Understanding occipital pressure sores in UK military casualties: a pilot study in healthy military personnel.

INTRODUCTION: The high prevalence of occipital ulcers in UK military casualties observed during the conflict in Afghanistan is a multifactorial phenomenon. However, the consensus is that ulceration is triggered by excessive pressure that is maintained for too long during the use of the general service military stretcher. Thresholds for capillary occlusion are accepted benchmarks to define excessive pressure, but similar thresholds for safe/excessive duration of pressure application do not exist. To address this gap in knowledge, we propose to use the time it takes for a healthy person to feel pain at the back of the head as an initial indication of safe exposure to pressure. METHODS: Healthy military personnel (16 male/10 female) were asked to lie motionless on a typical general service stretcher until they felt pain. Time-to-pain and the location of pain were recorded. To support the interpretation of results, baseline sensitivity to pain and pressure distribution at the back of the head were also measured. Independent samples t-test was used to assess differences between genders. RESULTS: Twenty participants felt pressure-induced soft-tissue pain at the back of the head. The remaining six participants terminated the test due to musculoskeletal pain caused by poor ergonomic positioning. On average, pain at the occiput developed after 31 min (±14 min). Female participants were significantly more sensitive to pain (t(24)=3.038,p=0.006), but time-to-pain did not differ significantly between genders (p>0.05). CONCLUSIONS: When people lie motionless on a typical military stretcher, the back of the head is the first area of the body that becomes painful due to pressure. The fact that pain develops in ≈30 min can help healthcare providers decide how frequently to reposition their patients who are unable to do this on their own. More research is still needed to directly link time-to-pain with time-to-injury.

Simulating the effect of eliminating routine bacterial screening on the negative predictive value of the Ontario fish hatchery disease monitoring program.

We determined the impact of eliminating routine screening for Aeromonas salmonicida and Yersinia ruckeri on the efficacy of the Ontario Ministry of Natural Resources (OMNR) fish disease monitoring program, using Monte Carlo simulation. Because the main purpose of the program is to prevent transferring infected fish among OMNR hatcheries, or to wild fish populations through stocking waterways, the hatchery-level negative predictive value (HNPV) was used as an indicator of monitoring efficacy. The present program (which includes both routine screening of asymptomatic hatchery fish, and diagnostic testing of hatchery mortalities and clinically diseased fish) was confirmed to have a high median HNPV (0.999) for both study pathogens. Simulations suggested that the median probabilities that a hatchery would be pathogen-free if only diagnostic testing were continued (i.e. if no asymptomatic lots were screened), and all diseased lots tested negative for A. salmonicida and Y. ruckeri would be 0.994 for both pathogens (with <5% probability that HNPV would be less than 0.953 and 0.957, respectively) - indicating acceptable monitoring efficacy. However, limitations of the theoretical monitoring model must be considered.

Group-level factors associated with chemotherapeutic treatment regimens in land-based trout farms in Ontario, Canada.

The lowest level at which fish farmers ordinarily make management decisions is the individual holding unit. To identify factors associated with chemotherapeutic treatment initiation at the holding-unit level, we created a unit of measurement called the "farm-tank-lot" (FTL), which allowed the movements and mixing of groups of fish to be followed during an entire production cycle. Each FTL was comprised of fish with a common history housed in a specific holding unit. Our 21-month prospective observational study (conducted on 14 land-based trout farms in Ontario, Canada) showed that the FTL was a biologically meaningful unit of concern and a feasible unit of measurement on land-based trout farms.Multivariable logistic and Poisson regressions revealed that fish size and growth rate both were associated negatively with the probability and frequency of treatment. FTLs that existed for longer periods of time were more likely to be treated and treated more often. There was a significant farm effect. Future field studies of disease in cultured fish should incorporate these factors into their design and analysis.

Host factors associated with the detection of Aeromonas salmonicida and Yersinia ruckeri in Ontario, Canada government fish hatcheries.

