SARS-CoV-2 transmitters have more than three times higher viral loads than non-transmitters - Practical use of viral load for disease control.

BACKGROUND: Quantitative results of SARS-CoV-2 testing reported as viral load copies/mL can provide valuable information, but are rarely used in practice. We analyze whether viral load in the upper respiratory tract is correlated with transmission and disease course and how this information can be used in practice. STUDY DESIGN: Municipal Health Service (MHS) and clinical patients ≥18 years tested positive for SARS-CoV-2 with RT-PCR between June 1 and September 25, 2020 were included. Transmission was defined as an index having at least one contact tested positive. Test delay was defined as the time between symptom onset and SARS-CoV-2 testing. RESULTS: 683 patients were included (656 MHS and 27 clinical patients). The viral load was considerably lower among clinical patients compared to MHS patients: median log10 copies/mL 2.51 (IQR -1.52 - 6.46) vs 4.92 (IQR -0.54 - 8.26), p < 0.0001. However, the test delay was higher for clinical patients (median 7 [IQR 2 - 19] vs 3 [IQR 0 - 26] days, p < 0.0001). SARS-CoV-2 transmitters showed much higher viral loads than non-transmitters (log10 copies/mL 5.23 [IQR -0.52 - 8.26] vs 4.65 [IQR -0.72 - 8.00], p < 0.0001), but not for those with a test delay > 7 days. Higher viral loads were significantly correlated with older age and with more (severe) COVID-19 related symptoms. CONCLUSION: Indexes that transmitted SARS-CoV-2 had more than three times higher viral loads than non-transmitters. Viral load information can be useful during source and contact tracing to prioritize indexes with highest risk of transmission, taking into account the test delay.

Performance of the Diasorin SARS-CoV-2 antigen detection assay on the LIAISON XL.

BACKGROUND: The current reference standard to diagnose a SARS-CoV-2 infection is real-time reverse transcriptase polymerase chain reaction (RT-PCR). This test poses substantial challenges for large-scale community testing, especially with respect to the long turnaround times. SARS-CoV-2 antigen tests are an alternative, but typically use a lateral flow assay format rendering them less suitable for analysis of large numbers of samples. METHODS: We conducted an evaluation of the Diasorin SARS-CoV-2 antigen detection assay (DAA) compared to real-time RT-PCR (Abbott). The study was performed on 248 (74 qRT-PCR positive, 174 qRT-PCR negative) clinical combined oro-nasopharyngeal samples of individuals with COVID-19-like symptoms obtained at a Municipal Health Service test centre. In addition, we evaluated the analytical performance of DAA with a 10-fold dilution series of SARS-CoV-2 containing culture supernatant and compared it with the lateral flow assay SARS-CoV-2 Roche/SD Biosensor Rapid Antigen test (RRA). RESULTS: The DAA had an overall specificity of 100% (95%CI 97.9%-100%) and sensitivity of 73% (95%CI 61.3%-82.7%) for the clinical samples. Sensitivity was 86% (CI95% 74.6%-93.3%) for samples with Ct-value below 30. Both the DAA and RRA detected SARS-CoV-2 up to a dilution containing 5.2 × 102 fifty-percent-tissue-culture-infective-dose (TCID50)/ml. DISCUSSION: The DAA performed adequately for clinical samples with a Ct-value below 30. Test performance may be further optimised by lowering the relative light unit (RLU) threshold for positivity assuming the in this study used pre-analytical protocol . The test has potential for use as a diagnostic assay for symptomatic community-dwelling individuals early after disease onset in the context of disease control.

Pre-autotransplantation alveolar process augmentation and premolar autotransplantation as a treatment method for single tooth replacement in adolescents.

The treatment of young patients with missing teeth and an atrophied alveolar process after trauma or agenesis of a tooth can be challenging. The aim of this study was to evaluate autotransplantation of a premolar after pre-autotransplantation alveolar process augmentation (PAPA) as a treatment option for these patients. A retrospective cohort study was implemented to analyse the PAPA procedure and subsequent autotransplantation procedure. Alveolar process augmentation was performed using different types of autologous bone grafts. Subsequent autotransplantation of one or more premolars was performed approximately 4 months later. Nine patients with a mean age of 12 years were included. Twelve premolars were transplanted after a PAPA procedure: seven in the maxillary incisor region, four in the mandibular premolar region, and one in the mandibular incisor region. Initially all transplanted teeth functioned well. However, one mandibular premolar that was transplanted in the maxillary incisor region was lost because of resorption after 6 years of follow-up. The other 11 transplanted teeth functioned well. The mean follow-up was 6 years (range 3-13 years). The results showed that autotransplantation can be facilitated by PAPA with a high chance of success. It can therefore be a valuable addition to other existing treatment options.

