to field ITN longevity. METHODS: Durability was monitored through a prospective study of a cohort of nets distributed during the 2019 mass campaign. Three health districts were selected for their similar pyrethroid-resistance, environmental, epidemiological, and population profiles. Households were recruited after the mass campaign, with annual household questionnaire follow-ups over three years. Each round, ITNs were withdrawn for bioassays and chemical residue testing. Key measures were the percentage of cohort ITNs in serviceable condition, insecticidal effectiveness, and chemical residue content against target dose. Cox proportional hazard models were used to identify determinants influencing ITN survival. RESULTS: At endline, the median useful life was 3.2 (95% CI 2.5-4.0) years for PermaNet(®) 3.0 ITNs in Orodara, 2.6 (95% CI 1.9-3.2) years for Interceptor® G2 ITNs in Banfora and 2.4 (95% CI 1.9-2.9) years for Interceptor® ITNs in Gaoua. Factors associated with ITN survival included cohort ITNs from Orodara (adjusted hazard ratio (aHR) = 0.58, p = 0.026), households seeing less rodents (aHR = 0.66, p = 0.005), female-headed households (aHR = 0.66, p = 0.044), exposure to social behavior change (SBC) messages (aHR = 0.52, ≤ 0.001) and folding nets when not in use (aHR = 0.47, p < 0.001). At endline, PermaNet® 3.0 ITN recorded 24-h mortality of 26% against resistant mosquitos on roof panels, with an 84% reduction in PBO content. Interceptor(®) G2 ITN 72-h mortality was 51%, with a 67% reduction in chlorfenapyr content. Interceptor(®) ITN 24-h mortality was 71%, with an 84% reduction in alpha-cypermethrin content. CONCLUSION: Only PermaNet(®) 3.0 ITNs surpassed the standard three-year survival threshold. Identified protective factors should inform SBC messaging. Significant decreases in chemical content and resulting impact on bioefficacy warrant more research in other countries to better understand dual AI ITN insecticidal performance.

PURPOSE: Population-based prevalence surveys are essential for decision-making on interventions to achieve trachoma elimination as a public health problem. This paper outlines the methodologies of Tropical Data, which supports work to undertake those surveys. METHODS: Tropical Data is a consortium of partners that supports health ministries worldwide to conduct globally standardised prevalence surveys that conform to World Health Organization recommendations. Founding principles are health ministry ownership, partnership and collaboration, and quality assurance and quality control at every step of the survey process. Support covers survey planning, survey design, training, electronic data collection and fieldwork, and data management, analysis and dissemination. Methods are adapted to meet local context and needs. Customisations, operational research and integration of other diseases into routine trachoma surveys have also been supported. RESULTS: Between 29(th) February 2016 and 24(th) April 2023, 3373 trachoma surveys across 50 countries have been supported, resulting in 10,818,502 people being examined for trachoma. CONCLUSION: This health ministry-led, standardised approach, with support from the start to the end of the survey process, has helped all trachoma elimination stakeholders to know where interventions are needed, where interventions can be stopped, and when elimination as a public health problem has been achieved. Flexibility to meet specific country contexts, adaptation to changes in global guidance and adjustments in response to user feedback have facilitated innovation in evidence-based methodologies, and supported health ministries to strive for global disease control targets.

INTRODUCTION: the goal of the Field Epidemiology Training Program (FETP) - Frontline is to strengthen the country's surveillance capacity at the district level to prepare and respond to health emergencies, including outbreaks, by training a skilled frontline public health workforce. We describe the FETP - Frontline program, including implementation, structure, achievements, impact, and its role in improving the epidemiological workforce capacity of Guinea-Bissau. METHODS: this cross-sectional descriptive study uses 2015-2019 program data collected through record reviews and historical narratives from FETP students and graduates. We generated descriptive summary statistics using the Guinea-Bissau's FETP-Frontline program database, student assignments, and investigation reports, after reviewing the FETP standardized curriculum and program guidelines. RESULTS: since its inception in 2016, FETP Frontline has implemented 14 cohorts and trained 198 frontline surveillance officers. Program participants improved surveillance data quality, investigated 51 outbreaks at national and regional levels, and contributed to disease research and surveillance in 227 separate field investigations. Participants frequently responded to priority health emergencies, including clusters or outbreaks of Zika, microencephalies, dengue, yellow fever, anthrax, malaria, and tuberculosis. CONCLUSION: Guinea-Bissau's FETP - Frontline program provides a practical example of an effective strategy to strengthen health systems through a well-prepared workforce trained to quickly detect and respond to health threats.

