Learning to Implement Dialogic Reading Through Video-Based Online Training: A Preliminary Study.

PURPOSE: Dialogic reading (DR) is an evidence-based method for reading with young children that is associated with improvements in children's oral language skills. There is, however, a lack of consensus on (a) how to train educators to deliver the intervention and (b) methods for assessing implementation fidelity. We designed this study to provide preliminary data about the viability of online video modules as an initial training option within a future tiered training model. METHOD: We employed a within-subject repeated-measures group design to evaluate educators' (N = 20) implementation of DR after viewing training videos. Educators filmed themselves reading three storybooks with a child "as they would typically" to establish pretest reading behaviors. After being given access to a series of DR training videos, the educators recorded themselves reading three storybooks with the child using DR strategies as a posttest measure. RESULTS: Educators improved their use of individual strategies included in the DR instructional sequence at posttest; however, most participants did not consistently follow the entire instructional sequence as designed. Only one educator delivered the complete DR instructional sequence in > 80% of opportunities at posttest. CONCLUSION: Modifications to video training modules and additional coaching support may be warranted for many educators to achieve the level of implementation fidelity needed to improve the child's oral language skills from the intervention. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25749387.

Diagnostic accuracy of a point-of-care antigen test for SARS-CoV-2 and influenza in a primary care population (RAPTOR-C19).

OBJECTIVES: Limited evidence exists for the diagnostic performance of point-of-care tests for SARS-CoV-2 and influenza in community healthcare. We carried out a prospective diagnostic accuracy study of the LumiraDx™ SARS-CoV-2 and influenza A or B assay in primary care. METHODS: Total of 913 adults and children with symptoms of current SARS-CoV-2 infection were recruited from 18 UK primary care practices during a period when Omicron was the predominant COVID variant of concern (June 2022 to December 2022). Trained health care staff performed the index test, with diagnostic accuracy parameters estimated for SARS-CoV-2 and influenza against real-time reverse-transcription PCR (rtRT-PCR). RESULTS: 151/887 participants were SARS-CoV-2 rtRT-PCR positive, 109 positive for Influenza A, 6 for Influenza B. Index test sensitivity for SARS-CoV-2 was 80.8% (122 of the 151, 95% CI, 73.6-86.7%) and specificity 98.9% (728 of the 736, 95% CI, 97.9-99.5%). For influenza A, sensitivity was 61.5% (67 of the 109, 95% CI, 51.7-70.6%) and specificity 99.4% (771 of the 776, 95% CI, 98.5-99.8%). Sensitivity to detect SARS-CoV-2 and influenza dropped sharply at rtRT-PCR cycle thresholds (Ct) > 30. DISCUSSIONS: The LumiraDx™ SARS-CoV-2 and influenza A/B assay had moderate sensitivity for SARS-CoV-2 in symptomatic patients in primary care, with lower performance with high rtRT-PCR Ct. Negative results in this patient group cannot definitively rule out SARS-CoV-2 or influenza.

Evaluation of the diagnostic accuracy of two point-of-care tests for COVID-19 when used in symptomatic patients in community settings in the UK primary care COVID diagnostic accuracy platform trial (RAPTOR-C19).

