Mental health diagnoses in adults with phenylketonuria: a retrospective systematic audit in a large UK single centre.

BACKGROUND: Recently published European Society for Phenylketonuria (ESPKU) guidelines have recommended a lifelong diet with phenylalanine (Phe) control ≤ 600 µmol/L for phenylketonuria (PKU) patients. This study aimed to identify whether PKU adult patients are at a higher risk of mental health diagnoses if their 2-year average Phe level is higher than the ESPKU European guidelines. Published studies identified by a literature review showed that related studies have been published in American and European PKU study populations but not in the United Kingdom (UK) study populations. Previous studies also involved a smaller number of participants due to this being a rare disease. RESULTS: We undertook a retrospective audit at a single large PKU centre in the UK. 244 adult PKU patients at the centre were included, 220 of which had a recorded Phe level. Approximately 75% of the patients in this study did not meet the ESPKU European guidelines for Phe control. A systematic search of the electronic patient record was undertaken looking for mental health diagnoses. Compared to two-year average Phe levels ≤ 600 µmol/L, PKU adult patients with two-year average Phe levels > 600 µmol/L were more likely to have diagnoses of low mood, depression, anxiety, or mood swings, but only low mood reached statistical significance (p < 0.05). CONCLUSIONS: PKU patients with two-year average Phenylalanine levels greater than ESPKU guidelines may be at greater risk of mental health diagnoses and symptoms. Many of these adult PKU patients will be lost to follow-up, and therefore may be receiving treatment for mental health conditions in the community. Multicentre UK studies and international collaborations are required to overcome low participant numbers in the study of this rare disease.

Multidisciplinary management of pregnancy and labour in a patient with glycogen storage disease type 1a.

Glycogen storage disease type 1a (GSD 1a) is a metabolic disorder caused by deficiency of an enzyme required for glycogen breakdown, causing hypoglycaemia and lactic acidosis. Metabolic derangements cause disease manifestations affecting the kidneys, liver and platelet function. Physiological changes in pregnancy worsen fasting intolerance and increase reliance on exogenous glucose to avoid lactic acidosis. Fetal macrosomia and declining respiratory function result in high rates of caesarean sections. We report the multidisciplinary team (MDT) management of a 25-year-old woman with GSD 1a in an unplanned pregnancy. Existing percutaneous endoscopic gastrostomy tube feeding, alongside high-calorie drinks and intravenous dextrose during labour, managed the risks of hypoglycaemia and lactic acidosis. Metabolic parameters were regularly monitored and fortnightly growth scans were assessed for macrosomia. Allopurinol was continued throughout the pregnancy to reduce the risk of hyperuricaemia. MDT management optimised maternal and fetal care throughout pregnancy and labour, resulting in a successful vaginal delivery.

Antagonism of STAT3 signalling by Ebola virus.

Many viruses target signal transducers and activators of transcription (STAT) 1 and 2 to antagonise antiviral interferon signalling, but targeting of signalling by other STATs/cytokines, including STAT3/interleukin 6 that regulate processes important to Ebola virus (EBOV) haemorrhagic fever, is poorly defined. We report that EBOV potently inhibits STAT3 responses to interleukin-6 family cytokines, and that this is mediated by the interferon-antagonist VP24. Mechanistic analysis indicates that VP24 effects a unique strategy combining distinct karyopherin-dependent and karyopherin-independent mechanisms to antagonise STAT3-STAT1 heterodimers and STAT3 homodimers, respectively. This appears to reflect distinct mechanisms of nuclear trafficking of the STAT3 complexes, revealed for the first time by our analysis of VP24 function. These findings are consistent with major roles for global inhibition of STAT3 signalling in EBOV infection, and provide new insights into the molecular mechanisms of STAT3 nuclear trafficking, significant to pathogen-host interactions, cell physiology and pathologies such as cancer.

Machine Learning Identifies Cellular and Exosomal MicroRNA Signatures of Lyssavirus Infection in Human Stem Cell-Derived Neurons.