This paper presents an epidemiological investigation of Ontario Ministry of Natural Resources Fish Health Laboratory data from 1981 to 1997, to determine whether fish species and age were associated with lot-level detection of Aeromonas salmonicida and Yersinia ruckeri in hatchery fish. In stepwise logistic regression, the species brook trout and back-cross (lake trout crossed with the hybrid "splake") were more likely to test A. salmonicida-positive compared to all other species reared in the hatcheries. Similarly, the species brook trout was significantly more likely to test Y. ruckeri-positive compared to all other species. For both pathogens, the 1-5-month age group was associated significantly with detection. These findings suggest that purposive sampling of higher-risk fish lots could increase the likelihood of detecting both study pathogens.

Hatchery-level predictive values for infectious pancreatic necrosis virus and Aeromonas salmonicida in Ontario, Canada.

The probability and uncertainty of correctly classifying the IPNV and Aeromonas salmonicida status of fish-rearing and natural sites in Ontario were estimated through Monte Carlo simulations. Propagating several uncertain inputs showed the extent to which natural variability and our present lack of knowledge affect the probability of site misclassification. For the scenarios investigated, the site-level negative predictive values (SNPVs) were high and fairly constant. The site-level positive predictive values (SPPVs) - given a test specificity ranging between 0.999 and 1.0 - were much lower, more variable, and highly affected by cut-off point and sample size. Substantial uncertainty resides in classifying the pathogen status of test-positive sites, whereas much less uncertainty resides in classifying pathogen status of test-negative sites.

Formal handling routines in Jamaican infants. Knowledge, attitudes and behaviour.

This study aimed to determine the frequency of use and the knowledge, attitudes and behaviour regarding the Formal Handling Routines (FHR) in rural and urban Jamaican infants. Analysis was made of the area of residence and educational level of the caregivers. The study included 194 caregivers, thirty-three community rehabilitation workers (CRWs) and 30 health care workers (HCWs). Depending on the level of understanding of the respondents, questionnaires were either self-administered or a personal interview was conducted. Caregivers with tertiary education differed significantly from the other caregivers both in frequency of use of the FHR and knowledge, attitudes and behaviour. Caregivers with tertiary education used the routine much less and had more negative attitudes towards it. This might be due to their better financial position, which allowed them to have helpers who cared for their children. HCWs also had significantly more negative beliefs about the FHR than CRWs and caregivers. It is possible that HCWs carried over their knowledge, attitudes and behaviour to the caregivers but if they did, it did not influence the majority of caregivers.

A field evaluation of an indirect immunofluorescent antibody test developed to diagnose plasmacytoid leukemia in chinook salmon (Oncorhynchus tshawytscha).

An immunofluorescent antibody test (IFAT) developed for the diagnosis for plasmacytoid leukemia was evaluated against histology under field conditions. Previously published results from a laboratory evaluation indicated that the IFAT had a much higher sensitivity than did histology. One hundred seventy-seven moribund chinook salmon from 3 farms located in British Columbia were sampled. Sensitivity, specificity and their respective quality indices were estimated for the IFAT relative to histology. The IFAT was shown to be unreliable, particularly with respect to sensitivity. Cohen's kappa was also calculated and revealed that the agreement between the 2 tests was no better than random. In contrast to previously published results the IFAT did not perform better than histology in the presence of bacterial kidney disease. The results emphasize the importance of evaluating tests in the field conditions in which they are to be used. The possible reasons for the shortcomings of the IFAT are discussed.

Experience of parents of children with disabilities with health services in Jamaica.