It is important for external quality assessment materials (EQAMs) to be commutable with clinical samples; i.e., they should behave like clinical samples when measured using end-user clinical laboratory in vitro diagnostic medical devices (IVD-MDs). Using commutable EQAMs makes it possible to evaluate metrological traceability and/or equivalence of results between IVD-MDs. The criterion for assessing commutability of an EQAM between 2 IVD-MDs is that its result should be within the prediction interval limits based on the statistical distribution of the clinical sample results from the 2 IVD-MDs being compared. The width of the prediction interval is, among other things, dependent on the analytical performance characteristics of the IVD-MDs. A presupposition for using this criterion is that the differences in nonselectivity between the 2 IVD-MDs being compared are acceptable. An acceptable difference in nonselectivity should be small relative to the analytical performance specifications used in the external quality assessment scheme. The acceptable difference in nonselectivity is used to modify the prediction interval criterion for commutability assessment. The present report provides recommendations on how to establish a criterion for acceptable commutability for EQAMS, establish the difference in nonselectivity that can be accepted between IVD-MDs, and perform a commutability assessment. The report also contains examples for performing a commutability assessment of EQAMs.

A secondary higher-order calibrator is required to be commutable with clinical samples to be suitable for use in the calibration hierarchy of an end-user clinical laboratory in vitro diagnostic medical device (IVD-MD). Commutability is a property of a reference material that means results for a reference material and for clinical samples have the same numeric relationship, within specified limits, across the measurement procedures for which the reference material is intended to be used. Procedures for assessing commutability have been described in the literature. This report provides recommendations for establishing a quantitative criterion to assess the commutability of a certified reference material (CRM). The criterion is the maximum allowable noncommutability bias (MANCB) that allows a CRM to be used as a calibrator in a calibration hierarchy for an IVD-MD without exceeding the maximum allowable combined standard uncertainty for a clinical sample result (umaxCS). Consequently, the MANCB is derived as a fraction of the umaxCS for the measurand. The suitability of an MANCB for practical use in a commutability assessment is determined by estimating the number of measurements of clinical samples and CRMs required based on the precision performance and nonselectivity for the measurand of the measurement procedures in the assessment. Guidance is also provided for evaluating indeterminate commutability conclusions and how to report results of a commutability assessment.

Background Guinea is a West African country with a high prevalence of vector-borne diseases where few entomological studies have been undertaken. Although several mosquito collection methods are routinely used for surveillance in vector control programmes, they target different behaviours causing bias in species diversity and abundance. Given the paucity of mosquito trap data in West Africa, we compared the performance of five trap-lure combinations and Human Landing Catches (HLCs) in Guinea.Methods Five mosquito traps were compared in a 5×5 Latin Square design for 15 days in three villages in Guinea between June and July 2018. CDC light traps, BG sentinel 2 traps (with BG and MB5 lures), gravid traps and Stealth traps were deployed for 24-hour intervals with mosquitoes collected every 12 hours (day and night collections). HLCs were also performed for 15 nights. A Generalised Linear Mixed Model was applied to compare the effect of the traps, sites and collection times on the mosquito abundance. Species identification was confirmed using PCR-based analysis and Sanger sequencing.Results In total, 10,610 mosquitoes were captured across all five traps. Significantly more mosquitoes (P&lt;0.005) were collected by Stealth traps (7,096) compared to the rest of the traps. Stealth traps and BG sentinel 2 traps were the best at capturing An. gambiae and Ae. aegypti mosquitoes respectively. HLCs captured predominantly An. coluzzii (41%) and hybrids of An. gambiae s.s. / An. coluzzii (36%) in contrast to the five adult traps, which captured predominantly An. melas (83%). Senguelen (rural) presented the highest abundance of mosquitoes and overall diversity in comparison with Fandie (semi-rural) and Maferinyah Centre One (semi-urban). To our knowledge, four species are reported for the first time in Guinea.Conclusions Stealth traps presented the best performance overall, suggesting that this trap may play an important role for mosquito surveillance in Guinea and similar sites in West Africa. We recommend the incorporation of molecular tools in entomological studies since it has helped to reveal, together with morphological identification, the presence of 25 mosquito species in this area.BG2BG sentinel 2 trapBG2-BGBG sentinel 2 trap with BG lureBG2-MB5BG sentinel 2 trap with MB5 lureGLMMgeneralized linear mixed modelGTGravid trapHLCHuman Landing CatchLTCDC light trapSTStealth trap

