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- PublicationA highly specific and sensitive monoclonal antibody-based ELISA for the detection of circulating antigen in bancroftian filariasisA monoclonal antibody, Og4C3, directed against antigens of Onchocerca gibsoni (but not phosphorylcholine) has been used in a sandwich ELISA to detect a circulating antigen of Wuchereria bancrofti in human serum. The interfering effect of host antibody was reduced by first boiling one part of serum for 5 min in the presence of three parts of 0.1 M Na2EDTA, pH 4.0. A total of 119 sera from individuals and 8 pooled sera from clinical and/or parasitologically defined cases of filariasis, plus 8 individual and 1 pooled endemic control sera, all from the filariasis serum bank of the World Health Organisation, as well as 20 non-endemic control sera, were screened with the assay. Circulating antigen was detected in serum from people infected with W. bancrofti but not Brugia malayi, B. timori, O. volvulus or Loa loa, and not in endemic or non-endemic controls. Of the 68 sera from W. bancrofti-infected subjects, 55/55 parasitologically confirmed and 12/13 clinically confirmed but amicrofilaraemic cases reacted in the assay. A weak but significant correlation (r2 = 0.4016) was found between numbers of microfilariae in blood and detectable levels of circulating antigen from patients with bancroftian filariasis.
17 - PublicationThe use of monoclonal antibody-based ELISAs to monitor chemotherapeutic effects in the bovine-Onchocerca gibsoni drug screenThree monoclonal antibodies directed towards antigens of Onchocerca gibsoni were used in antigen detection ELISAs to detect parasite antigens in sera from 100 cattle infected with O. gibsoni, in trials with the filaricidal compounds CGP 6140, CGP 20309, CGP 20376, CGP 21833, CGP 24589 and CGP 26702. Measurable levels of parasite antigens were highly variable, both within and between treatment and control groups of animals, with no consistent trends which related to time after treatment, micro or macrofilaricidal effects against O. gibsoni, or dose rate for any of the compounds used. It was concluded that these assays were unsuitable as a method of identifying drug-induced damage to O. gibsoni following the administration of these compounds. A detailed protocol for selecting suitable assays is discussed.
24 - PublicationThe use of monoclonal antibody-based ELISAs to monitor the efficacy of drugs against male Onchocerca gibsoni in vitroFour monoclonal antibodies directed against antigens of Onchocerca gibsoni were used in antigen detection ELISAs to monitor the efficacy of CGP 20309, CGP 20376, CGP 21833, CGP 24589 and CGP 26702 at 5 μg/ml against male O. gibsoni in vitro. No significant differences (P < 0.05) in antigen output between treated and control groups of parasites were recorded. However, consistently higher levels of antigen from treated (CGP 21833) as compared to control parasites were measured with all four assays, with differences being higher in the first 2 to 3 days post treatment than subsequently. The sensitivity of comparisons between groups was reduced by the high variability in output of antigen both between worms and also from the same worm, in part as a result of mechanical damage to worms sustained during collection or manipulation in vitro. This problem was reduced by zero handling once worms were established in vitro and it is recommended that future work should include a 24 to 48 hour period before treatment commences to detect raised antigen levels associated with physically damaged parasites so they can be excluded. It was concluded that this type of assay has no intrinsic technical or logistical advantage over other published methods of assessing drug-related damage in in vitro filarial screens. Nevertheless, further work using antigen detection ELISAs in this context is justified since these assays, unlike all other methods of assessing drug-induced damage in vitro, have direct application for use in identifying chemotherapeutic effects against similar parasites in vivo.
19 - PublicationAntigen detection ELISAs: pretreatment of serum to reduce interference by specific host antibodiesThe pretreatment of serum to reduce interference by specific host antibodies was investigated as a means of improving the sensitivity of antigen detection ELISAs whilst screening serum samples. Four antigen detection assays based on monoclonal antibodies directed against antigens of the bovine filariid Onchocerca gibsoni were used in this study and of these, three assays suffered a dramatic drop in sensitivity when detecting male O. gibsoni antigen in the presence of bovine serum as compared with antigen in buffer. A number of methods for pretreating serum to eliminate the problem of antibody interference with antigen detection were attempted, including heat and alkali treatments, detergent treatment of heat treated samples and the use of a reducing agent. The pretreatment of serum by boiling for 5 minutes in the presence of an equal volume of 0.1 M Na2EDTA pH 4.0 and recovery of the supernatant fluid following centrifugation at 16000 g was the most effective method of restoring the sensitivity of each of these three assays whilst screening bovine serum. Pretreatment of serum using this method produced up to a 512-fold increase in sensitivity compared with results obtained in assays with non-treated serum.