In order to determine the experiences with health services of caregivers of children with disabilities (CWDs), and the attitudes of health care workers (HCWs) towards CWDs and their caregivers, a survey was conducted of 26 caregivers of clients of 3D Projects, St. Mary, Jamaica, using a checklist, and of 113 HCWs in St Mary and Kingston who completed a questionnaire. Half of the 19 CWDs referred by HCWs to hospitals in Kingston because of the lack of facilities in St Mary eventually defaulted because there was no apparent improvement. 10 caregivers said that the cause of the disability was not explained, three others did not understand the explanation given, and only 4 understood the instructions of HCWs. These problems led to unrealistic expectations about the outcome of rehabilitation. 13 caregivers attributed disability of their CWDs to negligence, carelessness or poor treatment by HCWs during pregnancy or the early neonatal period. 87% of the HCWs, particularly Community Health Aides (CHAs), acknowledged at least some responsibility for the care of CWDs; but 10%, notably some nurses and midwives, denied responsibility. 90% referred patients for further care and 90% thought that they had made an impact on caregivers' 'beliefs'; but more than half the CHAs, and 25 to 30% of the other groups, expressed dissatisfaction with their management of CWDs. This study has highlighted inadequacies in the care of CWDs in St Mary and indicates that more appropriate preparation of all health staff for this important aspect of their work is required.

Assessing infections at multiple levels of aggregation.

The patterns of sero-prevalence of antibodies to four infectious diseases, representing a broad range of pathogens (bacteria: brucellosis; mycoplasma: contagious bovine pleuropneumonia; viruses: infectious bovine rhinotracheitis; protozoa: trypanosomosis) were investigated at three levels of organization (farm, area and district). Three contrasting districts in Kenya were compared: an arid and pastoral area (Samburu); a tropical highland area (Kiambu), and a tropical coastal area (Kilifi). Cattle in three districts were selected by two-stage cluster sampling between August 1991 and 1992. Schall's algorithm, a generalized linear mixed model suitable for multi-level analysis, was compared to ordinary logistic regression (OLR), which ignores clustering of responses; generalized estimating equations (GEE) or Jacknife, to account for clustering at the farm level; SAS VARCOMP, which provides normal-theory random-effects models. Schall's algorithm provided similar estimates to GEE (regression effects) and Jackknife (standard errors) for farm-level clustered data. Extending Schall's procedure for additional district and area-within-district random effects usually provided additional information. In general, models that included only a farm-level random effect consistently provided larger estimates of farms' variance components than did models with additional district and area random effects. The four type diseases exhibited various amounts of clustering. Brucellosis had moderate farm clustering plus some area and district clustering. Contagious bovine pleuropneumonia had only a small amount of clustering, mostly by area. Infectious bovine rhinotracheitis exhibited a large amount of clustering, primarily at the farm level. Trypanosomiasis antibody prevalence varied by district, area and farm. We believe that patterns of disease clustering identified by multi-level analysis can be used to better target high-risk units for disease control and guide research to understand disease transmission factors.

Neighbourhood support to families with a disabled child: observations on a coping strategy of caregivers in a Jamaican community-based rehabilitation programme.

In Jamaica, a low degree of practical helpfulness of neighbours of families with a disabled child has been described. This seems to cast doubt on the World Health Organization's concept of community-based rehabilitation which simply assumes that the community is a source of support. Our study tries to elucidate which reasons, in a Jamaican socio-cultural setting, make neighbours give support to or withhold it from disabled children and their caregivers. A concept of neighbourhood help is identified, according to which help is something to be asked for and provided under exceptional circumstances only. Caregivers claim to give and receive support in child rearing within the limits of this definition, generally irrespective of the presence of a disability. The impression that neighbours are unconcerned can arise when the support needed becomes too extensive to fit into the local definition of neighbourhood help--which is more likely in the case of disabled children.

Validity of the ten questions screened for childhood disability: results from population-based studies in Bangladesh, Jamaica, and Pakistan.

