The molecular epidemiology of parasite infections: Tools and applications

Fish Health Unit, School of Veterinary and Biomedical Sciences, Murdoch University, Murdoch WA 6150, Australia.
Molecular and Biochemical Parasitology (Impact Factor: 2.24). 02/2012; 181(2):102-16. DOI: 10.1016/j.molbiopara.2011.10.006
Source: PubMed

ABSTRACT Molecular epidemiology, broadly defined, is the application of molecular genetic techniques to the dynamics of disease in a population. In this review, we briefly describe molecular and analytical tools available for molecular epidemiological studies and then provide an overview of how they can be applied to better understand parasitic disease. A range of new molecular tools have been developed in recent years, allowing for the direct examination of parasites from clinical or environmental samples, and providing access to relatively cheap, rapid, high throughput molecular assays. At the same time, new analytical approaches, in particular those derived from coalescent theory, have been developed to provide more robust estimates of evolutionary processes and demographic parameters from multilocus, genotypic data. To date, the primary application of molecular epidemiology has been to provide specific and sensitive identification of parasites and to resolve taxonomic issues, particularly at the species level and below. Population genetic studies have also been used to determine the extent of genetic diversity among populations of parasites and the degree to which this diversity is associated with different host cycles or epidemiologically important phenotypes. Many of these studies have also shed new light on transmission cycles of parasites, particularly the extent to which zoonotic transmission occurs, and on the prevalence and importance of mixed infections with different parasite species or intraspecific variants (polyparasitism). A major challenge, and one which is now being addressed by an increasing number of studies, is to find and utilize genetic markers for complex traits of epidemiological significance, such as drug resistance, zoonotic potential and virulence.

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Available from: Alan Lymbery, Feb 24, 2014
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    • "The simplified morphology entailed in the adoption of a parasitic way of life is one of the main reasons for the difficulties associated with carrying out exhaustive systematic appraisals of many parasite groups. This research field has benefitted significantly from the development of molecular tools which allow a more comprehensive evaluation of parasite diversity (McManus and Bowles, 1996; Lymbery and Thompson, 2012). Avian haemosporidians (Phylum Apicomplexa, Order Haemosporida ) are among those parasite groups whose study has greatly improved with the advent of molecular techniques. "
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    • "Though we provide evidence from repeat-sampled individuals that ANME01 in bellbirds is a chronic infection and theoretically places a premium on duration of infection and not high virulence (Frank 1996), other unknown diseases may be present. It has been shown experimentally that multiple infections, e.g., simultaneous infection of Haemoproteus and filarial nematodes, can lower a host's resistance compared to single infections of each sub-clinical disease on its own (Davidar and Morton 2006; Knowles et al. 2011; Lymbery and Thompson 2012). Mixed pigmented haemosporidian infections have been shown to have additive costs to body condition in birds compared to single infections (Marzal et al. 2008). "
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