Population Health

Question 1

What is Ro

Answer 1

number of secondary transmissions expected from a single care of a disease

• depends on the infectivity of a pathogen

** if one person gets sick: how many others are expected to get sick from that one person

Question 2

What is Herd Immunity Threshold

Answer 2

name for a point in time when it’s hard for a disease to spread through a group of people

— vaccine rate needs to hit this

• proportional to Ro (higher == need more % immune)

Question 3

T or F: when have herd immunity, transmission of the disease no longer can occur

Answer 3

F - it can and does still occur but the extent of outbreak + transmission is low

Question 4

T or F: whether a disease is highly or not very infective, the same amount of the population is needed to be vaccinated in order to get herd immunity

Answer 4

F
- if highly infectious: majority of pop needs to be vaccinated to get immunity

if not infective; don’t need as much vaccination done to get herd immunity

Question 5

What are the main arguments for anti-vax

Answer 5

normally based on religious concerns, mistrust of science, concerns against suppression of personal freedom

— as vaccination rate increases: increase risk of SEs of vacccine increases + more visible

Question 6

What happens when you lose herd immunity

Answer 6

outbreaks of the illness

Question 7

T or F: unvaccinated HC workers are at the same risk of transmission of illnesses as normal person

Answer 7

F- higher risk because come in contact with a lot of shit

Question 8

What is the importance of vaccine registries with outbreaks

Answer 8

can help ID under immunized people to help control outbreaks

Question 9

T or F: Vaccines impact immunity of those you get the vaccine but also others

Answer 9

T - impacts others ability + risk of getting explored to microbe

Question 10

What impacts how quickly a disease spreads through pop

Answer 10

Based on the number of people a person who has the illness can affected (Ro)

basic reproduction number (Ro)
- Ro< 1: disease can die out (can’t infect 1 person)
- Ro> 1: aka any diseases because it can be passed to 1+ people

higher Ro—- impact more people

Question 11

T or F: there is a difference bw individual immunity vs herd immunity

Answer 11

T
individual immunity: is your own immunity against disease

herd immunity: immunity of those around you + how they affect or protect against disease spread

Question 12

T or F: the idea of smallpox vaccination started a long time ago when a person took shit from small box sores from people had been infected + blew it into the nose of healthy people

Answer 12

T- variolation: used actual smallpox shit to try and give immunity
- higher risk of death though compared to vaccination

Question 13

Edward Jenners + smallpox

Answer 13

Realized that those who had been exposed to cowpox —- didn’t get smallpox
- viruses from same family

• tried to see if cowpox could be used to protect: took some pus from cowpox pustule + inoculated into child (later repeated with shit from smallpox lesion)

— gave protection —- immunization/ vaccination

EDWARD JENNERS - father of immunology

Question 14

T or F: smallpox is eradicated from the world

Answer 14

T

Question 15

Why is it so hard to eradicate diseases?

Answer 15

• hard in undeveloped areas
• took decades

need to treat all of of those who are in close contact with people with diseases

Question 16

T or F: smallpox can only be spread through humans

Answer 16

T- have no reservoir hosts

Question 17

What did scientists figure out when they started vaccination those who had been exposed to someone with smallpox

Answer 17

helped prevent spread + could stop smallpox

• could actually get rid of it in that area

Question 18

What properties made small box an ideal candidate for eradication

Answer 18

• human are essential for LC (break human to human transmission)
  ——— not possible for all pathogens
• individuals infected with smallpox: easy to ID because of their skin symptoms
  —— diseases that don’t have this or have long incubation time: makes it harder to eradicate

— Smallpox vaccine was accessible

—-doing in developed countries + how it was possible —- let to global attempts to do the same

Question 19

Criteria to see if eradication is possible

Answer 19

1) human essential for LC
2) easy method of recognition
3) effective intervention
4) eradication proof of principle

Question 20

T or F: high density population (school, daycare etc) need high vaccine rates to prevent spread of illness

Answer 20

T