[Multidisciplinary treatment of amelogenesis imperfecta]. / Multidisciplinaire behandeling van amelogenesis imperfecta.

A healthy 13-year-old patient with amelogenesis imperfecta was referred by her orthodontist to the joint consultation hour (Center for Specialised Dentistry and Oral and Maxillofacial Surgery). In addition to her amelogenesis imperfecta, she was diagnosed with a class 2 malocclusion and a mandibular hypoplasia. She was treated successfully through a multidisciplinary approach.

Ektacytometry Analysis of Post-splenectomy Red Blood Cell Properties Identifies Cell Membrane Stability Test as a Novel Biomarker of Membrane Health in Hereditary Spherocytosis.

Hereditary spherocytosis (HS) is the most common form of hereditary chronic hemolytic anemia. It is caused by mutations in red blood cell (RBC) membrane and cytoskeletal proteins, which compromise membrane integrity, leading to vesiculation. Eventually, this leads to entrapment of poorly deformable spherocytes in the spleen. Splenectomy is a procedure often performed in HS. The clinical benefit results from removing the primary site of destruction, thereby improving RBC survival. But whether changes in RBC properties contribute to the clinical benefit of splenectomy is unknown. In this study we used ektacytometry to investigate the longitudinal effects of splenectomy on RBC properties in five well-characterized HS patients at four different time points and in a case-control cohort of 26 HS patients. Osmotic gradient ektacytometry showed that splenectomy resulted in improved intracellular viscosity (hydration state) whereas total surface area and surface-to-volume ratio remained essentially unchanged. The cell membrane stability test (CMST), which assesses the in vitro response to shear stress, showed that after splenectomy, HS RBCs had partly regained the ability to shed membrane, a property of healthy RBCs, which was confirmed in the case-control cohort. In particular the CMST holds promise as a novel biomarker in HS that reflects RBC membrane health and may be used to asses treatment response in HS.

[Surgical uprighting of partially impacted second molars]. / Chirurgisch oprichten van deels geïmpacteerde tweede molaren.

Eruption of mandibular second molars usually occurs around the age of 12. Incomplete eruption of second molars in such young patients can lead to loss of the molars, due to caries, root resorption or periodontal pathology. When a pathology of this kind develops, the treatment option for a mesially impacted molar is often to extract the tooth. If tooth eruption is, however, monitored closely by the dentist and/or orthodontist, early treatment can be considered in order to preserve the tooth. Partially impacted second molars can be placed in a functional anatomical position by surgical uprighting and repositioning. As long as certain conditions are met, this results in sound functionality with preservation of the full dentition. In cases of incomplete eruption, this treatment option should therefore be considered by dentists and orthodontists before extracting the second molars.

Successful containment of two vancomycin-resistant Enterococcus faecium (VRE) outbreaks in a Dutch teaching hospital using environmental sampling and whole-genome sequencing.

BACKGROUND: Vancomycin-resistant enterococci (VRE) may cause nosocomial outbreaks. This article describes all VRE carriers that were identified in 2018 at Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands. AIM: To investigate the genetic relatedness of VRE isolates and the possibility of a common environmental reservoir using environmental sampling and whole-genome sequencing (WGS). METHODS: Infection control measures consisted of contact isolation, contact surveys, point prevalence screening, environmental sampling, cleaning and disinfection. VRE isolates were sequenced using a MiSeq sequencer (Illumina, San Diego, CA, USA), and assembled using SPAdes v.3.10.1. A minimal spanning tree and a neighbour joining tree based on allelic diversity of core-genome multi-locus sequence typing and accessory genes were created using Ridom SeqSphere+ software (Ridom GmbH, Münster, Germany). FINDINGS: Over a 1-year period, 19 VRE carriers were identified; of these, 17 were part of two outbreaks. Before environmental cleaning and disinfection, 55 (14%) environmental samples were VRE-positive. Fifty-one isolates (23 patient samples and 28 environmental samples) were available for WGS analysis. Forty-four isolates were assigned to ST117-vanB, five were assigned to ST17-vanB, and two were assigned to ST80-vanB. Isolates from Outbreak 1 (N=22) and Outbreak 2 (N=22) belonged to ST117-vanB; however, WGS showed a different cluster type with 257 allelic differences. CONCLUSION: WGS of two outbreak strains provided discriminatory information regarding genetic relatedness, and rejected the hypothesis of a common environmental reservoir. A high degree of environmental contamination was associated with higher VRE transmission. Quantification of environmental contamination may reflect the potential for VRE transmission and could therefore support the infection control measures.

