Week 1 - Respiratory infections Flashcards
Virus that causes the common cold
Rhinovirus
Rhinovirus causes symptoms of both upper and lower respiratory tract
False, only the upper respiratory tract
What type of virus is rhinovirus?
Unenveloped (naked) RNA virus; part of the picornaviridae family
Rhinovirus is an “acid labile” virus, what does that even mean?
That it doesn’t cause GIT symptoms because it can’t survive @ acidic environment
Patient presents with fever, rhinorrhea, purulent nasal discharge and cough; they also present with pressure @ head, congestion and loss of smell and taste, who tf virus caused this?
Rhinovirus
The diagnosis for the common cold/ rhinovirus can only be done with a PCR test
False, the diagnosis for rhinovirus is clinical
Asthma exacerbations and sometimes bronchiolitis are common symptoms of adenovirus
False, these are common in rhinovirus
Therapy for the common cold/ rhinovirus
- Resting
- Hydration
- Antipyretic (paracetamol) when patient feels like shit
Common cold mechanism of transmission
Transmitted through secretions
Receptors to which rhinovirus binds
- LDL-R
- ICAM1
- CDHR-3
Most susceptible ppl for rhinovirus
- Bbys and elderly
- Immunocompromised
- Respiratory disease: COPD, asthma, cystic fibrosis
Where is the ICAM1 receptor rhinovirus adheres to located
At CD54 on epithelial cells lining the respiratory tract
Types and serotypes of rhinovirus
- More than 110 serotypes detected
- RV-A, RV-B and RV-C
The only DNA virus that causes respiratory tract infection we saw on this course
Adenovirus
Clinical symptoms of adenovirus
- Respiratory tract infections
- Ocular disease/ CONJUNTIVITIS
- Gastroenteritis + diarrhea sometimes
- Cystitis
- Inflamed adenoids/ lymphoid tissue
Mechanism of transmission of adenovirus
- Respiratory droplets
- Fecal-oral route
Adenovirus causes outbreaks @ daycare and summer camps and stuff like that
Yes
Types of adenovirus that cause gastroenteritis
40 & 41
Types of adenovirus that cause cistitis
7, 11 & 21
Pharyngoconjuntival fever is not a common sign of adenovirus because conjuntivitis isn’t even a sign for adenovirus
False, pharyngoconjuntival fever and conjuntivitis are signs and symptoms of adenovirus
Why tf is it called adenovirus?
Bc it was found @ adenoid tissue
Receptors to which adenovirus attaches itself
- Dsg-2
- CAR
- CD46
Is there a vaccine for adenovirus?
Yes, its a live oral vaccine given to the military
Epidemic keratoconjuntivitis is caused by which serological adenovirus types?
8, 19 & 37
HAdV was intended to be used as a vector for?
As gene therapy for Covid-19 vaccines
Enveloped, negative-sense, single strand RNA and a segmented genome virus; part of the Orthomyxoviruses
Influenza virus
Can influenza cause epidemics?
Yes, it can cause epidemic acute respiratory disease (fever, cough + systemic symptoms)
What are the 3 types of influenza virus
A, B and C
The constant antigenic evolution of the influenza virus can lead to 2 things called
Shift and Drift
Surface antigens present on the capsule of the influenza virus
- Hemagglutinin (HA)
- Neuraminidase (NA)
Receptor to which the influenza virus attaches to
Salic acid sugar receptor
Where does the influenza virus bind to the silica acid sugar?
@ epithelial cells located in the upper respiratory tract
Influenza virus transmission
Person to person: respiratory droplets or indirectly through contaminated surfaces
Diagnosis for influenza
- Clinically due to the epidemics
- Characteristic symptoms of cough and fever
- Antigen detection: PCR
- Viral culture
When do symptoms start after getting infected with influenza virus?
1 to 4 days later
Symptoms of Influenza
- Headache
- Fever
- Runny nose
- Sore throat + dry cough
Physical examination characteristics in a patient with influenza
- Conjuntivitis
- Pharyngeal erythema
- Abnormal lung sounds: wheezing, ronchi or crackles
Influenza complications include
- Acute otitis media
- Bronchiolitis
- CROUP
- Sinusitis
- Pneumonia (Staph aureus and Strep pneumoniae)
Who are at high risk for influenza complications?