21 - PublicationSome Perceptions of Footrot Eradication in North-Western New-South WalesThe Footrot Strategic Plan (FSP) aims to progressively eradicate non-benign footrot in sheep from New South Wales. All but a small portion of the drier regions of NSW is now gazetted with Protected Area status - placing legal requirements on farmers and relevant authorities in relation to disease notification and, where disease exists, farm quarantine and disease eradication. The author's experience from north western NSW suggests, however, that despite these legal requirements, many local producers would be unlikely to notify upon suspecting disease. Furthermore, of those producers with properties quarantined for footrot during the period 1990-1992 in the Coonamble Rural Lands Protection Board, almost half lacked a real commitment to footrot eradication.Research towards improving the FSP and related programs has been dominated by methods to overcome technical obstacles. In non-endemic regions of NSW, such as the north west, however, major constraints on the FSP include problems of an economic or social nature. This paper discusses some constraints limiting the acceptance and adoption of the FSP in the Coonamble region of NSW and identifies some possible solutions to these problems.
55 - PublicationThe performance of farmed ostrich hens in eastern AustraliaA prospective observational epidemiological study was undertaken in the south-eastern region of Queensland in eastern Australia to collect accurate information on the performance of farmed ostriches, and to identify the most important constraints facing on-farm production. This paper (the first in a series of three) focuses upon aspects of the general study design and the productivity of ostrich hens on 12 farms in this region. These farms were a convenience sample and were visited regularly for at least 12 months from July 1993. Some general farm information was collected using a questionnaire; however, the focus of the study was mainly upon the performance of defined cohorts of hens (a cumulative total of 61 hens), eggs (910 eggs) and chicks (394 chicks). A number of methods was used to improve data quality. The study farms were managed by producers with a median of 2.5 years of active ostrich industry involvement, reflecting the recent establishment and rapid growth of the industry in this region. During the study period, 61 hens were observed for a period of 41.1 hen-years. Most hens were young (median age 2.7 years at the end of the observation period) and held in pairs. Egg production was poor, with the more-productive hens significantly older than those less-productive. Egg laying among the more-productive hens was clustered in time, with half of all eggs being laid within 2 days of a previous egg. Clutches of eggs were generally small (weighted mean 3.5 eggs) but were laid frequently (weighted mean 9.4 days between clutches). The farm and hen prevalences of Libyostrongylus douglassi infection were 33% and 40%, respectively.
26Scopus© Citations 26 - PublicationThe performance of farmed ostrich eggs in eastern AustraliaA prospective observational epidemiological study was undertaken in the south-eastern region of Queensland in eastern Australia to collect accurate information on the performance of farmed ostriches, and to identify the most important constraints facing on-farm production. This paper (the second in a series of three) focuses upon the performance of 910 ostrich eggs laid on 12 farms in this region between 1 July 1993 and 30 June 1994. Each egg was observed from lay until it hatched, was permanently removed from the incubator unhatched, or reached the 46th day of incubation without hatching (whichever occurred first). Eggs weighed on average 1301.9 g at lay, were stored for a mean of 3.7 days prior to the start of incubation, and lost an average of 15.5% of the initial set weight during the period of incubation. Overall fertility and hatchability percentages of 68.1% and 67.0%, respectively, were achieved. Laboratory examination was performed on some eggs that were infertile or failed to hatch. Although bacteria were isolated from some of these eggs, bacterial infection may not have been an important cause of incubation failure. Egg-level factors were examined for association with egg fertility and with egg hatchability using random-effects logistic regression modelling. There was no unconditional association between egg fertility and either egg weight at the start of incubation, the season of lay or the duration of egg storage prior to incubation. There was evidence, however, indicating a relationship between egg fertility and nonexamined pair and farm-level factors. Egg hatchability was conditionally associated with egg weight at the start of incubation, the percentage egg weight loss during incubation and the season of lay, and random pair-level extra-binomial variation was also demonstrated. The relationship between hatchability and weight loss was curvilinear; fertile eggs were most likely to hatch with weight loss during incubation of between 12 and 15% of the egg weight at the beginning of incubation.