Background In recent years, the scale-up of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) has greatly reduced malaria transmission. However, malaria remains a global public health concern with the majority of disease burden in sub-Saharan Africa. Insecticide resistance is a growing problem among Anopheles vector populations, with potential implications for the continued effectiveness of available control interventions. Improved understanding of current resistance levels and underlying mechanisms is essential to design appropriate management strategies and to mitigate future selection for resistance.Methods Anopheles gambiae s.l. mosquitoes were collected from three villages in Faranah Prefecture, Guinea and their levels of susceptibility to seven insecticides were measured using CDC resistance intensity bioassays. Synergist assays with piperonyl butoxide (PBO) were also undertaken to assess the role of elevated mixed-function oxidases in resistance. RNA was extracted from 563 individuals and PCR was performed on cDNA to determine vector species, presence of target site mutations (L1014F kdr, N1575Y and G119S Ace-1), Plasmodium falciparum infection, and relative expression of three metabolic genes (CYP6M2, CYP6P3 and GSTD3).Results In Faranah, resistance to permethrin and deltamethrin was observed, as well as possible resistance to bendiocarb. All assayed vector populations were fully susceptible to alpha-cypermethrin, pirimiphos-methyl, clothianidin and chlorfenapyr. Plasmodium falciparum infection was detected in 7.3% (37/508) mosquitoes tested. The L1014F kdr mutation was found in 100% of a sub-sample of 60 mosquitoes, supporting its fixation in the region. The N1575Y mutation was identified in 20% (113/561) of individuals, with ongoing selection evidenced by significant deviations from Hardy-Weinberg equilibrium. The G119S Ace-1 mutation was detected in 62.1% (18/29) of mosquitoes tested and was highly predictive of bendiocarb bioassay survival. The metabolic resistance genes, CYP6M2, CYP6P3 and GSTD3, were found to be overexpressed in wild resistant and susceptible An. gambiae s.s. populations, compared to a susceptible G3 colony. Furthermore, CYP6P3 was significantly overexpressed in bendiocarb survivors, implicating its potential role in carbamate resistance in Faranah.Conclusions Identification of intense resistance to permethrin and deltamethrin in Faranah, is of concern, as the Guinea National Malaria Control Program (NMCP) relies exclusively on the distribution of pyrethroid-treated LLINs for vector control. Study findings will be used to guide current and future control strategies in the region.

Anopheles (An.) mosquitoes contain bacteria that can influence Plasmodium parasites. Wolbachia, a common insect endosymbiont, has historically been considered absent from Anopheles but has recently been found in An. gambiae populations. Here, we assessed a range of Anopheles species from five malaria-endemic countries for Wolbachia and Plasmodium infection. Strikingly, we found Wolbachia infections in An. coluzzii, An. gambiae s.s, An. arabiensis, An. moucheti and An. species ‘A’ increasing the number of Anopheles species known to be naturally infected by this endosymbiont. Molecular analysis suggests the presence of phylogenetically diverse novel strains, while qPCR and 16S rRNA sequencing indicates that Wolbachia is the dominant member of the microbiota in An. moucheti and An. species ‘A’. We found no evidence of Wolbachia/Asaia co-infections, and presence of these endosymbionts did not have significant effects on malaria prevalence. We discuss the importance of novel Wolbachia strains in Anopheles and potential implications for disease control.

Malaria, a major cause of child mortality in Africa, is engendered by Plasmodium parasites that are transmitted by anopheline mosquitoes. Fitness of Plasmodium parasites is closely linked to the ecology and evolution of its anopheline vector. However, whether the genetic structure of vector populations impacts malaria transmission remains unknown. Here, we describe a partitioning of the African malaria vectors into generalists and specialists that evolve along ecological boundaries. We next identify the contribution of mosquito species to Plasmodium abundance using Granger causality tests for time-series data collected over two rainy seasons in Mali. We find that mosquito microevolution, defined by changes in the genetic structure of a population over short ecological timescales, drives Plasmodium dynamics in nature, whereas vector abundance, infection prevalence, temperature and rain have low predictive values. Our study demonstrates the power of time-series approaches in vector biology and highlights the importance of focusing local vector control strategies on mosquito species that drive malaria dynamics.

The US National Institute of Standards and Technology (NIST) developed a Standard Reference Material (SRM) 3949 Folate Vitamers in Frozen Human Serum to replace SRM 1955 Homocysteine and Folate in Human Serum. The presence of increased endogenous levels of folic acid and 5-methyltetrahydrofolate (5mTHF) in SRM 3949, enhanced folate stability via addition of ascorbic acid, and inclusion of values for additional minor folates are improvements over SRM 1955 that should better serve the clinical folate measurement community. The new SRM contains folates at three levels. To produce SRM 3949, pilot sera were collected from 15 individual donors, 5 of whom were given a 400-g folic acid supplement 1h prior to blood draw to increase serum levels of 5mTHF and folic acid for the high-level material. To stabilize the folates, 0.5% (mass concentration) ascorbic acid was added as soon as possible after preparation of serum. These pilot sera were screened for five folates plus the pyrazino-s-triazine derivative of 4--hydroxy-5-methyltetrahydrofolate (MeFox) at the US Centers for Disease Control and Prevention (CDC) by isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS). Based on these results, a blending protocol was specified to obtain the three desired folate concentrations for SRM 3949. ID-LC-MS/MS analysis at the CDC and NIST was utilized to assign values for folic acid and 5mTHF, as well as several minor folates.

