communicable diseases Flashcards
infectious disease
lymes
when living organism enters body and causes disease
communicable disease
flu
transmitted from one human/nonhuman to another
all are infectious
communicable diseases and pandemics throughout history
downward trend in death at beginning of 1900s -> vax, sanitation, tm, abx
stigmatized -> communities affected and country of origin
biowarfare: 2001 = antrhax letters
1918
flu
1980s
causal connections with infectious organisms (chronic) -> PUD with H. pylori
resurg of infectious diseases in 80s, increase in abx resistance
1990s
food supply concers: unpasteruzied, improperly cooked beef
1993: hantavirus pulm syndrome -> SE US
1996: bovine spongiform encephalopathy (mad vow disease), vCJD in humans
1997: VRSA, H5N1 (avian influenza)
1999: west nile
2000s
viral hemorrhaghic fevers: ebola and marburg (largest outbreak in 2014), seen a lot in entertainment
SARS: select agent -> potential pose severe threat to public health and safety, keep eye on it
more food borne -> recalls, E. coli in green chiles and raw cookie dough, salmonella in PB, listeria in cantaloupes
H1N1 in 2009, MERS-Cov, zika, covid 19
factors influencing new infectious diseases
societal events: economics, poverty, war, pop growth and migration, urban decay
hc: +/-
food production: global processing
human behavior: sex, drugs, travel, diet, outdoor rec, facilities
env: deforest, reforest, water, food, flood, drought, famine
public health: prevent
microbial adaptation: virulence, resistance
epidemiologic change: agent
cause of disease
type: bacteria (reproduce on own), virus (cant reproduce on own), parasite (survive at expense of host)
ability to cause injury of illness of host
infectivity
ability to enter host and multiply
invasiveness
ability to spread through host
pathogenicity
ability to cause disease in hsot
virulence
severity of disease caused
toxigenicity
ability to produce damaging poison (toxin)
antigenicity
ability to stim an immune response in host
epidemiologic change: host
person or animal that harbors agent
exposure
host susceptibility: health status, genetics
host response: to agent, harbor v disease
epidemiologic change: env
external conditions that influence interaction btw agent and host
phys: geology and climate
bio: pop density, flora and fauna
psych: occupation, living location, economic dev and urbanization
reservoir
where agent survives and multiplies
concept, not part of triangle
can be internal (E. coli in colon) or external (water)
inanimate: water, soil, food, etc
animate:
human = symptomatic, non symptomatic carrier -> can still spread (typhoid mary)
nonhuman (animal): zoonosis = agents harbored by non human vertebrae animal reservoirs
reservoir host = host that serves as a reservoir
modes of transmisson: direct
immediate transfer of agent from 1 human to another -> less than 3 ft
contact: direct transfer with v close contact (STI)
droplet: expelled from 1 hand picked up by another (flu, RSV, diptheria)
modes of transmission: indirect
> 3 ft
vehicle borne
vector borne
airborne
modes of transmission: indirect - vehicle borne
animate (human) -> hc workers moving btw pt rooms
inanimate: formites = toys, stethoscope, shopping cart
food or liquid
modes of transmission: indirect - vector borne
mosquitoes
usually arthropods (invertebrates)
modes of transmission: indirect - airborne
TB, COVID, chicken pox, cold
expelled small droplets -> cough, sneeze, sing
travel further, stay in air longer, higher transmission
patterns of transmission: unidirectional
non human -> human
toxoplasmosis (cat)
patterns of transmission: vertical
parent to child during fetal dev, birth, breast feed
HIV
patterns of transmission: endogenous
internal source (already in body -> E. coli in colon)
patterns of transmission: bidirectional
non human <-> human
malaria
patterns of transmission: horizontal
person -> person
cold, flu, covid
patterns of transmission: exogenous
external source
botulism
latent period
btw entering host, find favorable conditions, replicate before shedding
incubation
btw invasion and s/s
can overlap with communicability
communicability period
contagious
can overlap with incubation
PH focused here
portals of entry
mucous mem, resp tract, skin, blood vessels, placenta
portals of exit
intestinal tract, resp tract, skin, blood, semen and vaginal fluids, wound exudate
how do we control communicable diseases?
control agent -> sterilize, disinfect
control restervoir -> eradicate non human (water), control human (treat infected, quarantine), control portals of entry and exit (mask, precautions), improve host resistance and immunity (vax, nutrition)
disease rates
more important with diseases with long duration
incidence = new
prevalence = total
focuses of PH: prevention
decrease or eliminate exposure or susceptibility to a disease
upstream
focuses of PH: control
decrease incidence or prevalence of disease
focuses of PH: eliminaiton
control of a disease w/n specific geographic area
focuses of PH: eradicate
decrease incident worldwide to zero
surveillance
ongoing systematic collection, analysis, interpretation of health data
purpose = alert to change, detect, monitor, control spread of communicable
organizations: hcp -> local/regional HD -> state health dp -> CDC -> WHO
state makes decision on which diseases will be reported (w/n jurisdiction)
isolation
individual level
communicable disesae
limit person to person transmission
quarantine
pop level
spectrum: communicable, natural or chm disasters
limit person to person transmission
quarantine: levels
shelter in place
targeted restrictions on movement and activities -> cancel concerts, games, activities
compulsory widespread restriction of movements and activities -> phys boundaries = airports, countries
contact tracing
how we find new cases and stop spread
outbreak action plan
assemble/activate team -> control
determine coverage in affected and surrounding area
enhance surveillance
notify appropriate people
educate case pts and contacts
proper case management
obtain specimens for lab confirmation
implement control activities to limit transmission -> isolate/quarantine
collect detailed data on cases and outbreak response
