Directory of
Higher degree by research students

Emily Johnston

Doctor of Philosophy

Health Sciences Divisional Office

Sch Pharmacy & Medical Sciences

Division of Health Sciences

Email: emily.johnston@mymail.unisa.edu.au


About me


I have taken a meandering route to my current position of PhD student. My undergraduate (bachelors) degree was in anthropology and psychology from the University of Buffalo, USA. I then spent a few years teaching outdoor education and travelling. During this time, my physical anthropology interest in primates intersected with my passion for ecology and I did an independent study investigating the impact of environmental degradation on the faecal parasite loads in monkeys in Costa Rica. That experience helped reignite my passion for research and I returned to school to conduct my masters degree at Michigan State University, USA. I investigated whether certain bird species could become infected with a tick-borne bacteria (Anaplasma phagocytophilum) and whether they could pass on that infection.

During my masters degree, I became more interested in the connections between human, animal and environmental health as we are increasingly realizing how interconnected they are (One Health). My current work as part of the Mosquitoes and Public Health Research Group explores how environmental factors (particularly human use of the environment) are impacting transmission of mosquito-borne infections in South Australia (which is, I might add, a wonderful place to live).

I am also passionate about improving public understanding and engagement with science through better science communication. I am the co-founder of Science in the Pub Adelaide (ScienceInThePubAdelaide.org.au) where, on the first Friday of each month (starting Spet. 5, 2014) at 6pm at the Brunswick Hotel, we organize a panel of 3 engaging, enthusiastic, knowledgeable scientists to explain their research and discuss the scientific topic with each other and the attendees over a Coopers Beer or a Barossa shiraz (or your beverage of choice). 

Teaching: I am currently a demonstrator for Physiology 100 and 101. 

Other: I really like running, eating, travelling, learning and my husband.


Thesis


Arboviruses in urban and peri-urban South Australia: an eco-spatial analysis

Broadly, my PhD research investigates how ecological factors relate to patterns of mosquito-borne virus (arbovirus) activity and human infection risk. I approach this question using a mixture of field, lab and computer modelling techniques. I hope that my research will give us insight into the factors driving mosquito-borne disease so that we can reduce or prevent human arbovirus infections.

Field work

My field work allows me to collect three main types of samples for my project: mosquitoes, viruses and blood-fed mosquitoes.

Mosquitoes: The first component of my field work is just to trap mosquitoes. I do so using CO2 and light as the attractant and a battery-powered fan to blow the mosquitoes into a container where they are trapped. I do this approximately every 2 weeks throughout the summer (Nov-May) at about 100 field sites, mostly centred around metropolitan Adelaide and the Riverlands regions. This allows me to compare the abundance and diversity of mosquitoes at the different field sites.

Virus: For Jan-April 2014, I adapted a technique developed by some colleagues in Queensland to sample the mosquitoes for infectious viruses (arboviruses) like Ross River virus. This technique takes cards, which are embedded with virus preserving chemical (FTA© cards) and coats them in honey. The mosquitoes feed on the honey and in the process, spit virus onto the card (if they are infected). Then I can later test the card to determine if any of the mosquitoes were infected with an arbovirus. My work is the first to adapt this honey-baited FTA© card technique to a broad-scale surveillance program.

Blood-fed mosquitoes: Throughout my field work, I have also been collecting any blood-fed mosquitoes (mosquitoes that have fed on an animal and have blood visible in their gut) so that I can find out what species the mosquito has been feeding on.

Lab work

I take my mosquito samples to our lab where I count and identify the species of mosquito under a microscope. For any blood-fed mosquitoes, I extract the DNA from the blood in the mosquito’s gut and then figure out what species it came from using PCR, gel electrophoresis and genetic sequencing.

Computer modelling

I will be using a combination of statistical modelling and Geographic Information System (GIS) spatial modelling techniques to analyse my data. I am accessing publicly available data to characterize the environments surrounding my traps. I am interested in factors like the biodiversity of animals, the density of human housing, the ratio of impermeable surface (e.g. pavement, roofs) to green space, socio-economic factors and land-use type because these may impact the prevalence of mosquito-borne diseases. I will work with this data in a computer program called ArcGIS© to see if I can connect the dots among mosquito species and abundances, environmental factors and virus abundance/human disease. 


Research publications


Johnston, E., et al. (2013). "Anaplasma phagocytophilum Infection in American Robins and Gray Catbirds: An Assessment of Reservoir Competence and Disease in Captive Wildlife." Journal of Medical Entomology 50(1): 163-170.

Johnston, E., et al. (2014). "Mosquito communities with trap height and urban-rural gradient in Adelaide, South Australia: implications for disease vector surveillance." Journal of Vector Ecology 39(1): 48-55.


Associations


Co-founder and organizer for Science in the Pub Adelaide (http://scienceinthepubadelaide.org.au/)


Collaborations:

South Australian Department of Health

Medical Entomology, Centre for Infectious Disease Microbiological Laboratory Services, Westmead Hospital

New York State Department of Health

University of Michigan

Professional Membership:

2012-present   Entomological Society of America

2012-present   Australian Entomological Society

2013-present   Field Naturalists Society of South Australia

2013-present   Royal Society of South Australia (student ambassador)

2014-present   Australian Science Communicators


Online resources


Science In The Pub Adelaide