Unit 12 - Lower RTI Flashcards
List some examples of Lower RTI’s
- laryngitis and tracheitis
- diphtheria
- pertussis
- bronchitis
- pneumonia
- tuberculosis
- cystic fibrosis
Anatomy of Upper RT
- epiglottis
- larynx
- nasal cavity
- pharynx
Anatomy of Lower RT
- trachea
- bronchi
- bronchioles
Laryngitis and Tracheitis:
Describe it
-Infection of larynx and trachea
Laryngitis and Tracheitis:
Adult symptoms?
hoarseness and burning pain
Laryngitis and Tracheitis:
Child symptoms?
narrow, easily obstructed
-causes hospitalization
Laryngitis and Tracheitis:
What are possible causes?
parainfluenza virus RSV influenza adenovirus GAS (group A streptococci) H. influenzae
Diphtheria:
What is it caused by?
Corynebacterium diphtheria
Diphtheria:
Common in ?
developing world
Diphtheria:
Complications?
- Myocarditis (inflammation of heart tissue)
- Polyneuritis (paralysis of soft palate and regurgitation of liquids - can lead to choking)
Diphtheria:
Treatment?
- Immediate, life-threatening
- Antitoxin (horse serum) + antibiotics
Diphtheria:
Vaccine?
Yes
Comes in combination with pertussis, tetanus, polio, and Haemophilus influenza B
TDap vaccine
Pertussis/Whooping Cough:
Cause?
Bordatella pertussis & parapertussis
B. Bronchiseptica
Pertussis/Whooping Cough:
Epidemiology
Highly transmissible; infants and young children
Attaches to and multiplies in ciliated respiratory mucosa
Pertussis/Whooping Cough:
Clinical manifestations & pathogenesis
- Early phase: viral upper RT infection
- Fever uncommon, paroxysms of coughing
- Sum of several toxins
Pertussis/Whooping Cough:
Toxins involved
1) Pertussis toxin
2) Adenylate cyclase
3) Tracheal toxin
______ ________ kills tracheal cells
tracheal toxin
______ _____ - AB type, A subunit: ADP ribosyl transferase that catalyzes transfer of ADP-ribose from NAD to host cell proteins, affects signal transduction
pertussis toxin
____ ______ enters neutrophils, causes increased cAMP which inhibits their chemotaxis, phagocytosis and bactericidal killing ability
adenylate cyclase
Pertussis/Whooping Cough:
List 2 complications
1) Pneumonia (secondary infection) can cause alveolar rupture
2) CNS effects: seizures
Pertussis/Whooping Cough:
Describe the 3 stages
1) Catarrhal
- mild cold, runny nose, mild cough
- can last several weeks
2) Paroxysmal
- severe coughing begin
- 15-25 paroxysmal fits/24 hours
- vomiting and whopping
3) Convalescent
- slow decrease of symptoms
- 4 weeks after infection
Pertussis/Whooping Cough:
Is there a vaccine available? If yes, describe it.
Yes. (part of Tdap)
Acellular vaccine:
-Pertussis toxoid + bacterial components (filamentous haemagglutinin and fimbrae)
*cannot vaccine newborns/infants
Acute Bronchitis:
What is it?
inflammation of the tracheobronchial tree
Acute Bronchitis:
Is often _____
viral
-rhinovirus, coronavirus, influenza virus, adenovirus
Acute Bronchitis:
If it’s not viral, it can be bacterial. List some possible bacterial causes.
-Bordetella pertussis, B. parapertussis, Mycoplasma pneumoniae, chlamydophilia pneumoniae
Acute Bronchitis:
Epidemiology & Clinical Manifestations
- peaks in winter
- cough, fever, variable amounts of sputum
Acute Bronchitis:
Pathogenesis?
- usually follows upper respiratory tract infection
- spreads from damage of respiratory epithelial cells by same (usually viral) pathogens
Acute Bronchitis:
List 2 Complications
1) Secondary bacterial infections
2) Presentation varies
Acute Bronchitis:
Has ____ ____ consequences
long term
Acute Bronchitis:
Pneumonia is usually from community acquired pathogens such as?
s. pneumoniae
h. influenzae
Acute Bronchitis:
Getting bronchitis can make you more susceptible to getting _____.
asthma
What is the primary cause of bronchiolitis and pneumonia in infants under 2?