The 2014-2016 Ebola outbreak in Guinea revealed systematic weaknesses in the existing disease surveillance system, which contributed to delayed detection, underreporting of cases, widespread transmission in Guinea and cross-border transmission to neighboring Sierra Leone and Liberia, leading to the largest Ebola epidemic ever recorded. Efforts to understand the epidemic's scale and distribution were hindered by problems with data completeness, accuracy, and reliability. In 2017, recognizing the importance and usefulness of surveillance data in making evidence-based decisions for the control of epidemic-prone diseases, the Guinean Ministry of Health (MoH) included surveillance strengthening as a priority activity in their post-Ebola transition plan and requested the support of partners to attain its objectives. The U.S. Centers for Disease Control and Prevention (US CDC) and four of its implementing partners-International Medical Corps, the International Organization for Migration, RTI International, and the World Health Organization-worked in collaboration with the Government of Guinea to strengthen the country's surveillance capacity, in alignment with the Global Health Security Agenda and International Health Regulations 2005 objectives for surveillance and reporting. This paper describes the main surveillance activities supported by US CDC and its partners between 2015 and 2019 and provides information on the strategies used and the impact of activities. It also discusses lessons learned for building sustainable capacity and infrastructure for disease surveillance and reporting in similar resource-limited settings.

New tools are needed for malaria control, and recent improvements in malaria surveillance have opened the possibility of transforming surveillance into a core intervention. Implementing this strategy can be challenging in moderate to high transmission settings. However, there is a wealth of practical experience among national malaria control programs and partners working to improve and use malaria surveillance data to guide programming. Granular and timely data are critical to understanding geographic heterogeneity, appropriately defining and targeting interventions packages, and enabling timely decision-making at the operational level. Resources to be targeted based on surveillance data include vector control, case management commodities, outbreak responses, quality improvement interventions, and human resources, including community health workers, as they contribute to a more refined granularity of the surveillance system. Effectively transforming malaria surveillance into a core intervention will require strong global and national leadership, empowerment of subnational and local leaders, collaboration among development partners, and global coordination. Ensuring that national health systems include community health work can contribute to a successful transformation. It will require a strong supply chain to ensure that all suspected cases can be diagnosed and data reporting tools including appropriate electronic devices to provide timely data. Regular data quality audits, decentralized implementation, supportive supervision, data-informed decision-making processes, and harnessing technology for data analysis and visualization are needed to improve the capacity for data-driven decision-making at all levels. Finally, resources must be available to respond programmatically to these decisions.

BACKGROUND: Care plans are central to effective care delivery for people with multiple chronic conditions. But existing care plans-which typically are difficult to share across care settings and care team members-poorly serve people with multiple chronic conditions, who often receive care from numerous clinicians in multiple care settings. Comprehensive, shared electronic care (e-care) plans are dynamic electronic tools that facilitate care coordination and address the totality of health and social needs across care contexts. They have emerged as a potential way to improve care for individuals with multiple chronic conditions. OBJECTIVE: To review the landscape of e-care plans and care plan-related initiatives that could allow the creation of a comprehensive, shared e-care plan and inform a joint initiative by the National Institutes of Health and the Agency for Healthcare Research and Quality to develop e-care planning tools for people with multiple chronic conditions. METHODS: We conducted a scoping review, searching literature from 2015 to June 2020 using Scopus, Clinical Key, and PubMed; we also searched the gray literature. To identify initiatives potentially missing from this search, we interviewed expert informants. Relevant data were then identified and extracted in a structured format for data synthesis and analysis using an expanded typology of care plans adapted to our study context. The extracted data included (1) the perspective of the initiatives; (2) their scope, (3) network, and (4) context; (5) their use of open syntax standards; and (6) their use of open semantic standards. RESULTS: We identified 7 projects for e-care plans and 3 projects for health care data standards. Each project provided critical infrastructure that could be leveraged to promote the vision of a comprehensive, shared e-care plan. All the e-care plan projects supported both broad goals and specific behaviors; 1 project supported a network of professionals across clinical, community, and home-based networks; 4 projects included social determinants of health. Most projects specified an open syntax standard, but only 3 specified open semantic standards. CONCLUSIONS: A comprehensive, shared, interoperable e-care plan has the potential to greatly improve the coordination of care for individuals with multiple chronic conditions across multiple care settings. The need for such a plan is heightened in the wake of the ongoing COVID-19 pandemic. While none of the existing care plan projects meet all the criteria for an optimal e-care plan, they all provide critical infrastructure that can be leveraged as we advance toward the vision of a comprehensive, shared e-care plan. However, critical gaps must be addressed in order to achieve this vision.

In 2017, the national agency for health security (L'Agence Nationale de Sécurité Sanitaire-ANSS) in Guinea implemented the District Health Information Software (DHIS2) as the Ministry of Health national surveillance system to capture and report aggregate disease data. During 2019, the ANSS started using DHIS2 Tracker to collect case-based (individual-level) data for epidemic-prone diseases. In 2020, the capability was expanded, and it was used during the COVID-19 pandemic to capture data relevant to the COVID-19 response. When an Ebola virus disease (EVD) outbreak was announced in February 2021, the Tracker module was updated, and enhanced functionalities were developed to meet the needs for the emerging epidemic. This novel EVD module has components to capture information on cases, contacts, alerts, laboratory and vaccinations and provides a centralised site for all EVD outbreak data. It has since been expanded for use with future viral haemorrhagic fever outbreaks.

