INFORMATIVE SPEECH
Mosquitoes
“When it comes to killing, no other animal comes close” (Gates “The Deadliest”). Mosquitoes are the deadliest creature on the planet. Surprisingly, mosquitoes that transmit diseases like malaria kill more people in one day than sharks have in 100 years! (Paynter). More than half a million people are killed by mosquito-borne diseases every year. Over half of the world’s population is threatened.
What is a mosquito? A mosquito is a small insect that bites and feeds on the blood of humans and animals. Male mosquitoes feed on fruit and plant nectar, as do female mosquitoes, however, female mosquitoes require protein in blood to help their eggs develop. Because of this need for protein, female mosquito bites are responsible for the transmission of mosquito-borne diseases.
There are more than 3,500 species of mosquitoes, however, only three are responsible for the transmission of human diseases. According to National Geographic, “Anopheles mosquitoes are the only species known to carry malaria. And Aedes mosquitoes, of which the voracious Asian tiger mosquito is a member, carry yellow fever, dengue, encephalitis, and west nile fever ” (“Mosquitoes”).
What are the major diseases spread by mosquitoes? “The major diseases spread by mosquitoes are yellow fever, malaria, dengue fever, and Zika” (“Mosquito-Borne Diseases”).
Yellow fever, common in tropical and subtropical Africa and South America, kills 30,000 people every year. According to the CDC, “people infected with the yellow fever virus can transmit the disease to mosquitoes shortly before the onset of fever and up to 5 days after onset” (“Yellow Fever”). In Andrew Spielman and Michael D’Antonio’s book, Mosquito A Natural History of our most Persistent and Deadly Foe, they describe the experience of an affected individual:
“Yellow fever caused panic, and if you consider what it does to the human body you can understand why. The illness begins with fevers, chills, and muscle pain so intense it can feel as if a leg or an arm has been broken in two. Blinding headaches and stabbing pains in the eyes are common. The liver fails. The skin turns yellow. The eyes become red.
Blood begins to ooze from the mouth and the nose. Internal hemorrhaging spills blood into the stomach, and this causes a telltale black vomit. Once this occurs, death follows in a matter of days” (58).
Yellow fever can be treated with a vaccine, but the vaccine is not widely available in impoverished regions.
When people think of mosquito-borne illness, most often malaria comes to mind. Malaria is most common in Africa, South America, Southeast India and the Western Pacific. Its origins can be traced back to ancient times. Once the malaria plasmodium has been transmitted by a mosquito bite it multiplies in the infected person’s liver, then proceeds to infect red blood cells (McMichael). Symptoms of malaria are chills, fever, fatigue, sweating, shivering, nausea, vomiting, convulsions, and coma. When untreated it can be life-threatening. Around 435,000 people are killed by malaria every year (“Mosquitoes”).
Bill Gates has developed a keen interest in mosquito-borne illnesses, and is donating a large amount of money to fund research and raise awareness about the dangers that mosquitoes pose to global health. Starting in 2014, Gates began hosting annual conferences to address the threat he believes mosquitoes pose. He spoke to a survivor of malaria, who shared this story:
“I awoke to what felt like lightning going through my legs, and then spreading through
my body and in my head. Probably the worst headache, body aches, and chills you could
possibly imagine. It felt like I was being stung repeatedly by an electric shock gun and
could barely control my movements. The pain was so intense; I actually believed that I
was dying, literally crying out in pain so bad that I was taken to a 24 hour clinic that night
at 3AM (Gates “What it feels like”).”
Another debilitating mosquito-borne illness, dengue, has a huge impact on global health annually. According to the CDC, each year up to 400 million people are infected (“About Dengue”). Around 25,000 people are killed by dengue fever every year. Dengue fever is most common in Southeast Asia and the western Pacific islands, but the disease has been increasing rapidly in Latin America and the Caribbean (“Dengue Fever”). The symptoms of dengue fever are bleeding, arthralgia, and fever. Humans can not directly infect each other, but they can infect mosquitoes, which pass the virus on to both their female offspring and to human victims. Severe dengue can be life-threatening, in the case of dengue hemorrhagic fever which “may progress to massive bleeding, shock, and death” (Ratini).
