Dr Michael Gaunt

Michael's work focuses on using evolutionary models to understand the molecular epidemiology or "microevolution" and "macroevolution" of the parasite Trypanosoma cruzi the causative agent of South American trypanosomiasis and its insect vector triatomine bugs.

Microevolution: T. cruzi is a zoonose and the genetic relationship, or "population structure", between sylvatic mammals and human reservoir hosts could have important public health implications.  Michael and colleagues have developed a population genomics method using "microsatellite" genetic markers that provides the most accurate typing tool available for T. cruzi. The application of this tool to field isolates demonstrates T. cruzi has a complex epidemiology. For example, some ecotopes show a close genetic association between sylvatic hosts (rodents) and humans but other ecotopes (opossums) show a mixture of close and distant genetic associations. The microsatellites panel identified multiclonal infections as being much more important than previously thought.

Macroevolution: His group's evolutionary studies on triatomine bugs have revealed the insect evolved blood-feeding behaviour once and this occurred exactly at the same time as the formation of South America. Finally, theoretical work on evolutionary models reveals that several commonly used assumptions (mutation matrices) may result in erroneous epidemiological inferences. Refining these models provides new epidemiological insights.