Gias E.,Investigation and Diagnostic Center |
Johnston C.,Investigation and Diagnostic Center |
Keeling S.,Investigation and Diagnostic Center |
Spence R.P.,Investigation and Diagnostic Center |
Mcdonald W.L.,Investigation and Diagnostic Center
Journal of Fish Diseases | Year: 2011
Megalocytiviruses have been associated globally with severe systemic disease and economic loss in farmed food fish and ornamental fish. The viruses have been spread internationally by translocation of live fish. In New Zealand, megalocytiviruses are regarded as exotic. A potential pathway for introduction has been identified, namely imported ornamental fish. In the present study, real-time PCR assays were developed for detection of megalocytiviruses using a conserved major capsid protein gene. A SYBR green assay was developed to target all known megalocytiviruses. A second real-time PCR assay using a molecular beacon was developed to specifically target gourami, Trichogaster trichopterus, iridovirus, a species of iridovirus previously linked to ornamental fish imports in Australia. The analytical sensitivity for the SYBR green and molecular beacon assays were 10 and 100fg, respectively. The analytical specificity of the real-time PCR assays determined using genomic DNA templates from three target viruses, 12 non-target viruses and 25 aquatic bacterial species were 100%. The intra-run and inter-run coefficients of variation of both assays were <5%. The real-time PCR assays developed in this study provide rapid, sensitive, and specific detection of megalocytiviruses and gourami iridovirus. © 2011 Blackwell Publishing Ltd.
Lockhart C.Y.,Massey University |
Stevenson M.A.,Massey University |
Rawdon T.G.,Investigation and Diagnostic Center |
Gerber N.,Poultry Industry Association of New Zealand |
French N.P.,Massey University
Preventive Veterinary Medicine | Year: 2010
Members of the Poultry Industry Association and the Egg Producers Federation of New Zealand (n=420) were sent a questionnaire asking them to describe the type and frequency of on- and off-enterprise movements relating to feed, live birds and hatching eggs, table eggs and poultry product, and manure and waste litter. Social network analyses were used to describe patterns of contact among poultry enterprises and their associates for these four movement types. The response rate to the survey was 58% (244 out of 420). Network structures for enterprise-to-enterprise movements of feed, live birds and hatching eggs, and table egg and poultry product were characterised by 'hub and spoke' type structures with small-world characteristics. Small worlds were created by network hubs (e.g. feed suppliers and hatcheries) providing goods and services to larger numbers of client farms. In addition to hubs acting as the predominant source of material moving onto farms we identified enterprises acting as bridges between identified small worlds. The presence of these bridges is a concern, since their presence has the potential to facilitate the spread of hazards (e.g. feed contaminants, infectious agents carried within feed) more readily throughout the population. An ability to predict enterprises with these network characteristics on the basis of factors such as shed capacity, enterprise type, geographic location would be useful for developing risk-based approaches to disease prevention, surveillance, detection, response and control activities. © 2010 Elsevier B.V.
McFadden A.M.J.,Investigation and Diagnostic Center |
Heath D.D.,DNA Investments Ltd |
Morley C.M.,Investigation and Diagnostic Center |
Dorny P.,Institute of Tropical Medicine
Veterinary Parasitology | Year: 2011
The paper describes the epidemiological investigation carried out on two dairy farms with cattle infected with Taenia saginata cysts. On the first affected farm it was estimated using Bayesian techniques that approximately 65% of 1400 mixed-age cattle were infected with Taenia saginata cysts. The investigation aimed to determine potential exposure pathways of cattle to Taenia saginata with a view to finding the human source of infection and to describe the epidemiology of the outbreak on the affected farms. In order to determine potential exposure pathways, investigation was centred on how feed or water could have been contaminated with eggs. The plausibility of pathways was determined by examining the spatial and temporal association between factors related to the pathway and the prevalence of infection in cattle strata. We describe the investigation carried out on affected farms. © 2010 Elsevier B.V.
Hine P.M.,Investigation and Diagnostic Center |
Carnegie R.B.,Virginia Institute of Marine Science |
Kroeck M.A.,National University of Comahue |
Engelsma M.Y.,Central Veterinary Institute of Wageningen UR |
Burreson E.M.,Virginia Institute of Marine Science
Diseases of Aquatic Organisms | Year: 2014
The ultrastructure of Bonamia from Ostrea angasi from Australia, Crassostrea aria - kensis from the USA, O. puelchana from Argentina and O. edulis from Spain was compared with described Bonamia spp All appear conspecific with B. Exitiosa. The Bonamia sp from Chile had similarities to the type B. Exitiosa from New Zealand (NZ), but less so than the other forms recognized as B. Exitiosa. Two groups of ultrastructural features were identified; those associated with metabolism (mitochondrial profiles, lipid droplets and endoplasmic reticulum), and those associated with haplosporogenesis (Golgi, indentations in the nuclear surface, the putative trans-Golgi network, perinuclear granular material and haplosporosome-like bodies). Metabolic features were regarded as having little taxonomic value, and as the process of haplosporogenesis is not understood, only haplosporosome shape and size may be of taxonomic value. However, the uninucleate stages of spore-forming haplosporidians are poorly known and may be confused with Bonamia spp uni-nucleate stages. The many forms of NZ B. Exitiosa have not been observed in other hosts, which may indicate that it has a plastic life cycle. Although there are similarities between NZ B. Exitiosa and Chilean Bonamia in the development of a larger uni-nucleate stage and the occurrence of cylindrical confronting cisternae, the clarification of the identity of Chilean Bonamia must await molecular studies. © Inter-Research 2014.
