Diebel: Micro Respiratory Infectious Diseases 2 Flashcards
What are infections of the LRT?
Bronchitis
Bronchiolitis
Pneumonia
(pertussis and influenza)
What pathogens are associated w/ borncihitis?
MAINLY viral infections
Bacterial secondary infections are possible
What pathogens are associated w/ bronchiolitis?
VIRAL infection of INFANTS (RSV)
What pathogens are associated w/ influenza?
VIRAL infection that can lead to pneumonia through a bacterial secondary infection
What pathogens are associated w/ pertussis?
BACTERIAL infection > 90% of cases are B. pertussis
What pathogens are associated w/ pneumonia?
Widely varying causes
Viruses- MC in children
Bacteria
Fungi
A pt presents w/ cough, fever and chest pain. What may they have?
Bronchitis
What do you often see prior to the onset of bronchitis?
Signs of the common cold
Do chest radiographs for bronchitis reveal consolidates or infiltrates?
No
What causes bronchitis?
Viral URI that extends DOWN to trachea, bronchi and bronchioles>
hacking COUGH w/ some SPUTUM produciton
Does bronchitis involve the alveoli?
NO
What population is bronchitis most commonly seen in?
Children and elderly
How do you diagnose bronchitis and differentiate it from pneumonia?
Clincial signs and sxs
CXR needed for differentiation
How do you tx Bronchitis?
Don’t it’s typically self limiting
What do you do if a bronchitis lasts longer than 14 days and a pt has a fever and purulent sputum?
Bacterial identification
Antibiotic treatment (erythromycin and azithromycin)
What microorganisms cause bronchitis?
Rhinovirus Parainfluenza virus RSV Influenza A and B Cox A and B Adenovirus
Rhinovirus
RNA
Nonenveloped
Class IV SS + Nonsegmented
Picornaviridae
Paramyxovirus
RNA
Enveloped
Class V SS = Nonsegmented
Paramyxoviridae
RSV
RNA
Enveloped
Class V SS - Nonsegmented
Paramyxoviridae
Pneumovirus
What is the MCC of penumonia in young children?
RSV
parainfluenza virus
Influenza A and B
RNA
Enveloped
Class V SS - Nonsegmented
Orthomyxoviridae
Cox A and B
RNA
Nonenveloped
Class V SS + Nonsegmented
Picornaviridae
Enterovirus
Adenovirus
DNA
Nonenveloped
Group I DS linear DNA
Adenoviridae
What is the MCC of aseptc meningitis?
Cosackie
Echo
Mumps
What is the MCC of palm and sole rash?
Syphilis
RMSF
Cosackie
What is the MCC of conjunctivitis?
H inflluenza
Adeno
S. pneumoniae
What bacteria cause bronchitis?
Mycoplasma pneumoniae
Chlamydia pneumoniae
Are Myoplasma pneumoniae and chlamydia pneunoniae gram + or -?
Neither!
What is the MCC of atypical pneumonia?
Mycoplasma
legionella
Chlamydia
Viruses
What ishte MCC of pneumonia in adults?
Mycoplasma
C. pneumoniae
s. pneumoniae
What are two obligate intracellular parasites (require host ATP for energy)? Which replicates w/ inclusion bodies?
Clamydiae–replicates w/ inclusion bodies
Rickettsiae
What is bronchiolitis?
Inflammation of the bronchial trees as LOW as the bronchioles but NO alveoli involvement
Who does bronchiolitis commonly affect?
Infants younger than 1 year d/t NARROW developing of the airways
- typically preceded by a minor viral URI
How do you diagnose bronchiolitis?
Clinical signs and sxs and chest x-ray to rule out pneumonia
In diagnosing bronchiolitis, how can you rule out pneumonia?
Ag testing for RSV
How can you protect pts at risk for bronchiolitis?
Passive immunization w/ anti-RSV antibodies
What are the causes of Bronchiolitis? Which is MC?
**RSV
Parainfluenza
Adeno
What are the two distinct symptom phases of pertussis?
Catarrhal stage
Second (paroxysmal stage)
What characterizes the catarrhal stage of pertussis? How long does it last?
Incubation period of 3-21 days>
Stage begins w/ bacteria present in RT and appearance of COLD sxs, esp RUNNY NOSE.
