Evaluating serological tests for foot-and-mouth disease while accounting for different serotypes and uncertain vaccination status

Controlling foot-and-mouth disease (FMD) by vaccination requires adequate population coverage and high vaccine efficacy under field conditions. To assure veterinary services that animals have acquired sufficient immunity, strategic post-vaccination surveys can be conducted to monitor the coverage and performance of the vaccine. Correct interpretation of these serological data and an ability to derive exact prevalence estimates of antibody responses requires an awareness of the performance of serological tests. Here, we used Bayesian latent class analysis to evaluate the diagnostic sensitivity and specificity of four tests. A non-structural protein (NSP) ELISA determines vaccine independent antibodies from environmental exposure to FMD virus (FMDV), and three assays measuring total antibodies derived from vaccine antigen or environmental exposure to two serotypes (A, O): the virus neutralisation test (VNT), a solid phase competitive ELISA (SPCE), and a liquid phase blocking ELISA (LPBE). Sera (n = 461) were collected by a strategic post-vaccination monitoring survey in two provinces of Southern Lao People's Democratic Republic (PDR) after a vaccination campaign in early 2017. Not all samples were tested by every assay and each serotype: VNT tested for serotype A and O, whereas SPCE and LPBE tested for serotype O, and only NSP-negative samples were tested by VNT, with 90 of them not tested (missing by study design). These data challenges required informed priors (based on expert opinion) for mitigating possible lack of model identifiability. The vaccination status of each animal, its environmental exposure to FMDV, and the indicator of successful vaccination were treated as latent (unobserved) variables. Posterior median for sensitivity and specificity of all tests were in the range of 92-99 %, except for the sensitivity of NSP (∼66%) and the specificity of LPBE (∼71 %). There was strong evidence that SPCE outperformed LPBE. In addition, the proportion of animals recorded as having been vaccinated that showed a serological immune response was estimated to be in the range of 67-86 %. The Bayesian latent class modelling framework can easily and appropriately impute missing data. It is important to use field study data as diagnostic tests are likely to perform differently on field survey samples compared to samples obtained under controlled conditions.

Engineering Synthetic Lipopeptide Antigen for Specific Detection of Mycobacterium avium subsp. paratuberculosis Infection

Unlike other MAC members, Mycobacterium avium subsp. paratuberculosis (MAP) does not produce glycopeptidolipids (GPL) on the surface of the cell wall but a lipopentapeptide called L5P (also termed Lipopeptide-I or Para-LP-01) characterized in C-type (bovine) strains. This lipopeptide antigen contains a pentapeptide core, D-Phenylalanine-N-methyl-L-Valine-L-Isoleucine-L-Phenylalanine-L-Alanine, in which the N-terminal D-Phenylalanine is amido-linked with a fatty acid (C18–C20). The molecular and genetic characterization of this antigen demonstrated that L5P is unique to MAP. Knowledge of the structure of L5P enabled synthetic production of this lipopeptide in large quantities for immunological evaluation. Various studies described the immune response directed against L5P and confirmed its capability for detection of MAP infection. However, the hydrophobic nature of lipopeptide antigens make their handling and use in organic solvents unsuitable for industrial processes. The objectives of this study were to produce, by chemical synthesis, a water-soluble variant of L5P and to evaluate these compounds for the serological diagnosis of MAP using well-defined serum banks. The native L5P antigen and its hydrosoluble analog were synthesized on solid phase. The pure compounds were evaluated on collections of extensively characterized sera from infected and non-infected cattle. ROC analysis showed that L5P and also its water-soluble derivative are suitable for the development of a serological test for Johne's disease at a population level. However, these compounds used alone in ELISA have lower sensitivity (Se 82% for L5P and Se 62% for the water-soluble variant of L5P) compared to the Se 98% of a commercial test. Advantageously, these pure synthetic MAP specific antigens can be easily produced in non-limiting quantities at low cost and in standardized batches for robust studies. The fact that L5P has not been validated in the context of ovine paratuberculosis highlights the need to better characterize the antigens expressed from the different genetic lineages of MAP to discover new diagnostic antigens. In the context of infections due to other mycobacteria such as M. bovis or the more closely related species M. avium subsp. hominissuis, the L5P did not cross react and therefore may be a valuable antigen to solve ambiguous results in other tests.

