How Humans Are Changing the Disease Cycle

This podcast episode explores the relationships between people, mosquitoes, and disease. To find out more, I talked with JR McMillan and Amanda Vicente, Emory doctoral students who do research in this area. Through our conversations, I realized that the disease cycle is complicated…and humans are making it even more complicated…

Tape Log of Sound Bites

TRT (2:35)

JR McMillan 

Emory Doctoral Student (:29)

Amanda Vicente

Emory Doctoral Student (1:00)

JR McMillan

Emory Doctoral Student (1:31)

Amanda Vicente

Emory Doctoral Student (1:58)

Transcript

NAT SOUND (:04)

REPORTER VOICER (:25)

Summer is coming, and so are mosquitoes. But what happens when an itchy annoyance turns deadly? Mosquitoes can carry diseases like malaria, which infects two-hundred sixteen million people each year according to the W-H-O. JR McMillan (JAY-are MICK-mill-in), an Emory doctoral student, explains how humans accidentally spread mosquito-borne diseases.

SOUND BITE OR ACTUALITY (:14)

JR McMillan

Emory Doctoral Student

When Columbus first started, discovered America, and so ships started coming in and out of the New World for fur trade, slave trade, all those types of things, part of what came with them were disease vectors, including mosquitoes.

REPORTER VOICER (:17)

In nature, organisms develop patterns of disease transmission. Deforestation and other human activities interrupt this cycle. Amanda Vicente (Vee-chen-tay), a doctoral student at Emory University, studies how dengue (deng-ay) virus is transmitted between mosquitoes, animals, and people.

SOUND BITE OR ACTUALITY (:14) 

Amanda Vicente 

Emory Doctoral Student

As humans start to get into the forest, they start getting into contact with mosquitoes in the forest, so as humans get into this cycle they get infected, they became a good host.

REPORTER VOICER (:13)

This is not just a problem in the rainforest. Even suburban development impacts disease cycles. For example, some types of mosquitoes breed in still water, in reservoirs called “Catch-water basins.” McMillan says these water puddles are commonly found in areas of human activity.

SOUND BITE OR ACTUALITY (:18)

JR McMillan

Emory Doctoral Student

Go walk around campus. How many catch-basin type things are there, these stormwater management things, they’re everywhere, it’s like they’re an essential part of human development, especially urbanization. It inadvertently creates a really good space for mosquitoes to breed. 

REPORTER VOICER (:09)

But disease is not just spread by mosquitoes: it is also spread by people. And Vicente says people can give disease to other animals. 

SOUND BITE OR ACTUALITY (:21) 

Amanda Vicente 

Emory Doctoral Student

We are spilling back the diseases that we have, back to nature. In the near tropics also, howler monkeys have been highly infected by the yellow fever that was brought by the man. And it’s not, yellow fever is not endemic from the near tropics from America, it was brought by the humans.

REPORTER CLOSING (:15)

Human development can accidentally encourage the breeding of mosquitoes and the viruses they carry. Summer is coming, and so are mosquitoes. Time to go get some bug spray. This is Deanna Altomara reporting from Emory University. 

Sources:

Fact Sheet about Malaria. World Health Organization, Nov. 2017, http://www.who.int/mediacentre/factsheets/fs094/en/.

Judy, Nick. “Mosquito Sound Effects.” YouTube, 26 Sept. 2015, http://www.youtube.com/watch?v=ZMoHkvUrga0.

McMillan, JR, and Deanna Altomara. “Humans and Mosquitoes.” 2 Mar. 2017.

Vicente, Amanda, and Deanna Altomara. “The Disease Cycle.” 27 Mar. 2018.