Australia's frontline defence against chikungunya
While the unusual outbreak of the mosquito-borne chikungunya virus in southern China raises the prospect of more widespread transmission, scientific research has provided Australia with a special biological line of defence.
Most common in South-East Asia and parts of Africa, more than 8,000 cases of chikungunya have been recorded in China’s Guangdong Province since the outbreak was detected in late July.
Transmitted by the Aedes aegypti mosquito, the virus can cause joint pain, swelling, stiffness and nausea and is most serious for newborns, the elderly or people with diabetes or high blood pressure.
Many chikungunya cases result in chronic disease lasting for months or years.
In Australia, Aedes aegypti is specifically found in northern Queensland, but the prospect of an outbreak of chikungunya there is obviated by a longstanding program focused on Wolbachia, a naturally occurring bacteria that interferes with the mosquito’s ability to transmit viruses.
“The World Mosquito Program has been working up in northern Queensland for more than 10 years now using Wolbachia, which they introduce into Aedes aegypti and it essentially creates an antiviral environment within that mosquito,” Dr Johanna Fraser, Head of Burnet’s Arbovirology working group, said.
“There’s been no local transmission that we know of, but there's so many different mosquito species in Australia it is possible that there could be another species that's able to transmit chikungunya that we don't know about yet.”
Dr Fraser said the chikungunya outbreak in China is consistent with statistics showing an exponential increase in virus incidence and the emergence of new viruses in places where they’re not typically seen.
“These outbreaks are occurring so frequently that forefront in my mind is that our changing climate and increasing extreme weather events are really driving these real events that we're seeing,” she said.
Dr Fraser said the lessons from chikungunya are much the same as the lessons from the emergence of Japanese encephalitis virus on mainland Australia in recent years.
“The lesson is that we're vulnerable,” she said.
“We live in a very globalised society now, which means that if a person has been in an endemic area or a region that was experiencing an outbreak, and they travel to Australia or anywhere in our region, and they happen to be bitten by a mosquito that is also able to transmit that virus, then there's a potential to spark a new outbreak.”
Find out more about Burnet’s Arbovirology research.
