Last actual lecture of the term!

We’ve learned a lot and had some fun

Zoonotic disease

• We’ve talked about zoonoses before (Lyme disease in the last lecture, Ebola, avian flu, trichinosis, etc.)

• zoonosis a pathogen that can be transmitted into humans through animals

• reverse zoonosis a pathogen that is transmitted from humans into animals

Zoonotic disease

• This distinction is not super important, but it does get at a key part of many zoonotic diseases, transmission from animals into humans is rare, and humans are normally dead end hosts capable of human-to-human transmission only

Zoonotic disease

• Pretty common (let’s name some examples)

• Around 60% of all human pathogens are zoonotic

Emerging infectious disease (EID)

• Newly appeared pathogens, or those that have increased in prevalence/range recently

• Recall definitions previously about outbreak, emergence, and re-emergence

• Around 75% of EIDs affecting humans are zoonotic

The rise of EID

Why the increase in EIDs?

• human-wildlife interface

• antibiotic resistance

• increased connectivity and movement of human populations

• poverty

• health care infrastructure

Preventable disease

Spillover

• Transmission from animals into humans

• Rare events that then lead to sustained human-to-human transmission

Spillover

_{Plowright et al. 2017 Nature Reviews Micro}

Spillover

_{Plowright et al. 2017 Nature Reviews Micro}

Spillover

_{Plowright et al. 2017 Nature Reviews Micro}

One Health

• Paradigm of infectious disease control which doesn’t solely focus on human population outcomes (like more traditional epidemiology does)

• Considers 3 things:

  • human health
  • environmental health
  • animal health

• The One Health approach argues that it’s at the intersection of all these

The rise of One Health

• A conference in 2004 created the Manhattan Principles , a list of 12 recommendations

• A step forward (in my mind) and indicative of how we treat natural systems over time

• But a huge departure from traditional thinking

  • e.g., principle 4: Recognize that human health programs can greatly contribute to conservation efforts

An example of One Health

• Salmonella that can infect humans are commonly found in migratory songbirds

• 2021 outbreak caused 3x more dead birds compared to 2016

An example of One Health

• One Health approach:

  • CDC messaging about bird feeders/baths and role of pets

  • “wash your hands” (classic public health)

  • bird monitoring!

  • cross-sector work (I research disease, but I rarely interface with CDC or conservation folks)

_{https://www.cdc.gov/onehealth/in-action/investigating-salmonella-and-wild-songbirds.html}

A generalized example of One Health

_{Karesh et al. 2012 The Lancet}

A generalized example of One Health

_{Karesh et al. 2012 The Lancet}

Emphasizes surveillence

3: Include wildlife health science as an essential component of global disease prevention, surveillance, monitoring, control and mitigation.

5: Devise adaptive, holistic and forward-looking approaches to the prevention, surveillance, monitoring, control and mitigation of emerging and resurging diseases that take the complex interconnections among species into full account.

Virus hunters

• Perhaps what surveillance should not look like?

Informed surveillance

• Link prediction methods like we went over previously can help target surveillance

• We shouldn’t just be sampling bats

How do we do informed surveillance?

(5 minutes small groups)

Also emphasizes animal conservation in concert with ecosystem services

Seek opportunities to fully integrate biodiversity conservation perspectives and human needs (including those related to domestic animal health) when developing solutions to infectious disease threats.

• ecosystem services : benefits to humans obtained from functioning ecosystems (e.g., pollination, recreation, etc.)

The need for better communication

12: Invest in educating and raising awareness among the world’s people and in influencing the policy process to increase recognition that we must better understand the relationships between health and ecosystem integrity to succeed in improving prospects for a healthier planet.

What are the challenges in communicating science to the public?

• Think of what just happened with COVID-19, as well as the shifting landscape of (mis)information availability

(5 minutes small groups)

Conclusions

“Multisectoral collaboration, including clinicians, public health scientists, ecologists and disease ecologists, veterinarians, economists, and others is necessary for effective management of the causes and prevention of zoonotic diseases”

_{Karesh et al. 2012 The Lancet}