Chapter 19 Flashcards
A) What makes a disease contagious or communicable? Give some examples.
can be transmitted from one host to another, colds, measles, flu etc
1) How is disease transmission determined? How can they be controlled?
it is determined by the environment, the pathogen, and the host. ie sanitation prevents pathogen from acessing the host
B) What makes a disease non-communicable?
when it doens’t spread from host to host. ie. tetanus tat enters the host from environment, or normal flora
C) What is the attack rate? What does it reflect?
percentage of people who get ill after exposure to a certain pathogen. this reflect how many people exposed verses how many get ill.
D) What is the incidence of a disease?
number of new cases within a specific timme period
E) What is prevalence of a disease?
number of cases at any time within a certain time period. usuaslly given as a rate
F) What does the term morbidity refer to?
incidence of disease of a population at risk
G) What does the term mortality refer to?
overall death rate in a population
1) What is the case fatality rate? Which diseases have a high rate?
percentage of a population that dies of a specific disease. Ebola and aids
2) Why has the case-fatality rate for AIDS gone down while the prevalence has gone up?
treatment has improves, but prevalence has increased because more people are living with aids
H) What makes a disease endemic vs. sporadic?
endemic:constantly present in a population ie cold
Sporadic: cases occur only time to time
I) What constitutes an epidemic? [Figure 19.1]
large numbers of cases in a poplulation
1) Can a disease not normally present in an area cause an epidemic?
yes
J) What constitutes an outbreak?
cluster f cases occuring in a brief amount of time and effecting a specific poplulation
K) When does an epidemic turn into a pandemic?
when an epidemic spreads world wide
L) What is a reservoir of infection? [Figure 19.2]
natural habitat of a certain pathogen. can be inn animals, soil,and water
1) Why doesn’t the United States have epidemics of plague?
because they control their rodents such as mice
2) Can humans be reservoirs?
yes
3) Why can it be easier to contain symptomatic illnesses?
- Can they be spread before symptoms appear?
because people are aware there is an issue and can take prevenative measures.
yes they can spread before symptoms apear
4) What is problematic about asymptomatic carriers?
they do not know they are ill and do not take prevenative measures
5) What are some diseases spread by non-human reservoirs?
-
poultry: campylobacter, and samonella
rabies caused by skunks, and bats
y pestis by mice
What are zoonoses?
diseases that can be transmitted to humans, but can cause disease is
6) What are some organisms that have environmental reservoirs?
tetanus, botulism
M) What is a portal of exit and what’s it used for? Give an example.
route in which it leaves its resivor to be transmitted. ie through feces
N) What is a portal of entry and what’s it used for? Give an example. [Figure 19.3]
how it enters the body to infect it. it through cut, or mouth
O) What is horizontal transmission? [Figure 19.4]
transimission of pathogen fro one person to the other, via air, water, skin, or insect
1) What types of direct contact aid horizontal transmission?
hand shake, sex,
-How can direct contact transmission be avoided?
washing hands, using condoms etc.
2) How does indirect contact occur? How can you control transmission through this?
This is through passing via inadimate objects. (fomites) . You can do this by cleaning the environment.
3) How does droplet transmission occur? How can this be minimized?
3 feet within a person just breathing droplets in the air can get to you. this can be prevented via masks and keeping beds and desks 3 feet apart
4) How can pathogens be transmitted through food and water? How can this be minimized?
food: ie samonella in chickens tract as it lays and egg, or people preparing do not wash hands. Fecal matter in water that is not properly treated
5) How are pathogens transmitted through the air? How can they be controlled?
particles in the air that are larger than 10 micrometers can get caught in mucous and swallowed, smaller can get into the lungs,
droplets.
ventalation systems and filters
- What are droplet nuclei?
- How can viable organisms in the air be counted? [Figure 19.5]
Small droplets that attach to at thin coat of dry material.
this can be measured by a machine that pumps a set amount of volume of air against a petri dish.
-How does a mechanical vector spread pathogens? [Figure 19.6a]
cary microbe on its body. ie flies from poop to food
-How do biological vectors spread pathogens and what are some examples?[Figure19.6B]
harbor the pathogen internally ie. ticks and mosquitos
-How can you prevent vector-borne disease?
control of anthrpods, spraying, net ect.
