Population Health Flashcards
What is Ro
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
What is Herd Immunity Threshold
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)
T or F: when have herd immunity, transmission of the disease no longer can occur
F - it can and does still occur but the extent of outbreak + transmission is low
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
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
What are the main arguments for anti-vax
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
What happens when you lose herd immunity
outbreaks of the illness
T or F: unvaccinated HC workers are at the same risk of transmission of illnesses as normal person
F- higher risk because come in contact with a lot of shit
What is the importance of vaccine registries with outbreaks
can help ID under immunized people to help control outbreaks
T or F: Vaccines impact immunity of those you get the vaccine but also others
T - impacts others ability + risk of getting explored to microbe
What impacts how quickly a disease spreads through pop
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
T or F: there is a difference bw individual immunity vs herd immunity
T
individual immunity: is your own immunity against disease
herd immunity: immunity of those around you + how they affect or protect against disease spread
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
T- variolation: used actual smallpox shit to try and give immunity
- higher risk of death though compared to vaccination
Edward Jenners + smallpox
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
T or F: smallpox is eradicated from the world
T
Why is it so hard to eradicate diseases?
- hard in undeveloped areas
- took decades
need to treat all of of those who are in close contact with people with diseases
T or F: smallpox can only be spread through humans
T- have no reservoir hosts
What did scientists figure out when they started vaccination those who had been exposed to someone with smallpox
helped prevent spread + could stop smallpox
- could actually get rid of it in that area
What properties made small box an ideal candidate for eradication
- 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
Criteria to see if eradication is possible
1) human essential for LC
2) easy method of recognition
3) effective intervention
4) eradication proof of principle
T or F: high density population (school, daycare etc) need high vaccine rates to prevent spread of illness
T