BACKGROUND AND OBJECTIVE: Point-of-care lateral flow device antigen testing has been used extensively to identify individuals with active SARS-CoV-2 infection in the community. This study aimed to evaluate the diagnostic accuracy of two point-of-care tests (POCTs) for SARS-CoV-2 in routine community care. METHODS: Adults and children with symptoms consistent with suspected current COVID-19 infection were prospectively recruited from 19 UK general practices and two COVID-19 testing centres between October 2020 and October 2021. Participants were tested by trained healthcare workers using at least one of two index POCTs (Roche-branded SD Biosensor Standard™ Q SARS-CoV-2 Rapid Antigen Test and/or BD Veritor™ System for Rapid Detection of SARS-CoV-2). The reference standard was laboratory triplex reverse transcription quantitative PCR (RT-PCR) using a combined nasal/oropharyngeal swab. Diagnostic accuracy parameters were estimated, with 95% confidence intervals (CIs), overall, in relation to RT-PCR cycle threshold and in pre-specified subgroups. RESULTS: Of 663 participants included in the primary analysis, 39.2% (260/663, 95% CI 35.5% to 43.0%) had a positive RT-PCR result. The SD Biosensor POCT had sensitivity 84.0% (178/212, 78.3% to 88.6%) and specificity 98.5% (328/333, 96.5% to 99.5%), and the BD Veritor POCT had sensitivity 76.5% (127/166, 69.3% to 82.7%) and specificity 98.8% (249/252, 96.6% to 99.8%) compared with RT-PCR. Sensitivity of both devices dropped substantially at cycle thresholds ≥30 and in participants more than 7 days after onset of symptoms. CONCLUSIONS: Both POCTs assessed exceed the Medicines and Healthcare products Regulatory Agency target product profile's minimum acceptable specificity of 95%. Confidence intervals for both tests include the minimum acceptable sensitivity of 80%. In symptomatic patients, negative results on these two POCTs do not preclude the possibility of infection. Tests should not be expected to reliably detect disease more than a week after symptom onset, when viral load may be reduced. REGISTRATION: ISRCTN142269.

The Impact of Point-of-Care Testing for Influenza on Antimicrobial Stewardship (PIAMS) in UK Primary Care: Protocol for a Mixed Methods Study.

BACKGROUND: Molecular point-of-care testing (POCT) used in primary care can inform whether a patient presenting with an acute respiratory infection has influenza. A confirmed clinical diagnosis, particularly early in the disease, could inform better antimicrobial stewardship. Social distancing and lockdowns during the COVID-19 pandemic have disturbed previous patterns of influenza infections in 2021. However, data from samples taken in the last quarter of 2022 suggest that influenza represents 36% of sentinel network positive virology, compared with 24% for respiratory syncytial virus. Problems with integration into the clinical workflow is a known barrier to incorporating technology into routine care. OBJECTIVE: This study aims to report the impact of POCT for influenza on antimicrobial prescribing in primary care. We will additionally describe severe outcomes of infection (hospitalization and mortality) and how POCT is integrated into primary care workflows. METHODS: The impact of POCT for influenza on antimicrobial stewardship (PIAMS) in UK primary care is an observational study being conducted between December 2022 and May 2023 and involving 10 practices that contribute data to the English sentinel network. Up to 1000 people who present to participating practices with respiratory symptoms will be swabbed and tested with a rapid molecular POCT analyzer in the practice. Antimicrobial prescribing and other study outcomes will be collected by linking information from the POCT analyzer with data from the patient's computerized medical record. We will collect data on how POCT is incorporated into practice using data flow diagrams, unified modeling language use case diagrams, and Business Process Modeling Notation. RESULTS: We will present the crude and adjusted odds of antimicrobial prescribing (all antibiotics and antivirals) given a POCT diagnosis of influenza, stratifying by whether individuals have a respiratory or other relevant diagnosis (eg, bronchiectasis). We will also present the rates of hospital referrals and deaths related to influenza infection in PIAMS study practices compared with a set of matched practices in the sentinel network and the rest of the network. We will describe any difference in implementation models in terms of staff involved and workflow. CONCLUSIONS: This study will generate data on the impact of POCT testing for influenza in primary care as well as help to inform about the feasibility of incorporating POCT into primary care workflows. It will inform the design of future larger studies about the effectiveness and cost-effectiveness of POCT to improve antimicrobial stewardship and any impact on severe outcomes. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/46938.

Development of a modified Cambridge Multimorbidity Score for use with SNOMED CT: an observational English primary care sentinel network study.

