disease terms

agent

A factor whose presence, excessive presence, or absence leads to occurrence of disease.

Determinant definition: (no examples)

any factor that influence the health status of population; (event, characteristic, condition).

 Reservoir:

habitat an agent can grow/thrive/multiply in; can have symptoms or no symptoms, long-term living place for the agent

host:

organism that is effected +may show symptoms (human)

carrier

a specific type of host that can transmit agent but shows no clinical signs of disease

cluster

aggregation of cases closely grouped in time/place (regardless of whether the number of cases was greater than expected or not)

 Sporadic:

disease that occurs infrequently and irregularly

endemic

constant presence/usual prevalence of disease or an infectious agent within a specified geographical area

epidemic

sudden increase abovbe normal

pandemic

global epidemic

infectivity

ability of agent to cause infection; no infectivity formula.

pathogenicity

ability of agent to cause clinical disease after infection

Virulence:

ability to cause severe illness or death

incidence

rate of new cases in a period of time

morbidity

any departure from a state of well-being (physical or mental)

prevalance

number of cases in a population at a specific point in time

infectious dose

min. dose of pathogens to cause infection in host

what does longitudinal mean?

a term in cohort studies; to follow same group for a long period of time to see outcome from exposure

Index case/patient 0

first reported case of an outbreak, first person that catches it

confounding variable

something not directly related to the result, a third party that seems like it’s the result but isn’t

focal infection

A localized infection that can spread to other parts of the body, entering through wounds by bacteria or microrganisms

A Paradoxical carrier

carrier that got agent from another carrier

convalescent carrier

person who has recovered from infectious disease but continues to harbor the pathogen (continues to pose risk)

primordial prevention

actions that prevents any risk of disease existing in the first place by changing people’s cultural, enviornmental, behavior living patterns.

primordial prevention ex

teaching children healthy eating habits

why is childhood vaccination not a type of primordial prevention?

any type of vaccination is considered primary because the risk is already there

Which of the following policies is NOT an example of primordial prevention?

chemotherapy for lung cancer

primary prevention

prevents disease itself

mandatory folic acid fortification in flour

primary prevention; risk already developed (poor folate intake)

airborne transmission

mucous droplets that stay in the air as aerosols; stays in the air even past 6 feet of distance.

vehicle transmission “vehicles into the body”

via mediums such as food, air, liquid

what type of meat is salmonella most commonly associated with?

chicken

what is prevalence? both definition+formula

proportion of cases in a moment of time (cases/total population)

what does relative risk measure? (definition)

how much more likely exposed group will contact the disease than unexposed group

RR formula

(A/A+B)/(C/C+D)

what does A in a contingency table represent?

exposed and gotten the disease

what does B on a contingency table represent?

exposed but not ill

what does C on con. table mean?

has disease, unexposed

what does D on table mean?

does not have disease, unexposed

what does sensitivity measure?

ability of a test to correctly identify those that have the disease from total cases that have disease (tp+fn)

what is sensitivity formula?

true positive/(total ppl, which is: true pos+false neg)=accuracy of sensitivity in %

what is specificity? 

abiltiy of test to identify those that don’t have disease (true negative)

formula for specificity

true negative/(true negative+false positive)=% of test to accurately calculate those who don’t have disease

what is PPV? (what acrynym stands for)

positive predictament value

PPV definition?

the chances it’s true if the test says you’re positive for a disease

PPV formula

TP/all positive results, no matter true or false: (TP+FP)

NPV acryonom

negative predictament value

NPV definition? (NOt ACRYNOM)

chances it’s true if a test says you’re negative for a disease

NPV formula

TN/(TN+FN)=% in chance

what is the accuracy in NPV+PPV measured in? (definition)

overall correct predictions in both NPV and PPV

formula for measuring accuracy in NPV+PPV?

TP+TN/total population

what is attack rate for?

used before calculating relative risk; a/ab=exposed, c/cd=unexposed

what diseases have been declared eradicated?

