ID terms Flashcards Preview

Occupational Health > ID terms > Flashcards

Flashcards in ID terms Deck (28):
0

Diagnostic test for flu/influenza

1. Viral cultures have to be sent to a specialized lab and take days to come back
2. Rapid antigen test can be done on site but has low sensitivity. So if negative, the employee could still have flu.
3. PCR: can be done rapid. The test is sensitive. Requires a nasopharyngeal swab, not nasal like the rapid antigen test. The advantage is that one can use the results to decide on need for treat and whether and when the employee can work.

1

Control of infectious diseases

1. Sanitation and hygiene
2. Vaccination
3. Antibiotics and other antimicrobial medicines

2

Colonization

Agent infects host continuously without overt evidence of disease or infection.

3

Covert infection

Agent infects host, time-limited, without overt disease (majority of infection)

4

Overt infection

Infection with disease (minority of infection)

5

Infectivity

Ability to evolve/multiply in host

6

ID50

Does of agent necessary to infect 50% of host

7

Infectiousness

Ability to be transmitted to other host

8

Pathogenicity

Ability to cause disease in a susceptible host; to produce clinical illness

9

Virulence

Ability to produce severe clinical illness, including death

10

LD50

Dose of agent necessary to kill 50% of hosts

11

Immunogenicity

Ability to elicit an immune response.

12

Factors to the natural history of infectious disease

Reservoir
Vector
Transmission
Host

13

Incubation time

Time between infection and the creation of overt disease.

14

Generation time

Period between infection and maximal communicability.

15

Herd immunity

Resistance of a population to the spread of disease based on prior immunity of the population.

16

Secondary attack rate

Measures the rate of spread of disease within an exposed group
= ( # of new cases - # of initial cases)/(# of susceptible - # of initial cases)

17

Type of infections in a population

Sporadic
Endemic
Hyperendemic
Epidemic
Pandemic

18

Sporadic

Occasional cases at irregular interval

19

Endemic

Low level(usual), expected frequency of disease occurrence, the constant presence of a disease within a given geographical area (usual prevalence)

20

Hyper endemic

A gradual increase in the frequency of disease occurrence above endemic level

21

Epidemic

A sudden increase in the frequency of disease occurrence above endemic level (clearly in excess of expected level)

22

Pandemic

An epidemic occurring across continents

23

Epidemic cure

Plot of # of. Cases against time

24

Epi curve for point source

A single jumped with rapid rise and slower return to baseline

25

Epi curve for ongoing source

Rapid rise at onset of exposure to persistent epidemic level

26

Propagated cure with multi- hump

1st peak: Primary attack rate for those exposed to the index case
Subsequent peaks represent 2ndary and beyond attack rates as those in the 1st peak infect others.

27

Vaccine Efficicy

= 1 - (attack rate in vaccinated/attack rate in unvaccinated)

= 1 - (incidence rate in vaccinated/incidence in unvaccinated)