BACKGROUND: People with multiple health conditions are more likely to have poorer health outcomes and greater care and service needs; a reliable measure of multimorbidity would inform management strategies and resource allocation. AIM: To develop and validate a modified version of the Cambridge Multimorbidity Score in an extended age range, using clinical terms that are routinely used in electronic health records across the world (Systematized Nomenclature of Medicine - Clinical Terms, SNOMED CT). DESIGN AND SETTING: Observational study using diagnosis and prescriptions data from an English primary care sentinel surveillance network between 2014 and 2019. METHOD: In this study new variables describing 37 health conditions were curated and the associations modelled between these and 1-year mortality risk using the Cox proportional hazard model in a development dataset (n = 300 000). Two simplified models were then developed - a 20-condition model as per the original Cambridge Multimorbidity Score and a variable reduction model using backward elimination with Akaike information criterion as the stopping criterion. The results were compared and validated for 1-year mortality in a synchronous validation dataset (n = 150 000), and for 1-year and 5-year mortality in an asynchronous validation dataset (n = 150 000). RESULTS: The final variable reduction model retained 21 conditions, and the conditions mostly overlapped with those in the 20-condition model. The model performed similarly to the 37- and 20-condition models, showing high discrimination and good calibration following recalibration. CONCLUSION: This modified version of the Cambridge Multimorbidity Score allows reliable estimation using clinical terms that can be applied internationally across multiple healthcare settings.

Representativeness, Vaccination Uptake, and COVID-19 Clinical Outcomes 2020-2021 in the UK Oxford-Royal College of General Practitioners Research and Surveillance Network: Cohort Profile Summary.

BACKGROUND: The Oxford-Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) is one of Europe's oldest sentinel systems, working with the UK Health Security Agency (UKHSA) and its predecessor bodies for 55 years. Its surveillance report now runs twice weekly, supplemented by online observatories. In addition to conducting sentinel surveillance from a nationally representative group of practices, the RSC is now also providing data for syndromic surveillance. OBJECTIVE: The aim of this study was to describe the cohort profile at the start of the 2021-2022 surveillance season and recent changes to our surveillance practice. METHODS: The RSC's pseudonymized primary care data, linked to hospital and other data, are held in the Oxford-RCGP Clinical Informatics Digital Hub, a Trusted Research Environment. We describe the RSC's cohort profile as of September 2021, divided into a Primary Care Sentinel Cohort (PCSC)-collecting virological and serological specimens-and a larger group of syndromic surveillance general practices (SSGPs). We report changes to our sampling strategy that brings the RSC into alignment with European Centre for Disease Control guidance and then compare our cohort's sociodemographic characteristics with Office for National Statistics data. We further describe influenza and COVID-19 vaccine coverage for the 2020-2021 season (week 40 of 2020 to week 39 of 2021), with the latter differentiated by vaccine brand. Finally, we report COVID-19-related outcomes in terms of hospitalization, intensive care unit (ICU) admission, and death. RESULTS: As a response to COVID-19, the RSC grew from just over 500 PCSC practices in 2019 to 1879 practices in 2021 (PCSC, n=938; SSGP, n=1203). This represents 28.6% of English general practices and 30.59% (17,299,780/56,550,136) of the population. In the reporting period, the PCSC collected >8000 virology and >23,000 serology samples. The RSC population was broadly representative of the national population in terms of age, gender, ethnicity, National Health Service Region, socioeconomic status, obesity, and smoking habit. The RSC captured vaccine coverage data for influenza (n=5.4 million) and COVID-19, reporting dose one (n=11.9 million), two (n=11 million), and three (n=0.4 million) for the latter as well as brand-specific uptake data (AstraZeneca vaccine, n=11.6 million; Pfizer, n=10.8 million; and Moderna, n=0.7 million). The median (IQR) number of COVID-19 hospitalizations and ICU admissions was 1181 (559-1559) and 115 (50-174) per week, respectively. CONCLUSIONS: The RSC is broadly representative of the national population; its PCSC is geographically representative and its SSGPs are newly supporting UKHSA syndromic surveillance efforts. The network captures vaccine coverage and has expanded from reporting primary care attendances to providing data on onward hospital outcomes and deaths. The challenge remains to increase virological and serological sampling to monitor the effectiveness and waning of all vaccines available in a timely manner.

