Publications by authors named "Angela K Todd"

4 Publications

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Rapid detection of human respiratory syncytial virus A and B by duplex real-time RT-PCR.

J Virol Methods 2021 08 10;294:114171. Epub 2021 May 10.

WHO Collaborating Centre for Reference and Research on Influenza, Victoria Infectious Diseases Reference Laboratory, Peter Doherty Institute for Infection and Immunity, Elizabeth Street, Melbourne, VIC, Australia. Electronic address:

Respiratory syncytial virus (RSV) is a common cause of acute respiratory disease worldwide, especially in young children. The World Health Organization (WHO) has initiated an RSV Surveillance Pilot program that aims to perform worldwide RSV surveillance, requiring the development of reliable and rapid molecular methods to detect and identify RSV. A duplex real-time RT-PCR assay developed for simultaneous detection of both A and B subtypes of RSV was included as part of this program. This duplex assay targeted a conserved region of the RSV polymerase gene and was validated for analytical sensitivity, specificity, reproducibility and clinical performance with a wide range of respiratory specimens. The assay was highly specific for RSV and did not react with non-RSV respiratory pathogens, including the SARS-CoV-2 virus.
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August 2021

Enterovirus 74 infection in children.

PLoS One 2013 2;8(10):e76492. Epub 2013 Oct 2.

Clinical Virology, The Institute of Environmental Science and Research, National Centre for Biosecurity and Infectious Disease, Wellington, New Zealand.

Enterovirus 74 (EV74) is a rarely detected viral infection of children. In 2010, EV74 was identified in New Zealand in a 2 year old child with acute flaccid paralysis (AFP) through routine polio AFP surveillance. A further three cases of EV74 were identified in children within six months. These cases are the first report of EV74 in New Zealand. In this study we describe the near complete genome sequence of four EV74 isolates from New Zealand, which shows only limited sequence identity in the non-structural proteins when compared to the other two known EV74 sequences. As is typical of enteroviruses multiple recombination events were evident, particularly in the P2 region and P3 regions. This is the first complete EV74 genome sequenced from a patient with acute flaccid paralysis.
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July 2014

Evaluation of rapid and simple techniques for the enrichment of viruses prior to metagenomic virus discovery.

J Virol Methods 2014 Jan 13;195:194-204. Epub 2013 Sep 13.

Institute of Environmental Science and Research, at the National Centre for Biosecurity & Infectious Disease, 66 Ward Street, Wallaceville, Upper Hutt 5018, New Zealand. Electronic address:

The discovery of new or divergent viruses using metagenomics and high-throughput sequencing has become more commonplace. The preparation of a sample is known to have an effect on the representation of virus sequences within the metagenomic dataset yet comparatively little attention has been given to this. Physical enrichment techniques are often applied to samples to increase the number of viral sequences and therefore enhance the probability of detection. With the exception of virus ecology studies, there is a paucity of information available to researchers on the type of sample preparation required for a viral metagenomic study that seeks to identify an aetiological virus in an animal or human diagnostic sample. A review of published virus discovery studies revealed the most commonly used enrichment methods, that were usually quick and simple to implement, namely low-speed centrifugation, filtration, nuclease-treatment (or combinations of these) which have been routinely used but often without justification. These were applied to a simple and well-characterised artificial sample composed of bacterial and human cells, as well as DNA (adenovirus) and RNA viruses (influenza A and human enterovirus), being either non-enveloped capsid or enveloped viruses. The effect of the enrichment method was assessed by both quantitative real-time PCR and metagenomic analysis that incorporated an amplification step. Reductions in the absolute quantities of bacteria and human cells were observed for each method as determined by qPCR, but the relative abundance of viral sequences in the metagenomic dataset remained largely unchanged. A 3-step method of centrifugation, filtration and nuclease-treatment showed the greatest increase in the proportion of viral sequences. This study provides a starting point for the selection of a purification method in future virus discovery studies, and highlights the need for more data to validate the effect of enrichment methods on different sample types, amplification, bioinformatics approaches and sequencing platforms. This study also highlights the potential risks that may attend selection of a virus enrichment method without any consideration for the sample type being investigated.
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January 2014

Detection and whole genome sequence analysis of an enterovirus 68 cluster.

Virol J 2013 Apr 2;10:103. Epub 2013 Apr 2.

Institute of Environmental Science and Research Limited, National Centre for Biosecurity and Infectious Disease, 66 Ward Street, Wallaceville, Upper Hutt 5018, New Zealand.

Background: Enteroviruses are a common cause of human disease and are associated with a wide range of clinical manifestations. Enterovirus 68 is rarely detected yet was reported in many countries in 2010. Here enterovirus 68 was identified for the first time in New Zealand in 2010 and was detected in a further fourteen specimens over a six month period.

Objectives: To genetically characterise enterovirus 68 specimens identified in New Zealand in 2010.

Study Design: The genome sequence of a New Zealand representative enterovirus 68 isolate was obtained. Ten clinical specimens were analysed by sequencing the VP1 region of the enterovirus 68 genome.

Results: Based on sequence analysis of the VP1 region and the full genome of one representative isolate, the New Zealand enterovirus 68 isolates clustered with contemporary enterovirus 68 viruses and do not show any clear distinguishing genetic diversity when compared to other strains. All fifteen specimens showed high similarity with enterovirus 68 by VP1 sequencing. The majority of New Zealand patients suffered from bronchiolitis, were less than two years of age and were of Pacific Island or Maori descent.

Conclusions: We document the rare occurrence of an enterovirus 68 cluster in New Zealand in 2010. These viruses shared similarity with other clusters of enterovirus 68 that occurred globally in 2010. A greater awareness in enterovirus 68 infection may help detect this virus with increased frequency and enable us to better understand the role this strain plays in disease and the reasons behind this global emergence in 2010.
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April 2013