Whole-genome sequencing links cases dispersed in time, place, and person while supporting healthcare worker management in an outbreak of Panton-Valentine leucocidin meticillin-resistant Staphylococcus aureus; and a review of literature

This is a report on an outbreak of Panton-Valentine leucocidin-producing meticillin-resistant Staphylococcus aureus (PVL-MRSA) in an intensive care unit (ICU) during the COVID-19 pandemic that affected seven patients and a member of staff. Six patients were infected over a period of ten months on ICU by the same strain of PVL-MRSA, and a historic case identified outside of the ICU. All cases were linked to a healthcare worker (HCW) who was colonized with the organism. Failed topical decolonization therapy, without systemic antibiotic therapy, resulted in ongoing transmission and one preventable acquisition of PVL-MRSA. The outbreak identifies the support that may be needed for HCWs implicated in outbreaks. It also demonstrates the role of whole-genome sequencing in identifying dispersed and historic cases related to the outbreak, which in turn aids decision-making in outbreak management and HCW support. This report also includes a review of literature of PVL-MRSA-associated outbreaks in healthcare and highlights the need for review of current national guidance in the management of HCWs' decolonization regimen and return-to-work recommendations in such outbreaks.

Development and operation of the defence COVID-19 lab as a SARS-CoV-2 diagnostic screening capability for UK military personnel

BACKGROUND

In the face of the COVID-19 pandemic, the Defence Science and Technology Laboratory (Dstl) and Defence Pathology combined to form the Defence Clinical Lab (DCL), an accredited (ISO/IEC 17025:2017) high-throughput SARS-CoV-2 PCR screening capability for military personnel.

LABORATORY STRUCTURE AND RESOURCE

The DCL was modular in organisation, with laboratory modules and supporting functions combining to provide the accredited SARS-CoV-2 (envelope (E)-gene) PCR assay. The DCL was resourced by Dstl scientists and military clinicians and biomedical scientists.

LABORATORY RESULTS

Over 12 months of operation, the DCL was open on 289 days and tested over 72 000 samples. Six hundred military SARS-CoV-2-positive results were reported with a median E-gene quantitation cycle (Cq) value of 30.44. The lowest Cq value for a positive result observed was 11.20. Only 64 samples (0.09%) were voided due to assay inhibition after processing started.

CONCLUSIONS

Through a sustained effort and despite various operational issues, the collaboration between Dstl scientific expertise and Defence Pathology clinical expertise provided the UK military with an accredited high-throughput SARS-CoV-2 PCR test capability at the height of the COVID-19 pandemic. The DCL helped facilitate military training and operational deployments contributing to the maintenance of UK military capability. In offering a bespoke capability, including features such as testing samples in unit batches and oversight by military consultant microbiologists, the DCL provided additional benefits to the UK Ministry of Defence that were potentially not available from other SARS-CoV-2 PCR laboratories. The links between Dstl and Defence Pathology have also been strengthened, benefitting future research activities and operational responses.

Severe group A streptococcal infections in mothers and their newborns in London and the South East, 2010-2016: assessment of risk and audit of public health management

OBJECTIVE

We describe cases of invasive group A Streptococcus (iGAS) in mothers or neonates and assess management according to national guidelines, which recommend administering antibiotics to both mother and neonate if either develops iGAS infection within 28 days of birth and investigation of clusters in maternity units.

DESIGN

Cross-sectional retrospective study.

SETTING AND POPULATION

Notified confirmed iGAS cases in either mothers or neonates with onset within 28 days of birth in London and the South East of England between 2010 and 2016 METHOD: Review of public health records of notified cases.

MAIN OUTCOME MEASURES

Incidence and onset time of iGAS in postpartum mothers and babies, proportion given prophylaxis, maternity unit clusters within 6 months.