Engineering Synthetic Lipopeptide Antigen for Specific Detection of Mycobacterium avium subsp. paratuberculosis Infection

Unlike other MAC members, Mycobacterium avium subsp. paratuberculosis (MAP) does not produce glycopeptidolipids (GPL) on the surface of the cell wall but a lipopentapeptide called L5P (also termed Lipopeptide-I or Para-LP-01) characterized in C-type (bovine) strains. This lipopeptide antigen contains a pentapeptide core, D-Phenylalanine-N-methyl-L-Valine-L-Isoleucine-L-Phenylalanine-L-Alanine, in which the N-terminal D-Phenylalanine is amido-linked with a fatty acid (C18–C20). The molecular and genetic characterization of this antigen demonstrated that L5P is unique to MAP. Knowledge of the structure of L5P enabled synthetic production of this lipopeptide in large quantities for immunological evaluation. Various studies described the immune response directed against L5P and confirmed its capability for detection of MAP infection. However, the hydrophobic nature of lipopeptide antigens make their handling and use in organic solvents unsuitable for industrial processes. The objectives of this study were to produce, by chemical synthesis, a water-soluble variant of L5P and to evaluate these compounds for the serological diagnosis of MAP using well-defined serum banks. The native L5P antigen and its hydrosoluble analog were synthesized on solid phase. The pure compounds were evaluated on collections of extensively characterized sera from infected and non-infected cattle. ROC analysis showed that L5P and also its water-soluble derivative are suitable for the development of a serological test for Johne's disease at a population level. However, these compounds used alone in ELISA have lower sensitivity (Se 82% for L5P and Se 62% for the water-soluble variant of L5P) compared to the Se 98% of a commercial test. Advantageously, these pure synthetic MAP specific antigens can be easily produced in non-limiting quantities at low cost and in standardized batches for robust studies. The fact that L5P has not been validated in the context of ovine paratuberculosis highlights the need to better characterize the antigens expressed from the different genetic lineages of MAP to discover new diagnostic antigens. In the context of infections due to other mycobacteria such as M. bovis or the more closely related species M. avium subsp. hominissuis, the L5P did not cross react and therefore may be a valuable antigen to solve ambiguous results in other tests.

Engineering Synthetic Lipopeptide Antigen for Specific Detection of Mycobacterium avium subsp. paratuberculosis Infection

Unlike other MAC members, Mycobacterium avium subsp. paratuberculosis (MAP) does not produce glycopeptidolipids (GPL) on the surface of the cell wall but a lipopentapeptide called L5P (also termed Lipopeptide-I or Para-LP-01) characterized in C-type (bovine) strains. This lipopeptide antigen contains a pentapeptide core, D-Phenylalanine-N-methyl-L-Valine-L-Isoleucine-L-Phenylalanine-L-Alanine, in which the N-terminal D-Phenylalanine is amido-linked with a fatty acid (C18-C20). The molecular and genetic characterization of this antigen demonstrated that L5P is unique to MAP. Knowledge of the structure of L5P enabled synthetic production of this lipopeptide in large quantities for immunological evaluation. Various studies described the immune response directed against L5P and confirmed its capability for detection of MAP infection. However, the hydrophobic nature of lipopeptide antigens make their handling and use in organic solvents unsuitable for industrial processes. The objectives of this study were to produce, by chemical synthesis, a water-soluble variant of L5P and to evaluate these compounds for the serological diagnosis of MAP using well-defined serum banks. The native L5P antigen and its hydrosoluble analog were synthesized on solid phase. The pure compounds were evaluated on collections of extensively characterized sera from infected and non-infected cattle. ROC analysis showed that L5P and also its water-soluble derivative are suitable for the development of a serological test for Johne's disease at a population level. However, these compounds used alone in ELISA have lower sensitivity (Se 82% for L5P and Se 62% for the water-soluble variant of L5P) compared to the Se 98% of a commercial test. Advantageously, these pure synthetic MAP specific antigens can be easily produced in non-limiting quantities at low cost and in standardized batches for robust studies. The fact that L5P has not been validated in the context of ovine paratuberculosis highlights the need to better characterize the antigens expressed from the different genetic lineages of MAP to discover new diagnostic antigens. In the context of infections due to other mycobacteria such as M. bovis or the more closely related species M. avium subsp. hominissuis, the L5P did not cross react and therefore may be a valuable antigen to solve ambiguous results in other tests.