Density of the mandibular ramus (cancellous:cortical bone volume ratio) as a predictor of the lingual fracture pattern in bilateral sagittal split osteotomy.

The aim of this retrospective cohort study was to evaluate the relative amount of cancellous bone in the mandibular ramus as a predictor of lingual fracture patterns after bilateral sagittal split osteotomy (BSSO). The study including 78 consecutive patients (156 osteotomy sites). In preoperative cone-beam computed tomographic (CT) scans, the volumes of cancellous and cortical bone in the BSSO surgical field were estimated. Patients were divided into two groups based on the cancellous:cortical bone ratio. We studied postoperative cone-beam CT scans for lingual fracture lines and subcategorised them according to the lingual split scale (LSS). Generalised linear mixed models (GLMM) were estimated to evaluate the association between the cancellous:cortical bone ratio and the lingual fracture pattern. There was a significant association between the cancellous:cortical bone ratio of the mandibular angle and the lingual fracture pattern after BSSO. Mandibular angles with a relatively small amount of cancellous bone showed significantly more LSS3 fracture lines (OR=1.990, 95%CI 1.043 to 3.796, p=0.043). These mandibular angles also showed more unfavourable fractures (LSS4), although this was not significant (OR=2.352, 95%CI 0.748 to 7.392, p=0.143). The relative amount of cancellous bone in the mandibular angle is significantly associated with the lingual fracture line after BSSO.

How can schistosome circulating antigen assays be best applied for diagnosing male genital schistosomiasis (MGS): an appraisal using exemplar MGS cases from a longitudinal cohort study among fishermen on the south shoreline of Lake Malawi.

We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.

Long-term outcomes 1-20 years after autotransplantation of teeth: clinical and radiographic evaluation of 66 premolars and 8 molars.

In this retrospective study we investigated the long-term survival of autotransplanted premolars and molars with incompletely developed roots. The presence of the transplanted teeth and their outcome after autotransplantation was ascertained from clinical and radiographic evaluation by a maxillofacial surgeon or dentist. Kaplan Meier survival curves were estimated for the total population and for the two groups (premolars and molars). Fifty-one patients with 74 transplanted teeth were included, and the median duration of follow-up was 10 (range 1-20) years. Four of 66 premolars and one of 8 molars were removed and the cumulative survival was 95.4% (95% CI 90.3 to 100). The difference in survival between the premolars and molars was not significant. These results show that the long-term survival of autotransplanted teeth is good. Replacement of a single tooth by autotransplantation should therefore always be considered and is preferred when a suitable donor tooth is available.

Innovation in oncology clinical trial design.

Progress in and better understanding of cancer biology causes a shift in cancer drug development: away from the evaluation of drugs in large tumour histology defined patient populations towards targeted agents in increasingly heterogeneous molecularly defined subpopulations. This requires novel approaches in clinical trial design by academia and industry, and development of new assessment tools by regulatory authorities. Pharmaceutical industry is developing new targeted agents generating many clinical studies, including target combinations. This requires improved operational efficiency by development of innovative trial designs, strategies for early-stage decision making and early selection of candidate drugs with a high likelihood of success. In addition, patient awareness and ethical considerations necessitate that agents will be rapidly available to patients. Regulatory Authorities such as the European Medicine Agency and national agencies recognise that these changes require a different attitude towards benefit-risk analysis for drug approval. The gold standard of randomised confirmatory Phase III trials is not always ethical or feasible when developing drugs for treatment of small cancer populations. Alternative strategies comprise accelerated approval via conditional marketing approval, which can be granted in the EU based on small non-randomised Phase II trials. The paper describes innovative trial designs with their pros and cons and efforts of pharmaceutical industry and regulatory authorities to deal with the paradigm shift. Furthermore, all stakeholders should continue to share their experiences and discuss problems in order to understand the position and concerns of the other stakeholders to learn from each other and to progress the field of novel oncology clinical trial design.

Added diagnostic value of broad-range 16S PCR on periprosthetic tissue and clinical specimens from other normally sterile body sites.

