Possible Eradication Of Dengue Mosquitos With The Help Of Emerging Water Contaminants (Article Sample)

Date: November 12, 2017Page Number: 5
By: Jaeger Dwayne G. TamaraySlug: EWCs
Suggested Heading: Eradication of Dengue Carrying Mosquitos: A Possibility or a Myth
Eradication of the Aedes Aegypti or commonly known as mosquitos has been a topic worth of researching for the past years. The main reason that scientists are in unison to find a way to eradicate this life form is because, according to Judith Yabut, a Pediatrician, it is the carrier of one of the most deadliest disease in the world, dengue. Scientists went as far as inventing insecticides to kill these insects to creating dengue vaccines to help humans defend themselves from this disease. But none of these can seem to stop insects from breeding and infecting disease. However, an emerging topic of study is currently showing signs of affecting the life cycle of mosquitos. These are called “Emerging Water Contaminants” (EWC).
Water bodies make up almost 71 percent of our earth’s surface and 3.5 percent of the water bodies is freshwater. According to an article in theguardain.com, as of 2011 out of the 8.7 million species residing earth, an approximated 2.2 million organisms live in the water. How does this relate to EWCs and mosquitos? Well EWCs are Emerging Contaminants that are found in water. Emerging contaminants are defined by Paraoan and Vidas, former biology students of University of the Philippines Baguio, in their undergraduate thesis, “Evaluating the Impact of Emerging Water Contaminants on the Life Stages of Aedes Aegypti L”, as “any synthetic or naturally occurring chemical or any microorganism that is not commonly included in the environment but has the potential to enter the environment and cause known or suspected adverse ecological and/or human health effects”. Apparently according to Mayer Calma, Biologist and Biology Instructor in the University of the Philippines Baguio, the study of EWCs are relatively new; therefore its ecological and human health effects are not yet fully understood and discovered.
1485900-25146000
In another note, these EWCs are commonly found in the freshwater such as rivers, lakes, and wetlands, which happens to be the place where mosquitos lay their eggs and grow into an adult mosquito. In Paraoan and Vidas’ 2013 study, they evaluated the impact of three EWCs: a. Erythromycin, which is an antibiotic, b. Naproxen, which is a pain reliever, and c. Propylparaben, which commonly comes in a form of cosmetic products such as hairstyling wax. How exactly does these contaminants end up in the freshwater?
According to Calma, “as we intake erythromycin and naproxen, we eventually release them through our urine and feces” the same goes with propylparaben “as we use them, we eventually wash them off when we bathe and these will all lead to the sewage”, which are all connected to the bodies of fresh water. Paraoan and Vidas, in their study, used these three EWCs to test if such contaminants have effects on the life cycle of mosquitos: a.) Eclosion or the hatching of mosquito’s egg, b.) Pupation or the process of mosquito to develop into pupa (a stage where the insect transform from immature to mature), c.) Emergence or the coming out of the mosquito from its pupa casing assuming into its adult form, and d.) Fecundity or the stage where the adult female mosquito will be laying its eggs.
First was the use of Erythromycin, a drug that belongs to the group of macrolide antibiotics. Macrolide drugs, according to doctor Yabut, are drugs “that slow the growth or sometimes kill bacteria by reducing the production of important proteins needed by the bacteria to survive”. In the study, exposing the eggs in 0.02mg/L, 12mg/L, and 24mg/L of erythromycin resulted in low success rate of eclosion, while 48mg/L of erythromycin resulted in 0 percent eclosion. Then afterwards exposing the surviving larvae in 0.02mg/L, 12mg/L, 24mg/L, 48mg/L, 96mg/L, 192mg/L, and 384mg/L resulted in an average of 58.05 percent pupation success rate. The third set up was getting the survived pupa and exposed them to 0.02mg/L, 12mg/L, 24mg/L, and 384 mg/L and resulted to an average of 78.61 emergence success rate. Finally surviving mosquitos were allowed to suck on male human blood and exposed them in 0.02 mg/L, 48mg/L, and 192mg/L and laid an average of 57.45 eggs.
As shown in the study of Paraoan and Vidas, surviving mosquitos from prior exposure to erythromycin are more likely to survive succeeding exposures to the contaminant. According to Mariel Lizbeth Agsaoay, Biology student in the University of the Philippines Baguio, explained that bacteria in organisms are somehow programmed to “develop resistance to antibiotics”.
Second was the use of Naproxen, a type of drug that functions as a “reliever of pain, fever, swelling, and stiffness”, Doctor Yabut explained. In the 2013 study of Paraoan and Vidas exposed the eggs in 0.02 mg/L, 41 mg/L, 82 mg/L, and 104 mg/L of naproxen garnered an average eclosion rate of 20.16 percent. Afterwards surviving larvae were exposed to 0.02 mg/L, 41 mg/L, 82 mg/L, 104 mg/L, 208 m...