This study aimed to determine the interactive physiological effect of backpack load carriage and slope during walking in professional mountain rescuers. Sixteen mountain rescuers walked on a treadmill at 3.6 km/h for 5 min in each combination of three slopes (1%, 10%, 20%) and five backpack loads (0%, 10%, 20%, 30%, and 40% body weight). Relative heart rate (%HRmax), relative oxygen consumption (%VO(2)max), and rating of perceived exertion (RPE, Borg 1-10 scale) were compared across conditions using two-way ANOVA. Significant differences in %VO(2)max, %HRmax, and RPE across slopes and loads were found where burden increased directly with slope and load (main effect of slope, p < 0.001 for all; main effect of load, p < 0.001 for all). Additionally, significant slope by load interactions were found for all parameters, indicating an additive effect (p < 0.001 for all). Mountain rescuers should consider the physiological interaction between slope and load when determining safe occupational walking capacity.

A robust epidemic-prone disease surveillance system is a critical component of public health infrastructure and supports compliance with the International Health Regulations (IHR). One digital health platform that has been implemented in numerous low- and middle-income countries is the District Health Information System Version 2 (DHIS2). In 2015, in the wake of the Ebola epidemic, the Ministry of Health in Guinea established a strategic plan to strengthen its surveillance system, including adoption of DHIS2 as a health information system that could also capture surveillance data. In 2017, the DHIS2 platform for disease surveillance was piloted in two regions, with the aim of ensuring the timely availability of quality surveillance data for better prevention, detection, and response to epidemic-prone diseases. The success of the pilot prompted the national roll-out of DHIS2 for weekly aggregate disease surveillance starting in January 2018. In 2019, the country started to also use the DHIS2 Tracker to capture individual cases of epidemic-prone diseases. As of February 2020, for aggregate data, the national average timeliness of reporting was 72.2%, and average completeness 98.5%; however, the proportion of individual case reports filed was overall low and varied widely between diseases. While substantial progress has been made in implementation of DHIS2 in Guinea for use in surveillance of epidemic-prone diseases, much remains to be done to ensure long-term sustainability of the system. This paper describes the implementation and outcomes of DHIS2 as a digital health platform for disease surveillance in Guinea between 2015 and early 2020, highlighting lessons learned and recommendations related to the processes of planning and adoption, pilot testing in two regions, and scale up to national level.

Melt crystallized polymers display an emergent, multi-hierarchical, ordered structure made up of stacked lamellar single crystals that form fibrous or other meso structures which, in turn, form macroscopic crystallites. A dominant feature of small-angle scattering from these complex assemblies is a correlation peak associated with the stacking period. A new model-based function is proposed for small-angle scattering data from such correlated lamellar multi-hierarchical structures. Generally, routine use of scattering data has been limited to a 1-d analysis to determine the long period from Lorentz corrected data (I(q)q2 versus q). Fourier transforms of the data are sometimes used to determine the 1-d pairwise correlation function for the electron-density distribution which has been further analyzed in terms of the structure of these materials. A simple 1-d fitting model limited to infinite width 2-d sheets was introduced by Hermans (1944; Hosemann, 1950) [1,2] in the 1940s with some success. A new approach, the Unified Born-Green Function (UBG), is proposed that uses the Unified Function as adapted to correlated lamellar structures and incorporates a Born-Green description of one-dimensional correlations. The UBG fit allows quantification of the average lamellar aspect ratio, the local degree of crystallinity within a stack, quantification of the stacking versus non-stacking amorphous, and two types of disorder in addition to the stacking period and lamellar thickness. UBG can account for higher levels of structure such as crystalline domains in block copolymers and convoluted lamellar structure. The UBG fit is compared to the Hermans (1944; Hosemann, 1950) [1,2] and a hybrid-Hermans function. Fits to data sets from a wide range of polyethylene are shown ranging from molecular weight standard samples that are isothermally crystallized, to commercial HDPE quenched from the melt and a metallocene blown film sample. Several other examples from the literature are explored. It is shown that the Unified fit allows for new understanding of the impact of thermal and mechanical history, chain structure, fillers, nucleating agents, and additives on the crystalline structure and the resulting physical properties. Limitations of the UBG approach are noted. © 2021 Elsevier Ltd