P) What is vertical transmission?
transmission from mother to baby via placenta, or breast feeding
Q) What influences the outcome of transmissions?
virulence of pathogen, dose, and incubation period
1)What are some of the things virulence factors do?
increased factors that cause disease, adherence to sufaces, thwart immune response, damage host via toxins, destructive enzymes, or stimulating strong inflamatory response
2) How does the dose affect the probability of infection?
the more of the microbe the more damage. causing disease
3) How does the incubation period affect the spread of pathogens?
the longer incubation the more people individuals contact spreading disease before they know they are sick
R) What causes some populations to be more affected by pathogens than others?
they can be an immunized. They can live in less sanitary and closer quarters like in 3rd world countries.Age can also effect it. kids with u
1) How can herd immunity protect a population?
when everyone is immunized and do not carry/ spread a disease and protects those who are not immmunized in the community
2) How does general health affect disease?
malnutrition, overcrowding, and fatigue increases peoples susceptibility
3) How does age relate to disease? [Figure 19.7]
kids have underdeveloped immune systems.
adults the immunity wanes over time, they do not update their vaccinations and live in care facility in close quaters.
4) How can gender and religious/cultural practices influence disease distribution?
females more prone due to pregnancy and shorter urethra.
cultural: some groups who eat raw fish at risk
and babies breast fed are safer
5) How can the genetic background of a population influence disease?
africans: are not at risk for malaria because they lack specific receptors on their rbc’s.
northern Europeans. less risk for HIV becaue of lack of receptor on wbc’s
A) What is included in a descriptive study?
when an outbreak occurs: seeking time, place of outbreak and individuals infected.
1) How does determining the profile of those who are ill help?
this allows you to know the population at risk. based on lifestyle, race, other risk factors
2) How can the location of disease acquisition help?
this helps pinpoint source , gives potential reservoirs , vectors
3) How can knowing the timing of an outbreak help?
help you know if the agent came from a common source aka food poisoning. or wether it is contangeous
- What is a common-source epidemic?
- What is a propagated epidemic? [Figure 19.8]
numbers grow slowly of those ill. because it is an infectious disease
-What is the index case?
first case that starts the outbreak
-How can the season the epidemic occurred be significant? [Figure 19.9]
winter: people all clustered together in a builidng
Summer: people are more likely to be bit by mosqiutos and food born ilnesses rise
B) What are analytical studies?
determine which of he potential risk factors identified by the studies are relevant in the spread of the disease
1) What is a cross-sectional study?
surveys a range of people to determine the prevalence of infection, behaviors, or etc.
2) What is a retrospective study?
follows a disease outbreak. actions and events are investigated of those who are infected and those not infected and then they are compares. tries to find causation
3) What is a case-control study?
studying a single individual
4) What is a prospective study?
looks into the future. they follow those who have risk factors of getting disease and follow them over time
-What are cohort groups?
study groups who are known to have a risk factor
C) What is an experimental study used for?
used to dertermine the cause and effect of risk factors, or development of disease, or prevenative factors
A) What does the Centers for Disease Control and Prevention do?
provides support for infectious disease labs in the US. They also gather information on 50 diseases and update weekly. researches, and sends teams to assist with identifying and controling.
1) Which diseases are reported to the CDC? [Table 19.1]
446
B) What does the public health department do?
q
C) What does the World Health Organization do?
provide guidaince in world health, set global standards of health, strengthen national health programs, and develop health technologies
D) How have humans eliminated or reduced many diseases? [Figure 19.10]
sanitation, vector andresivoir control, vaccinations and antibiotics
1) What are some examples of diseases that have been decreased? [Figure 19.11]
haemophilus influenzae, diptheria, tetanus, and pertussis, malaria plague,small pox, and cholera
A) What are emerging diseases and what factors contribute? [Figure 19.12]
SARS mad cow, avian flu, malaria, tb
- Microbial evolution
- Complacencey and public health factors
- Changes in society: ie daycare
- Advances in technology: provides new environments
- Population expansions: growing populations means expansion into new areas
- Development: ie dams providing habitat for snails carrying a parasite
- Mass production
- War and civil unrest- ie refugee camps and close quarters
- Climate changes
A) What are healthcare-associated infections?
Infections individuals aquire while receiving treatment in a healthcare setting.
1) What are some common causes? [Table 19.2]
450
B) What are nosocomial infections?
hospital aquired infections
1) What is the frequency of these infections? [Figure 19.13]
32% uti 22% surgical site 17% other 15% respiratory 14 % bacteremia
C) What are the reservoirs in a healthcare setting?
other patients
health care environment
workers
patient microbiota
D) How can pathogens be transmitted in the ICU? [Figure 19.4]
catheters, iv’s and other monitors. endoscopes, respirators, and surgical instraments
F) How can healthcare professionals prevent themselves from spreading pathogens?
wear ppe and wash hands !!!!!!
G) How do hospitals prevent air borne transmission of pathogens?
airflow regualtion into rooms. no brooms are use instead they wet the floor, hepa filters
H) How do hospitals prevent the development of healthcare-associated infections? [Per. 19.1]
452
1) What do ICP’s do?
they are infection control practitioners who watch types and numbers of infections in their hospital
2) What does the HICPAC do?
national committee that provide guidelines for survelence, prevention, and control of healthcare associated infections