First report of the use of mucosal swabs of the palatine tonsillar crypt for detection of Mycoplasma bovis in naturally infected calves

Aims: To compare detection by real-time PCR of DNA from Mycoplasma bovis on mucosal swabs taken from the palatine tonsillar crypt and the mainstem bronchi of clinically asymptomatic calves after slaughter. Methods: We compared the sensitivity of mucosal swabs taken from two sites: the palatine tonsillar crypt and the mainstem bronchi. Paired samples were taken post-mortem at slaughter from 55 clinically well calves from an infected herd and were tested by real-time PCR for the presence of M. bovis-specific DNA. Results: Mycoplasma bovis DNA was detected in 51 palatine tonsillar crypt swabs (92.7 (95% CI = 82.4-98.0)%) and seven mainstem bronchial swabs (12.7 (95% CI = 5.3-24.5)%). All seven calves with positive mainstem bronchial swabs also had positive palatine tonsillar crypt swabs. Conclusions: When compared to mucosal swabs of the mainstem bronchi, mucosal swabs of the palatine tonsillar crypt were seven times more sensitive for the post-mortem detection of M. bovis DNA. The viability of detected M. bovis was not assessed, because any cattle carrying viable or non-viable M. bovis DNA were determined to be a potential risk to eradication. Palatine tonsillar crypt mucosa may be a useful anatomical site for real-time PCR detection of M. bovis DNA in naturally infected calves. More work is needed to define the persistence and viability of M. bovis at this anatomical site. Clinical relevance: The results of this study helped form the basis of surveillance tools used in M. bovis control and eradication efforts. Familiarity with these results may help veterinarians better communicate with their clients about the science behind the eradication efforts.

Expression of genes associated with cholesterol and lipid metabolism identified as a novel pathway in the early pathogenesis of Mycobacterium avium subspecies paratuberculosis-infection in cattle

Johne's disease (JD) is a chronic disease affecting ruminants and other species caused by the pathogenic mycobacterium, Mycobacterium avium subsp. paratuberculosis (MAP). MAP has developed a multitude of mechanisms to persist within the host, and these in turn are counteracted by the host through various immune pathways. Identifying and characterising the different strategies employed by MAP to alter the host immune system in its favour, and thereby persist intracellularly, could hold the key to developing strategies to fight this disease. In this study we analysed a subset of bovine microarray data derived from early time points after experimental infection with MAP. A specifically developed integrated approach was used to identify and validate host genes involved in cholesterol homeostasis (24DHCR, LDLR, SCD-1), calcium homeostasis and anti-bacterial defence mechanisms, (CD38, GIMAP6) which were downregulated in response to MAP exposure. A trend for upregulation of granulysin gene expression in MAP-exposed cattle in comparison to unexposed cattle was also observed. From these analyses, a model of potential pathogen-host interactions involving these novel pathways was developed which indicates an important role for host lipids in mycobacterial survival and persistence.

Learner driver experiences and crash risk as an unsupervised driver

OBJECTIVE

The purpose of this study was to describe the driving experiences of learner licensed drivers and examine the association between these driving experiences, associated factors, and on-road car crash involvement during the unsupervised restricted license stage.

METHODS

Data were drawn from a cohort investigation of newly licensed drivers. Information on demographic characteristics, personality, and risk behaviors was collected at the baseline interview. At the first follow-up interview (restricted license stage) study members were asked details about their experiences as a learner licensed driver: professional driving lessons, supervised driving, unsupervised driving, and driving courses in which they participated. During the second follow-up interview (full license stage), data were collected on crash involvement and driving exposure during the restricted license stage. Regression analysis was used to determine independent relationships between learner license driving experience variables and crash involvement.

RESULTS

After adjusting for demographic, personality factors, and driving exposure at the restricted license stage, increased time spent on the learner license was associated with a reduced risk of crash involvement during the unsupervised restricted license stage.

CONCLUSION

Results presented in this paper suggest that learner drivers in New Zealand should be encouraged to spend more time on their learner license to enable them to gain skills and experience to help reduce their crash risk when they are allowed to drive unsupervised.

