History of Infectious Diseases | Alison Weiss | 01/16/25 Notes

What is set by birth and death rates?

Plateaus.

What are the limiting factors of a plateau?

Disease, famine, war, birth control.

What drives growth spurts in human population?

Technological advances from the invention of tools, agriculture, and industry.

After what event did life expectancy decrease while the human population increased?

The Agricultural Revolution.

What enhances disease transmission among populations?

Crowding.

What type of fertilizer can lead to waterborne and foodborne diseases?

Human/animal manure.

What was the source of poor nutrition for many populations?

Primary grain crops.

What factor increased the evolution of pathogens?

Animal domestication.

What are some origins of major human infectious diseases?

Ducks & pigs, wild birds, cattle, camels, mammals such as pigs.

Which diseases were not present in Pre-Columbian Americas?

Leprosy, Bubonic Plague, Smallpox, Cholera, Sleeping Sickness, River Blindness.

What domesticated animals are associated with disease in the Old World?

Dogs, sheep, goats.

What domesticated animals are associated with disease in the Pre-Columbian New World?

Dogs, Llamas, Alpacas, Guinea pigs, Turkeys, and ducks.

What disease did the slave trade introduce to the Americas?

Malaria.

What disease was not found in Pre-Columbian Europe?

Syphilis.

Why were native populations especially susceptible to disease?

They had no acquired immunity, no genetic immunity, and possibly low HLA diversity.

What large populations disappeared before the arrival of pilgrims?

Large indigenous populations.

Where did mysterious deaths occur among Native Americans from 1616-1619?

Coastal Massachusetts.

What caused the mysterious deaths in Native Americans between 1616-1619?

Leptospira infection.

What was the hypothesis regarding Leptospira's environmental contact with native populations?

Rodents escaped from European ships, contaminating soils and fresh water.

What percentage of all human pathogens emerged recently?

12%.

What is the term for disease transmission from animal reservoirs to humans?

Zoonotic transmission.

What is an example of an emerging infectious disease identified since 1973?

Escherichia Coli causing Hemorrhagic Colitis or SARS-CoV-2 causing COVID-19.

What are reservoir species for pathogens?

Host species like domestic animals, rodents, primates, and bats.

What influences spillover from reservoir species to humans?

Intensity of disease in the host, density of host species, proximity to humans.

What is the term for exposure to diseases via excrement and vectors?

Jumping to humans.

What percentage of new human viral infections often originate in primates, rodents, and bats?

60%.

How do Primates, Rodents, and Bats affect the risk of human disease emergence?

Primates primarily lower half of the world, rodents impact the entire world, and bats are primary in South America.

What increases zoonotic transmission risks among bats?

Ability to fly, body temperature fluctuations, roosting habits, migration, and hibernation.

What is the important immune defense mechanism in many species?

Reactive Oxygen Species (ROS).

What produces reactive oxygen species (ROS) in cells?

Mitochondria.

What happens to ROS levels when bats fly?

They undergo intense metabolism, causing high ROS levels.

How do bats minimize cellular damage from high ROS levels?

They dampen the immune response to ROS, resulting in reduced antiviral killing.

Is it true that bats have high viral loads and are generally unaffected by pathogens?

True.

What common infectious disease is linked to environmental changes?

Malaria.

What factors contribute to disease emergence?

Travel, microbial evolution, changes in human susceptibility, poverty, and social inequality.

What is an example of Agricultural Bioterrorism?

Xanthomonas Oryzae affecting rice crops.

How can we react to new diseases?

Reactive approach or protective approach.

What differentiates a reactive approach from a protective approach?

Reactive acts after outbreaks, while protective includes ongoing research and development.

What is a protective approach in therapeutics?

Using human monoclonal antibodies for rapid response to new diseases.

What are the patterns of current human disease and mortality?

Grouped into communicable, noncommunicable, and injuries.

What were the leading causes of death in high-income countries before COVID?

Ischaemic heart disease, Alzheimer's disease, and stroke.

What category dominated deaths in high-income countries?

Noncommunicable.

Which disease among the leading causes of death has seen a rise?

Alzheimer's disease.

What happened to gains in life expectancy recently?

They have slowed.

What are Ohio's leading causes of death?

Heart disease, cancer, Alzheimer's, Flu/pneumonia.

Why did male life expectancy fall in 2020?

Due to COVID, leading to a 'Survivorship Effect' for the future.

What are the leading causes of death in low-income countries?

Ischaemic heart disease and stroke.

What was the leading cause of death in low-income countries prior to recent changes?

Communicable diseases.

What is the 5th leading cause of death in low-income groups?

Diarrheal diseases.

How do we prioritize human health issues to address?

Using statistical methods to assess mortality.

What dominates crude mortality rates?

Diseases of the elderly such as heart disease and cancer.

What does Years of Potential Life Lost (YPLL) measure?

Premature, preventable, and unnecessary mortality.

What are the major causes of death for individuals aged 10-24?

Injuries, suicide, homicide, cancer.

What are some actual causes of death in populations?

Tobacco, poor diet and physical inactivity, alcohol abuse, motor vehicles, firearms.

How does pollution rank as a cause of global deaths?

It is one of the highest risk factors, causing 9 million premature deaths in 2015.

What is Disability Adjusted Life Years (DALY)?

The number of productive years lost due to ill health, disability, or early death.