- Young children <6 months
- Preggo women
- Adults >65
- Chronic health conditions (heart/ lung disease)
Neurologic complications that Influenza can cause in young children <6 months
- Encephalitis
- Febrile seizures
- Reye syndrome if aspirin is taken
Treatment for influenza A & B
Oseltamivir (oral): neuraminidase inhibitor
Medical profilaxis for influenza A & B
- Oseltamivir
- Zanamivir
M2 proton channel inhibitors like Adamantine work wonders because M2 mutations are very rare
Falsee, M2 mutations occur often and lead the virus to become resistant
Prevention for influenza
- Vaccines are effective @ preventing influenza
- Inactivated/ live-attenuated vaccines (sprayed)
- Trivalent
- A vaccine is generated every winter season
Virus that causes both upper and lower respiratory tract illnesses
RSV: Respiratory Syncytial Virus
Where tf did RSV get its name?
It causes cells lining the respiratory tract to merge and cause the cells to transform to a multi-nucleated syncitia
Leading cause of bronchiolitis @ infants
RSV
RSV signs and symptoms
- Pneumonia (crackeling rales heard)
- Bronchioles (wheezing + damage @ bronchioles)
Causes of bronchiolitis
- Edema
- Vasoconstriction
- Obstruction
What type of virus is RSV?
- Enveloped non-segmented RNA virus
- Pneumoviridae
- 2 groups: A & B
What’s the diagnosis for RSV?
- Clinical diagnosis accurate during winter (time of the year), age and symptoms
- $$$: lab culture, PCR or antigen
Not being breastfed, being born prematurely and having a neuromuscular disorder are all…
Risk factors for RSV
Is there any specific treatment or therapy for RSV?
Supportive treatment (oxygen and fluids)
Any experimental treatment for RSV?
Aerosolized Ribavirin @ high risk patients + immunocompromised patients (only @ USA)
How does RSV enter the cell?
By merging with the cell membrane
G protein @ RSV does what?
G protein stands for glycosylation which helps with antibody avoidance
F protein @ RSV does what?
F protein stands for conformational change and helps with infectivity and protection
NS1 & NS2 (present in RSV viral structure) inhibit…
IFN 1
Who are at risk for RSV
- Babies @ the NICU
- Babies
- Children
Mechanism of transmission for RSV
Contact with droplets or contaminated surfaces
Other symptoms of RSV
- Fever
- Congestion
- Difficulty breathing
- Acute otitis media
- Rhinorrhea
RSV complications include
- Central apnea: short periods of time with NO breathing
- Hypoxia
Most common cause of CROUP
Parainfluenza virus
Parainfluenza virus is also the second most common cause of…
Acute respiratory infections in children less that 5 years of age
Symptoms of parainfluenza virus
Acute respiratory illness
- Colds
- CROUP
- Bronchiolitis (narrow airways)
- Pneumonia
CROUP has a specific pulmonary sound, which one is it?
Inspiratory stridor (high pitched, whistling sound)
Types of PIV that can infect humans
PIV-1, PIV-2, PIV-3 and PIV-4
Seasonal outbreaks of parainfluenza virus are @?
Fall, PIV-1 and PIV-2
Which parainfluenza virus type causes outbreaks @ odd number years
PIV-1
PIV-1 is also commonly associated with
CROUP in children
Which PIV causes annual epidemics @ spring
PIV-3, also severe @ immunocompromised patients and children
PIV-4 is the most dramatic and deathly of them all
False, its milder disease that affects both upper and lower respiratory tract (super rare)
What type of virus is PIV?
Single-stranded enveloped (lipid membrane) RNA; paramixoviridae family
Glycoproteins preset on the viral structure of PIV
- F: fusion
- HN: Hemagglutinin-Neuraminidase
PIV virus is such a loser and copies Influenza and uses the same receptor, which one is it?
