Mosquitoes linked to acute onset of fever causes in Queensland

Published:09 May 2019

CQUniversity Professor Andrew Taylor-Robinson says mosquito-borne diseases such as Alfuy, Edge Hill, Kokoberra, Sindbis and Stratford viruses are possibly responsible for Undifferentiated Febrile Illnesses.

CQUniversity research has found that Australian arboviruses – including several lesser-known species - are the cause of a significant proportion of so-called Undifferentiated Febrile Illnesses (UFIs) in regional and rural Central and Northern Queensland.

Professor Andrew Taylor-Robinson, a medical microbiologist and researcher at CQUniversity, says mosquito-borne diseases such as Alfuy, Edge Hill, Kokoberra, Sindbis and Stratford viruses are possibly responsible for UFIs – defined as an acute onset of fever of more than 38 oC lasting for less than two weeks and for which no cause is found after a full medical history and thorough physical examination is conducted.

“Because these arboviruses have been ‘neglected’ or ‘under-researched’, they aren’t considered by health care services as an option for routine diagnostic testing,” Prof. Taylor-Robinson explains.

“While it has been thought for a long time that these viruses are capable of causing clinical manifestations in humans, how they are associated with UFIs has until now not been investigated.”

The research, titled Transmission cycles, evolution and emergence of Australian arboviruses, explores the common reservoir hosts on which mosquitoes native to Central Queensland feed, and has been conducted to safeguard against the possible epidemic emergence of Australian arboviruses.

“A diverse range of host animals including cattle, migratory birds and native mammals such as kangaroos and wallabies were found to provide a blood meal for mosquitoes,” Prof. Taylor-Robinson says.

“These host types are broadly similar to those recognised for their involvement in transmitting the arbovirus of greatest Australian public health interest: Ross River Virus (RRV).

“Most infections caused by these arboviruses are thought to produce mild flu-like symptoms or are entirely asymptomatic. Hence, the treating doctors presented with signs of a UFI may not consider a potential arboviral diagnosis.

“The study aims to increase awareness of the Australian medical community as to the potential public health threat, especially to rural communities, of native arboviruses other than RRV and Barmah Forest Virus (BFV).

“This may encourage health industry partners to invest in the development of further diagnostic tests, for which CQUniversity researcher expertise may be consulted.”

Prof. Taylor-Robinson says preliminary study outcomes have indicated that increased public awareness of the risk of Australian arboviruses is necessary.

“The major responsibility for implementing best-practice in prevention and control lies with Government (at local, state and federal levels) and policy makers, but all of which would act on accurate information provided by researchers such as us,” Prof. Taylor-Robinson says.

“Local council authorities and state governments should aim to increase awareness of the general public with regard to transmission of mosquito-borne infectious diseases. One part of the project has found a likely causal association between some of the 75 known Australian arboviruses and UFIs in patients in this country.”

Prof. Taylor-Robinson explains that the research has achieved a detailed profile of different species of mosquitoes commonly found in urban and semi-urban localities in an area representative of North Eastern Queensland.

“The mosquito mapping was undertaken in the coastal Capricornia region, in various locations within the local administrations of Livingstone Shire Council and Rockhampton Regional Council,” he says.

“The results shared with the vector control units of each of these local councils have assisted environmental health officers from Queensland Health to put in place an effective monitoring and management plan to combat potentially disease-carrying mosquitoes.”

Prof. Taylor-Robinson says a relatively high proportion of avian blood meals in the mosquitoes studied provided a rationale for focussing attention on wild birds as possible reservoir/amplifying hosts for Australian arboviruses.

“Further extensive studies are required to validate the trends observed to date.”

This research is funded by the Health Collaborative Research Network (CRN) and an endowment from the Cook Estate, administered through a research collaboration between the School of Health, Medical and Applied Sciences at CQUniversity and the Institute of Health and Biomedical Innovation at QUT.

The first part of this research has just been published in the journal Parasites & Vectors