Citizen Health Science: Foundations of a New Data Science Arena.

Citizen scientists with health interests have rapidly increased efforts to conduct their own health studies on themselves and in their communities, giving rise to a new transdisciplinary field of citizen health science. This science leverages long-standing traditions of single case or N-of-1 studies in psychology and also finds influential roots in the history of self-experimentation in health and medicine. These studies frequently incorporate new digital tools such as smartphone tracking and many other mobile health or "mHealth" devices. Citizen health scientists also tend to operate in social networks of people working to maintain or improve their health, increasing the complexity and richness of opportunities tied to this new platform. Population data scientists are well-positioned to seek new ways to derive scientific inferences from data generated in citizen health science projects. This paper provides an overview of citizen health science for population data scientists, including basic definitions, historical foundations, current challenges and opportunities, and future directions.

A comparison of paediatric and adult infectious diseases consultations in Australia and New Zealand.

The objective of this paper is to describe paediatric infectious diseases consultations across Australia and New Zealand. We surveyed infectious diseases physicians at 51 hospitals over a period of 2 weeks in 2012. Compared with adult consults, paediatric consults were more frequently received from general paediatricians/physicians and intensive care, yet less frequently from surgeons and emergency. Respiratory, skin/soft tissue and bone/joint infections were the most frequent consultations in children. These data demonstrate the breadth of formal infectious diseases consults in children. Differences between paediatric and infectious diseases consultations need to be considered when planning both paediatric and adult physician training and future curriculum development.

What do infectious diseases physicians do? A 2-week snapshot of inpatient consultative activities across Australia, New Zealand and Singapore.

The practice of an infectious diseases (ID) physician is evolving. A contemporary understanding of the frequency and variety of patients and syndromes seen by ID services has implications for training, service development and setting research priorities. We performed a 2-week prospective survey of formal ID physician activities related to direct inpatient care, encompassing 53 hospitals throughout Australia, New Zealand and Singapore, and documented 1722 inpatient interactions. Infections involving the skin and soft tissue, respiratory tract and bone/joints together accounted for 49% of all consultations. Suspected/confirmed pathogens were primarily bacterial (60%), rather than viral (6%), fungal (4%), mycobacterial (2%) or parasitic (1%). Staphylococcus aureus was implicated in 409 (24%) episodes, approximately four times more frequently than the next most common pathogen. The frequency of healthcare-related infections (35%), immunosuppression (21%), diabetes mellitus (19%), prosthesis-related infections (13%), multiresistant pathogens (13%) and non-infectious diagnoses (9%) was high, although consultation characteristics varied between geographical settings and hospital types. Our study highlights the diversity of inpatient-related ID activities and should direct future teaching and research. ID physicians' ability to offer beneficial consultative advice requires broad understanding of, and ability to interact with, a wide range of referring specialities.

Nosocomial vs community-acquired pandemic influenza A (H1N1) 2009: a nested case-control study.

BACKGROUND: The characteristics of nosocomial influenza in children are not well described. AIM: To compare the characteristics of nosocomial and community-acquired pandemic influenza A (H1N1) 2009 (pH1N1) in Australian children. METHODS: In a nested case-control study, the clinical and epidemiological features of nosocomial vs community-acquired pH1N1 were compared among hospitalized children aged <15 years in six paediatric hospitals in Australia between 1 June and 30 September 2009. FINDINGS: Of 506 hospitalized children with pH1N1, 47 (9.3%) were of nosocomial origin. These 47 cases were compared with 141 gender- and age-matched controls. Cases had a significantly higher proportion of underlying medical conditions compared with controls (81% vs 42%, P < 0.001), and were more likely to be exposed to household smokers (36% vs 20%, P = 0.02). Fewer children with nosocomial influenza presented with classical symptoms of influenza, including subjective fever and lethargy. A higher proportion of children with nosocomial influenza received treatment with oseltamivir (77% vs 43%, P < 0.001), and they required a longer stay in hospital following the onset of influenza (mean 8.5 days vs 4.5 days, P = 0.006). Three children (2%) in the community-acquired group died of pH1N1, but there were no deaths in the nosocomial group. CONCLUSION: This study shows that children with pre-existing diseases and those who are exposed to household smokers are more susceptible to nosocomial pH1N1. They may have 'occult presentation' of influenza, but their course of illness is not markedly different from that of children with community-acquired influenza.

Pre- and post-synaptic abnormalities associated with impaired neuromuscular transmission in a group of patients with 'limb-girdle myasthenia'.

