Multiple Sclerosis impact on employment and income in New Zealand.

BACKGROUND AND OBJECTIVES: We investigated the demographic, social and clinical characteristics associated with employment status and income for people with multiple sclerosis (MS) in New Zealand (NZ). METHODS: The NZ National MS Prevalence study included all persons resident in NZ on census day 2006 diagnosed with MS (96.7% coverage). Factors associated with employment and income status among the working age population (25-64 years) were identified by linear regression. RESULTS: Over 90% of working age people with MS (n=1727) had a work history, but 54% were not working. Work loss occurred early in the disease course, and at low disability (P<.001). Advancing age, progressive disease, longer disease duration, higher disability levels, partner loss and lower education were associated with work loss (P<.001). Working age people with MS had lower income than the NZ population (P<.0001). Higher qualifications yielded no additional income for MS females and about half the additional income for MS males (P<.0001). CONCLUSIONS: MS profoundly reduces employment and income early in the disease course, and at low levels of disability, however, unemployment is not entirely accounted for by clinical, social and demographic factors. These findings suggest social supports should be explored early in the disease course to reduce loss of income and unemployment for people with MS.

Control of Bovine Brucellosis from Persistently Infected Holdings Using RB51 Vaccination with Test-and-Slaughter: A Comparative Case Report from a High Incidence Area in Portugal.

Bovine brucellosis due to Brucella abortus infection causes significant reproductive and production losses in cattle and is a major zoonosis. Eradication of this disease has proved difficult to achieve in Portugal where it still occurs in some regions despite an ongoing national eradication programme. In 2004, the Alentejo region, a major cattle producing area, reported one of the highest levels of bovine brucellosis in the country, especially in one divisional area. In that area, bovine brucellosis was particularly problematic in a holding of ten herds, the largest extensive cattle unit in the country, which remained infected despite an extensive test-and-slaughter programme and depopulation of five herds. A 5-year programme of RB51 vaccination with biannual test-and-slaughter was thus implemented in 2004. The apparent animal seroprevalence decreased from 19% (646/3,400) to 3% (88/2930) on the third herd-level test and remained below 0.8% (27/3324) after the fourth test. After the tenth test, the holding had a prevalence of 0.1% (2/2332) and only one herd remained positive with a within-herd prevalence of 1.1% (2/177). The results were compared to all other herds (n = 10) in the divisional area that were also persistently infected but were subject only to test-and-slaughter before being depopulated. In these herds, the strategy of test-and-slaughter did not reduce the prevalence, which remained significantly higher than the vaccinated group (median = 0.48% and 8.5% in vaccinated versus non-vaccinated herds; Wilcoxon rank sum test; P < 0.01). The success of this pilot programme in continental Portugal provided a valuable case study to the official veterinary services by illustrating the value of RB51 vaccination with parallel testing and improved biosecurity as a comprehensive and sustainable strategy for bovine brucellosis control in persistently infected herds.

Risk factors for visible lesions or positive laboratory tests in bovine tuberculosis reactor cattle in Northern Ireland.

An observational case-control study was conducted to investigate risk factors for confirmed bovine tuberculosis (bTB) infection in cattle reacting positively to the single intradermal comparative cervical test (SICCT) in Northern Ireland in the years 1998, 2002 and 2006. Macroscopic lesions were detected at slaughter (positive visible lesion (VL) status) in 43.0% of reactor cattle, whilst 45.3% of those sampled were confirmed as bTB positive due to the presence of lesions or positive histopathology/mycobacterial culture (positive bTB status). In 97.5% of the reactors, the VL status and bTB status were either both negative or both positive. Generalized linear mixed model analyses were conducted on data of 24,923 reactor cattle with the variables herd identifier, local veterinary office (DVO) and abattoir being used as random effects within all the models generated at univariable and multivariable level. The other variables within the dataset were used as fixed effects. Significant risk factors associated with VL status and bTB status at multivariable level (p<0.05) included age at death, breed, sex, test year, net increase in skin thickness at bovine tuberculin injection site, epidemiological status of skin test, total number of reactors at the disclosure test, mean herd size and prior response to the skin test. These risk factors are likely related to the time since infection, the strength of the challenge of infection and the susceptibility of the animal. These findings are important as the detection of visible lesions and the confirmation of bTB are an integral part of the overall bTB control programme in Northern Ireland and the veterinary meat inspection and hygiene programme. The visible lesion status and bTB status of an animal can affect the way in which bTB breakdowns are managed, since failure to detect visible lesions and recovery of Mycobacterium bovis can lead to a less stringent follow-up after other risk factors have been taken into account.

