Graham F.F.,University of Otago |
Graham F.F.,Ministry of Health |
Harte D.J.G.,Kenepuru Science Center |
Baker M.G.,University of Otago |
And 2 more authors.
Epidemiology and Infection | Year: 2013
SUMMARY Between April and August 2005 Christchurch, New Zealand experienced an outbreak of Legionnaires' disease. There were 19 laboratory-confirmed case including three deaths. Legionella pneumophila serogroup 1 (Lpsg1) was identified as the causative agent for all cases. A case-control study indicated a geographical association between the cases but no specific common exposures. Rapid spatial epidemiological investigation confirmed the association and identified seven spatially significant case clusters. The clusters were all sourced in the same area and exhibited a clear anisotropic process (noticeable direction) revealing a plume effect consistent with aerosol dispersion from a prevailing southwesterly wind. Four out of five cases tested had indistinguishable allele profiles that also matched environmental isolates from a water cooling tower within the centre of the clusters. This tower was considered the most probable source for these clusters. The conclusion would suggest a maximum dispersal distance in this outbreak of 11.6 km. This work illustrated the value of geostatistical techniques for infectious disease epidemiology and for providing timely information during outbreak investigations. Copyright © Cambridge University Press 2012.
Cramp G.J.,Public Health Physician and Medical Officer of Health |
Harte D.,Kenepuru Science Center |
Douglas N.M.,University of Oxford |
Graham F.,University of Canterbury |
And 3 more authors.
Epidemiology and Infection | Year: 2010
Previous outbreaks of Pontiac fever have invariably been associated with water droplet spread of Legionella spp. In January 2007 three workers from a horticultural nursery were admitted to hospital with non-pneumonic legionellosis. Investigations showed that a working party of ten people had been exposed to aerosolized potting mix; nine of these workers met the case definition for Pontiac fever. The presence of genetically indistinguishable Legionella longbeachae serogroup 2 was demonstrated in clinical specimens from two hospitalized workers and in the potting mix to which they had been exposed. A further seven cases were diagnosed by serological tests. This is the first documented outbreak of Pontiac fever from L. longbeachae serogroup 2 confirmed from inhalation of potting mix. Pontiac fever is likely to be under-diagnosed. We advocate the introduction of an industry standard that ensures the use of face masks when handling potting mix and attaching masks and warning labels to potting mix bags sold to the public. Copyright © Cambridge University Press 2009.
Cornelius A.J.,Institute of Environmental Science and Research ESR |
Gilpin B.,Institute of Environmental Science and Research ESR |
Carter P.,Kenepuru Science Center |
Nicol C.,National Center for Biosecurity and Infectious Disease |
And 2 more authors.
Applied and Environmental Microbiology | Year: 2010
To overcome some of the deficiencies with current molecular typing schema for Campylobacter spp., we developed a prototype PCR binary typing (P-BIT) approach. We investigated the distribution of 68 gene targets in 58 Campylobacter jejuni strains, one Campylobacter lari strain, and two Campylobacter coli strains for this purpose. Gene targets were selected on the basis of distribution in multiple genomes or plasmids, and known or putative status as an epidemicity factor. Strains were examined with Penner serotyping, pulsed-field gel electrophoresis (PFGE; using Smal and KpnI enzymes), and multilocus sequence typing (MLST) approaches for comparison. P-BIT provided 100% typeability for strains and gave a diversity index of 98.5%, compared with 97.0% for SmaI PFGE, 99.4% for KpnI PFGE, 96.1% for MLST, and 92.8% for serotyping. Numerical analysis of the P-BIT data clearly distinguished strains of the three Campylobacter species examined and correlated somewhat with MLST clonal complex assignations and with previous classifications of "high" and "low" risk. We identified 18 gene targets that conferred the same level of discrimination as the 68 initially examined. We conclude that P-BIT is a useful approach for subtyping, offering advantages of speed, cost, and potential for strain risk ranking unavailable from current molecular typing schema for Campylobacter spp. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Lecomte M.M.J.,The Institute of Environmental Science and Research Ltd ESR |
Lecomte M.M.J.,University of Auckland |
Atkinson K.R.,The New Zealand Institute for Plant and Food Research Ltd |
Kay D.P.,Kenepuru Science Center |
And 2 more authors.