Despite being vaccine preventable, rabies (lyssavirus) still has a significant impact on global mortality, disproportionally affecting children under 15 years of age. This neurotropic virus is deft at avoiding the immune system while travelling through neurons to the brain. Until recently, research efforts into the role of non-coding RNAs in rabies pathogenicity and detection have been hampered by a lack of human in vitro neuronal models. Here, we utilized our previously described human stem cell-derived neural model to investigate the effect of lyssavirus infection on microRNA (miRNA) expression in human neural cells and their secreted exosomes. Conventional differential expression analysis identified 25 cellular and 16 exosomal miRNAs that were significantly altered (FDR adjusted P-value <0.05) in response to different lyssavirus strains. Supervised machine learning algorithms determined 6 cellular miRNAs (miR-99b-5p, miR-346, miR-5701, miR-138-2-3p, miR-651-5p, and miR-7977) were indicative of lyssavirus infection (100% accuracy), with the first four miRNAs having previously established roles in neuronal function, or panic and impulsivity-related behaviors. Another 4-miRNA signatures in exosomes (miR-25-3p, miR-26b-5p, miR-218-5p, miR-598-3p) can independently predict lyssavirus infected cells with >99% accuracy. Identification of these robust lyssavirus miRNA signatures offers further insight into neural lineage responses to infection and provides a foundation for utilizing exosome miRNAs in the development of next-generation molecular diagnostics for rabies.

Implementation and assessment of a telecytology quality assurance program.

INTRODUCTION: The College of American Pathologists mandates that telepathology services are included in laboratory quality management programs. The aim of this study was to assess a telecytology quality assurance (QA) process that we implemented in 2015. MATERIALS AND METHODS: Each month, a cytotechnologist randomly selected 3 telecytology fine-needle aspiration (FNA) cases from each cytopathologist on the FNA service that month. Data were recorded in a monthly worksheet and included onsite telecytology adequacy, final adequacy, concordance, onsite operator, cytopathologist, and reason for discrepancy, if present. The worksheet was reviewed monthly, discordant cases were re-examined, and feedback to cytologists was provided. For this study, worksheets from October 2015 to December 2019 were retrospectively reviewed. RESULTS: The QA program captured 488 cases, representing 25% of total cases that utilized telecytology during the evaluation period (n = 1983). The telecytology onsite assessment was concordant with the final cytologic assessment in 84% (410 of 488) of cases. The majority of discordant cases (72 of 78, 92%) were the result of an "Inadequate" onsite telecytology assessment, but a final diagnosis was able to be rendered; 92% of these cases were attributed to diagnostic material being present in cytologic preparations not available during the onsite assessment. Nine telecytology onsite interpretation errors were identified, of which 7 were provided by cytopathologists with less than 2 years of experience. CONCLUSIONS: Most telecytology cases with onsite assessment errors were evaluated by cytopathologists with less than 2 years of practice experience; therefore, careful monitoring of new staff should be considered when developing a telecytology QA program.

Dietary Management, Clinical Status and Outcome of Patients with Citrin Deficiency in the UK.

BACKGROUND: Little is known about the optimal dietary treatment for citrin deficiency. Our aim is to describe the management of UK citrin deficiency patients. METHODS: A longitudinal retrospective review was performed. Data were collected from medical records on presenting signs and symptoms, dietary management and clinical outcome. RESULTS: data were collected on 32 patients from 21 families. 50% were females (16/32). Median age at diagnosis was 4 y (5 days-35 y) with 12 patients diagnosed in the neonatal period with neonatal intrahepatic cholestasis (NICCD), eight later in childhood (FTTDCD) and 12 by family screening based on index cases from five families. No patient had adult-onset type II citrullinemia. The patient age at the time of data collection was a median of 11 y (1-44 y). 91% (29/32) of patients had normal physical and neurological development, 47% (15/32) experienced recurrent unexplained abdominal pain and 9% (3/32) episodes of hypoglycaemia. Siblings had different phenotypes (5 families had > 1 affected patient). Most patients preferred high protein foods, limiting sugar-containing foods. Only 41% (13/32) were prescribed a low CHO, high protein, high fat diet (restriction varied) and two used medium chain triglyceride (MCT) supplements. No patient was prescribed drug therapy. Twenty-five per cent (8/32) of patients were underweight and 41% (13/32) had height <-1 z-scores. CONCLUSIONS: patients presented with various phenotypes, symptoms and suboptimal growth. Symptoms and biochemical markers improved with age, but height remained low in some. More research is necessary to assess the effectiveness of dietary approaches in improving clinical outcomes and symptoms in citrin deficiency.