Revisioning aging: Indigenous, crip and queer renderings.

In this article, we re-vision Anishinaabe, crip and queer futures of aging against and beyond dominant successful aging narratives by drawing on our archive of digital/multimedia videos (short documentaries) produced in conjunction with older/e/Elder persons and the Re•Vision: Centre for Art and Social Justice. These documentaries are directed and come from the lives of those older and e/Elder persons whose aging embodiments intra-sect with their Indigenous, disabled and queer selves. Disrupting hegemonic successful aging narratives, and specifically heteronormative and ableist trajectories of aging, these alternative renderings of aging futures offer rich, affective relationalities and cyclical timescapes of older experience that draw on the past even as they reach into divergent futurities. Anishinaabe, crip and queer aging emerge. While we discern resonances in relationalities and temporalities among and between the Anishinaabe and non-Indigenous stories, we also identify significant differences across accounts, indicating that they cannot be collapsed together. Instead, we argue for holding different life-ways and futures alongside one another, following the 1613 Two Row Wampum Treaty between the Dutch and the Haudenosaunee, in which each party promised to respect the other's ways, and committed to non-interference, as well as to the development and maintenance of relationship.

Recipes of Ancient Egyptian kohls more diverse than previously thought.

Kohl, a dark eye cosmetic, is a well-known part of Ancient Egyptian culture. Modern chemical analyses of kohls have largely found lead-based inorganic constituents, whereas earlier studies argued for a much broader range of constituents. Furthermore, organic materials in kohls remain severely understudied. This raises questions regarding the true diversity of materials and recipes used to produce kohls. We analysed the contents of 11 kohl containers from the Petrie Museum collection in London. The objects selected cover a broad range of times and locations in Egypt. Our multi-analytical approach allowed us to characterise both inorganic and organic components. Our data show that inorganic ingredients in kohl recipes are not only lead-based but also manganese- and silicon-based. Our analyses also revealed that organic ingredients derived from both plant and animal sources were commonly used in kohl recipes and sometimes even represent the main constituent. All these findings point towards more varied recipes than initially thought and significantly shift our understanding of Ancient Egyptian kohls.

Stakeholders' assessment of US Centers for Disease Control and Prevention's contributions to the development of National Public Health Institutes in seven countries.

National Public Health Institutes (NPHIs) can strengthen countries' public health capacities to prevent, detect, and respond to public health emergencies. This qualitative evaluation assessed the role of the US Centers for Disease Control and Prevention (CDC) in NPHI development and strengthening of public health functions. We interviewed NPHI staff (N = 43), non-NPHI government staff (N = 29), and non-governmental organization staff (N = 24) in seven countries where CDC has supported NPHI development: Cambodia, Colombia, Liberia, Mozambique, Nigeria, Rwanda, and Zambia. Participants identified four areas of support that were the most important: workforce capacity building, technical assistance for key public health functions, identifying institutional gaps and priorities, and funding to support countries' priorities. Participants underscored the need for capacity building directed toward country-driven priorities during planning and implementation. Continued support for NPHI development from CDC and other partners is vital to building stronger public health systems, improving population health, and strengthening global health security.

Barriers, motivators and facilitators of physical activity in people with dementia and their family carers in England: dyadic interviews.

INTRODUCTION: Physical activity may have a number of physical and mental health benefits for people with dementia and their carers. However, there is limited evidence about factors that influence physical activity participation in these groups. This study therefore looks at the barriers, facilitators and motivators of physical activity in people with dementia, from both the perspective of the person with dementia and their carer. METHOD: Thirty participants (15 sets of community-dwelling people with dementia and their family carers) were recruited from the South East of England. The participants took part in semi-structured dyadic interviews about their views of physical activity. Interviews were analysed using inductive thematic analysis at an individual level and comparisons were made between the groups. RESULTS: Common motivator themes across persons with dementia and family carers were emotional and physical wellbeing, and social connectedness. Physical health was seen as a common barrier in both groups. Physical activity in the person with dementia was encouraged and supported by the family carer. For the carer, their caring role, and limited time acted as barriers to their participation. CONCLUSION: Themes such as social connectedness, positive emotion and health were seen as key motivators to physical activity, which indicate that people with dementia and carers use physical activity as a means to maintain and improve their quality of life. Supporting family members to better facilitate such activities could encourage physical activity in people with dementia.

