Midterm 1 Flashcards
Mortality rate (def)
of deaths in a given location, of a particular cause
Microbe/where did it come f: SARS
Coronavirus
Zoonosis: civet cat
Markets of Guandong (live game)
Zoonoses (def)
Natural infection of animals that, under the right conditions, can jump to humans
Epidemic (def)
Cases of an illness in excess of normal expectancy in a given place (old disease increasing or new one taking hold quickly)
Pandemic (def)
Disease present throughout entire country, continent, world (epidemic over large area)
Endemic (def)
Entrenched in a region, country, continent
Can cycle through epi phases
Medical intervention may cure, but doesn’t prevent spread
Transmission: SARS
Person to person:
- Direct contact
- Droplets f/respiratory secretions
- Fecal
Pestilence (def)
-Disease outbreak w/high MR
A plague (def)
- Idea of pestilence: disease outbreak w/high MR
- Special case of epidemic: high mortality, destructive, fear, lack of control, may transform society/belief systems
Palaeopathology
Interpreting of disease in ancient human remains
- Impact on individual AND society
- Framework: epidemiological transition theory
Types of remains
Skeletons, mummies, DNA f/microorganisms
Skeletal and Dental Pathology (what can we tell)
Bone formation/loss Fractures/dislocations Arthritis Developmental abnormalities (cleft palate, spina bifida) Genetic diseases Dental abscesses, hypoplasia
TB in skeleton
- Collapsed vertebrae
- Vertebral abscess
Leprosy on skeleton
Small holes and wearing away of layers of skull
Syphilis on skeleton
Worm-eaten appearance of skull
Saber shins
Other ev for diseases in past
- Burials
- Parasites in soil (ex: round worm)
- Animal remains
- Coprolites
- Macroparasites (ex: fleas, lice)
- Art and iconography
- Historical records
Limitations of arch ev for disease
- Uneven arch record
- Most infections leave no trace on bones
- Small samples, osteological paradox
- Must be understood w/in context of societies/cultures (factors that influence who gets sick)
Theories of Body/Medicine
- Humor Theory: balancing of humors
- Miasma Theory: bad air (middle ages-19th c)
- Germ Theory
- Koch’s Theory: specificy (1 microorganism=1 disease)
Epidemiology
Study of patterns, causes, and effects of health and disease in defined populations
Pathogen
Anything that produces disease
Types: micro/macroscopic
Microorganism and relationships
- Visible only w/microscope
- Symbiotic: micro and host benefit
- Commensal: one benefits w/o damaging the other
- Parasitic: one benefits at other’s expense
Bacteria
- Single-celled, fast growing organisms
- Cell wall
- Gram +/-, shape
Virus
- Much smaller, acellular organism, genomes consist of nucleic acid
- Only 1 type of acid
- No energy metabolism/protein synthesis
Modes of Disease Transmission
- Human to human (best): contact, respiratory/saliva, alimentary tract, fecal-oral, sexual, blood
- Zoonotic
Vector (def)
-Carries of transmits parasite (intermediary)
Reservoir
-Special in which pathogen multiplies and/or develops (even when active transmission isn’t occurring)
BD: time
- Started in mid 14th c
- Lasted ~350 years
- Recurred ~20 yrs
BD: origin
- No one knows exact origin, around Black Sea (Kaffa?)
- Spread through trade
BD: vector, reservoir, host
- Vector: rat flea
- Reservoir: wild rodent pop (immune)
- Microbe: Yersinia pestis
BD: cause of rats –> humans
-Climate change –> contact between wild and commensal rodents (not adapted, as they die fleas jump to humans, bite, throw up bacteria)
BD Forms and Transmission
- Bubonic: animal to human
- Pneumonic: blood sputum, highly transmissible person to person
- Septicaemic: secondary pneumonic form
BD Contributing Factors
- Snap cooling –> drought (Great Famine, movement of rodents)
- 100 Years’ War
Omran Transition Theory
-Shift in importance of infectious of infectious vs chronic disease
- Pestilence and famine (-1875)
- Receding Pandemics (1875-1930
- Degenerative and man made disease (1930+)
Omran critiques
- Eurocentric
- Short time scale
Armelagos, Barnes, Lin: Transition Theory
- Palaeo baseline: HG (4 mya-10 kya)
- 1st transition: food production and urbanisation (10 kya-100 ya)
- 2nd transition: industrialization
- 3rd transition: post-industrial world
Holmes: Transition Theory
- Co-divergence of hosts and pathogens (100 kya)
- Origins of ag (10 kya): zoonoses, density (TB)
- Urbanization (5 kya): density (measles)
- Colonization (Yellow Fever)
- Globalization and Enviro Change (SARS)
Ag and disease
- Monoculture –> nutritional disease, increased risk of famine
- Zoonoses
- Increased pop density –> increased transmission possibilities
War and disease
Create conditions conducive to infectious disease, the effects of which depend on the social context in which they occur
Typhus: Microorganism and vector
- Rickettsia (bacteria-like)
- Vector: louse (feces scratched in)
- Species specific
- Survival depends on growth/replication w/in the host cell
Web of Biosocial Interactions
- Hot, dry summer –> scarcity, contam of water
- Bad roads –> food scarcity
- Fear of attack –> crowding
- Syndemics (dysentery, etc.)
Factors in Bubonic Plague, Vietnam
- Sterilization of land –> bamboo –> rats
- Bombing –> crowded refugee camps
- Destruction of fields –> malnutrition
Pathogenicity (def)
Ability or an organism to cause harm/disease or not
Virulence (def)
-Degree of pathology, influence by ability to multiple w/in host
Spanish flu: shift in virulence
- Genetic change?
- Trench warfare: crowded, ambulance drivers
- Normally we are immobilized –> limited transmission
Bosnia Herzegovina: highlights and buffers
- 3-4x in mortality, mainly trauma/war related
- Low acute malnutrition
- Buffers: private homes, public health in tact, pre-war nourishment/affluence, effective food distribution
Somalia
- ID leading cause of death
- Refugee camps: water shortages, sanitation overwhelmed, crowding
- Pre-war: infrastructure/overall health much lower
Pathognomonic
-Symptoms readily identifiable
Smallpox: microbe, transmission
- Variola virus
- Transmission: contact/airborne transmission (highly contagious, initial outbreaks had high MR –> childhood disease)
- No animal reservoir (host-specific=long co-ev)
Smallpox: origins
-Unknown, maybe associated w/irrigation ag societies, ~10 kya (make sense b/c crowd disease)
Lithuanian mummies
- Their virus sits much farther back
- Coalescent date: 1588-1645 (more recent ev or genetic shift)
Smallpox vaccine inventor
Jenner, 1796
Smallpox Eradication Timeline
- Mid 50s: early campaign, failed
- Late 60s: intensified
- Last case: 1977
- How: campaigns, working w/religious groups, significant infrastructure
Why was smallpox eradicable?
- No animal reservoir
- Vaccine effective and easy to produce
- Herd immunity only reqs min # of ppl
Arguments for destroying smallpox
- Potential bioweapon
- Could escape
- Clones/sequences exist
- Study other diseases
Argument against destroying smallpox
- Eliminating stock =/= eliminating smallpox
- Bioweapon/escape unlikely, easily controlled
- Study has enormous benefits
- Could re-emerge