Modelling Lyssavirus Infections in Human Stem Cell-Derived Neural Cultures.

Rabies is a zoonotic neurological infection caused by lyssavirus that continues to result in devastating loss of human life. Many aspects of rabies pathogenesis in human neurons are not well understood. Lack of appropriate ex-vivo models for studying rabies infection in human neurons has contributed to this knowledge gap. In this study, we utilize advances in stem cell technology to characterize rabies infection in human stem cell-derived neurons. We show key cellular features of rabies infection in our human neural cultures, including upregulation of inflammatory chemokines, lack of neuronal apoptosis, and axonal transmission of viruses in neuronal networks. In addition, we highlight specific differences in cellular pathogenesis between laboratory-adapted and field strain lyssavirus. This study therefore defines the first stem cell-derived ex-vivo model system to study rabies pathogenesis in human neurons. This new model system demonstrates the potential for enabling an increased understanding of molecular mechanisms in human rabies, which could lead to improved control methods.

Novel role of SARM1 mediated axonal degeneration in the pathogenesis of rabies.

Neurotropic viral infections continue to pose a serious threat to human and animal wellbeing. Host responses combatting the invading virus in these infections often cause irreversible damage to the nervous system, resulting in poor prognosis. Rabies is the most lethal neurotropic virus, which specifically infects neurons and spreads through the host nervous system by retrograde axonal transport. The key pathogenic mechanisms associated with rabies infection and axonal transmission in neurons remains unclear. Here we studied the pathogenesis of different field isolates of lyssavirus including rabies using ex-vivo model systems generated with mouse primary neurons derived from the peripheral and central nervous systems. In this study, we show that neurons activate selective and compartmentalized degeneration of their axons and dendrites in response to infection with different field strains of lyssavirus. We further show that this axonal degeneration is mediated by the loss of NAD and calpain-mediated digestion of key structural proteins such as MAP2 and neurofilament. We then analysed the role of SARM1 gene in rabies infection, which has been shown to mediate axonal self-destruction during injury. We show that SARM1 is required for the accelerated execution of rabies induced axonal degeneration and the deletion of SARM1 gene significantly delayed axonal degeneration in rabies infected neurons. Using a microfluidic-based ex-vivo neuronal model, we show that SARM1-mediated axonal degeneration impedes the spread of rabies virus among interconnected neurons. However, this neuronal defense mechanism also results in the pathological loss of axons and dendrites. This study therefore identifies a potential host-directed mechanism behind neurological dysfunction in rabies infection. This study also implicates a novel role of SARM1 mediated axonal degeneration in neurotropic viral infection.

Whole Transcriptome Analysis of Aedes albopictus Mosquito Head and Thorax Post-Chikungunya Virus Infection.

Chikungunya virus (CHIKV) is transmitted by Aedes mosquitoes and causes prolonged arthralgia in patients. After crossing the mosquito midgut barrier, the virus disseminates to tissues including the head and salivary glands. To better understand the interaction between Aedes albopictus and CHIKV, we performed RNASeq analysis on pools of mosquito heads and parts of the thorax 8 days post infection, which identified 159 differentially expressed transcripts in infected mosquitos compared to uninfected controls. After validation using RT-qPCR (reverse transcriptase-quantitative polymerase chain reaction), inhibitor of Bruton's tyrosine kinase (BTKi), which has previously been shown to be anti-inflammatory in mammals after viral infection, was further evaluated for its functional significance. Knockdown of BTKi using double-stranded RNA in a mosquito cell line showed no significant difference in viral RNA or infectivity titer. However, BTKi gene knocked-down cells showed increased apoptosis 24 hours post-infection compared with control cells, suggesting involvement of BTKi in the mosquito response to viral infection. Since BTK in mammals promotes an inflammatory response and has been shown to be involved in osteoclastogenesis, a hallmark of CHIKV pathogenesis, our results suggest a possible conserved mechanism at play between mosquitoes and mammals. Taken together, these results will add to our understanding of Aedes Albopictus interactions with CHIKV.

