Week 9 Flashcards
Local Host Defence Mechanisms: Respiratory (3)
- epithelial host defence functions
- respiratory microecology
- immune cells
ways in which Epithelial Host Defence Functions can become defective (4)
- decreased mucocilary clearance
- increased pathogen adhesion
- decreased epithelial barrier
- decreased antimicrobial activity
why Respiratory Microeccology can be altered (2)
- decreased indigenous microflora
- increased in conditional pathogenic microorganisms
why Immune Cells can become dysfunctional (2)
- decreased alveolar macrophages
- decreased natural killer cells
Components of mucocilliary transport mechanism (3)
- epithelial barrier
- respiratory mucus
- respiratory cilla
Local defence mechanisms of respiratory tract (3)
- mucocilliary transport mechanism
- local production of immunoglobins
- phagocytosis by macrophages
Which cells make up airway (3)
- respiratory epithelium
- ciliated columnar calls
- goblet cells (secret mucous)
How mucociliary clearance works
- mucous layer (made of mucin) traps and protects epithelium from pathogen
- columnar cilia sweep out pathogen in synchronized waves
- pathogen and mucous is either coughed out or swallowed
Colonization and mucociliary clearance
damage to mucociliary clearance = easier colonization
Intrinsic factors to respiratory infection (5)
- previous infections of respiratory tract
- anatomical changes
- immunocompromising medical conditions
- biologic sex
- family history/ genetic predisposition
Intrinsic factors to respiratory infection - Anatomical change (2)
- congenital (ex; Cystic Fibrosis)
- extrinsic factors (ex; smoking, previous infection causing damage)
Intrinsic factors to respiratory infection - immunocompromised
- chronic disease (diabetes, heart disease, autoimmune) that weaken the immune system
- pre-existing respiratory conditions (COPD, CF)
Intrinsic factors to respiratory infection - bio sex
- male sex babies = higher risk for chronic middle ear infections (otitis media)
Extrinsic factors to respiratory infection - (8)
- smoking
- occupational/environmental exposure
- recurent infections (Damage)
- immunocomprimised (meds, IV drug use, nutrition)
- living environment (second hand smoke, overcrowding, low income)
- breast feeding
- daycare attendance
- vaccine status
Prevention of Respiratory Illness (5)
- immunization programs
- helping parents quit smoking/reducing smoke exposure
- advocating for living conditions + medical research
- addressing SDoH such as infant nutrition, over-crowding, etc.
- PPE/hand-washing
Strep throat - which bacteria
- group A betahemolytic streptococcus
- known as Streptococcus pyogenes
Strep throat - gram status
- gram positive, encapsuloated
Strep throat - how the microbe spreads through the body
- produces streptokinase, which breaks down fibrin clots
- this allows strep to spread to other tissues
Strep throat - symptoms (3)
- enlarged lymph nodes
- inflamed tissues
- pus found on tonsils
Strep throat - diagnosis
throat swab
Strep throat - treatment
- penicillin antibiotics
Strep throat - process of specimen collection (4)
1) patient tilts head backwards, opens mouth, stick tongue out as much as possible
2) use tongue depressor to hold tongue in place
3) without touching sides of the mouth use a charcoal swab to swab posterior pharynx and tonsillar arches (pt cough/gag)
4) C & S will take around 24 hours to obtain a result
Scarlet fever - bacterial agent
streptococcus pyogenes (same as strep throat)
Scarlet fever - pathogenesis
- streptococci produce an erythrogenic toxin, which causes the rash
Scarlet fever - symptoms (3)
- high fever
- inflamed throat tissues
- strawberry tongue
Scarlet fever - treatment
- penecillin antibiotics
Diphtheria - bacteria
- corynebacterium diptheriae
Diphtheria - gram status
gram-positive
Diphtheria - symptoms (3)
- sore throat
- neck swelling
- blockage of respiratory passageways (membrane like accumulations)
Diphtheria - pathogenesis (2)
- membrane like accumulations block respiratory passeageways
- these accumulations are caused by exotoxin that destroys epithelial lining
Diphtheria - treatment
- antibiotic therapy
- antitoxin therapy
- immunization (DPT vaccine)
Otitis Media - what
infection of the middle ear
Otitis Media - common population
- childhood
Otitis Media - symptoms
earache
Otitis Media - bacteria (3)
- streptococcus pneumoniae
- haemophilus influenzae
- staphylococcus aureus
Otitis Media - viral or bacterial
90% viral
Otitis Media - treatment
- 72 hours of watching (rule out viral)
- then initiate antibiotics
Otitis Media - specimen collection (2)
- no specimen collection
- tympanic membrane rupture and exudate mAY have specimen collection though not typical
Pneumonia - what
- lung inflammation where air sacs fill with pus and become solid