Paine S.,Institute of Environmental Science and Research ESR |
Paine S.,Australian National University |
Mercer G.N.,Australian National University |
Kelly P.M.,Australian National University |
And 7 more authors.
Eurosurveillance | Year: 2010
The first wave of pandemic influenza A(H1N1) has subsided in New Zealand as in other southern hemisphere countries. This study aimed to estimate the effective reproduction number (R) of 2009 pandemic influenza A(H1N1) taking into account imported cases. It also aimed to show the temporal variation of R throughout the New Zealand epidemic, changes in age- and ethnicity-specific cumulative incidence, and the effect of school holidays. Using a new modelling method to account for imported cases, we have calculated the peak R during the containment phase of the pandemic as 1.55 (95% confidence interval: 1.16 to 1.86). This value is less than previously estimated in the country early in the pandemic but in line with more recent estimates in other parts of the world. Results also indicated an increase in the proportion of notifications among school-age children after the school holiday (3-19 July 2009). This finding provides support for the potential effectiveness of timely school closures, although such disruptive interventions need to be balanced against the severity of the pandemic.
Pande A.,Victoria University of Wellington |
Pande A.,Investigation and Diagnostic Center |
Gardner J.P.A.,Victoria University of Wellington
New Zealand Journal of Marine and Freshwater Research | Year: 2012
Kapiti Marine Reserve (KMR) was established in May 1992 following a single baseline biological survey. We surveyed macroalgal, macroinvertebrate and fish species for abundance and/or size at two sites inside and two outside KMR and then conducted reservation status (inside vs outside KMR) and temporal (1992 baseline vs 1999-2000) tests to quantify biological responses after 8 years of protection. Reservation status has had a significant effect on abundance or size for four fish species (banded wrasse, blue cod, butterfish, blue moki), but not for heavily fished macroinvertebrates (two species of paua, kina, rock lobster). Temporal analyses revealed only one significant difference (banded wrasse), but that is not attributable to the reserve. Despite low statistical power to detect change, the value of the baseline survey is highlighted by our ability to understand and interpret better the biological responses that we observed and to demonstrate conservation outcomes at KMR. © 2012 Copyright The Royal Society of New Zealand.
Holder P.,Plant Health and Environment Laboratory |
Disbury M.,Wellington Mail Center |
Singe M.,Southern Monitoring Services New Zealand BioSecure |
Kean J.M.,Agresearch Ltd. |
McFadden A.,Investigation and Diagnostic Center
Journal of Medical Entomology | Year: 2010
A biosecurity response was triggered by the detection of Aedes albopictus (Skuse) (Diptera: Culicidae) at the Port of Auckland, New Zealand, Ae. albopictus does not occur in New Zealand and is the most significant mosquito threat to this country, The possibility that a founding population had established, resulted in a large-scale biosecurity surveillance and control program. The response was initiated in early March 2007 and completed by mid-May 2007. No further exotic mosquitoes were detected, The response surveillance program consisted of larval habitat surveys and high density ovi- and light trapping. It was coordinated with a habitat modification and S-methoprene treatment control program, The response policies were guided by analysis of surveillance and quality assurance data, population modeling, and trace-back activities. Mosquito habitat and activity close to port were both more abundant than expected, particularly in storm water drain sumps, Sumps are difficult to treat, and during the response some modification was required to the surveillance program and the control regime. We were assured of the absence or eradication of any Ae. albopictus population, as a result of nil detection from surveillance, backed up by four overlapping rounds of insecticide treatment of habitat. This work highlights the importance of port surveillance and may serve as a guide for responses for future urban mosquito incursions. © 2010 Entomological Society of America.