Development of national consensus statements on food labelling interpretation and protein allocation in a low phenylalanine diet for PKU.

BACKGROUND: In the treatment of phenylketonuria (PKU), there was disparity between UK dietitians regarding interpretation of how different foods should be allocated in a low phenylalanine diet (allowed without measurement, not allowed, or allowed as part of phenylalanine exchanges). This led to variable advice being given to patients. METHODOLOGY: In 2015, British Inherited Metabolic Disease Group (BIMDG) dietitians (n = 70) were sent a multiple-choice questionnaire on the interpretation of protein from food-labels and the allocation of different foods. Based on majority responses, 16 statements were developed. Over 18-months, using Delphi methodology, these statements were systematically reviewed and refined with a facilitator recording discussion until a clear majority was attained for each statement. In Phase 2 and 3 a further 7 statements were added. RESULTS: The statements incorporated controversial dietary topics including: a practical 'scale' for guiding calculation of protein from food-labels; a general definition for exchange-free foods; and guidance for specific foods. Responses were divided into paediatric and adult groups. Initially, there was majority consensus (≥86%) by paediatric dietitians (n = 29) for 14 of 16 statements; a further 2 structured discussions were required for 2 statements, with a final majority consensus of 72% (n = 26/36) and 64% (n = 16/25). In adult practice, 75% of dietitians agreed with all initial statements for adult patients and 40% advocated separate maternal-PKU guidelines. In Phase 2, 5 of 6 statements were agreed by ≥76% of respondents with one statement requiring a further round of discussion resulting in 2 agreed statements with a consensus of ≥71% by dietitians in both paediatric and adult practice. In Phase 3 one statement was added to elaborate further on an initial statement, and this received 94% acceptance by respondents. Statements were endorsed by the UK National Society for PKU. CONCLUSIONS: The BIMDG dietitians group have developed consensus dietetic statements that aim to harmonise dietary advice given to patients with PKU across the UK, but monitoring of statement adherence by health professionals and patients is required.

Evaluation of an African swine fever (ASF) vaccine strategy incorporating priming with an alphavirus-expressed antigen followed by boosting with attenuated ASF virus.

In this study, an alphavirus vector platform was used to deliver replicon particles (RPs) expressing African swine fever virus (ASFV) antigens to swine. Alphavirus RPs expressing ASFV p30 (RP-30), p54 (RP-54) or pHA-72 (RP-sHA-p72) antigens were constructed and tested for expression in Vero cells and for immunogenicity in pigs. RP-30 showed the highest expression in Vero cells and was the most immunogenic in pigs, followed by RP-54 and RP-sHA-p72. Pigs primed with two doses of the RP-30 construct were then boosted with a naturally attenuated ASFV isolate, OURT88/3. Mapping of p30 identified an immunodominant region within the amino acid residues 111-130. However, the principal effect of the prime-boost was enhanced recognition of an epitope covered by the peptide sequence 61-110. The results suggest that a strategy incorporating priming with a vector-expressed antigen followed by boosting with an attenuated live virus may broaden the recognition of ASFV epitopes.

Neurotropism and behavioral changes associated with Zika infection in the vector Aedes aegypti.