Pneumonia - anatomical classifiations
- double pneumonia
- single pneumonia
- lobar pneumonia
double Pneumonia
Pneumonia affecting both lungs
single Pneumonia
Pneumonia affecting one lung
lobar pneumonia
Pneumonia only affecting certain lobes
Pneumococcal Pneumonia - bacteria
Streptococcus pneumoniae
streptococcus pneumonia - gram status
gram-positive
streptococcus pneumonia - virrulence
a polysaccharide capsule (protects from phagocytosis)
Streptococcus pneumonia - lifetime immunity
- capsule is antigenic, so antibodies specific for this capsule can neutralize the pathogen
- however, 84 serotypes for this capsule so surviving one infection only provides immunity to 83 capsules
Streptococcus pneumonia - symptoms (5)
- rigors
- fever
- consolidation of the lung
- severe chest pain
- SOB
most common pneumonia bacteria in adults
streptococcus pneumonia
what is consolidation of the lung
- filling of the air spaces with bacteria, fluid, debris
Pneumonia and chest X-ray
- pneumonia is seen as a white consolidation on x ray
Streptococcus pneumonia - treatment
aggressive penicillin therapy
Haemophilus influenzae - growth medium
blood-containing medium
Haemophilus influenzae - ideal host
- transmitted respiratory
- often attacks lungs of a person debilitated by viral influenza
- grows in blood-containing medium
Bacteria for adult meningitis
streptococcus pneumoniae
bacteria for childhood meningitis
Haemophilus influenzae B
bacteria for childhood epiglotittis
Haemophilus influenzae B
Haemophilus influenzae - why it affects children
- antibodies to the capsule in infants and children between 6 months and 3 years of age
- under 6mo placental antibodies
- after Haemophilus influenzae takes 3-5 years to develop antibodies
Haemophilus influenzae - virrulence factor (2)
- polysaccharide capsule
- 6 types (type B = invasive)
Haemophilus influenzae - prevention
vaccination - stimulate early generation of protective antibodies
Main 2 bacteria causing Pneumonia
- Haemophilus influenzae
- Streptococcus pneumoniae
Bacteria causing Atypical Pneumonias
- mycoplasma pneumoniae
- chlamidial pneumoniae
Atypical pneumonia
- drier cough
- less sick appealing
Mycoplasamal pneumonia
- aka walking pneumonia
Mycoplasma pneumoniae
- exceptionally small sub-microscopic bacteria with no cell walls
Mycoplasma pneumoniae - treatment
erythromycin antibiotic
Chlamydial pneumoniae - gram status
gram negative
Chlamydial pneumoniae - appearance
resembles influenxa
Chlamydial pneumoniae - treatment
- tetracycline therapy
Pneumonia - sampling
- spread via droplets = cant sample
- sputum cultures not required unless failure with first line antibiotics
Tuburculosis - bacteria
mycobacterium tuburcolosis
Tuburculosis - acid fast ?
high lipid content in the cell wall = acid-fast on staining
Tuburculosis - oxygen status
- obligate aerobe (infects lungs)
Tuberculosis - portal of entry
respiratory droplets and infection of lung tissues
Legionella - bacteria
Legionella pneumophila
Legionella pneumophila - Gram status
- gram negative
Legionella pneumophila - resevoir
- collects and is airborne in wind gusts
Legionella pneumophila - symptoms
- high fever
- lung consolidation
- pneumonia
Legionella pneumophila - treatment
- erythromycin antibiotic
Legionella pneumophila - historic outbreaks
- poorly maintained artificial water systems (cooling towers, industry cooling systems, hot and cold water systems, whirlpool spas)
Legionella pneumophila - movement
flagella
Legionella pneumophila - oxygen status
aerobic
Legionella pneumophila - pathogenesis (2)
- invades macrophages
- surround themselves in membrane bound vacule (no lysosomes) to multiply
Legionella pneumophila - incubation period
2-10 days
Legionella pneumophila - initial symptoms (6)
- fever
- loss of appetite
- headache
- malaise
- lethargy
- mild cough
Legionella pneumophila - additional symptoms (4)
- muscle pain
- diarrhea
- confusion
- blood streaked phlegm (hemoptysis)
Legionella pneumophila - complication (2)
- blood streaked phlegm (hemoptysis)
- pneumonia leading to resp failure leading to shock/ multi-organ failure
hemoptysis
blood streaked phlegm
Bordetella Pertusis - common name
whooping cough
Bordetella Pertusis - mode of transmission
airborn droplets
Bordetella Pertusis - anatomical site
trachea and bronchi
Paroxysms of cough
- a type of cough sounding like whooping
Paroxysms of cough - described
1) paroxysm of trachea/bronchi
2) rapid inrush of air = high pitched whooping sound
Bordetella Pertusis - incubation period
1 week
Bordetella Pertusis - stages of disease (3)
1) catarrhal stage (1-2 weeks)
2) Paroxysmal stage (1-10 weeks)
3) convalescent stage (2-6 weeks or months)
Bordetella Pertusis - stages of disease - catarrhal stage
- 1-2 weeks
- symptoms like URI, runny nose, fever, mild cough
- most contagious here
Bordetella Pertusis - stages of disease - most cotagious
catarrhal stage (first stage)
Bordetella Pertusis - stages of disease - paroxymal stage (6)
- 1-6 weeks, up to 10 weeks
- fever subsides
- paroxysm (burst) of numerous rapid coughs
- followed by long inhale (whoop)
- infants/young children appear very ill, turn blue, vomit
- “whooping” does not necessarily have to accompany the cough
Bordetella Pertusis - stages of disease - convalescent stage
- 2-6 weeks or months
- cough usually disapears, but paroxysms may recur whenever the patient suffers any subsequent resp infection
Bordetella Pertusis - primary age
- can infect any age, but is worse in infants and children
Bordetella Pertusis - treatment
- erythromycin and other antibiotics
- DPT vaccien
The common cold - cause
- virus from Picornaviridae virus =
- rhinoviruses
- coronaviruses
- adenoviruses
Rhinoviruses (2)
- non-enveloped single-stranded RNA viruses
- most common cause for common cold
coronaviruses - what
single stranded enveloped RNA
adenoviruses
- double stranded DNA wrapped in a protective protein coat
Symptoms of rhinovirus vs coronavirus vs adenovirus
virtually indestinguishable
common cold - spread
- transmitted through hand to hand spread of mucous membrane and dropplet secretions
- cough and sneezing produce aerosols
- rhinovirus can stay on surfaces for up to a week
Common cold - treatment
- lessening symptoms
- antiviral therapies not available
Respiratory Synctial Virus (RSV) - symptoms
- mild, cold-like symptoms
Respiratory Synctial Virus (RSV) - recovery
most people recover in a week, more serious in infants and older adults
Respiratory Synctial Virus (RSV) - at risk poulations
- infants
- older adults
most common cause of pneumonia and broncholitis in children less than 1 year
- Respiratory Synctial Virus (RSV)
Respiratory Synctial Virus (RSV) - genetic material
RNA
Respiratory Synctial Virus (RSV) - pathogenesis
- cause cell cultures to fuse and form clusters called syncytia
Respiratory Synctial Virus (RSV) - symptoms in children
- severe coughing and wheezing
- distinct lung sound on lung auscultation (popping)
- signs of respiratory distress are usually evident
Coronaviruses - symptoms
- commmon cold to ultimately fatal illness
Coronaviruses - genetic material
single stranded RNA viruses encircled with a viral nucleocapsid envelope
SARS-CoV-2 - unique structure
- are spherical particles
- have proteins called spikes protruding from their surface, thus giving the apperance of a crown
SARS-CoV-2 - pathogenesis
- spike proteins latch onto human cells, then undergo structural change that allows the viral membrane to fuse with the cell membrane
- viral genes can then enter the host cell to be copied producing more viruses
Coronaviruses vs SARS CoV-2
- COVID-19 shows less severe pathogenesis
- COVID-19 shows higher transmission competence
Coronaviruses - specimen collection
- nasopharangeal swab (NP)
- swab inserted deeply into nasal cavity (pt. will likely flinch)
- twirl swab three times and kept in place for 10 seconds
Influenza - genetic material
- eight RNA strands helically wound and enclosed in a capsid
Influensa classifications
- A and B
influenza classification - which causes morbidity and mortality
- Influenza A viruses
Influenza - when epidemics occur
- yearly
- between late december and early march
Influenza - pathogenesis
- long glycoprotein spikes (HA and NA) attach and release newly formed virions
- mutation can occur in HA or NA during replication = new strains
- can cause Antigenic Drift (less virulent) or Antigenic Shift (more virrulent)
Antigenic drift
when influenzae HA or NA proteins mutate to become less attacked by immune system and cause milder disease
Antigenic shift
change of the HA or NA resulting in increased susceptibility to disease
Fungal Respiratory Infections
- histoplasmosis
- aspergillosis
- pneumocystis pneumonia
Histoplasmosis
- fungal disease
Histoplasmosis - caused by
- the yesat Histoplasma Capsulatum
Histoplasmosis - infection symptoms
- infection similar to TB (esp immunocompromised individuals)
Histoplasmosis - associated with
bird and bat droppings
Aspergillosis - caused by
- fungus Aspergillus fumigatus
Aspergillosis - pathogenesis
- fungus grows in lung tissues and forms compact ball of fungal mycelium, blocking respiratory passegways
Aspergillosis - treatment
- surgical excising of mass of fungi
- anti-fungals
Pneumocyctis pneumonia - fungus
- Pneumocyctis carinii
Pneumocyctis carinii - what is it
usually considered protozoan, it might be a fungus
Pneumocyctis pneumonia - patient population
- AIDS patients
Pneumocyctis pneumonia - pathogenesis
- organisms grow in lungs of immunocomprimised individuals and cause severe consolidation, which can lead to death (50% of AIDS deaths)