BACKGROUND: The JCTLM created a Task Force on Reference Measurement System Implementation (TF-RMSI) to provide guidance on metrological traceability implementation for the in vitro diagnostics (IVD) community. CONTENT: TF-RMSI investigated the reference measurement systems (RMS) for 13 common measurands by applying the following procedural steps: (a) extracting data from the JCTLM database of available certified reference materials (CRMs) and reference measurement procedures (RMPs); (b) describing the RMS to which each recruited CRM or RMP belongs; (c) identifying the intended use of the CRMs, and, if used as a common calibrator for IVD measuring systems and/or trueness assessment of field methods was included, checking the CRM's certificate for information about commutability with clinical samples; and (d) checking if the CRM or RMP measurement uncertainty (MU) has the potential to be small enough to avoid significantly affecting the analytical performance specifications (APS) for MU of clinical sample results when the MU from the IVD calibrator and from the end-user measuring system were combined. SUMMARY: We produced a synopsis of JCTLM-listed higher-order CRMs and RMPs for the selected measurands, including their main characteristics for implementing traceability and fulfilling (or not) the APS for suitable MU. Results showed that traceability to higher-order references can be established by IVD manufacturers within the defined APS for most of the 13 selected measurands. However, some measurands do not yet have suitable CRMs for use as common calibrators. For these measurands, splitting clinical samples with a laboratory performing the RMP may provide a practical alternative for establishing a calibration hierarchy.

Little is known about respiratory viruses infection in Guinea. Influenza surveillance has not been implemented in Guinea mainly because of the paucity of laboratory infrastructure and capacity. This paper presents the first influenza surveillance data in Guinea.Swabs were obtained from August 2018 through December 2019 at influenza sentinel sites and transported to the Institut National de Sante Publique for testing. Ribonucleic acid was extracted and tested for the presence of influenza A and B by real-time reverse transcription-polymerase chain reaction (RT-PCR). Positive samples were further characterised to determine the subtypes and lineages of influenza viruses.A total of 862 swabs were collected and tested. Twenty-three per cent of samples tested positive for influenza A and B viruses. Characterisation of positive specimens identified influenza A/H1N1pmd09 (2.5%), influenza A/H3N2 (57.3%), influenza B/Victoria lineage (36.7%) and 7 (3.5%) influenza B with undetermined lineage. Influenza B virus activity clustered in August through November while influenza A/H3N2 displayed two clusters of activities that appeared in May through August and November through December.For the first time in Guinea, the epidemiology, diversity and period of circulation of influenza viruses were studied. The results indicate the predominance and the periods of activities of influenza B Victoria lineage and influenza A/H3N2 which are important information for preventive strategies. It is warranted to extend the influenza surveillance to other parts of Guinea to better understand the epidemiology of the viruses and monitor the emergence of influenza strains with pandemic potential.

Cannon Matthew V, Bogale Haikel N, Bhalerao Devika, Keita Kalil, Camara Denka, Barry Yaya, Keita Moussa, Coulibaly Drissa, Kone Abdoulaye K, Doumbo Ogobara K, Thera Mahamadou A, Plowe Christopher V, Travassos Mark A, Irish Seth R, Yeroshefsky Joshua, Dorothy Jeannine, Prendergast Brian, St Laurent Brandyce, Fritz Megan L, Serre David. Biology open 2021 10(7)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019, and the outbreak rapidly evolved into the current coronavirus disease pandemic. SARS-CoV-2 is a respiratory virus that causes symptoms similar to those caused by influenza A and B viruses. On July 2, 2020, the US Food and Drug Administration granted emergency use authorization for in vitro diagnostic use of the Influenza SARS-CoV-2 Multiplex Assay. This assay detects influenza A virus at 10(2.0), influenza B virus at 10(2.2), and SARS-CoV-2 at 10(0.3) 50% tissue culture or egg infectious dose, or as few as 5 RNA copies/reaction. The simultaneous detection and differentiation of these 3 major pathogens increases overall testing capacity, conserves resources, identifies co-infections, and enables efficient surveillance of influenza viruses and SARS-CoV-2.

BACKGROUND: Efforts to contain the spread of Ebola in the eastern Democratic Republic of the Congo (DRC) during the 2018-2020 epidemic faced challenges in gaining community trust and participation. This affected implementation of community alerts, early isolation, contact tracing, vaccination, and safe and dignified burials. To quickly understand community perspectives and improve community engagement, collaborators from the DRC Red Cross, the International Federation of the Red Cross, and the U.S. Centers for Disease Control and Prevention explored a new method of collecting, coding, and quickly analyzing community feedback. METHODS: Over 800 DRC Red Cross local volunteers recorded unstructured, free-text questions and comments from community members during community Ebola awareness activities. Comments were coded and analyzed using a text-coding system developed by the collaborators. Coded comments were then aggregated and qualitatively grouped into major themes, and time trends were examined. RESULTS: Communities reported a lack of information about the outbreak and the response, as well as concerns about the Ebola vaccination program and health care quality. Some doubted that Ebola was real. The response used the feedback to revise some community engagement approaches. For example, 2 procedural changes that were followed by drops in negative community responses were: using transparent body bags, which allayed fears that bodies or organs were being stolen, and widening the eligibility criteria for Ebola vaccination, which addressed concerns that selectively vaccinating individuals within Ebola-affected communities was unfair. DISCUSSION: This system is unique in that unstructured feedback collected by local volunteers in the course of their work was rapidly coded, analyzed, and given to health authorities for use in making course corrections throughout the response. It provides a platform for local voices to be heard throughout an emergency response and provides a mechanism for assessing the effects of program adjustments on community sentiments.