Bovine tuberculosis in Northern Ireland: risk factors associated with time from post-outbreak test to subsequent herd breakdown.

Compulsory bovine tuberculosis testing has been implemented since 1959 in Northern Ireland. Initial rapid progress in the eradication of the disease was followed by a situation where disease levels tended to fluctuate around a low level. This study explores recrudescence of bovine tuberculosis (bTB) in Northern Ireland herds by assessing risk factors associated with time from the six-month post-outbreak skin test until a further herd breakdown. Bovine herds (n=3377) were recruited in 2002 and 2003 and their survival analysed using Kaplan-Meier survival estimates and a Cox proportional hazards model, with follow-up extending to August 2008. Exclusion criteria applied for study entry were bTB infection in a contiguous herd, changing of post restriction test to one of a higher risk status or chronic infection. Chronic infection was defined as any situation where disclosure preceded the post-outbreak test by two years or more. The application of these exclusion criteria meant that herds recruited to the study were largely cleared of infection and not directly contiguous to other infected herds. Of the 3377 herds, 1402 (41.5%) suffered a further herd breakdown before the end of follow-up. Median survival time was 582 days (interquartile range=336-1002 days). Breakdown severity (defined as the number of Single Intradermal Comparative Tuberculin Test (SICTT) reactors at disclosure test), local bTB prevalence, herd size and type were identified as significant risk factors (p<0.05), as was the purchase of higher numbers (n>27.38 per year) of cattle. Consistent with other studies this work shows bTB confirmation to not be predictive of a future herd breakdown. This work shows bTB history as not being a risk factor for a future breakdown. This result could be reflective of the exclusion criteria used in the study, which may have selected for incidents where historical status was of less importance.

Bovine tuberculosis trends in the UK and the Republic of Ireland, 1995-2010.

Selected demographic features and trends in bovine tuberculosis (BTB) from 1995 to 2010 are described for the countries of the UK and the Republic of Ireland, using standardised definitions and measures. All countries experienced a reduction in the number of cattle and herds and in the proportion of dairy herds, while average herd size increased. In general, the trends indicate a stable situation of very low BTB prevalence in Scotland and, over most of the period, a rising prevalence in England and Wales. The prevalence in the Republic of Ireland declined while Northern Ireland experienced both a rise and fall. Differences in demography, BTB programme structure and test results were noted, particularly between the island of Ireland and Great Britain. Further investigation of these differences may provide valuable insights into risk factors for BTB and optimisation of existing BTB programmes.

Field trial of six serological tests for bovine brucellosis.

Serum agglutination (SAT), complement fixation (CFT), indirect ELISA (iELISA), competitive ELISA (cELISA), Rose Bengal (RBT) and EDTA-modified agglutination (EDTA) tests were used in parallel on serological samples from 19,935 cattle in 301 herds. The study herds were selected according to putative exposure to Brucellaabortus with cases defined by bacteriological culture or test agreement. No single test identified all infected cattle and, at diagnostic thresholds, relative sensitivity was highest in the iELISA (67.9%) or RBT (78.1%), using bacteriological culture or test agreement, respectively, to define cases. As screening tests, the relative sensitivity of the SAT was highest (75.9% by culture or 84.9% by test agreement), with an optimal threshold of 31 IU. The relative specificity of the diagnostic tests ranged from 99.6% (SAT 31IU) to 100% (iELISA, RBT and CFT). The trial confirmed the value of the SAT as a screening test and the value of parallel testing.

A comparison of badger activity in two areas of high and low bovine tuberculosis incidence of Northern Ireland.

During 2005, a field survey of badger activity was carried out to evaluate differences between two areas with different levels of bovine tuberculosis (annual herd incidences of 16% and 4%) and to assess the awareness of herd keepers in relation to badgers. A random selection of herd keepers was interviewed and their farm land surveyed for the presence of badgers. The survey end point for each farm was the discovery of an active badger sett. Participation was very high in both areas (>80%). Evidence of badger activity was recorded on a higher proportion of farms in the area with a high tuberculosis herd incidence. However, when the difference in quality of agricultural land within each area was taken into account, a statistically significant association was not demonstrated. This suggests that the quality of agricultural land is a major determinant in the location of active badger setts. Nevertheless, the study did demonstrate the potential for increased exposure of cattle to badgers in the high incidence area. Herd keepers accurately identified the presence of badger setts on their land (positive predictive value=97%) but herd keepers reporting the absence of badger setts/activities on their land were found to be less accurate. Overall, the conclusions from this study tend to reflect the findings observed in other studies.

