LRTIs Flashcards
What is the pathogenesis of influenza?
Hemagglutinin binds host sialic acid to initiate infection,
Neuraminidase cleaves host cell contact to escape
Bacterial and Viral Causes of Acute Bronchitis
Respiratory syncytial virus, influenza virus, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Bordatella pertussis
If patient presents with a cough persisting >3weeks, what should be suspected?
Bordatella pertussis
What is the most common LRTI in children <2yo?
Bronchiolitis -> RSV
What are the 2 most common pathogens associated with pneumonia in neonates?
E. coli, S. agalactiae (GBS)
What antibiotic is used to treat CAP as an outpatient vs inpatient?
Out: Amoxicillin (S. pneumo)
In: Ceftrixaone (Enterobacter)
What antibiotic is used to treat M. pneumoniae?
Macrolides (e.g. azithro)
***M. pneumo does not have a cell wall, therefore beta-lactams will not work
What classes of antibiotics are used to treat Legionella infection?
1st line: macrolides, 2nd line: floroquinolones
Most common pathogen associated with ventilator-acquired-pneumonia and ABx to treat?
Pseudomonas aeruginosa
pipercillin-tazobactam
What is empyema? What are the common culprits of empyema? Treatment?
Infected fluid in pleural space, typically by anaerobes. Drain fluid, administer ceftriaxone + metronidazole if chronic
What is the most common culprit of chronic pneumonia in teenage CF patients?
Pseudomonas
2 major viral causes of acute bronchitis
- Influenza
2. RSV
What is hemagglutinin (H)?
Viral protein that binds sialic acid on epithelial cell surface to initiate infection
What is neuraminidase (N)?
A viral enzyme that cleaves viral progeny from the host cell to allow their escape
What is antigenic drift?
Minor change in viral envelope glycoproteins
What is antigenic shift?
Major change in viral envelope glycoprotein that is associated with major epidemics and pandemics. The segmented genome allows reassortment in co-infected cells.
Clinical presentation of influenza
Illness begins with abrupt onset of fever, headache, myalgias, malaise along with sore throat, rhinorrhea and cough
How long should uncomplicated influenza last?
2-5 days. Viral shedding stops after 6-7 days.
What is the most common complication of the flu?
Pneumonia
Management of influenza
- Most cases are self-limiting
- Antiviral therapy for severely ill or those at risk of complications
- Those in (2) get Oseltamivir 75 mg PO BID. Must be given within 48 hours of symptom onset to be of benefit.
What precautions can be taken to prevent influenza transmission?
- Flu shot
- Droplet precautions
- Hand washing
List 3 bacterial causes of acute bronchitis
- Mycoplasma pneumoniae
- Chlamydophila pneumoniae
- Bordetella pertussis
Bronchitis without pneumonia is almost always caused by what?
A VIRUS
When should you consider Whooping Cough?
In a patient with persistent cough for > 3 weeks
What is COPD?
Disease characterized by airflow limitation that is not fully reversible. This limitation is usually progressive and is associated with an inflammatory response.
When is chronic bronchitis suspected?
Productive cough for at least 3 months/year for at least 2 consecutive years