23Scopus© Citations 16 - PublicationThe performance of farmed ostrich chicks in eastern AustraliaA prospective observational epidemiological study was undertaken in the south-eastern region of Queensland in eastern Australia to collect accurate information on the performance of farmed ostriches, and to identify the most important constraints facing on-farm production. This paper (the third in a series of three) focuses upon the performance of 394 chicks that hatched on 11 farms in this region from eggs laid between 1 July 1993 and 30 June 1994. Each chick was observed from hatch until dying, leaving the farm of origin or reaching 4 months of age (whichever occurred first). A total of 60.8% of the chicks survived to 4 months of age, with an overall crude mortality rate during the period of observation of 14.0 deaths per 100 chick-months at risk. The most common causes of death were the development of a lower-limb deformity (most frequently tibiotarsal rotation which accounted for 36% of all chick deaths), 'fading chick syndrome' (13%), and salmonellosis (11%). Only 83% of the chicks remained free of tibiotarsal rotation during the period of observation. This condition was generally first detected in chicks between 2 and 10 weeks after hatch, and the median survival time following diagnosis was 10 days. 'Fading chick syndrome' mainly affected chicks less than 3 weeks of age and did not appear to spread in a contagious manner. Chicks died following infection with Salmonella typhimurium on only one farm. Chick-level factors affecting survival during the 4 months following hatch were examined using the Cox proportional hazards regression model. After accounting for farm-level effects, risk factors for death or euthanasia during the first 4 months following hatch included the weight of the chick at hatch, and the development of tibiotarsal rotation. The need of the industry-wide development and adoption of objective measures of productivity is discussed, and some relevant measures are proposed.
24Scopus© Citations 22 - PublicationMonitoring the health and productivity of farmed ostrich flocksThe Australian farmed ostrich industry is in a state of T transition. Since reestablishment in this country after anabsence of about 60 years, the industry has expanded rapidly, both in numbers of producers and birds. Until recently, most flocks were small and individual birds were of considerable value. Accordingly, veterinary attention has focused on the health and productivity of individual birds. However, a program of sustainable commercial slaughtering has now been instigated, resulting in the slaughter of young mature birds to produce high quality leather and meat. The monetary value of individual birds has also dropped substantially in recent months. With these changes, the overall performance of the flock, rarher than individual birds, will become increasingly important. With the shifting emphasis towards flock performance, there will be an increasing need for veterinarians to monitor the health and productivity of farmed ostrich flocks. Monitoring programs have been developed for many livestock industries, including poultry (RJ Jenner, personal communication), to provide an ongoing assessment of the health and productivity of animal and bird populations. However, no published information is available about similar programs for ostrich flocks. This paper briefly reviews issues relating to the development of monitoring programs for ostrich populations, and presents a case study to demonstrate the potential uses of monitoring information for ostrich producers and their veterinarians.