The properties of neuromuscular junctions (NMJs) were studied in motor-point biopsy samples from eight patients with congenital myasthenic syndromes affecting primarily proximal limb muscles ['limb-girdle myasthenia' (LGM)]. All had moderate to severe weakness of the proximal muscles, without short-term clinical fatigability but with marked variation in strength over periods of weeks or months, with little or no facial weakness or ptosis and no ophthalmoplegia. Most had a characteristic gait and stance. All patients showed decrement of the compound muscle action potential (CMAP) on repetitive stimulation at 3 Hz, and increased jitter and blocking was detected by SFEMG, confirming the presence of impaired neuromuscular transmission. None of the patients had serum antibodies against acetylcholine receptors (AChRs). Two of the patients had similarly affected siblings. Intracellular recording from isolated nerve-muscle preparations revealed that the quantal content (the number of ACh quanta released per nerve impulse) was only approximately 50% of that in controls. However, the quantal size (amplitude of miniature end-plate currents) and the kinetic properties of synaptic potentials and currents were similar to control values. The area of synaptic contact and extent of post-synaptic folding were approximately 50% of control values. Thus, the quantal content per unit area of synaptic contact was normal. The number of AChRs per NMJ was also reduced to approximately 50% of normal, so the local AChR density was normal. Immunolabelling studies revealed qualitatively normal distributions and abundance of each of 14 proteins normally concentrated at the NMJ, including components of the basal lamina, post-synaptic membrane and post-synaptic cytoskeleton. DNA analysis failed to detect mutations in the genes encoding any of the following proteins: AChR subunits, rapsyn, ColQ, ChAT or muscle-specific kinase. Response of these patients to treatment was varied: few showed long-term improvement with pyridostigmine and some even deteriorated with treatments, while others had intolerable side-effects. Several patients showed improvement with 3,4-diaminopyridine, but this was generally only transient. Ephedrine was helpful in half of the patients. We conclude that impaired neuromuscular transmission in these LGM patients results from structural abnormalities of the NMJ, including reduced size and post-synaptic folding, rather from any abnormality in the immediate events of neuromuscular transmission.

Reversible cytotoxic cerebral edema in cerebral fat embolism.

We present a case of cerebral fat embolism (CFE) that demonstrated evidence of diffuse white matter cytotoxic edema on diffusion-weighted magnetic resonance imaging, in addition to punctate hyperintensities on T2-weighted and diffusion-weighted imaging. The case suggests that CFE represents a combination of occlusive arteriolar disease and secondary neurotoxicity.

Improved outcome for children with disseminated adenoviral infection following allogeneic stem cell transplantation.

Adenovirus (AdV) infections are a frequent cause of morbidity and mortality following allogeneic stem cell transplantation (SCT), and disseminated infection is associated with high mortality, particularly in paediatric SCT. Here, we describe an approach to reduce mortality from adenoviraemia by combining prospective monitoring for the occurrence of adenoviraemia using a sensitive polymerase chain reaction method, early antiviral therapy and prompt withdrawal of immunosuppression. A total of 155 consecutive paediatric SCT procedures were prospectively monitored, of which 113 (73%) transplants involved donors other than matched siblings and 126 (83%) employed T-cell depletion. Adenoviraemia was detected in 26/155 (17%) transplants and developed exclusively in patients who had received T-cell-depleted grafts. Withdrawal of immunosuppression coupled with early antiviral therapy led to resolution of adenoviraemia in 19/26 (81%) patients with only five patients succumbing to disseminate AdV infection. Survival from adenoviraemia was associated with lymphocyte recovery to above 0.3x10(9)/l. Mortality was closely linked with the absence of lymphocyte recovery because of profound T-cell depletion of the graft with CD34+ magnetic-activated cell sorting. Mortality from disseminated AdV infection was 5/26 (19%) in this study, which is significantly lower than previously reported.

Predictors of outcome of myocarditis.

