Disease Geography

Geographical and environmental patterns of disease

Neglected tropical parasite infections

Neglected tropical diseases are a diverse group of communicable diseases that commonly infect people in tropical and subtropical areas around the world. These diseases are often caused by pathogens that collectively infect more than one billion people around the world, costing many billions of dollars to public health systems. People that live in poverty and do not have adequate access to sanitation are commonly the worst affected. In recent years, the advent of geostatistical modelling approaches has helped to steer data-driven programmes that aim to understand how risk is distributed across the landscape and make more efficient decisions about where and when preventative treatments should be delivered.

SpatialEpiLab’s involvement

Seveeral members of our lab are involved in collaborative studies that aim to characterise the spatial distributions of neglected pathogens and identify associated risk factors. All of these projects use sophisticated geospatial analytical techniques to develop spatial predictive models that can serve as decision-support tools for identifying areas in need of preventative treatments.

Team members on the project

Ricardo Soares Magalhães
Nicholas Clark
Pandji Dhewantara
Adrea Araujo Navas
Philip Mshelbwala

Key collaborators

Rwanda Biomedical Center
Schistosomiasis Control Initiative
The END Fund
Colleen Lau (Australian National University)
Archie Clements (Curtin University)

Publications

Clark, NJ, Owada, K, Ruberanziza, E, Ortu, G, Umulisa, I, Bayisenge, UJB, Mbonigaba, JB Mucaca, Lancaster, W, Fenwick, A, Soares Magalhães, RJ and Mbituyumuremyi, A. 2020. Parasite associations predict infection risk: incorporating co-infections in predictive models for neglected tropical diseases. Parasites & Vectors 13:1-16.

Ruberanziza, E, Owada, K, Clark, NJ, Umulisa, I, Ortu, G, Lancaster, W, Munyaneza, T, Mbituyumuremyi, A, Bayisenge, U, Fenwick, A, and Soares Magalhães, RJ. 2019. Mapping soil-transmitted helminth parasite infection in Rwanda: estimating endemicity and identifying at-risk populations. Tropical Medicine and Infectious Disease 4:93.

Dhewantara, PW, Mamun, AA, Zhang, Wy, Yin, WW, Ding, F, Guo, D, Hu, W, and Soares Magalhães, RJ. 2018. Geographical and temporal distribution of the residual clusters of human leptospirosis in China, 2005–2016. Scientific Reports 8:16650.

Dhewantara, PW, Mamun, AA, Zhang, Wy, Yin, WW, Ding, F, Guo, D, Hu, W, Costa, F, Ko, AI, and Soares Magalhães, RJ. 2018. Epidemiological shift and geographical heterogeneity in the burden of leptospirosis in China. Infectious Diseases of Poverty 7:57.

Tick paralysis in Australian pets

Tick paralysis, caused by neurotoxins contained in the saliva of Ixodes paralysis ticks, is a life-threatening condition for dogs and cats requiring immediate medical attention. In Australia tick paralysis is a leading cause of emergency admissions, with tens of thousands of cases admitted to veterinary emergency services each year. While preventative treatments and avoidance of tick-prone areas during periods of heightened risk are effective reduction measures, surveillance systems are inadequate to provide timely information to clinicians and pet owners located in areas most at-risk.

Ixodes spp. in Australia

Ixodes holocyclus and I. cornuatus are endemic tick species responsible for the debilitating and often fatal condition in companion animals known as tick paralysis. Symptoms include loss of appetite, poor mobility and coordination, respiratory problems and death. Both of the causative tick species are distributed along Australia’s east coast and are associated with wet and humid habitats (see the figure below). Unfortunately, these distributions coincide with some of Australia’s most populous centres, meaning that many pets are at risk of tick paralysis each year.

Previous studies of tick paralysis risk in Australia have been hampered by poor case reporting, lack of high-resolution data and reliance on aggregated climate variables. Better surveillance systems are needed to help reduce the burden of tick-paralysis in Australian pets by capitalising on big data to anticipate areas that are likely to have cases in the future and to identify key environmental and/or social correlates. Such systems can also provide decision support tools to help local veterinary practices in high-risk zones by reminding them when to prioritise dissemination of preventative medicines and information packets to local pet owners.

SpatialEpiLab’s involvement

Our lab is involved in a large collaborative project, driven by a University of Queensland Early Career Researcher Grant to Dr Nicholas Clark, with overall objectives to:
1. Develop a forecast model for tick paralysis risk using an automated, unsupervised learning pipeline to quantify spatiotemporal variation in tick paralysis cases.
2. Host real-time paralysis tick risk maps on a secure online server to provide up-to-date information to relevant end users.

Team members on the project

Ricardo Soares Magalhães
Nicholas Clark

Key collaborators

GreenCross Veterinary Clinics
VetCompass Australia
Paul McGreevy (University of Sydney)