23Scopus© Citations 7 - PublicationTuberculosis in cattle: the results of the four-area project(Springer (Biomed Central Ltd.), 2005)
; ; ; The four-area project was undertaken to further assess the impact of badger removal on the control of tuberculosis in cattle herds in Ireland. It was conducted between 1997 and 2002 in matched removal and reference areas in four counties, namely Cork, Donegal, Kilkenny and Monaghan, representing a wide range of Irish farming environments. In the removal areas, a proactive programme of badger removal was conducted, on two or three occasions each year, whereas in the reference areas, badger removal was entirely reactive following severe outbreaks of tuberculosis amongst cattle. A detailed statistical analysis of this study has already been presented by Griffin et al. [13]; this paper presents further, mainly descriptive, findings from the study. In total, 2,360 badgers were captured in the removal areas of which 450 (19.5%) were considered positive for tuberculosis and 258 badgers were captured in the reference areas, with 57 (26.1%) positive for tuberculosis. The annual incidence of confirmed herd restrictions was lower in the removal area compared to the reference area in every year of the study period in each of the four counties. These empirical findings were consistent with the hazard ratios found by Griffin et al. [13]. Further, the effect of proactive badger removal on cattle tuberculosis in the four-area project and in the earlier east-Offaly project, as measured using the number of reactors per 1,000 cattle tested, were very similar, providing compelling evidence of the role of badgers in the epidemiology of tuberculosis in Irish cattle herds. The validity of the four-area project was discussed in detail. Efforts to minimise badger-to-cattle transmission in Ireland must be undertaken in association with the current comprehensive control programme, which has effectively minimised opportunities for cattle-to-cattle transmission.342Scopus© Citations 15 - PublicationBartonella henselae and Domestic cats, JamaicaBartonella henselae has been isolated from domestic cats in most countries where it has been investigated, with the exception of some countries at northern latitudes, such as Norway. The prevalence of both bacteremia and seropositivity in cats is usually highest in warm and humid tropical countries. The worldwide distribution of cat scratch disease (CSD), a zoonotic disease caused mainly by the scratch of a B. henselae–infected cat, follows a similar pattern. Limited information is available about CSD in either humans or the feline reservoir in the Caribbean region.
288Scopus© Citations 6 - PublicationRegional red list of Irish bees(National Parks and Wildlife Service (Ireland) and Environment and Heritage Service (N. Ireland), 2006)
; ; ; ; In 2003 the Higher Education Authority awarded funding for a three year project on the conservation of native Irish bees under their North-South programme for collaborative research. This work was undertaken by Dr. Úna Fitzpatrick and Dr. Mark Brown in the School of Natural Sciences, Trinity College Dublin and by Mr. Tomás Murray and Dr. Rob Paxton in the School of School of Biological Sciences, Queen’s University Belfast. One important element of this research has been the documentation of the conservation status of native bees in Ireland. A three-step sequential process has been used to document the status of each of the native species, indicate the conservation action required, and highlight those species of most importance from a conservation perspective: (1) Identification of the threatened species using internationally recognized methodology - production of an IUCN regional red list for the island of Ireland. (2) Documentation of the total conservation actions required for the assessed group - completed IUCN conservation action authority files for threatened, near threatened and data deficient species. (3) Conversion from the regional red list to a national list of conservation priority species This summary report contains the Regional Red List of Irish bees, IUCN conservation actions authority files for all threatened, near threatened and data deficient species in the red list, and a list of national conservation priority species.598 - PublicationA case study of bovine tuberculosis in an area of County Donegal, Ireland(Springer (Biomed Central Ltd.), 2006)
; ; ; A descriptive analysis, to investigate the potential risk factors that might have contributed to the increased incidence of bovine tuberculosis (BTB) herd-breakdowns in the reference area of Co. Donegal during the fifth year of the four-area project (FAP), was performed. Seventy two different herds were restricted for BTB during the FAP; 10 of these herds were restricted twice, resulting in a total of 82 BTB breakdowns. During the first four years of the FAP, the number of BTB herd breakdowns in the area varied from a lowest of nine to a maximum of 18 per year, and were geographically dispersed. In the fifth year of the study a considerable increase in the number of BTB breakdowns (n = 32) was observed, and there was a spatial 'cluster' of infected herds in the eastern part of the study area. The increased number of BTB breakdowns during the fifth year most likely occurred because of the recrudescence of infection, herd-to-herd transmission and, to a lesser extent, purchase of infected cattle. Infected badgers remain as a possible but less likely source of infection, especially as an explanation for the cluster of infected herds. The analysis supports the hypothesis that BTB in herds is a problem that cannot be addressed successfully by dedicating our efforts to the elimination of single risk factors. Neither is it a problem that needs to be investigated only at the herd level, but rather at the area level, including groups of contiguous herds.362Scopus© Citations 5 - PublicationShaping our future: animal health in a global trading environmentIrish farming is facing a period of unprecedented change, in large part due to the increasing globalisation of agriculture. The challenges to Irish farming are substantial, given ongoing reductions in farm-gate returns to Irish farmers, as a consequence of increasing international competition, decreasing levels of subsidy support as a result of international (WTO) and EU-level decisions and a rapid increase in the relative cost of production of Irish product.
