Midterm 2 Flashcards
Flu viruses
Orthmyxoviridae:
- Family of RNA viruses
- Types/clades: A B C
- Virulent encapsulated
- ID’d based on combo of surface antigens: hemaggultinin and neuraminidase
Evolution of flu viruses
- Antigenetic drift: minor genetic changes, mostly non-beneficial (A B C)
- Antigenetic shift: major genetic changes, acquires genes f/other strains through reassortment, usually in pigs (A only)
History of flu
- Middle Ages: Florence 1387, possibly 1st case
- Late 18th c: first major pandemics
- Late 19th c: first detailed analysis of pandemic
- 1930s: virus isolated
Flu: experience (physical)
- Heliotrope cyanosis: lavender-grey hue on face/ears
- Drowned in lung fluid (attempt to protect itself)
- 20% developed secondary pneumonia (secondary infections=main killers)
Flu Origin Theories
Camp Funston, KS (Fort Riley)
- Farm country
- Early 1918: mysterious illness, spread f/camp to camp
- NYC: excessive mortality (port f/which soldiers left)
- European epidemic coincided w/US troops’ arrival
Etaples, France
- 1916: un-ID’d bug killing soldiers (descriptions: similar symptoms)
- Birds and pigs both there (everything and everyone in place)
Virus: Spanish flu specifically
- Influenza A
- Almost entirely avian, NOT reassortment virus
- Jumped f/fowl to humans, suggesting it had already circulated prior
Flu W-Curve Theories
- Age group fighting in trenches, probably fighting co-infections
- Over-reaction: reproduces quickly –> immune system goes into overdrive –> fluid in lungs
- Antigenetic imprinting: exposure to virulent flu in utero/infancy –> over-reactions to similar strains later (1889 Russian Flu)
Treatment for flu
- Anti-pneumonia vaccines (useless)
- Good nursing only effective remedy
- Drs: sleep, wash hands, don’t kiss, etc.
- Some isolation hospitals (Ham)
- Informal support networks (donations, care, adopted orphans, took care of animals)
Geographic Distribution of flu: Hamilton
- Started in West
- Higher MR in north (working class, smaller houses): shows how social inequalities affect mortality
Spanish flu: why was it forgotten?
- Lack of imagery/lit/news coverage (didn’t want to demoralize)
- Few high profile deaths
- Medical failure –> omitted f/textbooks
Syphilis transmission
- Bacteria crossing mucous membrane
- Mainly sexual but also through cuts, lesions, drug use
- Mainly horizontal, can be vertical
Venereal syphilis: microorganism
- Treponema pallidum pallidum
- Spirochete
Syphilis: primary stage
- 3-6 weeks post infection
- Painless ulcer: highly infectious, leaves no scar
Secondary: Syphilis
- Bacteraemic stage: multiply, spread through blood
- 6 weeks after primary chancre heals
- Widespread rash
- Condyloma lata: highly contagious wart-like lesions in warm, moist areas (genitals, mouth)
- Small, flat red lesions (palms, sores, mouth)
Tertiary: Syphilis
- 6-40 years after primary infection
- Gummas: soft, non-cancerous growths
- Bone lesions: painful, good skeletal indicator
- Irreversible damage to heart, liver, kidney, can cause death
Pinta
- T. pallidum carateum
- South/central America
- Skin to skin contact
- Flaky skin paules, hypo-pigmentation of skin
- Easily treated w/antibiotics
Yaws
- T. pallidum pertenue
- Across equatorial zone
- Spread most effectively by children
- Skin lesions, ulcers, may –> joint pain, fatigue, scarring of skin
- Easily treated w/antibiotics
Bejel
- T. pallidum endemicum
- E. Med/W. Af (arid regions)
- Contaminated drinking vessels/utensils
- Childhood disease
- Gums -> mouth -> raised lesions on limbs
- Very rare
Europe: Emergence (syphilis)
-First documented amongst soldiers in Naples, French soldiers brought disease back
Early 20th c: syphilis revealing social values
- Deep fears re: contagion, disease, death, sexuality (–>stigma)