IMPACT ON INDUSTRY

Compared with novice drivers who are on their learner license for the least amount of time, those who spend the most amount of time on their learner license have reduced risk of on-road crash involvement as an unsupervised driver. Learner drivers and their supervisors need to be aware of the length of time required for practice in order to reduce the risks of crash involvement when they are able to drive unsupervised (O'Brien et al., 2012). The recently introduced increase in the minimum driver licensing age in NZ, tougher restricted license stage driving test (aimed at encouraging 120 hours of supervised driving), and the Safe Teen driver campaign (NZ Transport Agency, 2012) are all strategies targeted at improving the safety of learner drivers. These strategies need to be evaluated to ensure they are achieving their goals.

Early biomarkers of resistance and susceptibility to mycobacterial disease (160.1)

Mycobacterial diseases such as tuberculosis and paratuberculosis continue to be of serious health and economic concern to humans and livestock globally. Lack of knowledge on the nature of the protective immune response as well as immunological markers of disease susceptibility and latency hamper the development of effective vaccines and other therapies. The use of a well-characterised ruminant infection model enabled us to follow the host response to mycobacterial challenge from the time of exposure until manifestation of clinical disease in a natural host. This study (30 controls and 58 challenged in 2 trials) tracked cellular and humoral responses, and quantity of mycobacterial shedding, for up to 30 months post challenge in sheep. Infection was defined as the presence of viable organisms in tissue sections taken at necropsy. The IFNγ response increased after exposure regardless of disease outcome. Parameters measured could distinguish severely diseased animals from those that had been exposed but were uninfected. Infectious or severely diseased animals were more likely to have a lower IFNγ response early (4 months post exposure) compared to exposed uninfected animals. This latter group were also more likely to have an elevated early IL-10 response. These studies demonstrate the complexity of the immune response to pathogenic mycobacteria and illustrate the fact that measurement of a single immunological parameter is insufficient to determine the outcome of disease.

Differential gene expression changes associated with sub-clinical Mycobacterium avium subsp. paratuberculosis infection in cattle: a transcriptomic study (160.2)

Paratuberculosis or Johne's disease is characterised by a lengthy sub-clinical phase that may persist for years prior to development of clinical disease. Mechanisms leading up to clinical disease are poorly understood although the early sub-clinical phase is reportedly characterised by a pro-inflammatory response largely driven by Th1 cytokines. The objectives of this study were to evaluate early gene expression changes in calves exposed to the causative agent, Mycobacterium avium subsp. paratuberculosis (MAP). Blood samples were drawn at three early time points, from a Johne’s field trial consisting of a mixed population of Holstein and Holstein Red cattle. Four MAP exposed and four unexposed control cattle were sampled at each time point and processed to Affymetrix GeneChip Bovine Arrays. Ontological analysis revealed a number of differences in gene expression between the two populations at the individual time points. In addition a subset of genes associated with the MHC were consistently altered across all MAP-exposed samples in comparison to the unexposed controls, suggesting significant changes to the antigen processing and presentation pathways in MAP-exposed animals. This differential regulation in response to MAP is a significant finding in the understanding of the mechanisms of pathogenesis and may lead to an aid to test for susceptibility.

Immunogenicity evaluation of in silico identified Mycobacterium avium subsp paratuberculosis recombinant proteins that were upregulated under stress conditions (160.3)

Mycobacterium avium subsp paratuberculosis (MAP) is the causative agent of Johne’s disease (JD) in ruminants. It is known to enter a dormant phase outside the host typically on soil and survive inside the host macrophage. In vitro experiments have reported differential regulation of certain MAP proteins when exposed to stressors similar to dormancy. It is believed that in vivo regulation of dormancy genes and associated proteins by MAP may play an important role in evading the host defence mechanisms and the host may also mount an immune response against these dormancy related proteins. Evaluation of such proteins may provide insight to host-pathogen interaction during the course of MAP infection and may be of diagnostic interest. A group of dormancy genes upregulated under stress conditions were examined using in silico analysis to identify B and T-cell epitopes. Five potential candidate genes based on epitope prediction results were selected and cloned. Recombinant proteins were produced, purified and evaluated for their immunogenicity using a panel of sera from sheep with a spectrum of JD and sheep free of MAP infection by detection of serum antibodies. Individually, the five proteins were found to have the ability to partially discriminate between sera from sheep unexposed and exposed to MAP infections. This study showed that the MAP proteins upregulated under in vitro stress conditions were recognised by host immune system.