352 - PublicationThe structure and regulation of the Irish equine industries: Links to considerations of equine welfare(Springer (Biomed Central Ltd.), 2008)
; ; ; The equine industries in Ireland are vibrant and growing. They are broadly classified into two sectors: Thoroughbred racing, and sports and leisure. This paper describes these sectors in terms of governance, education and training in equine welfare, and available data concerning horse numbers, identification, traceability and disposal. Animal welfare, and specifically equine welfare, has received increasing attention internationally. There is general acceptance of concepts such as animal needs and persons' responsibilities toward animals in their care, as expressed in the 'Five Freedoms'. As yet, little has been published on standards of equine welfare pertaining to Ireland, or on measures to address welfare issues here. This paper highlights the central role of horse identification and legal registration of ownership to safeguard the health and welfare of horses.1847Scopus© Citations 17 - PublicationControl of mycobacterium bovis infection in two sika deer herds in IrelandIn a number of countries, tuberculosis (due to infection with Mycobacterium bovis) is a significant health problem of captive deer. This paper describes outbreaks of bovine tuberculosis in sika deer (Cervus nippon) on two farms in Ireland and the methods used to control the disease. On Farm A, infection was first detected during 1993. The infection was eradicated using a programme of test and removal, in association with segregation of young animals. A second outbreak (also due to infection with M. bovis, but a different RFLP profile) was detected in 2002. In the latter outbreak, infection was particularly prevalent in two groups of young deer. M. bovis with the same RFLP profile was also isolated in a badger found dead on the farm. Control was achieved by test and removal in association with herd management changes. In Herd B, infection was first detected in 1995, and subsequently eradicated using test and removal alone. In Herd A, re-infection remains an ongoing risk. Control rather than eradication of infection may more realistic in the short-to medium-term.
341Scopus© Citations 7 - PublicationTrends in cow numbers and culling rate in the Irish cattle population, 2003 to 2006Cows are the main economic production units of Ireland's cattle industry. Therefore, demographic information, including overall numbers and survival rates, are relevant to the Irish agricultural industry. However, few data are available on the demographics of cows within a national population, either in Ireland or elsewhere, despite the recent development of comprehensive national cattle databases in many EU Member States. This study has sought: to determine the rate of cow culling from the national herd; to determine the rate of culling by type (dairy, beef), age, method of exit, date of exit and interval between last calving and exit; to calculate the national cow on-farm mortality rate; and to compare the Irish rates with published data from other countries. This work was conducted using data recorded in the national Cattle Movement Monitoring System (CMMS). Culling refers to the exit of cows from the national herd, as a result of death but regardless of reason, and cow-culling rate was calculated as the number of cow exits (as defined above) each year divided by the number of calf births in the same year. Culling rate was determined by type (dairy or beef), date of birth, method of exit (slaughter or on-farm death), month of exit and interval between last calving and exit. The average cow-culling rate during 2003 to 2006 was 19.6% (21.3% for dairy, 18% for beef). While comparisons must be treated with caution, it concluded that the overall rates of culling in Ireland fell within published internationally accepted norms. The on-farm mortality rate of 3.2-4.1% was similar to that reported in comparable studies.
