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The development, implementation and evaluation of a real-time PCR-based diagnostic service for viral causes of infectious intestinal disease

Outbreaks and sporadic cases of viral Infectious Intestinal Disease (IID) are a major public health issue resulting in significant morbidity and sometimes mortality each year. The economic costs associated are substantial. Laboratory diagnosis of viral IID is important as the many infectious and non-infectious causes cannot be reliably differentiated using clinical or epidemiological characteristics alone. An accurate diagnosis can aid patient management, infection control procedures and reduce health care costs by preventing unnecessary treatments, testing for alternative causes and hospital stay. It also aids public health surveillance. At the start of the research described in this thesis the West of Scotland Specialist Virology Centre (WOSSVC) used Electron Microscopy (EM) as the frontline test for outbreaks and sporadic cases of IID. However, although rapid on a small number of samples, this technique has been shown to be insensitive, laborious and is not suited to testing large numbers of samples. The research presented in this thesis sought to examine whether molecular diagnostic techniques such as conventional gel-based or real-time Polymerase Chain Reaction (PCR) assays could be a viable replacement for EM as the frontline test(s) for viral IID in a routine laboratory service of this type, and whether their implementation could bring benefits to the laboratory service in terms of improved rapidity, sensitivity and throughput. The aim was to adapt published PCR methods for use in routine diagnostic work rather than for research purposes, an approach that distinguishes this research from previous work in this area. In order to achieve this aim, the appropriate PCR techniques were first selected from the literature, based on a combination of clinical and laboratory requirements, and were adapted for use in the laboratory service. A series of laboratory experiments was then carried out in order to compare the sensitivity of the adapted methods to existing techniques such as EM and antigen detection assays (EIAs) and to other methods that emerged during the period of study including alternative PCR assays. Where found to be suitable, the selected PCR tests were implemented in the routine diagnostic service for viral IID. The effects of these changes on the laboratory service were then examined. The results show that since the introduction of molecular tests at WOSSVC for the detection of viral pathogens in cases of gastroenteritis the number of samples tested has risen steadily, as have the detection rates for each of the main viral causes of IID. Furthermore, this has been achieved at the same time as a substantial reduction in sample turn-around-times. Such improvements will have a positive impact in several areas of public health relating to viral IID and are discussed fully, including patient management, infection control and national surveillance.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:495275
Date January 2008
CreatorsGunson, Rory N.
PublisherUniversity of Glasgow
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://theses.gla.ac.uk/108/

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