Understanding Zika virus infection dynamics is essential, as its recent emergence revealed possible devastating neuropathologies in humans, thus causing a major threat to public health worldwide. Recent research allowed breakthrough in our understanding of the virus and host pathogenesis; however, little is known on its impact on its main vector, Aedes aegypti. Here we show how Zika virus targets Aedes aegypti's neurons and induces changes in its behavior. Results are compared to dengue virus, another flavivirus, which triggers a different pattern of behavioral changes. We used microelectrode array technology to record electrical spiking activity of mosquito primary neurons post infections and discovered that only Zika virus causes an increase in spiking activity of the neuronal network. Confocal microscopy also revealed an increase in synapse connections for Zika virus-infected neuronal networks. Interestingly, the results also showed that mosquito responds to infection by overexpressing glutamate regulatory genes while maintaining virus levels. This neuro-excitation, possibly via glutamate, could contribute to the observed behavioral changes in Zika virus-infected Aedes aegypti females. This study reveals the importance of virus-vector interaction in arbovirus neurotropism, in humans and vector. However, it appears that the consequences differ in the two hosts, with neuropathology in human host, while behavioral changes in the mosquito vector that may be advantageous to the virus.

Zika virus-induced hyper excitation precedes death of mouse primary neuron.

BACKGROUND: Zika virus infection in new born is linked to congenital syndromes, especially microcephaly. Studies have shown that these neuropathies are the result of significant death of neuronal progenitor cells in the central nervous system of the embryo, targeted by the virus. Although cell death via apoptosis is well acknowledged, little is known about possible pathogenic cellular mechanisms triggering cell death in neurons. METHODS: We used in vitro embryonic mouse primary neuron cultures to study possible upstream cellular mechanisms of cell death. Neuronal networks were grown on microelectrode array and electrical activity was recorded at different times post Zika virus infection. In addition to this method, we used confocal microscopy and Q-PCR techniques to observe morphological and molecular changes after infection. RESULTS: Zika virus infection of mouse primary neurons triggers an early spiking excitation of neuron cultures, followed by dramatic loss of this activity. Using NMDA receptor antagonist, we show that this excitotoxicity mechanism, likely via glutamate, could also contribute to the observed nervous system defects in human embryos and could open new perspective regarding the causes of adult neuropathies. CONCLUSIONS: This model of excitotoxicity, in the context of neurotropic virus infection, highlights the significance of neuronal activity recording with microelectrode array and possibility of more than one lethal mechanism after Zika virus infection in the nervous system.

Cost evaluation of out-of-country care for patients with eating disorders in Ontario: a population-based study.

BACKGROUND: Eating disorders, specifically anorexia nervosa, bulimia nervosa and eating disorder not otherwise specified, represent a substantial burden to the health care system. Our goal was to estimate the economic burden of patients who received specialized inpatient care for an eating disorder out of country. METHOD: We conducted a cost-of-illness study evaluating health care costs among patients in Ontario who received specialized inpatient care for an eating disorder out of country from 2003 to 2011, from the public third-party payer perspective. Using linked administrative databases, we estimated net costs of eating disorders for 2 patient groups: those who received specialized inpatient care both out of country and in province (n = 160), and those who received specialized inpatient care out of country only (n = 126). RESULTS: Patients approved for specialized out-of-country inpatient care were mostly girls and young women from high-income, urban neighbourhoods. Total net costs varied annually and were higher for patients treated both out of country and in province (about $11 million before 2007, $6.5 million after) than for those treated out of country alone (about $5 million and $2 million, respectively). The main cost drivers were out-of-country care and physician services. INTERPRETATION: Costs associated with eating disorder care represent a substantial economic burden to the Ontario health care system. Given the high costs of out-of-country care, there may be opportunity to redirect these funds to increase capacity and expertise for eating disorder treatment within Ontario.

Identification of Physician-Diagnosed Alzheimer's Disease and Related Dementias in Population-Based Administrative Data: A Validation Study Using Family Physicians' Electronic Medical Records.