RESULTS

We identified 134 maternal and 21 neonatal confirmed iGAS infections. The incidence (in 100 000 person years) of iGAS in women within 28 days postpartum was 109 (95% CI 90-127) compared with 1.3 in other females aged 15-44. For neonates the incidence was 1.5 (95% CI 9-23). The median onset time was 2 days postpartum [interquartile range (IQR) 0-5 days] for mothers and 12 days (IQR 7-15 days) for neonates. All eligible mothers and most (109, 89%) eligible neonates received chemoprophylaxis. Of 20 clusters (59 cases of GAS and iGAS) in maternity units, two clusters involved possible transmission. However, in 6 of 15 clusters, GAS isolates were not saved for comparison even after relevant guidance was issued.

CONCLUSIONS

iGAS infection remains a potential postpartum risk. Prophylaxis among neonates and storage of isolates from maternity cases can be improved.

TWEETABLE ABSTRACT

Are public health guidelines being followed in the management of mothers and their newborns to reduce the risk of iGAS infection?

Skeletal myopathy associated with nucleoside reverse transcriptase inhibitor therapy: potential benefit of coenzyme Q10 therapy

Zidovudine (ZDV) has been associated with 'ragged-red' fibre myopathy, due to its effects on myocyte mitochondria. Usually this is reversible with cessation of ZDV. We report a 52-year-old man, who in 1985 developed ragged-red fibre myopathy 14 years after diagnosis of HIV infection while on effective ZDV-based combination antiretroviral therapy (ART). He was treated with the mitochondrial anti-oxidant coenzyme Q10 and made an excellent recovery, without change of ARTs. This suggests a novel therapy for further investigation targeted at ZDV induced myopathy, potentially allowing continuation of antiviral treatments including ZDV.

Intra-articular injection of photo-activated platelet-rich plasma in patients with knee osteoarthritis: a double-blind, randomized controlled pilot study

Background

Improvements in knee osteoarthritis (OA) symptoms with platelet-rich plasma (PRP) have been attributed to its ability to modify intra-articular inflammatory processes. Photo-activation of peripheral blood also improves inflammatory mediators associated with OA, however combined photo-activated PRP (PA-PRP) has not been investigated. This pilot study assessed the feasibility, safety and symptomatic and functional change following injections of PA-PRP compared to hyaluronic acid (HA) in people with knee osteoarthritis (OA).

Methods

Thirty seven people with knee OA were enrolled in this double-blind randomized controlled pilot study set in a sports medicine clinic. Participants were randomly allocated to receive three injections of either PA-PRP or HA. The patients and the administering doctor were blinded to group allocation. Outcomes included recruitment and safety data, 100 mm visual analogue pain score (VAS), the Knee Osteoarthritis Outcome Score (KOOS), Knee Quality of Life (KQoL) scale, maximum hopping distance and number of knee bends in 30 s at four and 12 weeks.

Results

Twenty three (62 %) participants met the inclusion criteria, of which 12 (32 %) were randomized to the PA-PRP group and 11 (30 %) to the HA group. Two participants did not complete the intervention and two withdrew following their first assessment. Minor pain and swelling during the injection period was reported by two participants from the PA-PRP group. The PA-PRP group demonstrated significant improvements in the VAS (p < 0.01, ETA = 0.686), KOOS Pain (p < 0.05, ETA = 0.624), KQoL Physical (p < 0.05, ETA = 0.706) and KQoL Emotional subscales (p < 0.05, ETA = 0.715) at four and 12 weeks. The PA-PRP group also significantly improved hoping (p < 0.05, ETA = 0.799) and knee bends (p < 0.01, ETA = 0.756) at four or 12 weeks. The HA group showed improvements on only the KOOS Function subscale at 12 weeks (p < 0.01, ETA = 0.602). After controlling for baseline values, there were no significant between-group differences at either time-point.

Conclusions

This study provides proof-of-concept evidence concerning the feasibility and safety of PA-PRP injections necessary to inform a larger clinical trial in people with knee OA. Our preliminary results also suggest PA-PRP improves self-reported pain, symptoms and lower extremity function, however no between-group differences were found. Photo-activated PRP may provide a safe and effective novel treatment for knee OA.