Complex Enterally Tube-Fed Community Patients Display Stable Tolerance, Improved Compliance and Better Achieve Energy and Protein Targets with a High-Energy, High-Protein Peptide-Based Enteral Tube Feed: Results from a Multi-Centre Pilot Study.

This pilot study evaluated a high-energy, high-protein, peptide-based, (medium-chain triglycerides) MCT-containing enteral tube feed (Nutrison Peptisorb Plus HEHP®, Nutricia Ltd., Trowbridge, BA14 0XQ, UK.) containing 1.5 kcal/mL and 7.5 g protein/100 mL. Fifteen community-based, enterally tube-fed adults (42 (SD 16.3) years) received the intervention feed daily for 28 days, with gastrointestinal tolerance, compliance and nutrient intake assessed at baseline and after the intervention period. Incidence and intensity of constipation (p = 0.496), nausea (p = 1.000), abdominal pain (p = 0.366) and bloating (p = 0.250) remained statistically unchanged, yet the incidence and intensity of diarrhoea improved significantly after receiving the intervention feed (Z = -2.271, p = 0.023). Compliance with the intervention feed was significantly greater compared to the patient's baseline regimens (99% vs. 87%, p = 0.038). Compared to baseline, use of the intervention feed enabled patients to significantly increase total energy (1676 kcal/day (SD 449) to 1884 kcal/day (SD 537), p = 0.039) and protein intake (73 g/day (SD 17) to 89 g/day (SD 23), p = 0.001), allowing patients to better achieve energy (from 88% to 99%, p = 0.038) and protein (from 101% to 121%, p < 0.001) requirements. This pilot study demonstrates that a high-energy, high-protein, peptide-based, MCT-containing enteral tube feed maintains gastrointestinal tolerance and improves compliance, energy and protein intake in complex, enterally tube-fed, community-based adult patients, though more work is recommended to confirm this.

The role of multiple observations in small-molecule single-crystal service X-ray structure determination.

In order to gain a better understanding of how to improve the quality of small-molecule single-crystal X-ray diffraction data achievable in a finite time, a study was carried out to investigate the effect of varying the multiplicity, acquisition time, detector binning, maximum resolution and completeness. The results suggest that, unless there are strong arguments for a different strategy, a good routine procedure might be to optimize the conditions necessary to get the best data from single scans, and then choose a multiplicity of observations (MoO) to utilize the available time fully. Different strategies may be required if the crystal is highly absorbing, is larger than the incident beam, is enclosed in a capillary tube or is unusual in some other way. The signal-to-noise ratio should be used with care, as collecting data for longer or at higher multiplicity appears to give a systematic underestimate of the intensity uncertainties. Further, the results demonstrate that including poor-quality data in a refinement may degrade the result and, in the general case, the accidental omission of reflections has a very small impact on the refinement as long as they are omitted at random. Systematic omission of reflections needs a convincing procedural justification.

Clinical Efficacy and Safety Profile of Micropulse Transscleral Cyclophotocoagulation in Refractory Glaucoma.