Heart failure from myocarditis may be transient or may progress to unremitting severe cardiac failure. This study was performed to determine the outcomes and prognostic features of pediatric patients with myocarditis. Patients with the diagnosis of myocarditis between 1990 and 2001 were identified through the coding system of Yale-New Haven Hospital. A total of 28 patients were included, with ages ranging from 1 day to 20 years. Before discharge, 11 patients developed unremitting severe cardiac failure. Of the remaining 17 patients, at the time of discharge 10 had normal systolic function and 7 had decreased systolic function. Unremitting cardiac failure developed in 9 of 14 patients (64%) with an ejection fraction < 30% and in only 2 of 14 (14%) of those with an ejection fraction > or = 30% on admission (p < 0.01). Furthermore, shortening fraction < 15%, left ventricular dilatation, and moderate to severe mitral regurgitation on admission as well as arrhythmia were significantly associated with development of unremitting severe cardiac failure. In this series of patients with myocarditis, by the time of discharge 39% of the patients had developed unremitting severe cardiac failure, 25% had depressed systolic function, and 36% had normal systolic function. Predictive factors at admission for poor outcome were ejection fraction < 30%, shortening fraction < 15%, left ventricular dilatation, and moderate to severe mitral regurgitation.

Divry-Van Bogaert syndrome in a female: relationship to Sneddon's syndrome and radiographic appearances.

A 28-year-old woman presented with generalised livedo reticularis, dementia, epilepsy, and pyramidal and extrapyramidal signs. Multiple focal infarcts were seen on MRI. Angiography demonstrated widespread cerebromeningeal angiomatosis with multiple small and medium size arterial occlusions. A lifelong personal and family history of mental handicap in the absence of anticardiolipin antibodies suggests Divry-Van Bogaert syndrome, not previously been reported in a female. Similarities to Sneddon's syndrome are discussed.

A novel autosomal dominant distal myopathy with early respiratory failure: clinico-pathologic characteristics and exclusion of linkage to candidate genetic loci.

We describe a novel autosomal dominant myopathy presenting in mid-adult life with tibialis anterior weakness. We carried out a detailed clinical assessment of 24 individuals spanning three generations, documenting pathologic features of the muscles in 7 of the 11 affected individuals, including an autopsy study on one case. The second generation of affected individuals presented at an earlier age, and the disease progressed more rapidly than in the first generation. Lung function tests revealed progressive global respiratory muscle weakness detectable from the time of presentation, with preferential diaphragmatic involvement in some cases. Hip girdle and shoulder girdle weakness appeared later in the disease course. We observed a striking correlation between the clinical and pathological features. Clinically unaffected muscles had minimal pathologic change. Fiber splitting, eosinophilic inclusions, and vacuoles with basophilic rims were seen in moderately affected muscles, and fat and fibrous connective tissue replaced muscle fibers in the severely involved muscles. The inclusions were Congophilic and reacted with antibodies to desmin, beta-amyloid, and phosphorylated tau protein. The disease was not linked to any of the known loci associated with distal myopathies, confirming that the disorder in this family is both genetically and phenotypically distinct.

Case report: multiple thoracic haemangiomas--a rare cause of spinal cord compression.

Benign haemangiomas are a rare cause of mediastinal masses. We present a patient with multiple thoracic wall and mediastinal haemangiomas who developed spinal cord compression as a result of extradural extension of the haemangiomas. This is a rare cause of spinal cord compression.

Breathing pattern awake and asleep in patients with myotonic dystrophy.

Patients with myotonic dystrophy often have an irregular pattern of breathing at rest, implying abnormality of breathing control. No central medullary defect has been found in such patients. We postulated that irregular breathing in myotonic dystrophy due to abnormal central respiratory output would persist during slow-wave sleep. We examined the patterns of breathing whilst awake and asleep in seven patients with myotonic dystrophy, seven similarly weak nonmyotonic subjects and seven normal controls. Polysomnography was performed, and the coefficients of variation (CoV) of the breath intervals were analysed during different stages of sleep. The myotonic group showed significantly greater variation in breath intervals than the other two groups whilst awake (median CoV 37 vs 18% for nonmyotonics) and during light sleep (31 vs 13%). This difference was not evident during slow-wave sleep (median CoV 12 vs 9% in nonmyotonic). We conclude that irregular breathing in patients with myotonic dystrophy whilst awake and during light sleep, does not persist during slow-wave sleep. These results suggest that "behavioural" influences play a role in the abnormal breathing pattern found in myotonic dystrophy. The source of the irregular breathing is unlikely to be found in the medulla, but may originate from forebrain influences.

Malignant cerebrovascular thromboembolization by phaechromocytoma.

We describe an unusual case of malignant thromboembolization within the aortic arch of a 56-year-old man who presented with a stroke. The uncommon source of this malignant embolus was an adrenal phaeochromocytoma which had permeated the inferior vena cava, metastasized into the pleural cavity and colonized the intimal surfaces of the aortic arch and carotid vessels. The relevant literature has been briefly reviewed.