Annually, about 50 million Dengue cases are reported globally, out of which tropical countries are the most affected ones because of mosquitoes’ prevalence in those areas. Dengue bacteria is persistent in more than 100 countries globally, and 40% of the world’s population, which is about 3 billion people, live in dengue-prone areas.
However, Monash University’s study has come up with the most significant counter for the disease by introducing a strain of Wolbachia bacteria to prevent them from acting as carriers, contrary to the belief that we might end up developing a super anti-bacterial resistant pathogen. Before we get into those specifics, let’s understand how mosquitoes spread diseases.
How Mosquitoes Spread Disease
Mosquitoes act as carriers of viruses by biting infected people, and when they bite again, they can naturally transmit the virus to the next person. Mosquitoes don’t inherently carry viruses – they can only get them from other infected folks.
Since only female mosquitoes bite humans, while male feed on fruits, only female mosquitoes can transmit viruses. Only the female Aedes aegypti mosquito is the primary transmitter of dengue, Zika, chikungunya, and yellow fever viruses. These originated initially in Africa, but they have ended up spread through tropical and subtropical regions worldwide.
Aedes aegypti mosquitoes first grew outside Africa during the slave trade between the 15th and 19th centuries. They also spread through trade with Asia during the 18th and 19th centuries, following military advances during World War II.
Growing Number of Infected Humans
The number of humans affected by mosquito-borne diseases is rapidly growing over the years. In recent years, population growth, people from villages to cities, more international travel, and climate change have catered to the spread of Aedes aegypti mosquitoes in the world.
And due to it, the number of people affected by mosquito-borne diseases has also increased. According to the World Health Organization, dengue fever is now considered the most critical mosquito-borne viral disease globally. It’s also the most quickly spreading, with a 30-fold increase in global incidence over the past 50 years.
Wolbachia Bacteria Study From Monash University
Labelled as the World Mosquito Program, the Institute of Vector-Borne Disease with Monash University, Melbourne, has come together to tackle the diseases borne by mosquitoes. They chose Indonesia as its primary focus for the first round of their study.
Indonesia is one of the most severely hit countries from the dengue disease and encounters 8 million dengue cases each year. So, instead of killing all the mosquitoes in the world, the researchers thought of taking a somewhat different approach towards the problem.
Usage Of Wolbachia Bacteria
They decided to infect the mosquitos with a bacteria called ‘Wolbachia’ that would starve the virus to death, making these mosquitoes dengue free. Wolbachia reduces the ability of mosquitoes to transmit mosquito-borne diseases such as Zika, dengue, and chikungunya.
Simply after one round of infected mosquitoes, the bacteria would automatically be transferred to the mosquitoes’ offspring. So even if their offspring would have been likely to carry the virus, the bacteria will continue to do its work, leaving us dengue-free with a one-time effort. Evidence shows that in areas where Wolbachia is self-sustaining at a high level, there have been no dengue outbreaks.
Results of the Study
After three years of collecting and infecting dengue-carrying local mosquitoes, they were finally released back into the open in 12 areas of a city called Yogyakarta. After some wait, this experiment managed to eradicate the local transmission of dengue in the city.
Ever since the experimental mosquitoes have been released, the incidences of Dengue fever and symptoms decreased by 77%, significantly unique in terms of health improvement. Soon, they are looking to expand their horizons and move on to more at-risk countries to make them dengue free.