Emergency … Women with their children infected with dengue or chikungunya wait for medical assistance. The Honduran Medical Association suggested the government declare a state of emergency. AFP PHOTO / ORLANDO SIERRA Source: AFP
ONE by one the dominoes have fallen: India. Indonesia. Fiji. Australia is surrounded. It’s just a matter of time before a new and crippling virus establishes a bridgehead on our shores.
It’s called chikungunya (think ‘this chicken’s gunna gun ya down’ and you’ll have a good start point for the pronunciation).
It exploded out of Africa just 15 years ago. It has since swept through India, South-East Asia, Papua New Guinea and the Pacific Islands with its own, intense brand of fever, rash and crippling joint pain. It can linger for weeks. Maybe months. Sometimes longer.
“Chikungunya suddenly came out of nowhere,” says infectious disease expert Associate Professor Sanjaya Senanayake of the Australian National University.
“About 10 years ago we had this massive outbreak in the Indian Ocean on a number of small islands — Reunion, the Seychelles — then it moved to India where it caused more than a million cases.
“Everyone suddenly had to learn how to spell it and figure out what it was all about.”
It’s transmitted by mosquito. It doesn’t tend to kill people, but it does cause an intense fever and debilitating joint pains.
It’s why it is called what it is: Chikungunya translates roughly to “that which bends up”.
“You hear reports of whole villages being crippled, basically workforces coming to a stop for weeks because of a chikungunya outbreak,” Dr Senanayake says.
“It usually takes a couple of weeks for the arthritis to resolve, and in some people it can come back. It’s quite a nasty disease.”
The good news is people rarely get it twice.
Small but deadly … A lab technician studies mosquito larvae that carry the chikungunya virus. According to the Dominican health ministry, the mosquito-borne virus called Chikungunya has infected nearly 500,000 people in the country in its first 10 months. Source: AFP Source: Supplied
“With the Indian Ocean and Indian outbreak, it just swept through populations — hundreds of thousands or millions of cases in a short period of time. Very nasty,” Dr Senanayake says
And it’s not just an annoyance, like the flu.
Outbreaks have severe social and economic implications.
What happened at Reunion Island, a French outpost in the middle of the Indian Ocean, during the early stages of the virus’ march is a case in point: A third of the population — 250,000 people — were infected, bringing whole industries to a virtual standstill for months. Eventually it took 500 soldiers to drive the mosquitoes — and the disease they carried — back into the ocean.
In December 2013, the disease was first noticed in the Carribbean: Since then more than 1.3 million people have caught the disease.
“It could establish itself in Australia,” Dr Senanayake says. “But it hasn’t done so yet — thankfully. It’s something we have to watch out for.
“If the mosquitoes are there and you have a group of people who haven’t had it before, anything’s possible.”
Once established in Australia, the impact could be enormous.
Particularly vulnerable are blue-collar workers who use their hands a lot, and even white-collar workers who do a lot of typing. Such is the debilitating effect of the arthritis-like symptoms.
Chances of that happening are increasing exponentially as more places around the world get infected.
Primary carrier … The Aedes aegypti mosquito. Source: ThinkStock
New recruit … The Asian tiger mosquito (Aedes albopictus). Source: ThinkStock
So where is the disease at? Where is it headed?
It’s also in South America. It’s in Central America. It’s in the Caribbean.
It’s even starting to show up in Florida.
We haven’t seen many cases in Australia yet.
Dr Senanayake says the chikungunya cases we have seen are in travellers that have returned from infected regions and have been bitten by the mosquitoes there.
The mosquito is the key.
The main carrier had been the tropical Aedes aegypti mosquito. It’s a biter associated with transmitting dengue and Yellow Fever — and is found in far north Queensland and Cairns.
But it gets worse.
“Another reason for the big outbreak in recent times is that the virus mutated itself so that it could be carried and transmitted more efficiently by another mosquito — the Asian tiger mosquito (Aedes albopictus),” Mr Senanayake says. “That mosquito can travel long distances and has contributed to spreading the virus into the Caribbean. There’s even been local outbreaks in the US, around Florida and east of the Mississippi.”
The Asian tiger mosquito is not as fussy as A. aegypti. It doesn’t mind more temperate climates. Now well established in the Torres Strait Islands, this little nipper is just a hop, skip and buzz away from mainland Australia.
This presents a problem.
Once here, they have the potential to spread far — fast.
And while the A. aegypti mosquitoes in Queensland don’t yet have the virus, they are a ready-made highway for its spread once it arrives.
“If someone returns to your area with chikungunya in their blood and then one of your local mosquitoes bites them — then that mosquito fills up with virus,” Dr Senanayake says. “When that mosquito bites its next victim, it can transmit the virus to them.”
And so on. Eventually a local flare-up can occur.
The upshot: It’s simply a matter of time before Australia has an outbreak.
On the offensive … Pest control remains the only effective means of containing the chikungunya virus. Source: Getty Source: Supplied
How do we head-off the virus at the pass?
Short of stopping people travelling overseas and overseas travellers from visiting, there is no way of stopping the virus from landing on our shores.
Vaccination is one of the strongest options, Dr Senanayake says. There’s been some research into producing one, but it’s still very much in the early stages.
Are there treatments?
“Currently no. There is an antiviral agent which is pretty toxic and they’ve used in situations like SARS, but I don’t know if it’s really an option,” he says.
As the country warms, the particular brands of mosquito that carry the virus are already marching further south. It’s an effect already seen with dengue fever slowly expanding its reach.
On the front line are Queensland’s family doctors. They know what to look for. They can raise an alarm.
But there’s not a whole lot they can do for their patients.
Originally published as The crippling virus getting closer