1-2 Weeks
What characterizes the second stage of pertussis? What is the danger of uncontrolled coughing?
SEVERE and UNCONTROLLABLE COUGHING
It can lead to burst blood vessels in the eyes, vomiting, seizures from small hemorrhages in the brain.
What is the convalescent phase of pertussis?
Pertussis bacteria are decreasing and no longer causing ongoing symptoms.
What happens to the body during the active stages of Pertussis?
Damage to the CILIA on RT epithelial cells
complete recovery takes weeks or even months
How long does it take the body to recover from damage caused by pertussis? What can happen during this time?
weeks to months
other microorganisms can more easily COLONIZE and cause SECONDARY INFECTIONS
What toxins does pertussis have?
AB toxin
tracheal cytotoxin
What does the AB toxin do?
Results in high levels of cAMP>
Mucous production>
blocks airways>
coughing spasms
What does the tracheal cytotoxin do?
Kills ciliated cells
B. Pertussis
Bacteria
Gram -
Coccobacilli pleomorphic
Bordet gengou medium
What type of agar is the selective growth for Bordatella?
Bordet gengou
What initially causes influenza infection?
Influenza A and B
How does influenza infect the larynx mucosa?
Inhaled through aerosols. Infects the LARYNX mucosa via contact of the viral hemagglutinin HA envelope protein with SIALIC ACID on cell surfaces (leads to endocytosis).
What permits viral spread of influenza?
The viral neurominidase (NA) envelope protein is important for cleaving HA bound to sialic acid, this permits viral spread.
What does replication of Influenza lead to?
Virus replication in host cells can lead to death of the host cell leading to tissue damage and disease. The immune response to infection also contributes to disease via production of IL-1 and IFN-γ.
What is antigenic shift?
when MAJOR changes in Ag occur d/t GENE REASSORTMENT in the influenza virus.
How does antigenic shift occur?
Susceptible host get infected by two types of viruses. Both are in a single cell and get mixed and matched during replication leading to a NEW virus particle.
What is antigenic DRIFT?
When MINOR changes in Ags occur d/t GENE MUTATION.
What controls influenza outbreaks?
Immunization
Is there a new vaccine for immediate use when strains evolve?
NO
it takes 6 months
What is pneumonia?
Inflammatory condition of the lung in which FLUID fills the alveoli>
diffuse consolidation on CXR
What is the MCC of Pneumonia? Other causes?
S. Pneumoniae
S agalactiae (Group B strep)
N. Asteroides
S. Pneumoniae
Bacteria Gram + diplococci Catalase - Alpha hemolytic Bile esculin negative optochin susceptible
What are common causes of pneumonia in adults?
40-65
s. pneumoniae
h. influenzae
legionella
What are common causes of pneumonia in elderly?
> 65
s. pneumoniae
gram - rods
H. influenze
What are the MCC of meningitis in 60 year olds?
s. pneumoniae
gram - rods
listeria
What is the MCC of neonatal meningitis?
group B strep
e. coli
listeria
What is unique about nocardia and myocbacteria?
Both have acid fast staining
What is unique about nocardia and a. idraelii?
Both resemble FUNGI
but only A. israelii forms SULFUR GRANULES
only nocardia is ACID FAST
S. AGALACTIAE
Bacteria gram + cocci catalase - beta hemolytic bacitracin resistant
N. asteroides
Bacteria gram + beaded filaments weakly acid fast obligate aerobe
A 2-month-old girl suffered from a cough for more than 2 weeks. The patient’s mother became concerned when the child turned blue after a couple of coughing spells that ended with vomiting. She brought her to a pediatrician. The patient had not yet received any vaccinations. She had recently been healthy without any underlying medical problems.
Pertussis
Abrupt onset of a high fever, chest pain and brown colored sputum is indicative of what?
Pneumonia caused by klebsiella pneumonia
In DECEMBER, a 73-year-old man from a NURSING HOME was brought to the hospital in ARD. He had been in his usual state of health until 10AM the previous day when he SUDDENLY developed fever, chills, muscle aches, cough, and prostration. Several other nursing home residents had developed a similar illness during the previous week. His past history is unremarkable and he had NOT SEEN DOC IN PAST YAER.
SEasonal influenza