Trial registration

ACTRN12611000651987

The mechanism of action for hyaluronic acid treatment in the osteoarthritic knee: a systematic review

BACKGROUND

Knee osteoarthritis (OA) is one of the leading causes of disability within the adult population. Current treatment options for OA of the knee include intra-articular (IA) hyaluronic acid (HA), a molecule found intrinsically within the knee joint that provides viscoelastic properties to the synovial fluid. A variety of mechanisms in which HA is thought to combat knee OA are reported in the current basic literature.

METHODS

We conducted a comprehensive literature search to identify currently available primary non-clinical basic science articles focussing on the mechanism of action of IA-HA treatment. Included articles were assessed and categorized based on the mechanism of action described within them. The key findings and conclusions from each included article were obtained and analyzed in aggregate with studies of the same categorical assignment.

RESULTS

Chondroprotection was the most frequent mechanism reported within the included articles, followed by proteoglycan and glycosaminoglycan synthesis, anti-inflammatory, mechanical, subchondral, and analgesic actions. HA-cluster of differentiation 44 (CD44) receptor binding was the most frequently reported biological cause of the mechanisms presented. High molecular weight HA was seen to be superior to lower molecular weight HA products. HA derived through a biological fermentation process is also described as having favorable safety outcomes over avian-derived HA products.

CONCLUSIONS

The non-clinical basic science literature provides evidence for numerous mechanisms in which HA acts on joint structures and function. These actions provide support for the purported clinical benefit of IA-HA in OA of the knee. Future research should not only focus on the pain relief provided by IA-HA treatment, but the disease modification properties that this treatment modality possesses as well.

Caco-2 cell line as a model to evaluate mucoprotective proprieties

Physical protection of mucosa surface and reduction of inflammatory processes are currently considered the main strategies in the treatment and prevention of mucosal diseases. However, the majority of models used to verify the activity of new mucoprotective agents are based on limiting instrumental assessment or the sacrifice of experimental animals. In this study, for the first time, some in vitro experimental methods using Caco-2 cell line are proposed as predicting in vivo behaviour and action of mucoprotective agents. To this purpose, hyaluronic acid and natural polysaccharides for their bioadhesive activity, hydrocortisone and natural polyphenols as anti-inflammatory agents have been chosen. The obtained results demonstrated that the techniques (Con A/o-pd assay and Franz cell system) of mucoadhesive evaluation on Caco-2 cells are useful to compare the activity of each experimental sample and to assess the adhesion time to the mucosal cell surface. Moreover, the reduction of intercellular adhesion molecule-1 (ICAM-1) expression in Caco-2 cells can be considered directly correlated to the mucosal anti-inflammatory effect induced by the hydrocortisone and natural polyphenols. In conclusion, the study supported the use of Caco-2 cell as a model to compare and investigate the effect of different active substances on the mucosa and its diseases.

The contribution of XANES spectroscopy to tribology

X-ray absorption near edge structure spectroscopy (XANES) analysis has been routinely used to study the complex chemical interactions between additives in engine oil and metallic surfaces during high-temperature and pressure reciprocating wear conditions. XANES analysis provides detailed chemical and structural information on the resultant antiwear and tribo films formed on metallic surfaces. The following review will illustrate how XANES analysis on the macro scale can provide the information required to elucidate complex film formation mechanisms, then describes the use of emerging XANES spectromicroscopy to such systems, and concludes by showing the complementary nature of the macro and micro scale spatially resolved XANES analysis; Professor Bancroft has utilized the combination of these to stay at the forefront of XANES research in the field of tribology and in spectroscopy science in general.Key words: tribology, XANES, X-ray absorption near edge structure spectroscopy, metals, thiophosphates, spectromicroscopy, tribochemistry.

Management of hepatitis A in a food handler at a London secondary school

A case of hepatitis A in a food handler at a local secondary school prompted the institution of control measures including administration of human normal immunoglobulin (HNIG) to all pupils. This paper summarises the management of the incident and describes the use of HNIG to prevent secondary cases. Few adverse effects were reported and only one secondary case of hepatitis A occurred at the school.