- Why? Taboo, strict ideas about “correct” social relations, viewed sexuality w/suspicion
Message of syphilis campaigns
- STDs=enemy of war, female
- Women trick men/undermine war efforts
- Punishment for sexual license
- Triple threat to moral order: working women, disordered sexuality, subverted ideals of family
Syphilis today in Can
- Rising since 2001
- Highest in NWT, AB
HIV/AIDS history
- 1981: rare infections (P. carinii) in gay comms signalled severe immuno-deficiency
- Also present in drug users/hemophiliacs, signalled infectious agent
- 1983: HIV-1 virus isolated
- Few years later: HIV-2
HIV/AIDS viruses
- F/lentivirus groups of retroviruses
- RNA molecules, reverse transcription
- Host takeover, shuts down all other functions
- Evolution: 1m x faster due to high mutation and replication rate
- Majority: HIV-1, group M
HIV/AIDS peak
- 1997: peak in mortality
- On average, still stable/increasing in SE Asia, E Europe
Demographic Impact: HIV/AIDS
- Tremendous adult mortality –> orphans
- Reduced like expectancy (Swaziland, women: 40-45)
- Population structure inverted
HIV/AIDS virus: sources and origins
- Sources:
- HIV-1: chimps
- HIV-2: sooty mangabey monkeys
- Congo: origin (Kinshasa, Brazzaville)
- Bushmeat
- Civil war
- Hoover: unethical testing, possible use of chimp kidneys
NA: Blame
- “Plague”: othering, smw else, foreign
- Religious right, moral majority tied in with politics (Helm’s Amendment)
- Non-natural sex, punishment
Stats: TB
- Leading cause of death 2nd to HIV/AIDS
- 95% of deaths in middle/low income countries
- Developed countries: focalize on poor
- 20-40 hardest hit: huge social/econ impact
Mircoorganism: TB
- Mycobacterium tuberculosis
- Small, slow growing, non-motile, rod-shaped
- Well adapted to lung (long co-evolution) but can infect other organs
- Close relationship w/M. bovis
TB Epidemiology and Symptoms
- Highly infectious, airborne
- Transmission: droplet nuclei (reqs close proximity)
- Settings: crowded, dark, cold, moist
- Symptoms: fever, coughing, weight loss (often mild)
Infection Experience: TB
- Eventually: tubercles (small, hard lumps)
- Can lead to non-infection, dormant infection, or active infection
Antiquity/Origins
- Skeletal indicators: spinal lesions, kyphosis
- Firm ev for at least 6 kya, maybe before 10 kya
- Link to cattle domestication, ~10 kya
- Molecular clock: arose in Fertile Crescent, ~40 kya
- Indications in SA pre-contact: independent origins?
High point: TB
- 18th c pandemic
- Almost entire cities had it (Paris, London)
19th c view: TB
- Consumption: seen as seductive, romantic, aphrodisiac
- Caused by unconventional behaviours
Discovery of M. tuberculosis
- 1882, Koch
- Demystified disease, medicalized it, gave it an element of control
- Better understandings, focus on healthy living/environments–>sanatorium movement
Henle and Koch’s postulates
- Specific microorganism always found in association w/specific disease, and no other
- Culture in lab produces disease in animal
Sanatorium movement
- Ideas about best treatment/environment
- Defence against contagion (like Plague Houses)
- Laws requiring isolation (only disease)
- Lead to physical and social death
- Impact: already on decline, continued
TB risk factors
- Age: infancy, puberty, old age
- Gender: young women
- Genetics: poverty?
- Environment: crowing NOT density
- Nutrition
- Working conditions
- Industrialization: early vs late
TB: why resurgence in NA
- Herd immunity diminished
- MDR strains
- Research/funding disappeared
- Inadequate treatment programs
- Synergy w/HIV/AIDS
2006-08 outbreak
- Transmission in bursts, clusters
- Linked to arrival of crack houses, depressed immune systems)
- 10x normal rate
- 2 strains
- BC
Decline in TB in western nations: why?
-Social improvements –> reduction in co-infections –> decline in syndemic conditions?