An international study to validate the Ten Questions screen for serious childhood disability was undertaken in communities in Bangladesh, Jamaica, and Pakistan, where community workers screened more than 22,000 children ages 2-9 years. All children who screened positive, as well as random samples of those who screened negative, were referred for clinical evaluations. Applying comparable diagnostic criteria, the sensitivity of the screen for serious cognitive, motor, and seizure disabilities is acceptable (80-100%) in all three populations, whereas the positive predictive values range from 3 to 15%. These results confirm the usefulness of the Ten Questions as a low-cost and rapid screen for these disabilities, although not for vision and hearing disabilities, in populations where few affected children have previously been identified and treated. They also show that the value of the Ten Questions for identifying disability in underserved populations is limited to that of a screen; more thorough evaluations of children screened positive are necessary to distinguish true- from false-positive results and to identify the nature of the disability if present.

Factors associated with past and potential future use of veterinarians by Ontario trout farmers.

This study investigated whether certain variables were associated with Ontario trout farmers' use of the Fish Pathology Laboratory (FPL), Ontario Veterinary College, or their willingness to pay for private veterinary services. Sixty-two farmers, representing 91% of Ontario's 1990 farmed trout production, were personally interviewed. Logistic regression was used to compare the 26 farmers who had submitted fish to the FPL during the previous two years to those who had not. Submitters tended to have been fish farming for fewer years, and to produce more fish, use more workers, treat prophylactically less frequently, keep records of drug treatments, and not disinfect holding units (p<0.05). Most farmers stated they would occasionally hire a private veterinarian. Only 13 farmers anticipated hiring one more than once per year. Polychotomous regression showed that farmers who purchased, instead of hatched, their seed stock, kept records, treated therapeutically often, and used several workers would hire private veterinarians more frequently (p<0.05). Strategies are discussed by which the veterinary profession might better understand and meet the needs of the aquaculture industry.

Recent developments in low-cost screening and assessment of childhood disabilities in Jamaica. Part 2: Assessment.

This paper summarises the requirements and criteria for assessment of childhood disabilities. It reviews recent research carried out in Jamaica and outlines procedures for medical and psychological assessment used in the International Epidemiological Study of Childhood Disability as well as local experience in community-based rehabilitation. While the medical assessment procedures were considered to be validated, there is an urgent need for local research and development in psychological assessment. These approaches, while not perfect as yet, bring the possibility of local community capability closer. They will require changes in professional attitudes, training of health and educational personnel, and changes in the service systems, so that screening and assessment can be integrated into existing services. However, although this will obviate the need for new, specialised administrations, improved linkages and lines of referral will be necessary.

Recent developments in low-cost screening and assessment of childhood disabilities in Jamaica. Part 1: Screening.

This paper reviews and summarises the requirements and criteria for the screening of childhood disabilities. It reviews recent advances in research carried out in Jamaica and outlines available techniques for the screening of cognitive, motor, speech, hearing and visual disabilities and fits. The availability of validated, simple, low-cost techniques that can be used by community workers facilitates the conduct of surveys for the planning of programmes and the identification of cases for rehabilitation.

Portage guide to early intervention: cross-cultural aspects and intra-cultural variability.

The issues arising from implementing an early intervention service, developed in the rural United States in the late 1960s in a range of different cultural contexts over a period of a quarter of a century, are explained. Services from India, Bangladesh, Jamaica and the United Kingdom are compared. As well as considering cross-cultural aspects of Portage, variability within one country, the United Kingdom, is considered by comparing one service in an inner-city area and one in a rural area.