Skin Research and Technology | Year: 2013
Background: The use of biomarkers in skin is a novel diagnostic tool. Interstitial fluid (ISF) from skin provides a snapshot of proteins secreted at the time of sampling giving insights into the patient's health status. Methods: A minimally invasive technique for the transdermal collection of human ISF proteins. A low frequency ultrasonic skin permeation device (SonoPrep® ultrasonic skin permeation system) was used to produce micropores in the stratum corneum through which ISF was extracted using a portable pulsed vacuum ISF collection device. Results: On average, protein concentrations recovered ranged between 0.064 and 4.792 μg/μL (mean 1.258 μg/μL). Two-dimensional gel electrophoresis revealed that this sample type was amenable to this type of analysis. Gel images indicated that both highly abundant proteins and lower abundance proteins were isolated from the skin. Western blot analysis confirmed the presence of proteins commonly found in plasma and the epidermis. Conclusion: A minimally invasive method for the transdermal recovery of ISF proteins has been developed. We have demonstrated that ISF samples obtained using this approach can be analysed with proteomic techniques, such as two-dimensional gel electrophoresis and western blots, providing another tool for the identification of disease specific protein biomarkers. © 2012 John Wiley & Sons A/S.
Graham F.F.,University of Canterbury |
Graham F.F.,Environmental and Border Health |
White P.S.,Emergency Center for Transboundary Animal Diseases |
Harte D.J.G.,Kenepuru Science Center |
Kingham S.P.,University of Canterbury
Epidemiology and Infection | Year: 2012
This study evaluated the spatio-temporal variation of Legionella spp. in New Zealand using notification and laboratory surveillance data from 1979 to 2009 and analysed the epidemiological trends. To achieve this we focused on changing incidence rates and occurrence of different species over this time. We also examined whether demographic characteristics such as ethnicity may be related to incidence. The annual incidence rate for laboratory-proven cases was 2.5/100 000 and 1.4/100 000 for notified cases. Incidence was highest in the European population and showed large geographical variations between 21 District Health Boards. An important finding of this study is that the predominant Legionella species causing disease in New Zealand differs from that found in other developed countries, with about 30-50% of cases due to L. longbeachae and a similar percentage due to L. pneumophila for any given year. The environmental risk exposure was identified in 420 (52%) cases, of which 58% were attributed to contact with compost; travel was much less significant as a risk factor (6.5%). This suggests that legionellosis has a distinctive epidemiological pattern in New Zealand. © 2011 Cambridge University Press.
Langlet J.,Kenepuru Science Center |
Kaas L.,Kenepuru Science Center |
Greening G.,Kenepuru Science Center
Food and Environmental Virology | Year: 2015
Outbreaks of norovirus (NoV) gastroenteritis are often associated with consumption of shellfish contaminated with human NoVs. Strong non-specific binding and specific binding between NoVs and histo-blood group antigens (HBGAs) present in shellfish tissues may explain why depuration is ineffective. Recent studies on NoV-binding patterns in shellfish have examined the attachment of NoV virus-like particles (VLPs) to HBGAs present in shellfish using enzyme-linked immunosorbent assays (ELISAs). As NoVs are genetically diverse, it is not practical to produce a range of VLPs and specific antibodies for binding studies. Tank-based bioaccumulation experiments for binding studies also require laboratory space and time. The aim of this study was to develop an alternative method to determine binding patterns for a range of shellfish species and NoV genotypes without using VLPs, antibodies, or tanks. Pacific oysters, green-lipped mussels, two GI and four GII NoV genotypes were selected for assay development. Shellfish gut homogenates were coated onto microwell plates, then purified NoV suspensions were added to each well. Blocking and wash steps using similar reagents as used in ELISAs were carried out. RNA was extracted directly in each well, then RNA copies were quantified by RT-qPCR. Diluent buffer-coated wells spiked with NoVs were used as controls. Different binding patterns were observed. NoV binding was always higher with oysters than with mussels. The highest NoV binding was found with GI.3 and oysters, with 97 % NoV GI.3 bound to oyster homogenate compared with 5 % bound to mussel homogenate. GI.4 did not bind to mussels. © 2015, Springer Science+Business Media New York.
Jovanovic L.,University of Otago |
Delahunt B.,University of Otago |
McIver B.,Mayo Medical School |
Eberhardt N.L.,Mayo Medical School |
And 3 more authors.
Pathology | Year: 2010
Aims: This study was undertaken to investigate the genetic factors underlying the development of multifocality and phenotypic diversity in multifocal papillary thyroid carcinoma (mPTC). Methods: Loss of heterozygosity (LOH) and BRAFV600E mutation status were analysed in a total of 55 individual tumour foci from 18 cases of mPTC. The genetic findings and morphology of tumour foci were then compared. Results: Multifocal PTC LOH rates were higher than observed previously in solitary PTC. Different patterns of LOH and BRAFV600E positivity separated follicular variant tumours and tumour foci from other PTC histological subtypes. In five cases, genetic alterations were detected in morphologically normal thyroid epithelium. Conclusions: These findings support the concept that multifocal PTCs develop through clonal selection from a field of pre-neoplastic cells, with morphotype differentiation correlating with specific tumour-genetic alterations. The relatively high genetic disarray in multifocal PTC may underlie their ability to spread throughout the thyroid gland. © 2010 The Royal College of Pathologists of Australasia.