Sialic acid sugars
What test can be done to diagnose PIV
Culture or PCR but $$$
An X-ray of the neck will show narrowing of the trachea, what’s the name of this “sign”
Steeple sign
An X-ray of a patient with pneumonia caused by PIV will show consolidation
True
Treatment for the CROUP presented in PIV
Glucocorticoids and nebulized epinephrine @ children
Ribavirin & IV immunoglobulins work wonders in PIV
False, efficacy is uncertain
Signs and symptoms of CROUP
- Cough: loud barking
- Fast breathing + noisy breathing + wheezing
- Nasal congestion
- Hoarseness @ speech
- Worse @ night
Symptoms of bronchiolitis
- Chest congestion
- Clogged and sore throat
- Coughing
- Wheezing
Symptoms of pneumonia
- Shortness of breath
- Chest pain
- Productive cough (pus/ bloody sputum)
Which types of PIV cause CROUP
Types 1 and 2
Which type of PIV causes lower airway damage leading to pneumonia
Type 3
Since PIV infection is self-limiting it can be treated with antipyretics and hydration
Correct slay
Treatment for bronchiolitis caused by PIV
- Supplemental oxigen
- Fluids
Gram + diplococci, lancet shaped and alpha-hemolytic
Streptococcus pneumoniae
Most common cause of community-aquired pneumonia
Streptococcus pneumoniae
Microscopic characteristics of Streptococcus pneumoniae
- Gram + diplococci
- Polysaccharide outer capsule (virulence factor, serotypes and target for vaccines)
- Peptidoglycan cell wall (purple)
- Non-motile
- Facultative anaerobes
- NO spores
- Catalase negative
What type of hemolysis does S. pneumoniae cause on blood agar
Green hemolysis due to the production of hydrogen peroxide
Strep pneumoniae is a common cause of
Invasive Pneumococcal Disease
Clinical manifestations for pneumococcal disease are divided into 2
- Invasive
- Non-invasive or mucus related
Invasive pneumococcal disease can present as
- Meningitis
- Bacteriemia
- Sometimes pneumonia
Non-invasive pneumococcal disease can present as
- Pneumonia
- Acute otitis media
- Sinusitis
Mechanism of action in which S. pneumonia causes pneumonia
- Adheres to alveolar cells
- Release of pneumolysin
- Destruction of pneumocytes + alveolar capillaries
Fever, chills, chest pain and cough are all symptoms of pneumonia
Duh
Leading cause of pneumonia and bacterial meningitis @ children
Streptococcus pneumoniae
Is the incidence higher @ some ages for Streptococcus pneumoniae?
2 years old and adults > 65 years old
Large outbreaks are common whereas small outbreaks are uncommon when it comes to S. pneumoniae
False, the other way around
What even is pneumolysin found at S. pneumoniae
Pore forming toxin that causes epithelial and endothelial damage
Asymptomatic clinical manifestations of S. pneumoniae
- Otitis media
- Sinusitis
- Pneumonia
Symptomatic clinical manifestations of S. pneumoniae
- Bacteriemia
- Meningitis (by crossing the BBB)
- Empyema
- Endocarditis
- Septic arthritis
Bacteremia is caused when S. pneumoniae crosses the alveolar capillaries and enters the blood stream, it can lead to sepsis, which group of ppl are more at risk for developing sepsis?
Ppl with spleen problems bc of its important role in immunity (ppl with splenectomy or sickle cell anemia)
Other clinical manifestations of S. pneumoniae
Crackles and localized pleural pain
Diagnosis for S. pneumoniae
- Cultures of pus, sputum, CSF or peritoneal fluid
- PCR to detect S. pneumoniae DNA
Treatment for S. pneumoniae
- Beta-lactam antibiotics
- Resistance for penicillin and derivatives
- Fluroquinolones
- Amoxicillin + Clavulanic acid
- IV treatment (3rd gen cephs): ceftriaxone and cefotaxime
Are there any vaccines for S. pneumoniae? If so, mention them:)
2 vaccines provide protection against invasive pneumococcal disease
- PCV13 (polysaccharide-protein vaccine) protects up to 90% recommended for adults
- PCV23 (Conjugate vaccine) protects from 54-81% @ adults recommended in young children