AIMS: Evaluation of 16S PCR in addition to the standard culture to improve the pathogen detection rate in clinical specimens. METHODS AND RESULTS: Microbiological culture and direct 16S PCR was performed on specimens from suspected prosthetic joint infection patients (cohort-1) and on tissues and fluids from other normally sterile body sites (cohort-2). Based on clinical and microbiological data, the detection rate for both methods was assessed, assuming no superiority of either 16S PCR or culture. In cohort-1, 469 specimens were obtained. Culture was positive in 170 (36·2%) specimens, 16S PCR detected 70 (41·2%) of those pathogens. Additionally, 16S PCR detected pathogens in 13 of 299 (4·3%) culture-negative specimens. In cohort-2, pathogens were cultured in 52 of 430 (12·1%) specimens and 16S PCR revealed those pathogens in 32 (61·5%) specimens. 16S PCR detected pathogens in 31 of 378 (8·2%) culture-negative specimens. CONCLUSIONS: Overall, the yield with 16S PCR was low. For cohort-1 16S PCR detected pathogens in 4·3% of culture-negative specimens, where this was 8·2% for cohort-2. SIGNIFICANCE AND IMPACT OF THE STUDY: Although direct 16S PCR cannot replace culture, it may offer a valuable additional diagnostic option for detection of difficult to culture micro-organisms in culture-negative clinical specimens.

Multiplex real-time PCR for diagnosing malaria in a non-endemic setting: a prospective comparison to conventional methods.

Almost a decade ago our diagnostic laboratory implemented an in-house real-time PCR for the detection of Plasmodium DNA to diagnose malaria in parallel with conventional diagnostics, i.e., microscopy (thick and thin smears), quantitative buffy coat microscopy (QBC), and a rapid diagnostic test (RDT). Here we report our experiences and make a comparison between the different diagnostic procedures used in this non-endemic setting. All patients during the period February 2009-December 2017 suspected of malaria were prospectively tested at the moment of sample collection. Both PCR and conventional malaria diagnostics were carried out on a total of 839 specimens from 825 patients. In addition, three Plasmodium falciparum (Pf) patients were closely followed by real-time PCR and microscopy after treatment. Overall, 56 samples (55 patients) tested positive by real-time PCR, of which six were missed by microscopy and seven by QBC. RDT showed fairly good results in detecting Pf, whereas specificity was not optimal. RDT failed to detect 10 of 17 non-Pf PCR positive specimens. One Plasmodium malariae patient would have been missed if only conventional diagnostic tests had been used. The high sensitivity of the PCR was confirmed by the number of PCR positive, microscopy negative post-treatment samples. In conclusion, within our routine diagnostic setting, malaria real-time PCR not only showed a high level of agreement with the conventional methods used, but also showed higher sensitivity and better specificity. Still, for complete replacement of the conventional procedures in a non-endemic setting, the time-to-results of the real-time PCR is currently too long.

[A PhD completed. Bilateral sagittal split osteotomy: risk factors for complications and predictability of the splitter-separator technique]. / Serie: Hora est. De bilaterale sagittale splijtings­osteotomie: risicofactoren voor complicaties en voorspelbaarheid van de splijttang-splijtheveltechniek.

Bilateral sagittal split osteotomy (BSSO) is a surgical technique to correct hypoplasia, hyperplasia or asymmetry of the mandible. The risk of complications associated with BSSO with splitter and separators, the so-called splitter-separator technique, and the predictability of this technique were analysed. The average incidence of complications associated with classic BSSO techniques was determined by a review of the literature. With classic techniques, a bad split occurred in 2.3% of the operated sides, removal of osteosynthesis material on account of complaints in 11.2% of patients, and permanent neurosensory disturbances in the area of the mental nerve in 33.9% of patients. The incidence of complications for BSSO with splitter and separators is a bad split in 2.0% of the operated sides, necessary removal of osteosynthesis material in 5.6% of patients, and permanent neurosensory disturbances of the lower lip in 9.9% of patients. Removal of the third molars during BSSO may result in an increased chance of bad split but does not increase the risk of other complications. In conclusion, BSSO with splitter and separators is a reliable technique, with a remarkably low incidence of permanent neurosensory disturbances of the lower lip.

[Replacing heavily damaged molars with the use of 3D-techniques]. / Vervanging van ernstig beschadigde molaren met behulp van 3D-technieken.

