Molecular epidemiology and geospatial analyses of Giardia intestinalis in humans in NSW, Australia

Publication Type:
Thesis
Issue Date:
2024
Full metadata record
Giardia intestinalis (also known as Giardia lamblia or Giardia duodenalis) is a protozoan parasite that causes communicable gastrointestinal disease and has received increasing attention due to its rising prevalence worldwide. The extent to which these risk factors are relevant in Australia is relatively unknown, however ongoing surveillance has seen G. intestinalis cases in humans more than double in the last 20 years. To further complicate matters, G. intestinalis has been molecularly categorised into eight genetically diverse assemblages, all of which have varying host specificities. Of particular importance are G. intestinalis assemblage A and assemblage B, which have been isolated from human and animal hosts worldwide. This study combined molecular epidemiological tools and geospatial analyses to describe and explore the distribution of G. intestinalis cases and assemblages A and B in NSW, Australia. Giardia intestinalis assemblages that were successfully genotyped were coded into data on SPSS software and incorporated into comprehensive epidemiological analyses. This combination of molecular epidemiology aimed to determine the distribution, sources of transmission and patterns of infection of G. intestinalis assemblages in the context of NSW, Australia. Interestingly, groupings of cases were observed in urban communities, and seasonal trends suggested that outdoor water activities played a larger role in transmitting G. intestinalis than previously suggested. A combination of geospatial tools was also applied to the data and identified ‘hotspots’ of cases in metropolitan Sydney. As infrastructure in Australia’s cities and regional centres continue to rapidly urbanise, it is more important than ever to continue surveillance on enteric protozoa such as G. intestinalis. Issues of overcrowding, waterborne-outbreaks and cases imported from overseas play a large role in the re-emergence and increasing trends of G. intestinalis infection in Australia.
Please use this identifier to cite or link to this item: