Indonesian researchers from a non-profit World Mosquito Program (WMP) have come out with a solution to fight disease-bearing mosquitoes, which generally cause dengue.
Dengue is a disease that spreads rapidly due to bites by female Aedes aegypti mosquitoes. The mosquitoes breed in pools of fresh water, such as water stagnated in discarded tyres, air coolers, or uncovered pots, etc. Dengue continues to wreak havoc on a global level. As per the World Health Organization (WHO), the global dengue infections have been increasing at a rapid pace in this decade. About 100 to 400 million dengue infections are reported each year though over 80 per cent are mild and asymptomatic. The virus causes severe pain in muscles and bones. Over 1 lakh cases of Dengue have been reported in India itself. States like Haryana, Uttar Pradesh, Punjab, Kerala, Tamil Nadu, Rajasthan, Delhi, Uttarakhand, etc., have registered most of the cases. Some other diseases caused by mosquito bite are malaria, chikungunya, zika, yellow fever, etc.
For thousands of years, mosquito-borne diseases have been a great problem. Burkina Faso, a West-African country, has a long and hot season, followed by monsoon rains when mosquitoes emerge in large numbers. That’s why clinical trials wee started there to develop an effective vaccine by the University of Oxford and the Serum Institute of India. The vaccine, R21, has shown as efficacy of 77 per cent, and targets the ‘circumsporozoite’ protein (CSP) of plasmodium falciparum, the malarial parasite.
How to Fight Dengue
There are many methods to fight dengue, and one of them is the use of parasites. Wolbachia pipientis is a bacterium that is commonly found in many insects such as mosquitoes, fruit flies, moths, dragonflies, and butterflies but not found in the dengue-carrying mosquitoes. Therefore, if this is introduced into mosquito’s cells, where it fights against viruses that cause dengue, chikungunya, yellow fever, and zika.
The Study In December 2017, a joint study was conducted by the WMP at Australia’s Monash University and Gadjah Mada University, Indonesia. The researchers from the Gadjah Mada University placed clusters of lab-bred mosquito eggs, infected with Wolbachia in 12 localities in the Indonesian city of Yogyakarta. For this study, five million mosquito eggs infected with Wolbachia were placed in buckets of water in the city every two weeks. The researchers took nine months to build up their mosquito population. However, the study was halted in March 2020 due to the COVID-19 pandemic. Nevertheless, the study proved that those 12 localities had registered 77 per cent fewer cases of the dengue fever. Also, the intensity of the fever was less. There was an 86 per cent drop in the hospitalisation due to dengue.
The study was published by The New England Journal of Medicine in June 2021. The researchers have found that dengue disease-bearing mosquitoes can be fought by breeding a species of the insect, which carries a kind of bacteria that prevents virus like dengue from growing inside them. The researchers have labelled the mosquitoes as ‘good mosquitoes’ which mate with mosquitoes carrying Wolbachia, and in turn, hatch Wolbachia mosquitoes or the good mosquitoes. Now, even if these good mosquitoes bite humans, they would not cause any harm to them. The researchers are confident that this technique would definitely yield good results, particularly in areas where the Aedes aegypti mosquito is responsible for infection.
Dengue is a viral infection, caused by the bite of female Aedes aegypti mosquitoes or Ac. albopictus. The virus which causes dengue is called dengue virus (DENV), which is of four serotypes (groups within a single species). Dengue is found in tropical or sub-tropical climate. Severe dengue is a cause of serious illness or death in some Latin American and Asian countries.
© Spectrum Books Pvt Ltd.