Rinder Pest, smallpox 

what type of disease is rinder pest?

virus

is smallpox a virus?

YES

is smallpox extinct? 

no; only eradicated as samples still exist in human labs

Why can’t we calculate risk for OR? (odds ratio)

BECAUSE you don’t know the full population; only the selected infected+controls doesn’t include everybody

what is transfusion?

blood is transfered from donor to recipient

what is ecological fallacy? 

incorrect assumption that trends observed at group level applies to all individuals

what is incubation period?

exposure until symptoms, only infectious disease

latent period def (less common)?

chronic diseases, exposure until diagnosed

latent period (more COMMON definition)?

contact with a pathogen until infectious

what is the first step in the outbreak investigation

prepare for fieldwork; ask ppl questions, who needs to be contacted, what materials are needed.

what are the leading causes of death? in order MOST TO LEAST TOP 5

heart disease, cancer, accidents, stroke, chronic lower respitory diseases

what is the difference between epidemic and outbreak?

outbreak is in a more limited area

what is a host?

organism that is infected by agent

sporadic

disease occurs infrequently and irregularly

virulence

severity of disease

etiology 

cause of disease

efficancy

intervention that does more harm than good

peron-time

combined participents length of tiem they are observed until they die, leave, or shws outcome. "

herd immunity

when enough people/animals in a population has been vaccined or immune it’s unlikely to spread to other people, making the whole group immune

what is fulminant disease?

severe, acute, rapidly progressing illness that developes suddenly; high risk, poor outcomes

quaratine

seperation with the risk that they may be sick

isolation

seperation after confirmed sick

give 5 examples of zootonic disease

rabies, west nile infection, anthrax, ebola, lyme disease

what is PuseNet? (defintion only, not key premises)

network of labs across US that identifys waterborne, foodborne, zootonic disease outbreaks and reports real time data to CDC.

PuseNet key premises

known for rapid precision and early detection/reporting, faciliates specific control methods in a short period of time that stops outbreaks.

what is a strain in epidemiology

geneti variant or subtype of microorganism with unique biological or genetic features that make it distinct within the same species

what are strains used for?

to trace outbreaks, understand disease patterns, and develope targeted vaccines or treatments.

purpose of surveillance

The purpose of surveillance is to gain knowledge of patterns of disease, injury, or other health problems in a community for prevention and control purposes. Surveillance is necessary to influence public health decisions and evaluate control measures.

what is convalescent carrier

people that cna still spread disease after infectious stage

Incubatory carrier

when individual can transmit infections prior to to developing symptoms, because the body hasn’t mounted strong enough immune system to cause systems, yet pathogen load is high enough to spread

chronic carrier

someone who can transmit a disease for a long period of time, even after years of infection due to failure of immune system to completely get rid of disease

gene carrier

inheritated disease even if the person did not have any symptoms

transient/temporary carrier

can transmit infectious disease for a period of time, but heals quick as normal immune system. 

what type of carrier was Typhiod Mary? where did the name come from?

chronic, came from the bacteria typhoid fever of salmonella typhi

who was typhoid mary?

irish immagrant, cook in 1900s, carried s.typhi in gallblader, spread through food as a cook

what was the privacy rule? (the HIPAA)

the HIPAA Protects Patients, but Public Health, Police, and Peril come first.

when was the privacy rule established?

1996

how can iodine deficiency diseases be prevented? when did this become widespread?

iodized salt, 1924

what is the case finding process?

a data gathering process that allows public health officials to gather data on an outbreak

what is the epidemiological triad for the foundation of descriptive epidemiology? 

person, place, time

chain of transmission triad

agent, host, enviornment

retrospective cohort study

looks back at who has been exposed and who got disease by following them in the historical records, exposure to outcome 

cohort vs case control

exposure first, then we follow, case control is disease first, then we look back to see what exposure. 

what is PulseNet?

lab network that finds outbreaks from DNA fingerprints of pathogens