Using immersive VR as a tool for preoperative planning for minimally invasive donor nephrectomy

For surgeons approaching minimally invasive donor nephrectomy it is important to identify variant anatomy preoperatively since this anatomy can vary significantly from patient to patient. The goal of this operation is to preserve the architecture and function of the organ so it can be transplanted and function successfully. The ability of the surgeon to navigate through an individual patient's anatomy in a virtual three-dimensional (3D) immersive environment augments understanding of anatomical relationships particular to that individual patient and facilitates conveying that information to other physicians and students. Utilizing automated 3D reconstruction of high contrast computed tomography (CT) scan files viewed in this way, surgeons reported a better preoperative understanding of the anatomical variations and encountered fewer surprises at the time of surgery.

Breathing patterns and heart rate during simulated occupational upper limb tasks in normal subjects

BACKGROUND AND PURPOSE

Despite the arms being used extensively in the performance of many occupational tasks, little is known about the pattern of breathing and physiological cost of such work. The purpose of this study was to establish whether a simple change in arm support could alter the workload, pattern of breathing and respiratory muscle recruitment during a low intensity arm task.

METHODS

Ten normal subjects performed a simulated work task when sitting, once with the arms supported and once unsupported. Subjects were required, over a five-minute period, to repeatedly pick up a 2 kg object, inspect and hold it for 15 seconds and then pack it in a box. Breathing pattern responses, measured by pneumotachograph and respiratory inductive plethysmography, were minute ventilation (VE), respiratory frequency (Rf), tidal volume (VT) and change in functional residual capacity (FRC).

RESULTS

The main findings were that unsupported arm work was more physiologically demanding than supported arm work. During work VE increased as a result of a change in respiratory frequency but not VT which was much more limited when the arms were unsupported. At the completion of activity, when the arms were unloaded, VT initially increased as VE decreased. FRC and VT were reduced during arm work and increased during recovery, mainly as a result of a change in ribcage excursion.

CONCLUSIONS

These findings support the theory that during arms activity, intercostal and accessory respiratory muscles act to stabilize the arms and torso, impeding chest wall movement and shifting the respiratory load from these muscles to the diaphragm. This may adversely effect performance of workers who have ventilatory limits to arm work tasks.

The development of a treatment protocol for patients with chronic radiation-induced rectal bleeding

BACKGROUNDS AND METHODS: This study reviews the clinical features and reports the preliminary results of treatment of 34 consecutive patients with clinically significant bleeding from chronic, radiation-induced proctitis, using a combination of endoscopic YAG Laser and the application of topical formalin dressings to the rectal mucosa.

RESULTS

Bleeding ceased in 25 patients (74%); bleeding continued but occurred only slightly and occasionally in five patients (15%); and three patients required operation to control the bleeding (9%). One patient relapsed after treatment and died while receiving a further transfusion.

CONCLUSIONS

This experience has been used to develop a management protocol for patients with this serious complication.

Transfusion does not influence patient survival after resection of colorectal cancer

Two recent reviews reached opposing conclusions regarding the apparent detrimental effect of peri-operative blood transfusion on patient survival after resection of colorectal cancer. However, both sides agree that the influence of confounding variables has not been controlled adequately in most studies. The present study is based on 433 patients who had a curative resection for colorectal cancer between 1984 and 1989 and whose details and follow-up information were recorded in the Concord Hospital Colorectal Cancer Registry, Sydney. The association between peri-operative transfusion and patient survival after resection of colorectal cancer was examined taking into account 20 other prognostic variables. A proportional hazards regression model showed that transfusion did not have a statistically significant independent effect on survival after controlling for the patient's poor general condition, the complexity of the surgery and the occurrence of postoperative complications.

A medical illustration information management system for the Apple Macintosh computer

Collection and collation of statistical information is an ever-increasing requirement in the modern medical illustration department. Business planning and general management decisions are all based on such criteria. As the NHS 'market place' philosophy evolves, traditional manual systems of record-keeping are no longer adequate. This paper describes the 'in-house' development of a customized database using the Apple Macintosh computer, and outlines the reasons for this choice of system.