BACKGROUND: Population-based surveillance of Alzheimer's and related dementias (AD-RD) incidence and prevalence is important for chronic disease management and health system capacity planning. Algorithms based on health administrative data have been successfully developed for many chronic conditions. The increasing use of electronic medical records (EMRs) by family physicians (FPs) provides a novel reference standard by which to evaluate these algorithms as FPs are the first point of contact and providers of ongoing medical care for persons with AD-RD. OBJECTIVE: We used FP EMR data as the reference standard to evaluate the accuracy of population-based health administrative data in identifying older adults with AD-RD over time. METHODS: This retrospective chart abstraction study used a random sample of EMRs for 3,404 adults over 65 years of age from 83 community-based FPs in Ontario, Canada. AD-RD patients identified in the EMR were used as the reference standard against which algorithms identifying cases of AD-RD in administrative databases were compared. RESULTS: The highest performing algorithm was "one hospitalization code OR (three physician claims codes at least 30 days apart in a two year period) OR a prescription filled for an AD-RD specific medication" with sensitivity 79.3% (confidence interval (CI) 72.9-85.8%), specificity 99.1% (CI 98.8-99.4%), positive predictive value 80.4% (CI 74.0-86.8%), and negative predictive value 99.0% (CI 98.7-99.4%). This resulted in an age- and sex-adjusted incidence of 18.1 per 1,000 persons and adjusted prevalence of 72.0 per 1,000 persons in 2010/11. CONCLUSION: Algorithms developed from health administrative data are sensitive and specific for identifying older adults with AD-RD.

Population-based analysis of health care contacts among suicide decedents: identifying opportunities for more targeted suicide prevention strategies.

The objective of this study was to detail the nature and correlates of mental health and non-mental health care contacts prior to suicide death. We conducted a systematic extraction of data from records at the Office of the Chief Coroner of Ontario of each person who died by suicide in the city of Toronto from 1998 to 2011. Data on 2,835 suicide deaths were linked with provincial health administrative data to identify health care contacts during the 12 months prior to suicide. Sub-populations of suicide decedents based on the presence and type of mental health care contact were described and compared across socio-demographic, clinical and suicide-specific variables. Time periods from last mental health contact to date of death were calculated and a Cox proportional hazards model examined covariates. Among suicide decedents, 91.7% had some type of past-year health care contact prior to death, 66.4% had a mental health care contact, and 25.3% had only non-mental health contacts. The most common type of mental health contact was an outpatient primary care visit (54.0%), followed by an outpatient psychiatric visit (39.8%), an emergency department visit (31.1%), and a psychiatric hospitalization (21.0%). The median time from last mental health contact to death was 18 days (interquartile range 5-63). Mental health contact was significantly associated with female gender, age 25-64, absence of a psychosocial stressor, diagnosis of schizophrenia or bipolar disorder, past suicide attempt, self-poisoning method and absence of a suicide note. Significant differences between sub-populations of suicide decedents based on the presence and nature of their health care contacts suggest the need for targeting of community and clinical-based suicide prevention strategies. The predominance of ambulatory mental health care contacts, often close to the time of death, reinforce the importance of concentrating efforts on embedding risk assessment and care pathways into all routine primary and specialty clinical care, and not only acute care settings.

Validation of a Population-Based Algorithm to Detect Chronic Psychotic Illness.

OBJECTIVE: To validate algorithms to detect people with chronic psychotic illness in population-based health administrative databases. METHOD: We developed 8 algorithms to detect chronic psychotic illness using hospitalization and physician service claims data from administrative health databases in Ontario to identify cases of chronic psychotic illness between 2002 and 2007. Diagnostic data abstracted from the records of 281 randomly selected psychiatric patients from 2 hospitals in Toronto were linked to the administrative data cohort to test sensitivity, specificity, and positive predictive values (PPV) and negative predictive values. RESULTS: Using only hospitalization data to capture chronic psychotic illness yielded the highest specificity (range 69.9% to 84.7%) and the highest PPV (range 55.2% to 80.8%). Using physician service claims in addition to hospitalization data to capture cases increased sensitivity (range 90.1% to 98.8%) but decreased specificity (range 31.1% to 68.0%) and PPV (range 38.4% to 71.1%). CONCLUSION: Using health administrative data to study population-based outcomes for people with chronic psychotic illness is feasible and valid. Researchers can select case identification methods based on whether a more sensitive or more specific definition of chronic psychotic illness is desired.

