Infectious Disease Outbreaks in Competitive Sports, 2005–2010

Context

Old, evolving, and new infectious agents continually threaten the participation of competitors in sports.

Objective

To provide an update of the medical literature on infectious disease outbreaks in sport for the last 5 years (May 2005–November 2010).

Main Outcome Measure(s)

A total of 21 outbreaks or clusters were identified.

Results

Methicillin-resistant Staphylococcus aureus (n = 7, 33%; mainly community acquired) and tinea (trichophytosis: n = 6, 29%) were the most common pathogens responsible for outbreaks. Skin and soft tissue was the most common site of infection (n = 15, 71%).

Conclusions

The majority of outbreaks reported occurred in close-contact sports, mainly combat sports (ie, wrestling, judo) and American football. Twelve outbreaks (57%) involved high school or collegiate competitors. Common community outbreak pathogens, such as influenza virus and norovirus, have received little attention.Key Words: methicillin-resistant Staphylococcus aureus, tinea, trichophytosis, pathogens, athletes

Key Points

• Most reported outbreaks occurred in competitors participating in close contact sports.
• Of the reported outbreaks, 71% involved infections of the skin and soft tissue.
• Methicillin-resistant Staphylococcus aureus accounted for 33% of reported outbreaks.
• High school or collegiate competitors were affected in 57% of reported outbreaks.

It has been more than 5 years since Turbeville et al¹ performed a literature review identifying 59 infectious disease outbreaks or clusters among athletes in competitive sports from 1922 through May 2005. They found that herpes simplex virus (HSV) and Staphylococcus aureus were the most common pathogens reported. However, new or evolving pathogens continue to emerge, posing potentially significant risks to the health of competitors.In 2009, the world experienced its first global influenza virus pandemic since 1968; infections occurred more commonly in younger people.^2,3 Within the last decade, community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has continued to emerge, with outbreaks and increasing rates reported in several countries.⁴ Infectious diseases commonly disrupt both an individual athlete''s participation in sports and a team''s ability to perform.It is clearly important that the nature of outbreaks of infection among athletes are documented and delineated so that preventive measures may be undertaken. In an ever-changing environment, a review that spanned more than 80 years may not provide an accurate reflection of the pathogens currently of concern among sports competitors.¹ With this 5-year update of infectious disease outbreaks in sports, our goal was to provide a current picture of the pathogens involved in published outbreaks in athletes.     

In situ handheld three‐dimensional bioprinting for cartilage regeneration

Articular cartilage injuries experienced at an early age can lead to the development of osteoarthritis later in life. In situ three‐dimensional (3D) printing is an exciting and innovative biofabrication technology that enables the surgeon to deliver tissue‐engineering techniques at the time and location of need. We have created a hand‐held 3D printing device (biopen) that allows the simultaneous coaxial extrusion of bioscaffold and cultured cells directly into the cartilage defect in vivo in a single‐session surgery. This pilot study assessed the ability of the biopen to repair a full‐thickness chondral defect and the early outcomes in cartilage regeneration, and compared these results with other treatments in a large animal model. A standardized critical‐sized full‐thickness chondral defect was created in the weight‐bearing surface of the lateral and medial condyles of both femurs of six sheep. Each defect was treated with one of the following treatments: (i) hand‐held in situ 3D printed bioscaffold using the biopen (HH group), (ii) preconstructed bench‐based printed bioscaffolds (BB group), (iii) microfractures (MF group) or (iv) untreated (control, C group). At 8 weeks after surgery, macroscopic, microscopic and biomechanical tests were performed. Surgical 3D bioprinting was performed in all animals without any intra‐ or postoperative complication. The HH biopen allowed early cartilage regeneration. The results of this study show that real‐time, in vivo bioprinting with cells and scaffold is a feasible means of delivering a regenerative medicine strategy in a large animal model to regenerate articular cartilage.     

Direct and Indirect Economic Consequences of Multiple Sclerosis in Ireland

Introduction

Multiple sclerosis (MS) has significant financial consequences for healthcare systems, individual patients and households, and the wider society. This study examines the distribution of MS costs and resource utilisation across cost categories and from various perspectives, as MS disability increases.