PubMed | Investigation and Diagnostic Center
Type: Case Reports | Journal: New Zealand veterinary journal | Year: 2012
Poor reproductive performance was observed in 62 dairy heifers, with a pregnancy rate of 23% following 57 days mating with one 3-year-old and two 2-year old Belted Galloway bulls that were sourced from separate sheep and beef farms.The 3-year-old bull was small for its age with small testes. This bull was seropositive for bovine viral diarrhoea virus type I (BVDV 1) using an Ag-ELISA, and positive on PCR for border disease virus (BDV). DIAGNOSTIC INVESTIGATION: Phylogenetic analysis of the BDV isolate from the affected bull indicated that it was part of the BDV 1 group. For 40 of the heifers exposed to the bull that were tested, all of them had a positive VNT (virus neutralisation test) titre to both BDV (titre1:4) and BVDV 1 (titre>1:4). On the farm of origin of the affected bull there was no evidence of BDV circulating between cattle.Persistent infection of a bull with BDV.Cattle persistently infected with BDV can act as a source of virus for infection of other cattle. The benefit of testing cattle for bovine viral diarrhoea could be enhanced by using tests that also detect BDV.
PubMed | Investigation and Diagnostic Center
Type: Journal Article | Journal: New Zealand veterinary journal | Year: 2015
To develop rapid, quantitative PCR (qPCR) assays using high resolution melt (HRM) analysis and type-specific TaqMan assays for identifying the prevalent types of Theileria orientalis found in New Zealand cattle; and to evaluate their analytical and diagnostic characteristics compared with other assays for T. orientalis.Nucleotide sequences aligned with T. orientalis Buffeli, Chitose and Ikeda types, obtained from DNA extracted from blood samples from infected cattle, were used to design HRM and type-specific probe-based qPCR assays. The three type-specific assays were also incorporated into a single-tube multiplex qPCR assay. These assays were validated using DNA extracted from blood samples from cattle in herds with or without clinical signs of T. orientalis infection, other veterinary laboratory samples, as well as plasmids containing T. orientalis type-specific sequences. Diagnostic specificity (DSp) and sensitivity (DSe) estimates for the qPCR assays were compared to blood smear piroplasm results, and other PCR assays for T. orientalis. Copy number estimates of Ikeda DNA in blood were determined from cattle exhibiting anaemia using the Ikeda-specific qPCR assay.The T. orientalis type-specific and the HRM qPCR assays displayed 100% analytical specificity. The Ikeda-specific qPCR assay exhibited linearity (R(2)=0.997) with an efficiency of 94.3%. Intra-assay CV were 0.08 and inter-assay CV were 0.095. For blood samples from cows with signs of infection with T. orientalis, the DSp and DSe of the multiplex probe qPCR assay were 93 and 96%, respectively compared with blood smears, and 97 and 100%, respectively compared with conventional PCR assays. For the Ikeda-specific qPCR assay, the number of positive samples (n=66) was slightly higher than a conventional PCR assay (n=64). The concentration of Ikeda genomes in blood samples from 41 dairy cows with signs of infection with T. orientalis ranged between 5.610(4) and 3.310(6) genomes per L of blood.All qPCR assays had improved specificity and sensitivity over existing conventional PCR assays for diagnosis of T. orientalis Ikeda. The burden of Ikeda DNA in blood was demonstrated using an Ikeda-specific qPCR assay with titrated synthetic gene target.Adoption of high-throughput DNA extraction and qPCR reduced T. orientalis and Ikeda diagnosis times. The Ikeda-specific qPCR assay provides a specific diagnosis for Ikeda in animals with signs of infection with T. orientalis and can be used to monitor the parasite load of Ikeda in blood.
PubMed | Massey University, b Matamata Veterinary Services Ltd, c New Zealand Veterinary Pathology and Investigation and Diagnostic Center
Type: Journal Article | Journal: New Zealand veterinary journal | Year: 2016
On 9 January 2014 (Day 0) a mare from a stud farm in the Waikato region presented with urinary incontinence without pyrexia. Over the following 33 days 15 mares were clinically affected with neurological signs. All but one mare had a foal at foot. The most commonly observed clinical signs were hind limb paresis and ataxia. In some cases recumbency occurred very early in the course of disease and seven mares were subject to euthanasia for humane reasons.Equid herpesvirus (EHV) type 1 was detected using PCR in various tissues collected post mortem from two mares with neurological signs. DNA sequencing data from the DNA polymerase gene of the virus showed a nucleotide transition at position 2254, a mutation encoding amino acid D752 that is highly associated with the neuropathogenic genotype of EHV-1. In total 12/15 mares were confirmed positive for EHV-1 on PCR. Results from a virus neutralisation test and ELISA on paired serum samples, and PCR on whole blood and nasal swabs, indicated that of four paddocks in a high-risk area where a cluster of cases had occurred, 20/21 (95%) horses were likely to have been exposed or were confirmed infected with EHV-1. Subsequent to the outbreak two mares aborted, one at 9 months and one at 10 months of gestation. The cause of abortion was confirmed as EHV-1 with the same genotype as that involved in the outbreak.Equine herpesvirus myeloencephalopathy.The outbreak described shows the considerable impact that can occur in outbreaks of equine herpesvirus myeloencephalopathy in New Zealand. Early biosecurity controls not only reduced the effect on the farm but mitigated the potential for the virus to spread to other horse enterprises.