PURPOSE: To investigate the clinical efficacy and safety profile of micropulse transscleral cyclophotocoagulation (MP-CPC) in patients with refractory glaucoma. MATERIALS AND METHODS: Retrospective case series of 79 consecutive patients who underwent MP-CPC at the Wills Eye Hospital from March 23, 2014 to June 23, 2016 and who had at least 3 months of follow-up. Treatment success was defined as an intraocular pressure (IOP) of 6 to 21 mm Hg or a reduction of IOP by 20%. Failure was defined as an inability to meet the criteria for success, need for retreatment >3 times, or need for incisional glaucoma surgery. RESULTS: Patients had a mean follow-up time of 7.8±4.5 months. The mean IOP before MP-CPC was 31.9±10.2 mm Hg. The IOP was reduced by an average of 51% at the last follow-up and the mean number of IOP lowering medications was reduced from 2.3 at baseline to 1.5 at last follow-up. Treatment success rates were 75% at 3 months, 66% at 6 months, and 67% at last follow-up. Complications of MP-CPC included 7 patients with hypotony (8.8%), 21 patients with prolonged anterior chamber inflammation (1+ cell or flare for >3 mo, 26%), 13 patients with loss of ≥2 lines of best-corrected visual acuity at 3 months (17%), 4 patients with macular edema (5%), 2 patients with corneal edema and 2 patients with phthisis. CONCLUSIONS: MP-CPC is an effective treatment for patients with refractory glaucoma. Shorter treatment times with more frequent repeat treatments, if necessary, should be considered given the incidence of significant vision loss in this study.

Trypan Blue for the Assessment of Filtering Bleb Function During Cataract Surgery.

PURPOSE: Phacoemulsification has been cited as a possible cause of bleb failure in eyes with prior trabeculectomy. No method has been developed to directly evaluate the risk of bleb failure after phacoemulsification. We investigate the use of trypan blue during cataract surgery in the setting of a preexisting trabeculectomy to evaluate the functional status of the bleb and predict postoperative bleb function. MATERIALS AND METHODS: In total, 14 patients contributing 1 eye each with a history of prior trabeculectomy with mitomycin C undergoing phacoemulsification with intraocular lens implantation were enrolled in this prospective, nonrandomized clinical trial. At the time of phacoemulsification, trypan blue was instilled into the anterior chamber before capsulorhexis creation. Staining of the bleb was grouped as being mild or diffuse using intraoperative photographs. These eyes were followed for 1 year postoperatively and evaluated for intraocular pressure (IOP) control. RESULTS: The change in IOP was not significantly different between the 2 groups (P=0.14). A trend towards greater need for IOP-lowering medications was noted (P<0.10) in eyes with mild bleb staining. No statistically significant difference in rates of decreased bleb function was noted at 1-year follow-up after phacoemulsification. CONCLUSION: The intensity of bleb staining with trypan blue during phacoemulsification is not associated with changes in IOP postoperatively. A trend towards decreased need for IOP-lowering medications was noted in eyes with diffuse bleb staining at 1 year after cataract surgery.

Pilot Study Assessing the Use of High-density Polyethylene (Su-Por) for Tube Shunt Patch Grafts.

PURPOSE: To assess the viability of a manufactured high-density polyethylene patch graft material (Su-Por) for prevention of tube shunt exposure. MATERIALS AND METHODS: Retrospective review of the first 11 patients from the Wills Eye Hospital Glaucoma Service to receive the high-density polyethylene patch graft during tube shunt surgery. RESULTS: Four patients (36.3%) experienced an extrusion of the Su-Por patch without a leak within 2.5 months of postoperative follow-up. All 4 patients developed either symptomatic or progressive extrusion. Operative repair was completed with Su-Por removal and replacement with a new human donor patch graft. No patient developed any sign of infection despite the extrusions. The remaining 7 patients had an uneventful postoperative course and continue to have no complications from the Su-Por patch with 9 months of follow-up. CONCLUSIONS: Given the high rate of extrusion of the Su-Por graft, this material seems to be an inadequate alternative for covering tube shunts. Harvested human tissue or other more flexible, manufactured grafts remain the standard of care for covering tube shunts.

Quantitative historical analysis uncovers a single dimension of complexity that structures global variation in human social organization.

