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

  • What is set by birth/death rates? Plateas 

  • What are the limiting factors of a plateau? Disease, famine, war, birth control

  • What is driven by technological advances? Growth Spurts by the invention of tools, agriculture, & industry

  • While the number of humans increased, life expectancy decreased after what? The Agricultural Revolution which is associated with increase in human infectious diseases

  • What enhances disease transmission & can cause respiratory problems? Crowding

  • What was used as fertilizer that could cause water/foodborne diseases? Human/animal manure

  • What did poor nutrition come from? Primary grain crops

  • What increased pathogen evolution? Animal Domestication

  • What are some origins of major human infectious diseases? Ducks & pigs, wild birds, cattle, camels, mammals possibly pigs, etc.

  • What are some diseases that were not present in Pre-Columbian Americas? Leprosy, Bubonic Plague, Smallpox, Cholera, Sleeping Sickness, River Blindness

  • What are the domesticated animals associated with disease in the old world? Dogs, sheep, goats, etc. 

  • What are the domesticated animals associated with disease in the Pre-Columbian new world? Dog, Llamas, Alpacas, Guinea pigs, Turkey, and ducks

  • What disease did the slave trade bring? Malaria

  • Pre-Columbian Europe did not have what? Syphilis

  • Why were native populations so susceptible to disease? No acquired immunity, no genetic immunity, perhaps low HLA diversity, biased towards wrong immunological response (TH1 viruses/bacteria versus TH2 parasites)

  • What large populations documented before pilgrims arrived vanished? Large indigenous populations

  • Between 1616-1619, there were mysterious deaths of native americans living where before Plymouth Colony? Coastal Massachusetts; disease systems included nose bleeds, jaundices, & fever; Possible causes were yellow fever, smallpox, plague, chicken pox & trichinosis but these do not cause nose bleeds or jaundices 

  • They ended up discovering that between 1616-1619 there were mysterious deaths of native americans living in coastal massachusetts before Plymouth Colony due to what? Leptospira that causes all reported symptoms

  • What was the hypothesis behind the environmental contact of Leptospira to the native populations? Rodents with Leptospira escaped from European ships, contaminated soils and fresh water, infected native mammals

  • How much percent of all human pathogens emerged recently? 12%

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

  • What is an example of an emerging infectious disease or etiologic agents identified since 1973? Year Agent was 1982 Escherichia Coli & the disease was Hemorrhagic Colitis/hemolytic Uremic Syndrome. Another example is the year Agent 2019 SARS-CoV-2 & the disease COVID-19.

  •  What is the term for when pathogens need a host species like domestic animals, rodents, primates, bats, etc? Reservoir species 

  • In Reservoir species what is spillover influenced by? Intensity of disease in host, density of host species, proximity to humans

  • What is the term for when people are exposed to diseases by excrement, during slaughter, bites, & shared vectors like mosquitoes/arthropods? Jumping to Humans

  • 60% of new human viral infections most often originate in what animals? Primates, rodents, & bats

  • How do Primates, Rodents, & Bats impact the risk of human emergence of diseases across the world? Primates primarily lower half of world but not much, rodents impact entire world, & bats impact entire world but primary in south america

  • How is there increased zoonotic transmission by bats? Due to Ability to fly, body temperature fluctuations, roosting habits, migration, hibernation

  • What is the important immune defense in most species? Reactive Oxygen Species (ROS)

  • ROS is produced by what? Mitochondria

  • When bats fly, they undergo intense what that causes high levels of what? Undergo intense metabolism causing high ROS levels 

  • What do bats do to minimize cellular damage? Dampen the immune response to ROS that results in reduced antiviral killing in bats

  • Is it true or false that bats have high viral loads but in general are unaffected by the pathogens? True

  • What is a common infectious disease that is caused by environmental changes? Malaria

  • What are some other factors that contribute to disease emergence? Travel, microbial evolution, changes in human susceptibility, poverty & social inequality, etc.

  • What’s an example of Agricultural Bioterrorism? Xanthomonas Oryzae which is this dry rice spread by wind and rain & bacteria enters leaves & multiplies & can cause serious loss of human field if fields aren’t guarded. Low moral impact.

  • How do we react to new diseases? Either reactive approach or protective approach.

  • What's the difference between reactive & protective approach? Reactive is when first cases cause media-driven global panic & money drives vaccine development and the funding ends when epidemic ends. Protective is when there is ongoing research and development such as COVID-19.

  • What is a protective approach in therapeutics? Human monoclonal antibodies where there is a rapid response for each new disease, isolating the antibody-producing cells in individual, cloning and sequence those genes, then prep synthetic human antibodies. 

  • What are current human disease and mortality patterns? Health disparities, and causes of death can be grouped into 3 categories which are communicable (infectious & parasitic diseases, maternal, perinatal, & nutritional), noncommunicable (chronic), and injuries. 

  • Before COVID what were the leading causes of death in high income countries? Ischaemic heart disease, Alzheimer's disease & other dementias, and stroke. 

  • Most deaths in high income countries were due to what causes of 3 categories? Noncommunicable 

  • Which disease of leading causes of death has taken over? Alzheimers

  • What happened to life expectancy gains? They have slowed

  • What are Ohio's leading causes of death? Heart disease, cancer, Alzheimers, Flu/pneumonia 

  • Male life expectancy fell in 2020 due to what? COVID, this means “Survivorship Effect” for future

  • What are the leading causes of death in low income countries? Ischaemic heart disease, stroke

  • Most deaths in low income countries were due to what causes of 3 categories? communicable , but have decreased since 2000, however specific leading causes of death cases have increased

  • What is the 5th leading cause of death in low income groups? Diarrheal diseases 

  • How do we prioritize which human health issues to address? Using Statistical methods to assess mortality such as crude mortality, years potential life lost, & disability adjusted life years

  • Crude mortality is dominated by what? Diseases of the elderly such as heart disease and cancer 

  • Years of Potential Life Lost (YPLL) assesses what? Premature, preventable, and unnecessary mortality

  • What are the major causes of death years 10-24? Injuries, suicide, homicide, cancer

  • What are some actual causes of death? Tobacco, poor diet & physical inactivity, alcohol abuse, motor vehicles, firearms, risky illicit behavior

  • How does pollution compare to other causes of global deaths? It’s one of the highest risk factors & caused 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