Tetanus prophylaxis in horses: guidelines for New Zealand and Australia based on a critical appraisal of the evidence.

Horses are exquisitely sensitive to tetanus neurotoxin and are exposed to the risk of infection with Clostridium tetani throughout life. The vaccine against tetanus is highly effective at preventing disease, whereas tetanus in unvaccinated populations is associated with high mortality rates. Current guidelines in New Zealand and Australia for the available vaccine contain contradictions and limitations surrounding the optimal tetanus immunisation protocols for both adult horses and foals. This review critically evaluates the scientific literature on tetanus prophylaxis in horses within the context of equine practice and available products in New Zealand and Australia. The review was conducted by a panel of industry and specialist veterinarians to obtain agreement on nine equine tetanus prophylaxis guidelines for practising veterinarians. The primary protocol for tetanus toxoid (TT) immunisation consists of a three-dose series IM for all horses ≥ 6 months of age, and a four-dose series IM is proposed if commencing vaccination in foals between 3 and 6 months of age. Tetanus prophylaxis in foals < 3 months of age relies on passive immunity strategies. Following the completion of the primary protocol, a TT booster dose IM should be administered within 5 years, and every 5 years thereafter. When followed, these protocols should provide adequate protection against tetanus in horses. Additional tetanus prophylaxis guidelines are provided for veterinarians attending a horse experiencing a known "risk event" (e.g. wound, hoof abscess, surgery, umbilical infection). When a correctly vaccinated horse experiences a risk event, pre-existing immunity provides protection against tetanus. When an unvaccinated horse or one with unknown vaccination status, or a foal born to an unvaccinated dam, experiences a risk event, TT IM and tetanus antitoxin (TAT) 1,500 IU SC should be administered simultaneously at separate sites, and the TT primary immunisation protocol should subsequently be completed for the horse's respective age. In previously immunised pregnant broodmares, a TT booster dose administered 4-8 weeks prior to parturition optimises the transfer of passive immunity against tetanus to the newborn foal via colostrum; provided that post-natal IgG concentration in serum is > 800 mg/dL (8 g/L), such foals should be passively protected against tetanus up to 6 months of age. Survivors of clinical tetanus must still receive the primary protocol for vaccination against tetanus. In summary, all horses in New Zealand and Australia should be vaccinated against tetanus with protection maintained throughout life via TT booster doses, facilitated by accurate medical record keeping and client education.

Mapping nectar-rich pollinator floral resources using airborne multispectral imagery.

Wild pollinator numbers are known to be positively associated with amounts of flower-rich habitat at landscape level. Increasing floral resources can be particularly beneficial in relatively nectar-poor agricultural systems and having a baseline understanding of the temporal and spatial availability of resources can allow targeted habitat management. Very high-resolution remote sensing has potential to facilitate accurate mapping of fine-scale, within-habitat pollinator foraging resources, thereby allowing spatial and temporal gaps to be identified and addressed, improving predictions of pollinator numbers, and enabling remote monitoring of pollinator conservation measures. Concentrating on hedgerow and flower-rich field margins in a UK agricultural landscape, we showed that multispectral airborne imagery with 3 cm and 7 cm spatial resolutions can be used to classify five nectar-rich flowering plant species (Prunus spinosa, Crataegus monogyna, Rubus fruticosus, Silene dioica and Centaurea nigra) using a maximum likelihood classification algorithm. In 2019, we separately acquired 3 cm and 7 cm imagery for the months of March, May and July, respectively. Overall accuracies were above 90% for each month at both 3 cm and 7 cm resolutions (range 92.32%-98.72%), supporting previous research that suggests higher spatial resolutions do not necessarily lead to higher accuracies, as pixel variability is increased. Remaining challenges include determining which co-flowering species of similar colours in the visible range can be distinguished from one another within classifications and quantifying floral unit density from classifications so that the nectar sugar supply can be calculated. Nonetheless, we provided a prototype approach for mapping pollinator foraging resources in an agricultural context, which can be extended to other nectar-rich species. The foundation is set for developing a remote sensing pipeline that can provide valuable data on the availability of nectar-rich flowering plant species at different time-points throughout the year.

Tackling agricultural diffuse pollution: What might uptake of farmer-preferred measures deliver for emissions to water and air?

