Singapore, a country located in South-East Asia is well known for its high rise buildings and cleanliness. Many know it as a country where they can’t chew gum! But what many people might not know about the country, is its fight against Dengue Virus. The geographic location and climate of Singapore give it all suitable conditions for the mosquitoes to breed and as a result, the country has been in a fight with the deadly disease since a long time back.
One interesting thing to note here is how the country has chosen to deal with the disease. In a path-breaking method, Singapore is amongst those countries that are making use of special mosquitoes to keep Dengue at bay.
We know Dengue is a vector-borne disease and the female Aedes Aegypti mosquito acts as the vector of the deadly virus. It picks up the virus from some infected person and when it bites someone else who is not infected, the disease gets transmitted. But with the unique approach adopted by Singapore, this whole process can be altered. This method is called the Biological Vectors and makes use of special mosquitoes that are infected with Wolbachia bacteria.
What is Wolbachia Bacteria and how it is useful to fight Dengue?
The Wolbachia Bacteria is found in almost 60% of insects like mosquitoes, fruit flies, and dragonflies. This bacteria lives in the cells of the insects and gets transmitted from one generation to another. Studies have found out that when Aedes mosquito, responsible for Dengue, carries this bacteria, then it becomes difficult for viruses like Dengue and Zika to reproduce within the mosquito. And thus the transmission ability of the insect drops down. Also, it has been found that the bacteria is safe for humans, animals, and the environment.
So, in experiments, it has been seen that when the male Aedes mosquitoes are infected with Wolbachia Bacteria, they do not bite humans. And when they are released to breed with the female mosquitoes, the resultant eggs do not hatch. This means the number of mosquitoes that cause Dengue and even Zika gets reduced. Also, in the other case, if a female mosquito has been infected with the bacteria and it breeds with a male mosquito, the resultant eggs do hatch, but they also carry the Wolbachia Bacteria. Therefore, the next generation of mosquitoes also becomes less competent in transmitting the disease
As a result over the years, the number of Dengue carrying vectors can be expected to reduce significantly and the disease can be controlled.
According to WHO, the disease has spread alarmingly from just nine countries in 1970 to more than a hundred today and most of them are in Asia or Latin America. Therefore as this experiment looks promising, many other countries have signed for it. This list includes Brazil, Indonesia, Columbia, and many more.
The whole process wherein male mosquitoes are infected with Wolbachia bacteria is quite costly as it requires sorting of male mosquitoes from the female, but is more effective as it directly suppresses the number of dengue-carrying diseases. It has been in use in Singapore and China since a very long time.
Just like the Corona Virus, we have still not found any drug or vaccine to cure Dengue and as a result, it becomes deadly. Moreover, the situation gets tense this year as now they have to deal with the COVID pandemic as well. Where on one hand, every country is working towards making its hospitals
ready for COVID patients, on the other hand, they might not be able to pay much attention to other patients.
In Singapore people have already seen the wrath of the Dengue virus back in 2013-2014 when the cases went up to more than 40,000. Back in 2019, the country reported more than 14,000 cases of dengue. Therefore, in this scenario, a method as unique as the “Biological Vector” can be extremely helpful in dealing with diseases like Dengue while the doctors fight Covid-19.