Respiratory Syncytial Virus (RSV)
Respiratory Syncytial Virus (RSV):
Describe the pathophys
bronchioles narrow which causes difficulty in breathing
Respiratory Syncytial Virus (RSV):
Transmission
droplets
Respiratory Syncytial Virus (RSV):
Inhaled and establishes infection in ________ and _________________________
nasopharynx
lower RT
Respiratory Syncytial Virus (RSV):
Causes _____ and _______
bronchiolitis
pneumonia
Respiratory Syncytial Virus (RSV):
Signs & symptoms
- cough
- fast respiratory rate
- cyanosis
HPS
Hantavirus Pulmonary Syndrome
What is the new world hantavirus called?
Sin Nombre Virus (SNV)
Hantavirus Pulmonary Syndrome (HPS):
Recent outbreak in ??
deer mouse
Hantavirus Pulmonary Syndrome (HPS):
Transmission?
-Inhalation of SNV-infected rodent feces, saliva, or urine
Hantavirus Pulmonary Syndrome (HPS):
Signs & Symptoms
- flu like symptoms
- viral invasion of pulmonary capillary endothelium
- fluid pours into lungs due to increased vascular permeability
Hantavirus Pulmonary Syndrome (HPS):
____% mortality rate
35%
What does old world hantavirus cause?
hemorrhagic fever and renal syndrome
Pneumonia is more common in _____ due to their decreased immune system
elders
List some ways a pathogen can get into the deepest possible layers of RT?
1- upper airway gets infected first and then the infection spreads to lower RT
2- direct aspiration of organisms (eating or drinking something large # of bacteria - something goes directly from your oral cavity to your lungs)
3-inhalation of airborne droplets
4-seeding of lung via blood from distant site
Describe Pneumonia
Inflammation of the lower RT
-lung invasion (alveolar spaces, interstitial, terminal bronchioles)
Pneumonia can be _____ or ______ acquired
community or nosocomial (hospital)
List the 4 routes for lung infection
1-upper airway colonization or infection that extends into lung
2-aspiration of organisms
3-inhalation of airborne droplets
4-seeding of lung via blood from distant site
Pneumonia can be a _____ ________ infection
secondary bacterial
List traits that contribute to pneumonia
- alcoholics and vagrants
- underlying respiratory tract disease
- occupational exposure
- travel exposure
- exposure to animals
- HIV positive
- immunocomprimised
List the 4 types of pneumonia
1-Lobar pneumonia
2-Bronchopneumonia
3-Interstitial pneumonia
4-Lung abscess
_____ ______ - distinct region of the lung
lobar pneumonia
_________- diffuse patchy
bronchopneumonia
______ ______ - invasion of the lung interstitial, viral
interstitial pneumonia
_____ ______ - cavitation and destruction of the lung parenchyma
lung abscess
Bacterial pneumonia:
Makes up what % of cases?
25-60% (down from 90%)
Bacterial pneumonia:
Haemophilus influenza makes up ____% of cases
5-15%
Bacterial pneumonia:
Is _____ pneumonia
atypical
Bacterial pneumonia:
_____ sputum and ____ onset
minimal sputum
chronic onset
Bacterial pneumonia:
List some causes
M. pneumoniae
Chlamydiophila psittaci
Coxiella burnetti
Legionella pneumophila
Bacterial pneumonia:
What type of specimen do we use to diagnose?
sputum is specimen of choice (collected in the morning before breakfast)
Bacterial pneumonia:
Other types of diagnostic tools?
- gram stain
- serology
Bacterial pneumonia:
Treatment?
- antibiotics
- resistance issues
Bacterial pneumonia:
vaccine available?
Adults: Pneumococcus capsular (23-valent) vaccine
Infants:
7-valent vaccine
Viral pneumonia:
Causes?