Epidemiology and management of a bovine brucellosis cluster in Northern Ireland.

An epidemiological investigation was undertaken of 41 bovine brucellosis outbreaks that occurred within a 10-month period, in a region where eradication measures appeared to be succeeding. The primary outbreak comprised three herds with significant within-herd spread and a high probability of multiple abortions. Direct contact between cattle at pasture was the most likely means of between-herd transmission for most (71%) outbreaks, with an attack rate of 28.1% in herds immediately neighbouring the primary outbreak herds and 11.3% in the next concentric ring of farms. Resolution of the incident was attributed to a rapid response by the veterinary authorities, detailed epidemiological investigations, repeated, prolonged testing of contact herds and employment of parallel testing.

Risk associated with animals moved from herds infected with brucellosis in Northern Ireland.

The movement of cattle from herds infected with Brucella abortus was investigated in order to assess the control measures for eradication of brucellosis from the cattle population of Northern Ireland. Using recorded cattle movement data, a historical cohort study was designed and carried out to quantify the risk of seropositivity in bovine animals moved from herds infected with brucellosis. The study found that 3.1% of animals, moved in the 6-month period prior to disclosure of infection in the source herd and subsequently tested, were interpreted as seropositive in their destination herds. The odds of seropositivity were approximately 19 (95% confidence interval: 7.8-46.4) times higher in this cohort compared with animals from herds with no history of infection. A multivariate logistic regression model was constructed to examine factors influencing the risk of seropositivity in the exposed cohort of animals, identifying maternal status (whether the dam had been a brucellosis reactor) and age at leaving the infected herd as the main risk factors.

Epidemiology of bovine brucellosis in Northern Ireland between 1990 and 2000.

Between 1990 and 2000, 317 herds of cattle in Northern Ireland were identified as being seropositive to Brucella abortus, and 68 per cent of them were attributed to transmission from neighbouring herds or to local spread. Of particular significance were three primary outbreaks in 1997, which resulted in significant secondary and tertiary spread. Three spatial clusters were identified, corresponding to two of the primary outbreaks, and the herd density and within-herd spread were highest in the largest cluster. Abortions in an infected herd and the disease-risk status of the disclosure test were positively associated with an increased within-herd prevalence.

Motor neurone disease presenting as postoperative respiratory failure.

We present the case of a woman who developed respiratory failure in the postoperative period secondary to previously unsuspected motor neurone disease. This case highlights the difficulty in detecting subtle neuromuscular weakness during anaesthetic pre-assessment.

The Northern Ireland programme for the control and eradication of Mycobacterium bovis.

Bovine tuberculosis is endemic in Northern Ireland and a comprehensive eradication scheme has been in operation since 1959. The current programme involves annual testing, extensive computerized tracing, short-interval testing of herds contiguous to outbreaks and compulsory slaughter of positive cattle. Despite initial reductions in disease prevalence, eradication has proved elusive and potential explanatory factors include high cattle density and potential for between-herd contact, the impact of exotic diseases on resource priorities, and significant levels of bovine tuberculosis in a wildlife reservoir, the European badger (Meles meles). Both the role of the infected bovine and that of the badger in spreading disease have to be addressed to ensure progress towards eradication. Current measures are described and future options for enhancing the programme are outlined.

On-line coal analysis using fast neutron-induced gamma-rays.

On-line measurement of bulk elemental composition is often best achieved with highly penetrative neutron-gamma techniques. CSIRO has developed and implemented one such technique, neutron inelastic-scattering and thermal-capture analysis (NITA). A distinctive feature of NITA is its use of fast neutron sources to generate inelastic scattering reactions, thus exciting gamma-rays from industrially important elements such as carbon and oxygen. A full-scale prototype for on-line coal quality measurement has been tested under simulated industrial conditions. The effect of sample compositional inhomogeneity and stream thickness will be discussed.

Depression in multiple sclerosis: a review.

Several studies have reported high rates of depression in multiple sclerosis (MS) with a lifetime prevalence of approximately 50% and an annual prevalence of 20% not uncommon. Concern about the potential of new drug treatments to exacerbate or precipitate depression in MS has led to increased interest in the relation between MS and depression. This review on MS and depression identifies the following key issues: How common is depression in people with MS? Is depression in MS associated with lesions in specific regions of the central nervous system? Is there an increased risk of suicide in MS? Is there a higher than expected incidence of anxiety disorders in MS? Are fatigue and depressed mood related in MS? Is there a relation between depression and cognitive impairment in MS? Which psychosocial variables affect the development of depression in MS? Does treatment with interferon increase the risk of depression? How effective are treatments for MS patients with depression? Each of these issues is briefly reviewed with critical commentary, and some priorities for future research are suggested.