Mitigation of agricultural diffuse pollution poses a significant policy challenge across Europe and particularly in the UK. Existing combined regulatory and voluntary approaches applied in the UK continue to fail to deliver the necessary environmental outcomes for a variety of reasons including failure to achieve high adoption rates. It is therefore logical to identify specific on-farm mitigation measures towards which farmers express positive attitudes for higher future uptake rates. Accordingly, a farmer attitudinal survey was undertaken during phase one of the Demonstration Test Catchment programme in England to understand those measures towards which surveyed farmers are most receptive to increasing implementation in the future. A total of 29 on-farm measures were shortlisted by this baseline farm survey. This shortlist comprised many low cost or cost-neutral measures suggesting that costs continue to represent a principal selection criterion for many farmers. The 29 measures were mapped onto relevant major farm types and input, assuming 95% uptake, to a national scale multi-pollutant modelling framework to predict the technically feasible impact on annual agricultural emissions to water and air, relative to business as usual. Simulated median emission reductions, relative to current practise, for water management catchments across England and Wales, were estimated to be in the order sediment (20%)>ammonia (16%)>total phosphorus (15%) ≫ nitrate/methane (11%)>nitrous oxide (7%). The corresponding median annual total cost of the modelled scenario to farmers was £3 ha(-1)yr(-1), with a corresponding range of -£84 ha(-1)yr(-1) (i.e. a net saving) to £33 ha(-1)yr(-1). The results suggest that those mitigation measures which surveyed farmers are most inclined to implement in the future would improve the environmental performance of agriculture in England and Wales at minimum to low cost per hectare.

Developing Demonstration Test Catchments as a platform for transdisciplinary land management research in England and Wales.

Whilst a large body of plot and field-scale research exists on the sources, behaviour and mitigation of diffuse water pollution from agriculture, putting this evidence into a practical, context at large spatial scales to inform policy remains challenging. Understanding the behaviour of pollutants (nutrients, sediment, microbes and pesticides) and the effectiveness of mitigation strategies over whole catchments and long timeframes requires new, interdisciplinary approaches to organise and undertake research. This paper provides an introduction to the demonstration test catchments (DTC) programme, which was established in 2009 to gather empirical evidence on the cost-effectiveness of combinations of diffuse pollution mitigation measures at catchment scales. DTC firstly provides a physical platform of instrumented study catchments in which approaches for the mitigation of diffuse agricultural water pollution can be experimentally tested and iteratively improved. Secondly, it has established national and local knowledge exchange networks between researchers and stakeholders through which research has been co-designed. These have provided a vehicle to disseminate emerging findings to inform policy and land management practice. The role of DTC is that of an outdoor laboratory to develop knowledge and approaches that can be applied in less well studied locations. The research platform approach developed through DTC has brought together disparate research groups from different disciplines and institutions through nationally coordinated activities. It offers a model that can be adopted to organise research on other complex, interdisciplinary problems to inform policy and operational decision-making.

The assimilation of dioxins and PCBs in conventionally reared farm animals: occurrence and biotransfer factors.

The assimilation of PCDD/Fs and PCBs in chickens, pigs and sheep was investigated in studies using conventional animal husbandry practices. Closely matched samples of muscle (meat), liver, kidneys, eggs, milk, feed, soil and grass were collected of which 105 were analysed. The data obtained were consistent with the PCB and PCDD/F TEQ concentrations to be expected in rural background locations. A slight decline in TEQ values in meat with increasing age was evident in pigs, sheep and broiler chickens. Higher TEQ values in meat from outdoor pigs compared to those raised indoors, and an increase in TEQs in eggs as a result of free-range conditions might be attributable to additional contaminant intakes from soil. TEQ values in samples of sheep meat were slightly higher than those for pigs and chickens and market ready lowland sheep showed higher meat TEQs than the highland species. PCDD/F TEQs were considerably higher in the liver than meat. Contaminant transfer from dietary sources was investigated using biotransfer factors (BTFs) which tended to be higher in chickens than in sheep or pigs. BTFs for all animals declined in magnitude with age, but on average, BTFs for pigs and chickens showed a sharper initial decline than for sheep. The relative magnitude of the BTFs usually followed the order: (highest first) PCB 153, PCB 169, PCB 126, 1,2,3,7,8-PeCDD/2,3,4,7,8-PeCDF and 2,3,7,8-TCDD. This may suggest that higher chlorinated congeners accumulate more readily in meat tissues. Congener-specific BTF variations were found to be associated with variables such as dietary composition during rearing, differences between feed and animal species.