Canadian administrative health data can identify patients with myasthenia gravis.

INTRODUCTION: Incidence and prevalence estimates for myasthenia gravis (MG) have varied widely, and the ability of administrative health data (AHD) records to accurately identify cases of MG is yet to be ascertained. The goal of the current study was to validate an algorithm to identify patients with MG in Ontario, Canada using AHD - thereby enabling future disease surveillance. METHODS: A reference standard population was established using automated key word searching within EMRALD (Electronic Medical Record Administrative data Linked Database) and chart review of potential cases. AHD algorithms were generated and tested against the reference standard. The data was used to calculate MG prevalence rates. RESULTS: There were 123,997 eligible adult patients, and 49 patients had definite MG (forming the reference standard). An algorithm requiring: (1 hospital discharge abstract with MG listed as a reason for hospitalization or a comorbid condition), or (5 outpatient MG visits and 1 relevant diagnostic test, within 1 year), or (3 pyridostigmine prescriptions, within 1 year) identified MG with sensitivity = 81.6%, specificity = 100%, positive predictive value = 80.0% and negative predictive value = 100%. The population prevalence within our cohort was 0.04%. CONCLUSIONS: This novel validation method demonstrates the feasibility of using administrative health data to identify patients with myasthenia gravis among the Ontario population.

Mouse fibroblast L929 cells are less permissive to infection by Nelson Bay orthoreovirus compared to other mammalian cell lines.

In recent years, bats have been identified as a natural reservoir for a diverse range of viruses. Nelson Bay orthoreovirus (NBV) was first isolated from the heart blood of a fruit bat (Pteropus poliocephalus) in 1968. While the pathogenesis of NBV remains unknown, other related members of this group have caused acute respiratory disease in humans. Thus the potential for NBV to impact human health appears plausible. Here, to increase our knowledge of NBV, we examined the replication and infectivity of NBV using different mammalian cell lines derived from bat, human, mouse and monkey. All cell lines supported the replication of NBV; however, L929 cells showed a greater than 2 log reduction in virus titre compared with the other cell lines. Furthermore, NBV did not induce major cytopathic effects in the L929 cells, as was observed in other cell lines. Interestingly, the related Pteropine orthoreoviruses, Pulau virus (PulV) and Melaka virus (MelV) were able to replicate to high titres in L929 cells but infection resulted in reduced cytopathic effect. Our study demonstrates a unique virus-host interaction between NBV and L929 cells, where cells effectively control viral infection/replication and limit the formation of syncytia. By elucidating the molecular mechanisms that control this unique relationship, important insights will be made into the biology of this fusogenic virus.

Development and validation of an administrative data algorithm to estimate the disease burden and epidemiology of multiple sclerosis in Ontario, Canada.

BACKGROUND: Few studies have assessed the accuracy of administrative data for identifying multiple sclerosis (MS) patients. OBJECTIVES: To validate administrative data algorithms for MS, and describe the burden and epidemiology over time in Ontario, Canada. METHODS: We employed a validated search strategy to identify all MS patients within electronic medical records, to identify patients with and without MS (reference standard). We then developed and validated different combinations of administrative data for algorithms. The most accurate algorithm was used to estimate the burden and epidemiology of MS over time. RESULTS: The accuracy of the algorithm of one hospitalisation or five physician billings over 2 years provided both high sensitivity (84%) and positive predictive value (86%). Application of this algorithm to provincial data demonstrated an increasing cumulative burden of MS, from 13,326 patients (0.14%) in 2000 to 24,647 patients in 2010 (0.22%). Age-and-sex standardised prevalence increased from 133.9 to 207.3 MS patients per 100,000 persons in the population, from 2000 - 2010. During this same period, age-and-sex-standardised incidence varied from 17.9 to 19.4 patients per 100,000 persons. CONCLUSIONS: MS patients can be accurately identified from administrative data. Our findings illustrated a rising prevalence of MS over time. MS incidence rates also appear to be rising since 2009.