The Impact of Diseases | Disease Ecology Explained

TL;DR

Disease ecology examines how wildlife, hosts, vectors, and ecosystem composition affect infections in humans. Angie Lewis explains that white-footed mice are the main reservoir for Lyme disease, while ticks transmit it; adding mammals such as chipmunks and possums can reduce the proportion of infected ticks. Because biodiversity does not affect every disease or ecosystem identically, read on to understand the key mechanisms and limits.

Transcript

hello and welcome to scishow talk show that day where we talk to interesting people about interesting stuff here on scishow today we're talking to angie lewis professor of wildlife biology at the university of montana hi angie how are you doing good uh so i would never i'll be honest have thought that your job existed you study wildlife biology yes... Read More

Key Insights

• 🧑‍⚕️ Wildlife biology and public health are connected as many diseases can be transmitted between animals and humans.
• 💋 Mosquitoes and ticks are important vectors for transmitting diseases from animals to humans.
• 🥺 Increasing biodiversity in an ecosystem can lead to a decrease in disease prevalence in certain cases, but the relationship between biodiversity and disease transmission is not consistent for all diseases.
• 🖐️ The diversity of immune genes, such as the major histocompatibility complex (MHC), plays a role in determining attraction between potential partners.
• 🥺 Biodiversity loss and human activities that contribute to it can lead to an increase in disease outbreaks due to changes in ecosystems and species interactions.
• 💋 Invasive species, such as the giant Indian stick insect, can have negative impacts on ecosystems and native species but do not pose health risks to humans.
• 😘 Stick insects reproduce asexually and sexually, and asexual reproduction can provide a backup strategy when the population is low or males are scarce.

Questions & Answers

Q: How does biodiversity affect disease transmission?

Higher biodiversity can reduce infection prevalence in some cases, but the effect is not universal and depends on the disease and ecosystem. For Lyme disease, having mammals such as chipmunks and possums alongside white-footed mice can leave fewer ticks infected and therefore reduce transmission to humans.

Q: What is the connection between wildlife biology and public health?

Wildlife biology and public health intersect because some infections spill over from animals to humans. Studying wildlife hosts, disease reservoirs, vectors, and ecosystem composition can help explain when human exposure becomes more likely.

Q: How is Lyme disease transmitted from wildlife to humans?

White-footed mice are the main reservoir that maintains the infection in nature. Ticks acquire the bacteria while feeding on infected mice and can later transmit the infection when they bite humans.

Q: What is a reservoir species in disease ecology?

A reservoir is the main population responsible for maintaining an infection as it spreads among members of that population. In the Lyme disease example, white-footed mice are the most important reservoir hosts, while ticks move the infection between hosts.

Q: Why can chipmunks and possums reduce Lyme disease prevalence?

White-footed mice are competent hosts that grow the Lyme disease bacteria well, so ticks feeding on them can become infected. Chipmunks and possums do not grow the bacteria as well, so ticks feeding on these animals are less likely to continue spreading the infection.

Q: Does greater biodiversity eliminate ticks or Lyme disease?

No. In the example discussed, plenty of ticks remain, but a smaller proportion of them carry Lyme disease because some feed on hosts that do not grow the bacteria well.

Q: What other diseases can pass from animals to humans?

The discussion names bird flu and Ebola as diseases associated with animal-to-human transmission. It also identifies mosquitoes as important vectors for spreading many harmful diseases.

Q: Are some infectious diseases maintained only in humans?

Yes. The cold and measles are given as examples that have circulated in humans for a very long time and for which animals are not important to current transmission.

Summary & Key Takeaways

• Angie Lewis, a wildlife biology professor, discusses the connection between wildlife biology and public health and how diseases are transmitted between animals and humans.

• Various diseases, such as Lyme disease, bird flu, and Ebola, can be transmitted from animals to humans. Mosquitoes and ticks serve as important vectors for many diseases.

• Increasing biodiversity in an ecosystem can help decrease the prevalence of certain diseases, but the relationship between biodiversity and disease transmission is not universal and depends on the disease and ecosystem.