683Scopus© Citations 31 - PublicationRisk factors for the introduction and within-herd transmission of Mycobacterium avium subspecies paratuberculosis (MAP) infection on 59 Irish dairy herdsSince 1994, Irish cattle have been exposed to greater risks of acquiring Mycobacterium avium subspecies paratuberculosis (MAP) infection as a consequence of the importation of over 70,000 animals from continental Europe. In recent years, there has been an increase in the number of reported clinical cases of paratuberculosis in Ireland. This study examines the prevalence of factors that promote the introduction and within-herd transmission of Mycobacterium avium subspecies paratuberculosis (MAP) on selected Irish dairy farms in the Cork region, and the association between these factors and the results of MAP screening tests on milk sock filter residue (MFR). A total of 59 dairy farms, selected using non-random methods but apparently free of endemic paratuberculosis, were enrolled into the study. A questionnaire was used to collect data about risk factors for MAP introduction and transmission. The MFR was assessed on six occasions over 24 months for the presence of MAP, using culture and immunomagnetic separation prior to polymerase chain reaction (IMS-PCR). Furthermore, blood samples from all entire male and female animals over one year of age in 20 herds were tested by ELISA. Eighteen (31%) farms had operated as closed herds since 1994, 28 (47%) had purchased from multiple sources and 14 (24%) had either direct or indirect (progeny) contact with imported animals. Milk and colostrum were mixed on 51% of farms, while 88% of farms fed pooled milk. Thirty (51%) herds tested negative to MFR culture and IMS-PCR, 12 (20%) were MFR culture positive, 26 (44%) were IMS-PCR positive and seven (12%) were both culture and IMS-PCR positive. The probability of a positive MFR culture was significantly associated with reduced attendance at calving, and with increased use of individual calf pens and increased (but not significantly) if mulitiple suckling was practised. There was poor agreement between MFR culture and MFR IMS-PCR results, but moderate agreement between MFR culture and ELISA test results. This study highlights a lack of awareness among Irish dairy farmers about the effect of inadequate biosecurity on MAP introduction. Furthermore, within-herd transmission will be facilitated by traditional calf rearing and waste management practices. The findings of viable MAP in the presence of known transmission factors in non-clinically affected herds could be a prelude to long-term problems for the Irish cattle and agri-business generally.
365Scopus© Citations 22 - PublicationTuberculosis in alpaca (Lama pacos) on a farm in Ireland. 1. A clinical reportThis case report describes tuberculosis (TB) due to infection with Mycobacterium bovis (M. bovis) in alpaca (Lama pacos) on a farm in Ireland. Two severely debilitated alpaca were presented to the University Veterinary Hospital, University College Dublin in November 2004. Bloods were taken, and haematology and biochemistry results were indicative of chronic infection. Radiological examination showed evidence of diffuse granulomatous pneumonia suggestive of tuberculosis. On necropsy there were granulomatous lesions present throughout many body organs including lung, liver, kidney, intestine as well on peritoneum and mesentery. Culture of acid-fast bacilli from lesions led to a diagnosis of tuberculosis due to M. bovis. The use of intradermal skin testing proved inefficient and unreliable for ante mortem diagnosis of tuberculosis in alpaca. Infection due to M. bovis should be considered among the differential diagnoses of debilitating diseases in alpaca, particularly those farmed in areas known to be traditional black spots for tuberculosis in cattle.
686Scopus© Citations 26 - PublicationTuberculosis in alpaca (lama pacos) on a farm in ireland. 2. results of an epidemiological investigationTuberculosis (TB), due to infection with Mycobacterium bovis was diagnosed in a flock of alpaca in Ireland in 2004. An epidemiological investigation was conducted to identify the risk of TB for farmed alpaca where TB is endemic, the origin of the infection, the potential for alpaca-to-alpaca transmission and appropriate control measures. The investigation focused on the alpaca flock (including the farm, animal movements and breeding, feeding and flock health practice), the disease episode (including animal disease events and subsequent control measures) and TB infection risk in the locality. The TB risk to alpaca is high in areas where infection is endemic in cattle and badgers and where biosecurity is inadequate. It is most likely that the source of infection for the alpaca was a local strain of M. bovis, present in cattle in this area since at least 2001. Genotyping of isolates identified a single variable number tandem repeat (VNTR) profile in both cattle and alpaca in this region. Although a tuberculous badger was also removed from the vicinity, bacterial isolation was not attempted. On this farm, infection in alpaca was probably derived from a common source. Alpaca-to-alpaca transmission seems unlikely. Two broad control strategies were implemented, aimed at the rapid removal of infected (and potentially infectious) animals and the implementation of measures to limit transmission. Tests that proved useful in detecting potentially-infected animals included measurement of the albumin-to-globulin ratio and regular body condition scoring. Skin testing was time consuming and unproductive, and early detection of infected animals remains a challenge. The flock was managed as a series of separate groupings, based on perceived infection risk. No further TB cases have been detected.
430Scopus© Citations 12