An on-belt elemental analyser for the cement industry.

On-line control of raw mill feed composition is a key factor in the improved control of cement plants. A new and improved on-conveyor belt elemental analyser for cement raw mill feed based on neutron inelastic scatter and capture techniques has been developed and tested successfully in Adelaide Brighton's Birkenhead cement plant on highly segregated material with a depth range of 100 to 180 mm. Dynamic tests in the plant have shown analyser RMS total errors of 0.49, 0.52, 0.38 and 0.23 wt% (on a loss free basis) for CaO, SiO2, Al2O3 and Fe2O3 respectively, when 10-minute counting periods are used.

Neural architecture in transected rabbit sciatic nerve after prolonged nonreinnervation.

Observations have been made on the rabbit sciatic nerve distal to a transection, with survival periods of up to 26 mo and prevention of reinnervation. It was confirmed that the nerve becomes compartmented by fibroblast processes and that a zone of fine collagen fibrils develops around the Schwann cell columns that constitute the Büngner bands. The Schwann cells become progressively more atrophic but after 6 mo of denervation still expressed low affinity p75 nerve growth factor receptor (NGFR), the latest stage at which this was examined. NGFR was also expressed by the processes of the fibroblasts producing the endoneurial compartmentation. By 26 mo after transection the site of previous nerve fibres was indicated by sharply demarcated domains of approximately circular outline in transverse section consisting of densely packed longitudinally oriented collagen fibrils. Some of these domains still possessed centrally situated Schwann cells or residual basal lamina but many were acellular. The central collagen fibrils in these domains were of smaller diameter than those situated peripherally but were of larger size than those that form around the Büngner bands during wallerian degeneration. The peripherally located fibrils in the domains were of the same calibre as for normal endoneurial collagen. The collagen domains were encircled by fibroblast processes or at times enclosed in a perineurial cell ensheathment. Long-standing axonal loss therefore leads to a striking reorganisation of the internal architecture of peripheral nerve trunks. The findings may be relevant for the interpretation of the appearances in chronic peripheral neuropathies in man.

Mutual attraction between emigrant cells from transected denervated nerve.

It is known that regenerating axons emerging from the proximal stump of a transected nerve are attracted towards the distal stump. It is not certain whether this neurotropic effect is on the axons themselves or whether it is on supporting cells such as Schwann cells that the axons then follow. In order to investigate this question in rats, segments of the sciatic nerve were either isolated or removed and reinserted as grafts, and then sutured into the opposing ends of double-Y silicone tubes. In these tubes, a central conduit was formed by connecting the centrally facing limb of each Y tube. The nerve segments were sutured into one of the limbs at either end. The third limbs of the Y tubes formed side arms, one of which was left open; a plug of mobilised fatty connective tissue was sutured into the other. A gap of 6 mm was left between the cut ends and the fat pads (or openings from the side arms). After 2-3 wk a significantly greater outgrowth (P < 0.001) was found to link the nerve segments than to invade the side arms. The major cell component in the outgrowth was Schwann cells, supported by fibroblasts and capillaries and surrounded by a lamellated layer of flattened fibroblasts. The growth into the side arms had a looser cellular architecture and contained considerably fewer Schwann cells. The results strongly suggest the existence of mutual attraction between emigrant Schwann cells, or possibly endoneurial fibroblasts, from the 2 cut ends of transected nerves. This conclusion has implications for the guidance of axons across gaps in nerves. It does not exclude an additional neurotropic effect from the distal stump on axons.

Neurotropic influence of the distal stump of transected peripheral nerve on axonal regeneration: absence of topographic specificity in adult nerve.

Observations have been made on the growth of regenerating axons from transected rat sciatic nerve through Y-shaped silicone tubes. When the distal stump of the nerve was sutured into 1 distal limb of the tube and a fat pad into the other, a clear preference for the axons to regenerate towards the distal stump was found. In other experiments regenerating axons from the peroneal or tibial divisions of the sciatic nerve were given the choice of growing towards either the peroneal or tibial nerves, each being inserted into 1 of the 2 distal limbs of the Y-tube. No significant preference of the proximal stump to regenerate towards its appropriate distal stump was detected. A neurotropic influence of the distal stump on the nerve has therefore been confirmed, but topographic specificity of regeneration at the level of the nerve trunk has not been established.