The impact of our research
The Aedes aegypti mosquito can infect humans with the potentially deadly dengue virus. This type of mosquito is so widespread that over half the global population is at risk of infection.
Our sophisticated mosquito laboratories are among the largest in the southern hemisphere and we collaborate with regional, national, and international networks to make advancements in dengue fever research.
QIMR Berghofer scientists have helped map the most complete genetic picture of the Aedes aegypti mosquito. Understanding how this mosquito efficiently transmits dengue can accelerate our search for better treatments.
In ground-breaking work, we’ve found that the Wolbachia bacteria prevent mosquitoes from becoming infected with dengue virus. Such a discovery means we can prevent mosquitoes from transmitting the virus to humans.
Dangerous mosquito-borne viruses are spreading through tropical and sub-tropical regions at an alarming rate. To combat this threat, we’re facilitating training workshops for Pacific Island nations and international institutions.
We’re developing new surveillance techniques to track mosquitoes’ movement and numbers, identify new invasions, and pinpoint where to implement control strategies.
About dengue fever
Dengue is a viral infection that’s transmitted to humans by infected female mosquitoes. It has been recorded in more than 130 countries.
There are four types of dengue viruses. Infection with one type gives lifelong immunity to that form. However, subsequent infection with different types can increase the risk of developing severe dengue.
Dengue fever is caused by the dengue virus, which is spread by infected mosquitoes, usually from the Aedes aegypti species.
Around 400 million people are infected with dengue fever each year, predominantly in the Asian tropics.
Symptoms typically develop 3–14 days after being bitten by a mosquito carrying the virus. These include:
- fever
- headache
- vomiting
- muscle and joint pains
- rash.
Most people have the virus for a few days and make a full recovery within weeks. However, a small percentage of cases result in internal haemorrhaging and even death.
Although the dengue virus is not normally present in Australia, outbreaks of the disease can occur in North Queensland. That’s because the Aedes aegypti mosquito can be found in some parts of far north and central Queensland.
Local infections occur when someone is infected with dengue overseas, returns with the infection in their blood, and is then bitten by a local Aedes aegypti mosquito. That mosquito can then spread dengue virus to others.
There is no cure for dengue, but people can take painkillers for muscle and joint pain. In severe cases, patients might need intravenous drips and transfusions to maintain their fluid volumes and replace lost blood or plasma.
A vaccine for dengue fever (Dengvaxia®) took 20 years to develop at a cost of more than $1.5 billion USD. Unfortunately, this vaccine has limitations – it is only 60% effective and can only be given to people between the ages of 9 and 45 who have previously been infected with dengue
Globally, dengue is best managed by controlling the mosquito that spreads the virus. Unfortunately, the Aedes aegypti mosquito is hard to control for a few reasons:
- The female mosquito, which transmits the virus, receives all its nutritional needs from human blood. As a result, it has become remarkably well-adapted to urban landscapes, where it can best access its food source.
- Aedes aegypti mosquitoes are so efficient at transmitting dengue that they can cause outbreaks even when mosquito numbers are low. This means control programs have largely failed to prevent epidemics or slow mosquitoes’ geographic expansion.
- Mosquitoes can become resistant to insecticides.
We desperately need to develop more efficient ways to control mosquitoes and prevent outbreaks.