Effects of distances to hospital and GP surgery on hospital inpatient episodes, controlling for needs and provision.

Age and sex adjusted inpatient episode ratios were calculated from hospital records over a two year period for 555 census wards in Cambridgeshire, Norfolk and Suffolk, UK. Hospital episodes were divided into acute, psychiatric and geriatric specialties, and elective and emergency acute admissions were distinguished. Variations in inpatient episode ratios between wards were compared with census indicators of the 'needs' of local populations for inpatient services, measures of the local provision of hospital and other related services, and measures of the distance to the nearest general practitioner surgery and the distance to the nearest hospital. Hospital episodes were found to be strongly related to both distance measures, but the associations were partially explained by a tendency for the health status of local populations (measured by the needs indicators) to be worst in urban areas close to health services. Including needs and provision variables together with the distance variables explained most of the variations in age and sex adjusted inpatient ratios for small areas. Needs were the most important determinants of emergency acute and psychiatric inpatient rates, but service provision was more important for elective acute and geriatric inpatients. Controlling for needs and provision, distance to hospital produced 17% reduction in acute episodes, 37% reduction in psychiatric episodes and 23% reduction in geriatric episodes over the range of distances observed. Distance to nearest GP surgery reduced elective acute episodes by up to 15% after controlling for confounders. These results demonstrate that the NHS is falling short of its aim to provide fair access to services irrespective of geography, and new policies will be required if geographical inequities are to be reduced.

Accidents to preschool children: comparing family and neighbourhood risk factors.

Accidental injury in young children is more common among poorer families and in deprived areas but little is known about how these factors interact. This paper describes a study to measure the contribution of individual family factors and area characteristics in determining risk of accidental injury among preschool children. We conducted a population based study of preschool accident and emergency attendances over two years in and around the city of Norwich, UK. Information on individual families was extracted from the district child health information system while "social areas" were constructed from adjacent census enumeration districts with homogeneous social and demographic characteristics. Statistical analysis was by multilevel modelling. Accidental injury rates were much higher in deprived urban neighbourhoods than in affluent areas but the multilevel analysis showed that, for all accidents, much of the variation in rates was accounted for by factors at the individual level i.e. male sex, young maternal age, number of elder siblings and distance from hospital, with a smaller, but independent, influence of living in a deprived neighbourhood. The model for more severe injuries was similar except single parenthood was now significant at the level of individuals and the effect of area deprivation was stronger. We conclude that preschool accidental injuries are influenced by factors operating at both the level of individual families and between areas. This evidence suggests that both social policy changes to improve child care among unsupported young families and targeting accident prevention measures at a local level towards deprived neighbourhoods would reduce accidents.

PCB and PCDD/DF concentrations in egg and poultry meat samples from known urban and rural locations in Wales and England.

A survey was undertaken of PCB and PCDD/DF congeners in eggs and poultry meat from a smallholding close to a chemical waste incinerator, other sites in the surrounding district, and three rural locations. The concentrations from the site close to the incinerator were appreciably greater than those found elsewhere, although the contrast was less marked for poultry meat than eggs. All types of poultry produce displayed noticeable variations in congener composition when the samples were grouped according to geographical origin. These results support the view that the environment in which poultry live does influence the PCB and PCDD/DF characteristics of their products. Exposure calculations indicated that consumption of eggs from the site close to the incinerator would constitute a substantial proportion of recommended daily intakes for such contaminants and at the present time these products are not being eaten.

The public health risks of Lyme disease in Breckland, U.K.: an investigation of environmental and social factors.

This paper considers the public health risks of Lyme disease, a borrelial infection transmitted to humans chiefly by nymphal Ixodes ticks. A study undertaken in the Breckland area of East Anglia, U.K., combined analysis of the spatial and temporal factors affecting tick activity at recreational sites with a survey of current levels of disease awareness among visitors to these locations. Significant relationships were found between densities of questing ticks and vegetation type, relative humidity and temperature. More than two thirds of the general public visiting the sites were aware ticks could carry diseases, but only 13% recognized an unfed nymph, and under half knew that Lyme disease could be contracted from tick bites. Such results need to be taken into account when formulating public health and education measures.