Vector-borne pathogens cause many human infectious diseases and are responsible for high mortality and morbidity throughout the world. They can also cause livestock epidemics with dramatic social and economic consequences. Due to its high costs, vector-borne disease surveillance is often limited to current threats, and the investigation of emerging pathogens typically occurs after the reports of clinical cases. Here, we use high-throughput sequencing to detect and identify a wide range of parasites and viruses carried by mosquitoes from Cambodia, Guinea, Mali and Maryland. We apply this approach to individual Anopheles mosquitoes as well as pools of mosquitoes captured in traps; and compare the outcomes of this assay when applied to DNA or RNA. We identified known human and animal pathogens and mosquito parasites belonging to a wide range of taxa, as well as novel DNA sequences from previously uncharacterized organisms. Our results also revealed that analysis of the content of an entire trap could be an efficient approach to monitor and identify rare vector-borne pathogens in large surveillance studies. Overall, we describe a high-throughput and easy-to-customize assay to screen for a wide-range of pathogens and efficiently complement current vector-borne disease surveillance approaches.

Malaria incidence is generally lower in cities than rural areas. However, reported urban malaria incidence may not accurately reflect the level of ongoing transmission, which has potentially large implications for prevention efforts. To guide mosquito net distribution, we assessed the extent of malaria transmission in Conakry, Guinea, in 2018. We found evidence of active malaria transmission.

BACKGROUND: The commensal microbiota of mosquitoes impacts their development, immunity, and competency, and could provide a target for alternative entomological control approaches. However, despite the importance of the mosquito/microbiota interactions, little is known about the relative contribution of endogenous and exogenous factors in shaping the bacterial communities of mosquitoes. METHODS: We used a high-throughput sequencing-based assay to characterize the bacterial composition and diversity of 665 individual field-caught mosquitoes, as well as their species, genotype at an insecticide resistance locus, blood-meal composition, and the eukaryotic parasites and viruses they carry. We then used these data to rigorously estimate the individual effect of each parameter on the bacterial diversity as well as the relative contribution of each parameter to the microbial composition. RESULTS: Overall, multivariate analyses did not reveal any significant contribution of the mosquito species, insecticide resistance, or blood meal to the bacterial composition of the mosquitoes surveyed, and infection with parasites and viruses only contributed very marginally. The main driver of the bacterial diversity was the location at which each mosquito was collected, which explained roughly 20% of the variance observed. CONCLUSIONS: This analysis shows that when confounding factors are taken into account, the site at which the mosquitoes are collected is the main driver of the bacterial diversity of wild-caught mosquitoes, although further studies will be needed to determine which specific components of the local environment affect bacterial composition.

BACKGROUND: Anti-malarial resistance is a threat to recent gains in malaria control. This study aimed to assess the efficacy and safety of artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) in the management of uncomplicated malaria and to measure the prevalence of molecular markers of resistance of Plasmodium falciparum in sentinel sites in Maferinyah and Labe Health Districts in Guinea in 2016. METHODS: This was a two-arm randomised controlled trial of the efficacy of AL and ASAQ among children aged 6-59 months with uncomplicated Plasmodium falciparum malaria in two sites. Children were followed for 28 days to assess clinical and parasitological response. The primary outcome was the Kaplan-Meier estimate of Day 28 (D28) efficacy after correction by microsatellite-genotyping. Pre-treatment (D0) and day of failure samples were assayed for molecular markers of resistance in the pfk13 and pfmdr1 genes. RESULTS: A total of 421 participants were included with 211 participants in the Maferinyah site and 210 in Labe. No early treatment failure was observed in any study arms. However, 22 (5.3%) participants developed a late treatment failure (8 in the ASAQ arm and 14 in the AL arm), which were further classified as 2 recrudescences and 20 reinfections. The Kaplan-Meier estimate of the corrected efficacy at D28 was 100% for both AL and ASAQ in Maferinyah site and 99% (95% Confidence Interval: 97.2-100%) for ASAQ and 99% (97.1-100%) for AL in Labe. The majority of successfully analysed D0 (98%, 380/389) and all day of failure (100%, 22/22) samples were wild type for pfk13. All 9 observed pfk13 mutations were polymorphisms not associated with artemisinin resistance. The NFD haplotype was the predominant haplotype in both D0 (197/362, 54%) and day of failure samples (11/18, 61%) successfully analysed for pfmdr1. CONCLUSION: This study observed high efficacy and safety of both ASAQ and AL in Guinea, providing evidence for their continued use to treat uncomplicated malaria. Continued monitoring of ACT efficacy and safety and molecular makers of resistance in Guinea is important to detect emergence of parasite resistance and to inform evidence-based malaria treatment policies.