Seriously damaged molars can be replaced by autotransplantation with the help of 3D techniques. In the present case, involving an 18-year old patient, 18, 38 and 48 were used to replace, respectively, 14, 36 and 37. Preoperatively, the width of the crowns and the root development of 18, 38 and 48 were analysed using 3D imaging. During the autotransplantation procedure, the new alveoli are formed with the help of replicas of the donor molars printed in 3D, in order to prevent iatrogenic damage to the actual donor molars.. The extra-alveolar time was less than 2 minutes for all donor molars. Postoperative follow-up showed physiologic integration of the transplanted molars. There was no ankylosis. Autotransplantation with the help of 3D techniques makes it possible to perform complex procedures with good results.

Extended-spectrum ß-lactamase (ESBL) polymerase chain reaction assay on rectal swabs and enrichment broth for detection of ESBL carriage.

BACKGROUND: Extended-spectrum ß-lactamase (ESBL) screening and contact precautions on patients at high risk for ESBL carriage are considered important infection control measures. Since contact precautions are costly and may negatively impact patient care, rapid exclusion of ESBL carriage and therefore earlier discontinuation of contact precautions are desired. AIM: In the present study, the performance of an ESBL polymerase chain reaction (PCR) targeting blaCTX-M genes was evaluated as a screening assay for ESBL carriage. METHODS: Two methods were assessed: PCR performed directly on rectal swabs and PCR on enrichment broth after incubation overnight. The reference standard was culture of ESBL-producing Enterobacteriaceae on selective agar after overnight enrichment and confirmation by the combination disc diffusion method. Microarray was used for discrepancy analysis. A secondary analysis was performed to evaluate the added value of including a blaSHV target in the PCR. FINDINGS: A total of 551 rectal swabs from 385 patients were included, of which 28 (5%) were ESBL positive in culture. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 86%, 98%, 67%, and 99%, respectively, for PCR directly on swabs, and 96%, 98%, 75%, and 100%, respectively, for PCR on enrichment broth. Adding a blaSHV target to the assay resulted in a lower PPV without increasing the sensitivity and NPV. CONCLUSION: Screening for ESBL by PCR directly on rectal swabs has a high negative predictive value, is up to 48h faster than traditional culture and therefore facilitates earlier discontinuation of contact precautions, thereby improving patient care and saving valuable resources in the hospital.

[Incision of the third molar in the Netherlands. Incision tech-niques for the removal of impacted third molars in the mandible.] / Incisietechnieken bij verwijdering van geïmpacteerde derde molaren in de onderkaak.

Various incision techniques to remove impacted third molars in the mandible have been described, for example, the flap incision, the envelope incision, the distal incision and the modified envelope incision. The aim of this study was to record the incision techniques used by oral and maxillofacial surgeons in the Netherlands for the removal of impacted third molars in the mandible. All members of the Dutch Association of Oral and Maxillofacial Surgery (NVMKA) received a questionnaire. In this questionnaire, the surgeons specified their standard incision technique for the removal of, respectively, mesially impacted, upright, or distally impacted mandibular third molars. Of the 323 questionnaires sent, 172 were returned (53,3% response rate). The flap incision and the distal incision were the most frequently used incisions by oral and maxillofacial surgeons (including residents) in the Netherlands. The academic centre seems to have a lasting impact on the preferred way of removing an impacted third molar. It also seems that an oral and maxillofacial surgeon more frequently removes a third molar in the mandible from a sitting position than a resident.

Autotransplantation of teeth using computer-aided rapid prototyping of a three-dimensional replica of the donor tooth: a systematic literature review.

This systematic review provides an overview of studies on autotransplantation techniques using rapid prototyping for preoperative fabrication of donor tooth replicas for preparation of the neo-alveolus. Different three-dimensional autotransplantation techniques and their treatment outcomes are discussed. The systematic literature search yielded 19 articles that satisfied the criteria for inclusion. These papers described one case-control study, four clinical observational studies, one study with a clinical and in vitro part, four in vitro studies, and nine case reports. The in vitro studies reported high accuracy for the printing and planning processes. The case reports all reported successful transplantation without any pathological signs. The clinical studies reported a short extraoral time of the donor tooth, with subsequent success and survival rates of 80.0-91.1% and 95.5-100%, respectively. The case-control study reported a significant decrease in extraoral time and high success rates with the use of donor tooth replicas. In conclusion, the use of a preoperatively designed surgical guide for autotransplantation enables accurate positional planning, increases the ease of surgery, and decreases the extraoral time. However, the quality of the existing body of evidence is low. Further research is therefore required to investigate the clinical advantages of this innovative autotransplantation technique.