PIP: In the late 1960s in rural Wisconsin, the Portage Guide to Early Intervention was developed to manage development delay in preschool children. A parent, usually the mother, teaches the child each day and keeps a record. A home visitor monitors progress weekly and teaches the parent by modelling the program with the child. It operates under basic assumptions, some of which many countries cannot meet. For example, services available in developed countries (e.g., health services) are not available in Bangladesh and India, because resources are limited and the population is so large. Further, there are considerable differences in culture between these countries and the West (e.g., extended family vs. nuclear family). Moreover, the major causes of developmental delay in these South Asian countries are different than in developed countries (birth asphyxia, malnutrition, and deficiency diseases vs. genetic causes). Professionals in India and Bangladesh have incorporated Portage into a variety of early intervention services, thereby modifying the model considerably. In Jamaica, however, professionals use the Portage model with only a few modifications. Fore example, they use it with all disabled children rather than just those with learning disabilities. A problem with using the model is the lack of manufactured toys and play materials listed in the curriculum. Jamaica has a training program for child development aides. Portage services exist throughout the UK. Urban programs serve many more immigrants from developing countries than do the rural programs. This requires modifying the Portage model. In all countries, costs pose a constraint. This overview of Portage services in various countries indicates that these services alone are relatively unimportant as direct agents of social change and may be an important element of broader social changes.

Categories, classes and criteria in childhood disability--experience from a survey in Jamaica.

This paper reports a new classification and criteria for disabilities and handicaps used in a survey of childhood disability in Jamaica. Part of the International Classification of Impairments, Disabilities and Handicaps was used, with an alternative classification for disabilities similar to that of impairment, and with a complete set of criteria for levels of severity. For handicaps, the set proposed in the WHO manual, Training Disabled People in the Community, was used. No difficulties were encountered in the use of definitions or severity criteria. The inter-rater reliability for disability as a whole by community workers was 79% (kappa statistic 0.58), and for the physician and psychologist 90 and 100%. The handicap classification was easy to use but there was some confusion with resulting poor inter-rater reliability for some questions. This could be corrected by clarification of the meaning of the questions during training. We recommend use of this classification and criteria as being simple and realistic for surveys of childhood disability conducted by community workers.

Estimates of the prevalence of childhood seizure disorders in communities where professional resources are scarce: results from Bangladesh, Jamaica and Pakistan.

Although numerous estimates of the prevalence of seizure disorders in populations in the less developed world have now been published, these estimates are difficult to interpret due to lack of comparability of study methods and criteria for case definition. The results reported in this paper are from a large, collaborative study of disabilities in 2- to 9-year-old children in which standard research procedures and case definitions were used in three diverse populations (located in Bangladesh, Jamaica and Pakistan). A two-phase study design (screening followed by professional evaluations) was used in this study allowing for the professional evaluation to serve as the criterion in the estimation of prevalence, even for rare disorders. As a result, the prevalence estimates reported here have a high degree of comparability across populations and exhibit unusually strong validity for population surveys. Febrile seizures were the most common type of seizure history in all three populations, with point estimates of lifetime prevalence ranging from 10.9 to 62.8 per 1000. The lifetime prevalence rates of epilepsy (recurrent unprovoked seizures) ranged from 5.8 to 15.5 per 1000. Lifetime prevalence rates of neonatal, all provoked and all unprovoked seizures, as well as estimates of the prevalence of active epilepsy, are also reported.

The prevalence of childhood disability and related medical diagnoses in Clarendon, Jamaica.

In a population-based survey in a defined area in the parish of Clarendon, Jamaica, the prevalence of six types of childhood disabilities was sought. All children aged 2-9 years who screened positive for disability, with 8% of children screening negative (out of a total of 5,468 children), were assessed by a physician and a psychologist. Disabilities were categorised by types and levels of severity. The estimated prevalence rate for all types and levels of disabilities was 93.9 per 1,000 children and for serious disability was 24.9 per 1,000. The rates for specific disabilities showed wide variation (cognitive, 81/1,000; speech, 14/1,000; visual, 11/1,000; hearing, 9/1,000; motor, 4/1,000; seizure, 2/1,000). Of the disabled children, 70% had only one disability, 23% had two and 6% had three or four disabilities. If disability is to be seen as a major outcome of a range of interacting factors, then these prevalence rates, taken with the specific aetiologies, would provide a framework for planning preventive and rehabilitative interventions.