CARDIFF, Wales- Researchers from Swansea University in Wales recently published a study that explains the process in which a fungus kills mosquito larvae, which may aid in the control of malaria, dengue and yellow fever.
Published December 13 in the research journal PLOS One, the report details how, when dispersed onto mosquito breeding grounds (namely shallow water sources), ingesting the fungus metarhizium anisoplia results in an “accidental death” for the mosquito.
“Normally what happens is the fungus attaches to its hosts, germinates and penetrates the body of the insect, colonizes the insect and in the process the insect dies,” said Professor Tariq Butt in an interview with BBC Radio Wales.
“But, in this case it doesn’t germinate it just stays as spores packed in the body, in the gut, of the insect where it causes stress, which activates a number of genes that trigger a whole range of responses leading to the death of the insect.”
While researchers initially hoped that the fungus would germinate and spread vertically from mosquito to mosquito, thereby causing an endemic, it appears that the fungus must be administered frequently to water sources.
The results foster hope that the arguably largest disease-spreading vector in the world may be controlled. As parasites, mosquitoes transmit several infectious and fatal diseases through their bites. Malaria, as perhaps the most notable of a mosquito’s repertoire of transmutable diseases, affected approximately 207 million people in 2012.
In the same year, the World Health Organization (WHO) reports malaria resulted in approximately 670,000 deaths, more than 90 percent of which occurred in Africa. Children residing in Africa comprise the majority of these deaths, with typically one child dying every minute from malaria. Sub-Saharan Africa, Asia and Latin America remain the greatest areas at risk, although parts of Europe and the Middle East are also affected.
Prevention techniques such as insecticide-treated malaria nets and vector control have helped several countries such as the United Arab Emirates, Morocco, Turkmenistan and Armenia to eradicate malaria in the past six years. However, reports of insecticide resistance hasten the need for a substitute method of limiting mosquito populations.
“In recent years, mosquito resistance to pyrethroids (a type of insecticide) has emerged in many countries,” states the WHO website. “In some areas, resistance to all four classes of insecticides used for public health has been detected.”
Despite these concerns and until improved methods of fungus distribution can be developed, insecticides remain the best and most efficient means for vector control in nearly all at-risk areas.
– Emily Bajet
Sources: BBC Entomology Today How Stuff Works
Photo: No Mosquito