infectious disease - exam 1 Flashcards
how are we regularly exposed to microorganisms?
immunizations
vulnerabilities i.e., comorbidities
infectious pathogens mutate
resistant organisms spread quickly without adequate precautions
why are older adults more susceptible to infectious diseases?
changes in cell-mediated or T-cell function
immune system slower to respond and requires a stronger stimulus to respond
extrinsic factors can lead to increased susceptibility to infection - lack of cough and gag reflexes make it difficult to control secretions & decreased lung elasticity
impaired thermoregulatory system - little to no fever to fight infection
what is infection?
transmission
pathogen establishes parasitic relationship with host
what 3 things can a pathogen do?
- contaminate body surface and be destroyed by first line defenses
- subclinical infection - no symptoms other than immune response to host
- apparent infection - host-parasite interaction causes one or more clinical symptoms –> infectious disease
what is incubation period?
period between pathogen entering host and appearance of clinical symptoms
– beginning of symptoms indicates end of incubation period
what is the period of communicability or infectious period?
time period when an organism can be shed - when one can become infected
what are viruses?
needs host cell
not susceptible to antibiotics
antiviral meds only limit virus
what is bacteria?
grows independent of host
susceptible to antibiotics
what is rickettsiae?
combination of virus and bacteria
- requires host but treated with antibiotics
what does a successful transmission depend on?
pathogenic agent - microorganism that produces disease
reservior - environment for pathogen
portal of exit from reservoir
how can microorganisms be transmitted?
contact - direct (person to person) and indirect (object to person)
airborne
droplet - fluid
vehicle - through common source (water supply)
vector-borne - animal to person
portal of entry - ingestion, inhalation
susceptible host
Most infectious diseases are confined to ______ _______ _______
specific organ systems
what is a common host for bacterial infections?
persons with low gut flora or good bacteria
what are factors that decrease a persons good bacteria?
antibiotics - most common
compromised immune health
comorbidities
SAD
hospitalized
how is E. coli transmitted?
vehicle through ingestion of infected food
hand to mouth contact
who are most at risk for e coli?
organ transplant recipients
vented pts
catheters
traumatic injury
what are symptoms of e coli?
GI and infection S&S
(indigestion, P! in thoracic/ab region, N&V)
(malaise, fatigue, N&V, enlarged lymph nodes)
what is the most common cause of C diff?
persistent diarrhea
suppresses good bacteria
who are most at risk for C diff?
medicare aged (> 65) white females
what are S&S of C diff?
GI and infection S&S
what is one of the most common bacteria normally resting on skin?
staph infections - MRSA
what is unique about MRSA?
resistant to antibiotics even though its a bacteria
how is MRSA spread?
direct contact or inhalation - greater risk with a skin opening
what is the most common cause of cellulitis?
group A Strep
acute skin inflammation usually from an opening