Many viruses capable of causing pneumonia:
- influenza A or B
- parainfluenza (types 1-4)
- measles
- RSV
- adenovirus
- cytomegalovirus
- VZV
Viral pneumonia:
Clinical condition associated with:
Influenza A or B
primary viral pneumonia or pneumonia associated with secondary bacterial infection
Viral pneumonia:
Clinical condition associated with:
Parainfluenza (types 1-4)
Croup, pneumonia in children <5 years of age; upper respiratory illness (often subclinical) in older children in adults
Viral pneumonia:
Clinical condition associated with:
Measles
Secondary bacterial pneumonia common; primary viral (giant cell) pneumonia in those with immunodeficiency
Viral pneumonia:
Clinical condition associated with:
RSV
bronchiolitis - infants
common cold syndrome - adults
Viral pneumonia:
Clinical condition associated with:
Adenovirus
Pharyngoconjunctival fever, pharyngitis, atypical pneumonia (military recruits)
Viral pneumonia:
Clinical condition associated with:
CMV
interstitial pneumonitis
Viral pneumonia:
Clinical condition associated with:
VZV
pneumonia in young adults suffering primary infection
Influenza Virus:
A
epidemics and pandemics animal reservoirs (birds)
Influenza Virus:
B
epidemics, no animal involvement
Influenza Virus:
C
no epidemics (does not jump continents), mild respiratory illness
Influenza Virus:
Describe the basic structure
H and N antigens
-Characterization of different strains
Full nomenclature
-Ex. A/Philippines/82/H3N2
- eight segments of single-stranded RNA
- RNA viruses mutate faster which leads to resistance, proof reading for RNA viruses is not very good which causes these mutations
Describe antigenic drift
1) influenza virus 1 enters host cell
2) mutations in antigen genes occur during replication within host cell
3) influenza virus 1’ differs slightly from virus 1
Describe antigenic shift
1) influenza viruses 1 and 2 enter host cell
2) genes and antigens from both viral types are incorporated into new visions
3) influenza virus 3 very different from viruses 1 and 2
What is the “Missing Vessel Hypothesis”?
- new influenza strains emerge because influenza virus type A infects pigs, horses and other mammals
- avian H5N1 & H3N2 + human H1N1 or H3N2
Influenza Virus:
Outbreaks of southern hemisphere
May-Oct
Influenza Virus:
Outbreaks of northern hemisphere
Nov-Apr
Influenza Virus:
Transmission of Avian flu
movement of poultry and products
Influenza Virus:
Entry
in droplets, attaches to sialic acid receptor on epithelial cell surface via H-spikes
Influenza Virus:
Cytokines cause ??
fever and chills, muscle aches, runny nose and cough
Influenza Virus:
If it lasts longer than 7-10 days, may lead to _____ or _________________________
bronchitis
interstitial pneumonia
Influenza Virus:
can have a ____ _____ infection
secondary bacterial
Influenza Virus:
higher risk pts
> 60 yrs
pregnant
Influenza Virus:
Vaccines available?
1) egg-grown virus - purified - formalin inactivated (dead, but antigenic structure still intact) - ether extracted
2) purified H and N Ags, ‘split’ vaccine
* exact virus strains reviewed annually
Influenza Virus:
vaccines provide ____% protection
70%
Influenza Virus:
Antiviral agents available for treatment
- neuraminidase inhibitors
- zanamivir and osteltamivir
Influenza Virus:
Diagnosis?
PCR
SARS-CoV
Severe acute respiratory syndrome associated coronavirus
SARS-CoV is ____-______ _____
single-stranded RNA
SARS-CoV:
___% are cold-like infections
15%
(fever >38, cough, shortness of breath/difficulty breathing, chest X-ray - pneumonia
SARS-CoV:
___% fatality
10%
SARS-CoV:
Causes ??
changes in viral reservoir and human eating habits
SARS-CoV:
You can get it from consumption of ??
exotic animals (ex. bats, civet cats)
SARS-CoV:
What type of animals is SARS-CoV-like virus detected in?
himalayan palm civet cats
chinese ferret badgers
horseshoe bats
SARS-CoV:
How long is it stable for?
stable at RT for 2 days on surfaces and 4 days in feces
MERS
middle east respiratory syndrome
MERS-CoV
middle east respiratory syndrome coronavirus
MERS-CoV:
__________ transmission is rare
human to human is rare so that is why its mostly confined to one country, it jumps from human to camels. The receptors for MERS-CoV are found in LRTI so it is less likely to spread human to human.