The early lymphocyte proliferation response in sheep exposed to Mycobacterium avium subsp. paratuberculosis compared to infection status

Johne's disease (JD) is an enteric mycobacterial infection of ruminants that has significant global economic impact. Not all individuals exposed to pathogenic mycobacteria succumb to disease. Therefore although early detection of infectious individuals is vital, it is equally important to distinguish how the host response differs in those that are able to successfully clear or control mycobacterial infection and those that are unable to do so. To further our understanding of this issue we studied the antigen-specific proliferation of lymphocytes, including lymphocyte subsets, during the course of early experimental ovine paratuberculosis and assessed differences in this response between animals that eventually succumbed to disease and those that remained disease-free. While proliferation of blood lymphocytes was significantly higher in sheep exposed to Mptb compared to unchallenged controls as early as 4 months post inoculation (p.i.), there was no difference in PBMC proliferation between sheep that had been exposed to Mptb and became infected and those that were disease-free at the termination of the study. However, jejunal lymph node cells of Mptb-exposed infected animals had a significantly lower antigen-specific proliferative response compared to exposed uninfected animals. This may be useful when assessing JD status in animals of high commercial value. Multibacillary sheep had a lower proliferative response in peripheral blood compared to paucibacillary animals as early as 8 months p.i. and this was significantly different at 13 months p.i.

Normal levels of immunocompetence in possums (Trichosurus vulpecula) exposed to different laboratory housing conditions post capture

Specific and non-specific immunological tests were used to monitor aspects of the immune response in captive possums. The tests included total and differential white blood cell counts, lymphocyte transformation assay, and enzyme linked immunosorbant assay. The level of free cortisol present in possum plasma samples was evaluated as an endocrine marker for stress. Four different housing conditions were used to test whether stress could be managed or avoided in captive animals. Animals were caged individually or as groups in pens. Bacille Calmette-Gurein (BCG) and tetanus toxoid immunization was used to evoke primary cell mediated and antibody responses in test animals. The results indicated that there was no significant difference in immunological responses or endocrine parameters in animals held under any of the housing conditions. The results infer that wild possums adapt quickly post-capture to novel housing conditions and produce representative patterns of immunity when held in housing conditions and fed ad libitum.

Tumor necrosis factor-alpha induces stress fiber formation through ceramide production: role of sphingosine kinase

Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine that activates several signaling cascades. We determined the extent to which ceramide is a second messenger for TNF-alpha-induced signaling leading to cytoskeletal rearrangement in Rat2 fibroblasts. TNF-alpha, sphingomyelinase, or C(2)-ceramide induced tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin, and stress fiber formation. Ly 294002, a phosphatidylinositol 3-kinase (PI 3-K) inhibitor, or expression of dominant/negative Ras (N17) completely blocked C(2)-ceramide- and sphingomyelinase-induced tyrosine phosphorylation of FAK and paxillin and severely decreased stress fiber formation. The TNF-alpha effects were only partially inhibited. Dimethylsphingosine, a sphingosine kinase (SK) inhibitor, blocked stress fiber formation by TNF-alpha and C(2)-ceramide. TNF-alpha, sphingomyelinase, and C(2)-ceramide translocated Cdc42, Rac, and RhoA to membranes, and stimulated p21-activated protein kinase downstream of Ras-GTP, PI 3-K, and SK. Transfection with inactive RhoA inhibited the TNF-alpha- and C(2)-ceramide-induced stress fiber formation. Our results demonstrate that stimulation by TNF-alpha, which increases sphingomyelinase activity and ceramide formation, activates sphingosine kinase, Rho family GTPases, focal adhesion kinase, and paxillin. This novel pathway of ceramide signaling can account for approximately 70% of TNF-alpha-induced stress fiber formation and cytoskeletal reorganization.

Physical assault in New Zealand: the experience of 21 year old men and women in a community sample

AIM

To obtain epidemiological information on physical assault in a high risk group of New Zealanders.

METHOD

Rates of physical assault in the preceding twelve months were ascertained by interview in a cohort of 21 year old, Dunedin-born men (n = 482) and women (n = 462).