How to run an induction meeting for house officers

Images

Computer-aided manipulation of photographs for leg lengthening

The use of composite photographs to aid the patient and the consultant to assess the visual effects of different degrees of leg lengthening is now a well-established practice at the Royal Hallamshire Hospital, Sheffield. The original photographic composite technique was both time consuming and intricate. By the use of the Apple Macintosh computer and software such as Digital Darkroom, major advances over the old technique have been achieved resulting in a more accurate representation of what is hoped will be the final operative appearance.

Haematological aspects of renal disease

Renal diseases are associated with a variety of haemopoietic changes. Anaemia parallels the degree of renal impairment and its most important cause is failure of renal erythropoietin secretion. Other factors include depressed red cell production and reduced red cell survival. Purpura and bleeding are predominantly due to platelet dysfunction and usually respond to dialysis. Cryoprecipitate and 1-deamino-8-d-arginine vasopressin may be of value in the bleeding patient. Abnormal coagulation with fibrin deposition in the microcirculation is now recognised as a mechanism of renal impairment. Plasma infusion and anticoagulants may be useful in the therapy of conditions in which this occurs. Plasma exchange is now used in the investigation and management of some varieties of immunologically mediated renal disease. Blood transfusion has been found to improve graft survival if given prior to renal transplantation and this effect is currently under active investigation.

Bone marrow transplantation in 33 patients with malignant blood diseases and severe aplastic anaemia

Allogeneic bone marrow transplantation using HLA-identical sibling donors was performed in 29 patients with malignant blood diseases and in four patients with severe aplastic anaemia. Twenty-five patients received immunosuppressive therapy with cyclosporin A to minimize graft-versus-host disease (GVHD) and eight received methotrexate. Twenty-one of 29 patients (72%) with malignant blood diseases and three of the four patients with severe aplastic anaemia remained alive and disease-free from 0.5 to 16 (median, seven) months after transplantation. Acute GVHD, predominantly of the skin, occurred in 25 of 28 evaluable cyclosporin A recipients (of whom two died), and in all five evaluable methotrexate recipients. Mild chronic GVHD occurred in 10 of 16 evaluable patients. Interstitial pneumonitis occurred in five patients, of whom two died. HLA-identical sibling marrow transplantation is associated with a mortality similar to that of induction chemotherapy for acute leukaemia, and should be considered in adults with acute leukaemia in remission or relapse, chronic myelogenous leukaemia in metamorphosis or blastic transformation, lymphoma unresponsive to conventional therapy, and in severe aplastic anaemia.

Isotypic discordance of paraproteins and lymphocyte surface immunoglobulins in myeloma

B lymphocyte surface immunoglobulins (Smlg) were studied in 24 patients with multiple myeloma by means of anti-isotypic antisera, and their heavy and light chain isotypes were compared in each patient with those of the paraprotein. In 21 patients, lymphocyte Smlg consisted of only one light chain type, and in 16 of only 1 heavy chain type. However, the Smlg and paraprotein heavy and light chain types were identical in only 5 patients while in 6 they differed in heavy and light chain types, in 7 in light chain type, and in 4 in heavy chain type. In 2 patients with light chain myeloma, Smlg light chains were isotypically the same as the paraprotein. Isotypic discordance between paraprotein and Smlg may signify the proliferation of a second malignant clone with failure to differentiate into secreting plasma cells. Alternatively, it is conceivable that the lymphocyte Smlg could have the same idiotypic specificity as the paraprotein despite the isotypic differences, but this will require further studies using anti-idiotypic antisera.

Oral histoplasmosis treated with miconazole

A case of localised histoplasmosis of the gingivae, with no osseous involvement is described in a 50-year-old man. The diagnosis was based on histology, growth on culture and a positive histoplasmin latex test. Therapy was commenced with intravenous amphotericin but was changed to intravenous miconazole because of serious immediate side effects and the development of marked renal impairment and moderate suppression of erythropoiesis. Rebiopsy of the gingival margin showed therapy to be effective. No source of the infection could be traced.