Tuberculosis:
A disease of ____
poverty
Tuberculosis:
Cause?
Mycobacterium tuberculosis
Tuberculosis:
_______ documented communicable disease
oldest
Tuberculosis:
Infects ___ of the world population
1/3
Tuberculosis:
Kills _______ per year
3 million
Tuberculosis:
Infects _______ per year
9 million
Tuberculosis:
______ resistant
disinfectant
Tuberculosis:
_____-fast
acid-fast
Tuberculosis:
Describe the pathology
- primary infection in lung (asymptomatic)
- causes hypersensitivity rxn to mycobacterium Ag
- granuloma
- dissemination through bloodstream (military TB)
Tuberculosis:
Describe the diagnostic process
-diagnose based on signs & symptoms
-culture ?
(Tb culture can be done but can take up to 6 weeks for visible colonies to form, so probably would initiate treatment before determining results)
-Tb test
Tuberculosis:
Describe the Tb test
- standardized amount of PPD (purified protein derivative) is injected subdermally (upper layers of skin)
- If there is an immune response, this means the person has Ab against Tb and therefore has been exposed to Tb
- This does not tell you if they have active Tb cells right now, someone who has been vaccinated against Tb will likely text positive so it is important to ask if they have been vaccinated.
Tuberculosis:
Describe the Tb test for immunocompetent individuals
“induration” > 10 mm - positive
Tuberculosis:
Describe the Tb test for immunosuppressed individuals
“induration” > 5 mm - positive
*they will have a weaker immune response so that’s why the size is smaller
Tuberculosis:
Which antibiotics treat it?
- Rifampin (RNA synthesis inhibitor)
- Isoniazid (cell wall synthesis inhibitor)
- Ethambutol (cell wall synthesis inhibitor)
- Pyrazinamide (cell wall synthesis inhibitor)
Tuberculosis:
Describe treatment
at least 3 of the antibiotics previously listed
Tuberculosis:
Length of treatment
6-9 months
*non-compliance is an issue
Tuberculosis:
What is MDR-TB?
Resistant to at least isoniazid and rifampin
Tuberculosis:
What is XDR-TB?
MDR-TB + fluoroquinolone, and at least one of the three injectable second-line drugs (capreomycin, kanamycin, and amikacin)
What is cystic fibrosis?
Inherited disease of secretory glands
- cystic fibrosis transmembrane conductance regulator 9CFTR gene)
- The transport protein is not expressed properly and it results in a fluid imbalance across the membrane
Cystic fibrosis:
Most common lethal inherited disorder in ______
caucasians
1/2500 births
Cystic fibrosis:
What does it cause?
- pancreatic insufficiency
- abnormal sweat electrolyte concentrations (salt concentration in their sweat is 5x that of a normal person)
- production of very viscid bronchial secretions
Cystic fibrosis:
Describe the microbes that colonize in the lung
- P. aeruginosa (almost all patients 15-20 yrs)
- S. aureus (younger pts)
- B. cepacia
Cystic fibrosis:
If the infection is drug resistant, what is the only option available?
lung transplant
Cystic fibrosis:
Most damage is from?
our own immune cells
- P. aueruginosa produces virulent factors that cause the immune system to start attacking the lungs
- see slide 39 for diagram
Summary:
LRT infections spread through _____ route
airborne
Summary:
____ if not treated properly
fatal
Summary:
Pneumonia is caused by a variety of _____
pathogens
Summary:
Predisposing factors for pneumonia?
- age
- underlying disease
- occupational/geographical factors
Summary:
Tb complicated with ____
AIDS
Summary:
Cystic fibrosis is an _____ disease
inherited