Methods

Two hundred and fourteen patients with MS were recruited from a specialist MS outpatient clinic in Ireland and included in an interview-based study on MS-related healthcare resource consumption and costs. Patients were grouped into three categories based on disability: mild [Expanded Disability Status Scale (EDSS) score 0–3.5, n = 114], moderate (EDSS 4.0–6.5, n = 72) and severe (EDSS 7.0–9.5, n = 27). The mean annual direct and indirect costs (in year 2012 values) were estimated using non-parametric bootstrapping.

Results

Participants were 66.4 % female, with a mean age of 47.6 years and a mean EDSS score of 3.6. The majority had relapsing-remitting MS (RRMS) (53 %). The mean annual direct (indirect) costs per person were €10,249 (€9,447), €13,045 (€31,806) and €56,528 (€39,440) in mild, moderate and severe MS, respectively. Direct costs are driven by the cost of disease-modifying therapies and professional home help in mild and severe MS, respectively. Between 74 % (severe MS) and 96 % (mild MS) of all direct costs are borne by the healthcare payer, the remainder being incurred by patients, their families or other non-healthcare organisations.

Conclusions

MS is associated with high levels of healthcare resource consumption and costs, and these costs increase with increasing disability. There is potential to significantly reduce the economic burden of MS through interventions that prevent progression from mild or moderate MS to severe MS, help support independent living at home and keep people with MS in the work force.     

Paediatric chronic illness and educational failure: the role of emotional and behavioural problems

Background

Chronic illness in childhood is associated with worse educational outcomes. The association is usually explained via lowered cognitive development, decreased readiness to learn and school absence. However, this paper examines whether worse psychological adjustment may also play a role.

Methods

We use data from the Growing Up in Ireland study, a cohort study, which collected data on 8,568 nine-year-old children through the Irish national school system using a two-stage sampling method. Maximum likelihood path analytic models are used to assess the direct effect of child chronic illness on reading and maths test scores and the mediating role of emotional and behavioural problems.

Results

In unadjusted analyses, children with a mental and behavioural condition scored 14.5 % points less on reading tests and 16.9 % points less on maths tests than their healthy peers. Children with non-mental and behavioural conditions scored 3 % points less on both tests, a significant difference. Mental and behavioural (OR, 9.58) and other chronic conditions (OR, 1.61) were significantly more likely to have ‘high’ levels of difficulties on the SDQ. Path analysis models showed that the association between chronic illness and educational test scores was completely mediated by emotional and behavioural problems controlling for school absence and bullying by peers.

Conclusions

Child and adolescent chronic illness can have significant effects on educational development and a long-lasting impact on future life-chances. The psychological adjustment of the child is important in mediating the effect of chronic illness on educational outcomes. Interventions should target this developmental pathway.     

Semi-supervised Nonnegative Matrix Factorization for gene expression deconvolution: a case study

Heterogeneity in sample composition is an inherent issue in many gene expression studies and, in many cases, should be taken into account in the downstream analysis to enable correct interpretation of the underlying biological processes. Typical examples are infectious diseases or immunology-related studies using blood samples, where, for example, the proportions of lymphocyte sub-populations are expected to vary between cases and controls. Nonnegative Matrix Factorization (NMF) is an unsupervised learning technique that has been applied successfully in several fields, notably in bioinformatics where its ability to extract meaningful information from high-dimensional data such as gene expression microarrays has been demonstrated. Very recently, it has been applied to biomarker discovery and gene expression deconvolution in heterogeneous tissue samples. Being essentially unsupervised, standard NMF methods are not guaranteed to find components corresponding to the cell types of interest in the sample, which may jeopardize the correct estimation of cell proportions. We have investigated the use of prior knowledge, in the form of a set of marker genes, to improve gene expression deconvolution with NMF algorithms. We found that this improves the consistency with which both cell type proportions and cell type gene expression signatures are estimated. The proposed method was tested on a microarray dataset consisting of pure cell types mixed in known proportions. Pearson correlation coefficients between true and estimated cell type proportions improved substantially (typically from about 0.5 to approximately 0.8) with the semi-supervised (marker-guided) versions of commonly used NMF algorithms. Furthermore known marker genes associated with each cell type were assigned to the correct cell type more frequently for the guided versions. We conclude that the use of marker genes improves the accuracy of gene expression deconvolution using NMF and suggest modifications to how the marker gene information is used that may lead to further improvements.