Do human societies from around the world exhibit similarities in the way that they are structured, and show commonalities in the ways that they have evolved? These are long-standing questions that have proven difficult to answer. To test between competing hypotheses, we constructed a massive repository of historical and archaeological information known as "Seshat: Global History Databank." We systematically coded data on 414 societies from 30 regions around the world spanning the last 10,000 years. We were able to capture information on 51 variables reflecting nine characteristics of human societies, such as social scale, economy, features of governance, and information systems. Our analyses revealed that these different characteristics show strong relationships with each other and that a single principal component captures around three-quarters of the observed variation. Furthermore, we found that different characteristics of social complexity are highly predictable across different world regions. These results suggest that key aspects of social organization are functionally related and do indeed coevolve in predictable ways. Our findings highlight the power of the sciences and humanities working together to rigorously test hypotheses about general rules that may have shaped human history.

An evaluation of the NHS England Youth Forum.

Aim To use qualitative data collection approaches to enhance insight and understanding of the NHS England Youth Forum, including its role, value and potential effects. Method A qualitative evaluation research approach was used. Two focus groups were conducted: one with five young people from the NHS England Youth Forum and another with five members of the Adult Reference Group that supports the forum's work. Individual semi-structured interviews were undertaken with four employees of NHS England and the British Youth Council who had a central role in the development and implementation of the forum. Findings The members of the NHS England Youth Forum were participating in an extensive range of activities, and their work is having a direct and positive influence on the provision of healthcare services. The day-to-day management of the forum, in terms of personnel, time and commitment, should be acknowledged. Conclusion Young people are not only highly capable of participating in decision making related to healthcare, but also want to be involved and value the opportunity.

Sensitive and specific nested PCR assay for detection of rotavirus A in samples with a low viral load.

Techniques such as the real-time reverse transcription-polymerase chain reaction (qRT-PCR) can detect RNA in samples with a low viral load. However, these amplicons typically are either too short or at insufficient concentrations for use in subsequent sequencing reactions for genotyping and detection confirmation. The assay developed in this study detects rotavirus G genotypes and P genotypes with viral loads as low as 6.2 and 8.2 copies per reaction, respectively. The assay was validated using a panel of 91 stool samples, 32 reference rotavirus strains, and 6 non-target enteric virus samples.

Multiplexed one-step RT-PCR VP7 and VP4 genotyping assays for rotaviruses using updated primers.

The current two-step VP7 and VP4 genotyping RT-PCR assays for rotaviruses have been linked consistently to genotyping failure in an estimated 30% of RVA positive samples worldwide. We have developed a VP7 and VP4 multiplexed one-step genotyping assays using updated primers generated from contemporary VP7 and VP4 sequences. To determine assay specificity and sensitivity, 17 reference virus strains, 6 non-target gastroenteritis viruses and 725 clinical samples carrying the most common VP7 (G1, G2, G3, G4, G9, and G12) and VP4 (P[4], P[6], P[8], P[9] and P[10]) genotypes were tested in this study. All reference RVA strain targets yielded amplicons of the expected sizes and non-target genotypes and gastroenteritis viruses were not detected by either assay. Out of the 725 clinical samples tested, the VP7 and VP4 assays were able to assigned specific genotypes to 711 (98.1%) and 714 (98.5%), respectively. The remaining unassigned samples were re-tested for RVA antigen using EIA and qRT-PCR assays and all were found to be negative. The overall specificity, sensitivity and limit of detection of the VP7 assay were in the ranges of 99.0-100%, 94.0-100% and 8.6×10(1) to 8.6×10(2) copies of RNA/reaction, respectively. For the VP4 assay, the overall specificity, sensitivity and limit of detection assay were in the ranges of 100%, 94.0-100% and ≤1 to 8.6×10(2) copies of RNA/reaction, respectively. Here we report two highly robust, accurate, efficient, affordable and documentable gel-based genotyping systems which are capable of genotyping 97.8% of the six common VP7 and 98.3% of the five common VP4 genotypes of RVA strains which are responsible for approximately 88.2% of all RVA infections worldwide.