Australian tool predicts how dengue will spread globally

Researchers at CSIRO, Australia’s national science agency, the Queensland University of Technology (QUT) and Queensland Health have developed a new tool to predict the global spread of human infectious diseases, like dengue, and track them to their source.

The tool draws on travel data from the International Air Transportation Association and dengue incidence rates from the Global Health Data Exchange to derive new insights about the spreading dynamics of dengue, a mosquito-borne disease.

Dr Jess Liebig, postdoctoral fellow at CSIRO’s data science arm Data61, said international travel significantly contributes to the rapid spread of dengue from endemic to non-endemic countries.

“According to the World Health Organisation, around half the world’s population is at risk of contracting dengue,” Dr Liebig said.

“By understanding the travel behaviour of infected individuals, we can estimate the number of infections that are imported into different countries each month.

“The tool also determines the infections’ country of origin and is able to uncover the routes along which dengue is most likely spread.”

The World Health Organisation says that there has been an increase in cases in 2019. In the Western Pacific region, increase in cases have been observed in Australia, Cambodia, China, Laos, Malaysia, Philippines, Singapore, and Vietnam. Bangladesh, Nepal, Sri Lanka, Thailand, and parts of India have also recorded increases in dengue cases in Southeast Asia.

In non-endemic countries such as Australia, local outbreaks are triggered by individuals who acquire the disease overseas and transmit the virus to local mosquitoes, CSIRO said.

Professor Raja Jurdak, QUT, said that in many locations, infected individuals are not diagnosed, and dengue can be under-reported to health authorities, making it challenging to monitor risk and prevent the spread of infection.

“According to recent studies, around 92% of symptomatic infections are not reported to health authorities mainly due to low awareness levels and misdiagnosis,” Professor Jurdak said.

“Our tool is one of the first to be able to forecast the absolute number of dengue importations, rather than the relative risk, at a global level.”

“This provides a useful tool to assist public health authorities with dengue preparedness,” Dr Cassie Jansen, Researcher at Queensland Health said.

“It can also help authorities to identify those locations where new dengue outbreaks may occur, following the arrival of infected passengers.”

The tool can be applied to other vector-borne diseases of global concern such as malaria, zika and chikungunya.
It expands on previous work which modelled how dengue infections from overseas might spread in Australia.

The research is part of the Disease Networks and Mobility (DiNeMo) project aimed at developing a real-time alert and surveillance system for human infectious diseases. DiNeMo combines CSIRO’s expertise in health and biosecurity with the deep technology capabilities of its data science arm, Data61.

The model was recently published in PLOS ONE and can be downloaded at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0225193