Zika is most common in Africa, Southeast Asia, the Pacific Islands, and South America. Many areas in the US also harbor the type of mosquitoes that can spread the Zika virus, though most cases come from residents traveling outside the country. The symptoms of zika are rash, itching, fever, headache, joint pain, conjunctivitis, and birth defects for fetuses in pregnant women. The most serious birth defect that can result from a Zika infection is microcephaly in which a baby’s brain does not develop properly during pregnancy or stops growing after birth (“Zika Virus”).
Mosquitoes are clearly a formidable threat to human health. The number of people affected by mosquito-borne diseases is increasing at an alarming rate. In warmer and wetter weather conditions the possibility that their range will spread and their ability to transmit infections to previously unaffected areas will increase. In order to address the threat of diseases spread by mosquitoes, it is important to educate the public about the dangers they pose to global health.
Bibliography
“About Dengue: What You Need to Know.” Centers for Disease Control and Prevention,
Centers for Disease Control and Prevention, 3 May 2019,
www.cdc.gov/dengue/about/index.html.
This article summarizes important information about Dengue virus from the CDC. This supports my thesis by providing information about the threat of Dengue virus.
“Dengue Fever.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 16 Feb.
2018, www.mayoclinic.org/diseases-conditions/dengue-fever/symptoms-causes/
syc-20353078.
This article provides information about dengue fever and its symptoms. This article also describes how dengue fever is spread.
Gates, Bill. “The Deadliest Animal in the World.” Gatesnotes.com, 25 Apr. 2014,
www.gatesnotes.com/Health/Most-Lethal-Animal-Mosquito-Week.
This article provides information about how deadly mosquitoes are. The article also describes where mosquitoes can be found.
Gates, Bill. “What It Feels Like to Have Malaria.” Gatesnotes.com, 25 Apr. 2014,
www.gatesnotes.com/Health/What-Malaria-Feels-Like-Mosquito-Week.
This article provides an account of a person’s experience with Malaria. This article supports my thesis because it provides a real-life example of the effects of malaria.
“Global Health - Newsroom - Yellow Fever.” Centers for Disease Control and Prevention,
Centers for Disease Control and Prevention, 14 Sep. 2018,
www.cdc.gov/globalhealth/newsroom/topics/yellowfever/index.html.
This article describes the impact of yellow fever and who is at risk. This article supports my speech because it provides statistics on yellow fever.
McMichael, A. J., et al. Climate Change and the Health of Nations: Famines, Fevers, and the
Fate of Populations. Oxford UP, 2019.
This book provides information on how malaria spreads once it enters the body. This book supports my speech because it provides information on how malaria spreads.
“Mosquito-Borne Diseases.” Baylor College of Medicine, Baylor College of Medicine,
www.bcm.edu/departments/molecular-virology-and-microbiology/emerging-infections-a
nd-biodefense/mosquitoes.
This article provides information on the major diseases spread by mosquitoes. This article supports my thesis because it provides information to back my claims about the major diseases spread by mosquitoes.
“Mosquitoes.” National Geographic, National Geographic, 24 Sep. 2018,
www.nationalgeographic.com/animals/invertebrates/group/mosquitoes/.
This article provides information about the impact of mosquitoes. This article supports my thesis because it provides information on what kinds of mosquitoes spread what diseases.
Paynter, Ben. “Bill Gates Isn't Scared of Sharks, but He Wants Nothing to Do with Mosquitoes.”
Fast Company, Fast Company, 16 Apr. 2019, www.fastcompany.com/90335810/bill-gates
-isnt-scared-of-sharks-but-he-wants-nothing-to-do-with-mosquitoes.
This article explains the difficulties in combating the threat of mosquitoes. This article supports my speech by describing how mosquitoes are the deadliest creatures in the world.
Ratini, Melinda. “Dengue Fever: Symptoms, Causes, and Treatments.” WebMD, WebMD, 28
June 2019, www.webmd.com/a-to-z-guides/dengue-fever-reference.
This article describes information about the spread and impact of dengue fever. This article supports my thesis because it provides information about the symptoms and treatments of dengue fever.
Spielman, A., and Michael D'Antonio. Mosquito: a Natural History of Our Most Persistent and
Deadly Foe. Hyperion, 2001.
This book describes the history of mosquitoes and their impact on history. This book supports my thesis because it demonstrates the continued impact of diseases.
“Zika Virus.” Centers for Disease Control and Prevention, Centers for Disease Control and
Prevention, 4 Jun. 2019, www.cdc.gov/zika/index.html.
This article describes the symptoms and effects of Zika virus. This article supports my thesis because it describes the risk of Zika in the developing world.