Using GIS in risk analysis: a case study of hazardous waste transport.

This paper provides an illustration of how a geographic information system (GIS) can be used in risk analysis. It focuses on liquid hazardous waste transport and utilizes records archived by the London Waste Regulatory Authority. This data source provides information on the origin and destination of each waste stream, but not the route followed during transport. A GIS was therefore employed to predict the paths used, taking into account different routing criteria and characteristics of the available road network. Details were also assembled on population distribution and ground-water vulnerability, thus providing a basis for evaluating the potential consequences of a waste spillage during transport. Four routing scenarios were implemented to identify sections of road which consistently saw heavy traffic. These simulations also highlighted that some interventions could lead to risk tradeoffs rather than hazard mitigation. Many parts of the research would not have been possible without a GIS, and the study demonstrates the considerable potential of such software in environmental risk assessment and management.

Validation of a congener specific method for ortho and non-ortho substituted polychlorinated biphenyls in fruit and vegetable samples.

An on-line procedure has been developed and validated for the clean-up and fractionation of ortho and non-ortho-PCBs in fruit and vegetable samples. The procedure combines silica/acid and carbon/glass fibre columns with gas chromatography-mass spectrometry. Chromatography on carbon/glass fibre allowed collection of mono-ortho/di-ortho and non-ortho-PCB fractions, which were determined separately by GC-MS. The method was validated by replicate analyses and by inter-laboratory comparison of data for PCB congeners determined in fruit and vegetable samples collected in South Wales. The concurrent determination of ortho and non-ortho substituted PCBs is reported with recoveries ranging from 55-95% and a mean intra-laboratory precision (%COV) of 9.5% for apple extracts.

Effect of labour market conditions on reporting of limiting long-term illness and permanent sickness in England and Wales.

STUDY OBJECTIVE: To identify any bias in the reporting of limiting long term illness and permanent sickness due to labour market conditions, and show the absence of the effect in mortality rates. DESIGN: A geographically based study using data from the 1991 census. Standardised ratios for mortality and long term illness in people aged 0-64 years and permanent sickness in people of working age were compared with Carstairs deprivation scores in multilevel models which separated the effects operating at three geographical scales: census wards, travel to work areas, and standard regions. Holding ward and regional effects constant, variations between travel to work areas were compared with long term unemployment rates. SETTING: Altogether 8690 wards and 262 travel to work areas in England and Wales. MAIN RESULTS: Variations in mortality, limiting long term illness, and permanent sickness were related to Carstairs deprivation scores and standard region. With these relationships controlled, limiting long term illness and permanent sickness were significantly related to long term unemployment levels in travel to work areas, but mortality was not affected. Self reported morbidity was more sensitive to variations in long term unemployment rates in conditions of high social deprivation than in affluent populations. CONCLUSIONS: Limiting long term illness and permanent sickness measures may reflect a tendency for higher positive response in difficult labour market conditions. For average social deprivation conditions, standardised limiting long term illness for people aged 0-64 years was 20% higher in travel to work areas where employment prospects were relatively poor compared with areas with relatively good employment prospects. This casts doubt on the use of limiting long term illness as an indicator of objective health care needs for resource allocation purposes at national level.

PCB and PCDD/DF congeners in locally grown fruit and vegetable samples in Wales and England.

A survey was undertaken of PCB and PCDD/DF congeners in fruit and vegetables grown in an urban areas close to a chemical waste incinerator and three rural locations. All of the concentrations detected were low and there was considerable overlap between those found in urban and rural samples. Some similarities with the congener composition of air samples were identified and concentrations in apple skin were noticeably higher than those in the flesh of the fruit. These results suggest that atmospheric deposition was an important contamination pathway. Assessments using the highest concentrations found indicated that consumption of such fruit and vegetables would represent an additional 3% of the normal dietary intake for PCBs and 8% for PCDD/DFs.

Unemployment rate as an updatable health needs indicator for small areas.