RESULTS

Forty-five percent of the men and one quarter of the women reported at least one physical assault, either completed, attempted or threatened. A small proportion of these received medical treatment. Most serious assaults were by a perpetrator who was thought to have been drinking alcohol. Most assaults on men were by strangers but partners carried out more assaults against women, especially those receiving medical treatment. One quarter of all assaults on women were by other women, compared to 15% of the assaults on men. Differences between patterns of assaults on women and on men are discussed.

CONCLUSION

It is important for doctors to be aware of the widespread occurrence of interpersonal violence in New Zealand and its underreporting.

Personality differences predict health-risk behaviors in young adulthood: evidence from a longitudinal study

In a longitudinal study of a birth cohort, the authors identified youth involved in each of 4 different health-risk behaviors at age 21: alcohol dependence, violent crime, unsafe sex, and dangerous driving habits. At age 18, the Multidimensional Personality Questionnaire (MPQ) was used to assess 10 distinct personality traits. At age 3, observational measures were used to classify children into distinct temperament groups. Results showed that a similar constellation of adolescent personality traits, with developmental origins in childhood, is linked to different health-risk behaviors at 21. Associations between the same personality traits and different health-risk behaviors were not an artifact of the same people engaging in different health-risk behaviors; rather, these associations implicated the same personality type in different but related behaviors. In planning campaigns, health professionals may need to design programs that appeal to the unique psychological makeup of persons most at risk for health-risk behaviors.

Personality differences predict health-risk behaviors in young adulthood: evidence from a longitudinal study

In a longitudinal study of a birth cohort, the authors identified youth involved in each of 4 different health-risk behaviors at age 21: alcohol dependence, violent crime, unsafe sex, and dangerous driving habits. At age 18, the Multidimensional Personality Questionnaire (MPQ) was used to assess 10 distinct personality traits. At age 3, observational measures were used to classify children into distinct temperament groups. Results showed that a similar constellation of adolescent personality traits, with developmental origins in childhood, is linked to different health-risk behaviors at 21. Associations between the same personality traits and different health-risk behaviors were not an artifact of the same people engaging in different health-risk behaviors; rather, these associations implicated the same personality type in different but related behaviors. In planning campaigns, health professionals may need to design programs that appeal to the unique psychological makeup of persons most at risk for health-risk behaviors.

Characterization of sea urchin egg endoplasmic reticulum in cortical preparations

The cortical endoplasmic reticulum (ER) of sea urchin eggs was localized on isolated egg cortices by staining with aqueous suspensions of the dicarbocyanine "DiI." Immunofluorescence localization of a calsequestrin-like protein was essentially identical; this is consistent with a role for the ER in calcium regulation. The ER often encircles cortical granules, making it well-suited for initiating fusion and propagating the calcium wave. Thiazole orange and Hoechst dye 33258 at pH 2 stain ribosomes bound to the ER, providing evidence that the cortical ER is rough ER. High chloride concentrations were found to disrupt ER continuity.

Do patients cash prescriptions? An audit in one practice

It has been suggested that up to 20 per cent of patients do not cash their prescriptions. To investigate this possibility, the rate of uncashed prescriptions in a group practice was measured. Out of 1,395 prescriptions studied, 89 (6.4 per cent) were uncashed. An association between having to pay prescription charges and prescriptions being uncashed was shown. Measurement of the rate of uncashed prescriptions deserves to be more widely used as a means of self-audit.

Short-term variability of pulse rate and blood pressure in cardiac surgery patients

The magnitude and mathematical nature of short-term variations of pulse rate and mean arterial blood pressure has been studied in 27 post-operative cardiac surgical patients over a continuous period of 200 min in each case. Similar variability was observed in all patients. Short-term variations were composed predominantly of a series of rhythmic changes ranging from one synchronous with respiration to others between 2 and 5 min in cycle length. There was consistent variance of the beat-by-beat values for both variables about a continuously updating 5 min mean. The average standard deviation was 3.75 beats/min for pulse rate and 0.48 kPa (3.64 mm Hg) for mean arterial blood pressure. For both variables the distribution about the 5-min mean did not differ significantly from a normal distribution in 50 out of the 54 records. These findings have implications for the reproducibility of current methods of estimating mean pulse rate and blood pressure, and the change necessary before two estimates may be regarded as significantly different. The results are applicable both to the interpretation of Ward Charts by medical staff and to automated monitoring systems.