S. pneumoniae has a reservoir, where tf?
Nasopharynx
Virulance factors present in S. pneumoniae
- Capsular polysaccharides + pili and fimbriae
- Biofilm production
- PspA
- IgA1 protease: toxin that destroys IgA
- Autolysin
- Pneumolysin
What the fuck does pneumolysin do
Binds to cholesterol in cell membranes and forms pores; causing cell lysis
Individuals at risk for S. pneumoniae
- Infants and elderly
- HIV infection
- Diabetes
- Malignancy
- Alcohol and tobacco use
Gram - cocobacillus fastidioso asf
Haemophilus influenzae
Micro characteristics of Haemphilus influenzae
- Non motile
- Facultative anaerobic
- Catalase and oxidase +
- Cultivated on chocolate agar bc it has factor V and factor X (white/ transparent colonies)
Haemophilus influenzae virulenze factors
- Polysaccharide capsule
- Pili
- Adhesion proteina HMW1 and HMW2
- IgA protease to destruct IgA
2 extra virulance factors that only UNENCAPSULATED Haemophilus influenzae has
- Phase variation: allows oligosaccharides to change/ variate; immune system can’t remember
- Biofilms
With the help of… Haemophilus influenzae can colonize the respiratory tract
Lipooligosaccharides (LOS)
Two types of Haemophilus influenzae
- Non-encapsulated
- Encapsulated
Encapsulated Haemophilus influenzae has surface antigens, which ones?
A B C D E F
Another name unencapsulated Haemophilus influenzae gets is
Non-typable, bc of lack of antigens
Which strains of H. influenzae are more known to cause a disease
- Encapsulated type B
- Unencapsulated/ Nontypanble
Non-encapsulated Haemophilus influenzae causes…
- Otitis media @ children
- Sinusitis
- Bronchitis
- Exacerbations of COPD @ adults
Encapsulated Haemophilus influenzae causes…
Invasive infections like:
- Meningitis
- Epiglotitis
- Septic arthritis
- <6 y/o | type B
- Cellulitis @ face
- Bacteremia
What even is epiglottitis
- Swollen epiglottis
- Blockage of airway
- Sore throat
Encapsulated H. influenzae type B causes epiglottitis, what are the symptoms?
- Fever
- Sore throat
- Difficulty speaking
- Dyspnea
Encapsulated H. influenzae type B can cause meningitis, what are the symptoms present?
- Fever
- Lethargy
- Irritability
- Vomiting
- Sore/stiff neck
- Altered mental state
Encapsulated H. influenzae may cause cellulitis, what symptomatology accompanies it?
- Fever
- Warm tender area of erythema @ cheek and periorbital area
Patients with epiglottitis can’t swallow soooo
They drool
Ecologic niche of nontypable Haemophilus influenzae
Human respiratory tract + colonization of nasopharynx
Haemophilus influenzae is most common during adulthood
False, its common during childhood and decreases @ adulthood
A common characteristic of the growth requirements of Haemophilus influenzae is
Fastidious growth
Haemophilus influenzae is not part of the normal flora of the human upper respiratory tract
False, it is
Therapy for Haemophilus influenzae type B
Ceftriaxone or cefotaxime
Therapy for nontypable Haemophilus influenzae
- Amoxicillin +/- clavulanate
- 3rd and 2nd generation cephalosporins
- Macrolides or quinolones
Vaccine for Haemophilus influenzae type B is given @ how many months?
2 months
Fever, ear pain and otorrhea are all symptoms of… caused by nontypable H. influenzae
Otitis media
Fever, tenderness of affected sinuses and persistent purulent nasal discharge are all symptoms of… caused by nontypable H. influenzae
Sinusitis
Gram - diplococcus
Moraxella catarrhalis
Common cause of otitis media in children and exacerbations of COPD in adults (besides H. influenzae)
Moraxella catarrhalis
Respiratory tract infections that M. catarrhalis can cause in loser kids
- Bronchitis
- Rhinosinusitis
- Laryngitis
Microbiological characteristics of Moraxella catarrhalis
- Non-motile
- Non-spore forming
- Aerobic
- Maltose fermentation negative (solution stays red)
- Oxidase +
- Grows well on blood and chocolate agar
M. catarrhalis can be moved around the agar without breaking, this means its positive for…
Hokey puck test
M. catarrhalis’ favorite place for colonization
Nasopharynx + upper respiratory tract (as well as the others:()
M. catarrhalis looks like _____ @ the gram stain and culture
Neisseria
M. catarrhalis produces…
- Oxidase
- Catalase
- DNAse
Can you treat M. catarrhalis with beta-lactam antibiotics
- No, they produce beta-lactamase which means RESISTANCE
- Amoxicilin + calvulanate, Macrolides, Fluroquinolones and Extended spectrum Cephalosporines should do the trick
Vaccine for M. catarrhalis is applied at 4 months
False, there isn’t even a vaccine
M. catarrhalis is an opportunistic bitch
Yuh
Mycoplasma pneumoniae causes
Atypical pneumonia
Characteristics of M. pneumoniae
- Slower onset & generally milder
- No lobar consolidation
- Lacking cell wall
- Adhesins and adhesion organelle (pathogenesis)
- Fastidious
- Facultative anaerobe
List 3 common places someone can get an M. pneumoniae infection… GO
- Children @ school
- Young adults @ uni
- Military recruits
Where does Mycoplasma pneumoniae replicate?