Establishing metrological traceability to an assigned value of a matrix-based certified reference material (CRM) that has been validated to be commutable among available end-user measurement procedures (MPs) is central to producing equivalent results for the measurand in clinical samples (CSs) irrespective of the clinical laboratory MPs used. When a CRM is not commutable with CSs, the bias due to noncommutability will be propagated to the CS results causing incorrect metrological traceability to the CRM and nonequivalent CS results among different MPs. In a commutability assessment, a conclusion that a CRM is commutable or noncommutable for use with a specific MP is made when the difference in bias between the CRM and CSs meets or does not meet a criterion for that specific MP when compared to other MPs. A conclusion regarding commutability or noncommutability requires that the magnitude of the difference in bias observed in the commutability assessment remains unchanged over time. This conclusion requires the CRM to be stable and no substantive changes in the MPs. These conditions should be periodically reverified. If an available CRM is determined to be noncommutable for a specific MP, that CRM can be used in the calibration hierarchy for that MP when an appropriately validated MP-specific correction for the noncommutability bias is included. We describe with examples how a MP-specific correction and its uncertainty can be developed and applied in a calibration hierarchy to achieve metrological traceability of results for CSs to the CRM's assigned value.

BACKGROUND: Several mosquito collection methods are routinely used in vector control programmes. However, they target different behaviours causing bias in estimation of species diversity and abundance. Given the paucity of mosquito trap data in West Africa, we compared the performance of five trap-lure combinations and Human Landing Catches (HLCs) in Guinea. METHODS: CDC light traps (LT), BG sentinel 2 traps (BG2T), gravid traps (GT) and Stealth traps (ST) were compared in a 5 x 5 Latin Square design in three villages in Guinea between June and July 2018. The ST, a portable trap which performs similarly to a LT but incorporates LEDs and incandescent light, was included since it has not been widely tested. BG2T were used with BG and MB5 lures instead of CO2 to test the efficacy of these attractants. HLCs were performed for 5 nights, but not as part of the Latin Square. A Generalised Linear Mixed Model was applied to compare the effect of the traps, sites and collection times on mosquito abundance. Species identification was confirmed using PCR-based analysis and Sanger sequencing. RESULTS: A total of 10,610 mosquitoes were captured across five traps. ST collected significantly more mosquitoes (7096) than the rest of the traps, but resulted in a higher number of damaged specimens. ST and BG2T collected the highest numbers of Anopheles gambiae (s.l.) and Aedes aegypti mosquitoes, respectively. HLCs captured predominantly An. coluzzii (41%) and hybrids of An. gambiae and An. coluzzii (36%) in contrast to the five traps, which captured predominantly An. melas (83%). The rural site (Senguelen) presented the highest abundance of mosquitoes and overall diversity in comparison with Fandie (semi-rural) and Maferinyah Centre I (semi-urban). Our results confirm the presence of four species for the first time in Guinea. CONCLUSIONS: ST collected the highest number of mosquitoes suggesting this trap may play an important role for mosquito surveillance in Guinea and similar sites in West Africa. We recommend the incorporation of molecular tools in entomological studies since they have helped to identify 25 mosquito species in this area.

BACKGROUND: Beginning August 2017, we conducted a prospective case-control investigation in Monterrey, Mexico to assess the association between Zika virus (ZIKV) and Guillain-Barre syndrome (GBS). METHODS: For each of 50 GBS case-patients, we enrolled 2-3 afebrile controls (141 controls in total) matched by sex, age group, and presentation to same hospital within 7 days. RESULTS: PCR results for ZIKV in blood and/or urine were available on all subjects; serum ZIKV IgM antibody for 52% of case-patients and 80% of controls. Subjects were asked about antecedent illness in the two months prior to neurological onset (for case-patients) or interview (for controls). Laboratory evidence of ZIKV infection alone (PCR+ or IgM+) was not significantly different between case-patients and controls (OR: 1.26, 95% CI: 0.45-3.54) but antecedent symptomatic ZIKV infection [a typical ZIKV symptom (rash, joint pain, or conjunctivitis) plus laboratory evidence of ZIKV infection] was higher among case-patients (OR: 12.45, 95% CI: 1.45-106.64). GBS case-patients with laboratory evidence of ZIKV infection were significantly more likely to have had typical ZIKV symptoms than controls with laboratory evidence of ZIKV infection (OR: 17.5, 95% CI: 3.2-96.6). This association remained significant even when only GBS case-patients who were afebrile for 5 days before onset were included in the analysis, (OR 9.57 (95% CI: 1.07 to 85.35). CONCLUSIONS: During ZIKV epidemics, this study indicates that increases in GBS will occur primarily among those with antecedent symptomatic ZIKV.