BACKGROUND: The objective of the study was to compare updatable unemployment rates with the unemployment rate and composite deprivation indices from the 1991 Census as health needs indicators for small areas. METHODS: Townsend, Carstairs and Jarman indices and male unemployment rates were calculated from the 1991 Census, for 275 wards of the former East Anglian health region with unchanged boundaries between 1981 and 1991. Male unemployment rates were also derived from April 1991 unemployment benefit claimant figures, using both Office of Population Censuses and Surveys mid-year estimates of population and estimates derived from Family Health Services Authority patient registers as the denominator. Ward values were compared using Pearson product moment correlation. RESULTS: All three unemployment measures were closely related to each other and all were broadly as effective in predicting ward variations in mortality and long-term illness in 1991 as the compound deprivation indices of Jarman. Townsend and Carstairs. CONCLUSION: Updatable unemployment rates were as suitable as the composite indices as an indicator of relative health needs for small areas in the year of the Census and might be expected to be superior in inter-censal years.

Limiting long-term illness and its associations with mortality and indicators of social deprivation.

STUDY OBJECTIVE: To examine geographical variation in limiting long-term illness in England and Wales and assesses the extent of its similarity with the distribution of mortality rates and of deprivation. DESIGN: A geographically based study using data from the 1991 census on limiting long term illness. Maps and regression analysis are used to compare the distribution of standardised illness ratios with standardised mortality ratios and indicators of social deprivation. SETTING: A total of 401 local authority districts in England and Wales. PARTICIPANTS: The population of England and Wales enumerated in the 1991 census. MAIN RESULTS: The geographical pattern of limiting long term illness shows many similarities with that of mortality but there are also some differences. Both are positively associated with indicators of social deprivation, with limiting long term illness tending to show stronger correlations, particularly in the elderly. Most of Wales and many industrial areas of northern England have higher rates of long term illness than would be expected from their mortality rates, while much of south eastern England has lower than expected rates. CONCLUSIONS: Moves towards using data on limiting long term illness instead of standardised mortality rates would have important implications for NHS resource allocations. Further assessment of the reliability of these data on self reported morbidity is required. in particular, there is a need to assess how much they reflect real differences in ill health rather than the influence of socioeconomic or cultural factors affecting the likelihood of a positive answer to the census question on limiting long term illness.

Comparison of ward population estimates from FHSA patient registers with the 1991 Census.

"Postcode addresses from National Health Service patient registers for Norfolk and Suffolk [counties in England] current on census day 1991 were assigned to census wards, and estimates of populations in wards were produced for the total population and for twelve age-sex groups. These were compared with adjusted counts of usual residents from the 1991 Census." The results indicate that family health service authority registers "are an acceptable alternative to the census for population estimation purposes. This supports recent arguments for wider use of population registers and suggests that they may be particularly valuable as a source of intercensal information."

Evaluation of methods for calculating census health indicators for GP practices.

The patients registered with a general practice are usually spread over many census areas and overlap with the distribution of neighbouring practices, so a validated method of aggregating census data to describe the characteristics of practice patients is required. Four methods were used to provide estimates of the percentage of patients aged 75 years and over from census data for 81 practices in Suffolk, England, and these were compared with values derived from the FHSA patient register. Census values for practice areas produced better estimates than those based on the location of the surgery, but the best methods were based on patient-weighted averages of ward and enumeration district data. The finer geographical detail of enumeration districts did not produce substantially more accurate estimates than the ward-level data: both gave estimates with limits of agreement within 2% of the patient register values. Errors in the census, errors in patient registers and selective geographical distributions of practice patients prevent close matching of census and register measures, but two of the methods tested produced estimates that allow broad comparisons between practices.

Factors affecting non-response to cervical cytology screening in Norfolk, England.

A geographic information system was used to integrate information on the uptake of cervical cytology screening for general medical practices in Norfolk with other data on the characteristics of the practices and the population they served. Regression analysis was employed to explore the extent to which variations in non-response were associated with explanatory factors. Non-response to the earlier system of opportunistic screening was found to be associated with the size of practice, the presence of a female doctor, the District Health Authority in which the practice was located, the age structure of the practice population, its degree of socio-economic deprivation and levels of rural remoteness. Compared with the earlier system, the new population-based call and recall system was found to be reaching a larger proportion of the population at risk. The former relationships were weaker under the new system, but non-response was still significantly associated with both social and organisational factors.