Inside the cell… evades immune system
Extrapulmonary skin manifestations caused bc M. pneumoniae
- Macopapular vesicular rashes
- Stevens-Johnson Sx.
Extrapulmonary cardiac manifestations caused bc M. pneumoniae
- Pericarditis
- Miocarditis
Extrapulmonary CNS manifestations caused bc M. pneumoniae
- Encephalitis
- Myelitis
- Radiculopathy
Extrapulmonary musculoskeletal manifestations caused bc M. pneumoniae
- Myalgia
- Rhabdomyolysis
- Arthritis
Extrapulmonary renal manifestations caused bc M. pneumoniae
- Glomerulonephritis
- Nephrotic syndrome
What can aid in the diagnosis of M. pneumoniae
Presence of cold agglutinins
Treatment for M. pneumoniae consists of
- Macrolides (azithromycin)
- Tetracyclins (doxycycline)
- Fluroquinolones (maxifloxacin)
Lab tests done on someone with pneumonia caused by M. pneumoniae
- CBC @ hospitalized patients
- Blood culture @ patients with failed antimicrobial therapy
- PCR + viral cultures NOT RECOMMENDED
Otitis media + fever + other systemic manifestations can be caused by many microorganisms, what is the virulence factor responsible for this?
Capsid (Haemophilus influenzae type b, Streptococcus pneumoniae)
Virus that can cause gastrointestinal, respiratory and genitourinary infections
Adenovirus
Adenovirus manifestations per system
- Respiratory: common cold, sore throat and pneumonia
- GIT: diarrhea
- Genitourinary: cystitis
4 F of the fecal-oral route
- Flies
- Fluids
- Fields
- Fingers
Adenovirus attaches itself to the receptor via the “fiber-like” projections it has, what effects does it have on a cellular level?
- Inhibition of DNA synthesis
- Inhibition of the production of proteins
- Cellular lisis
- Inflammatory response from the host
Inflammatory response caused by adenovirus
Leukocytes produce pro-inflammatory cytokines and histamine, dilation of blood vessels
Upper and lower manifestations of adenovirus
- Upper: infectious rhinitis (common cold), pharyngitis and tonsillitis
- Lower: pneumonia
GIT adenovirus infection symptoms
- Fever
- Nausea and vomiting
- Watery diarrhea
Conjunctivitis symptoms in regards to an adenovirus infection
- Eye irritation
- Soreness
- Redness
- Photophobia
- Excessive tearing
Adenovirus can cause pharyngoconjunctival fever, what signs and symptoms need to be present for it to occur?
- Conjuntivitis
- Fever
- Pharyngitis
- Inflammation of lymph nodes in the neck
Disseminated adenovirus infection is more common in
Immunocompromised patients (it has a high mortality rate)
Virus that causes “the flu”
Influenza
All three types of influenza can infect both humans and animals
False, type B influenza only affects humans
Most severe type of lnfluenza
Type A
Why can you get sick from influenza year after year? (shift or drift)
Because of the antigenic “drift”
Mycoplasma pneumonia may be asymptomatic or have nonspecific symptoms such as:
- Fatigue
- Sore throat
- Mild fever
- Dry hacking cough
In comparison to a pneumonia caused by Streptococcus pneumoniae, a pneumonia caused by Mycoplasma pneumonia is (more severe/ milder)
Mild, the patient may actually feel kinda good
Atypical pneumonia can also be called
Walking pneumonia
Chest X-ray of walking pneumonia looks…
Patchy infiltrates
Why are beta lactam antibiotics inefficient in treating Mycoplasma pneumoniae
Bc they don’t have a cell wall, use tetracylines or macrolides
Agar in which Mycoplasma pneumoniae grows
Eaton’s agar, it formes dome-shaped colonies that look like fried eggs (takes 2 to 3 weeks tho)