Lower Respiratory Tract Infections Flashcards
Common LRTIs
Bronchitis
Bronchiolitis
Pneumonia
Influenza
Acute Bronchitis Aetiology
90% viruses
10% bacteria
Acute bronchitis viruses
Adenovirus Coronavirus Parainfluenza Influenza Rhinovirus Severe bronchiolitis (children <2)- respiratory syncytial virus
Acute bronchiolitis bacteria
Bordetella pertussis
Mycoplasma Pneumonia
Acute bronchitis symptoms
Sore throat
Fatigue
Fever
Body ache
Inflammation of bronchi
Viral RNA recognised by TLR3 and RIG-I-like receptors
Release of inflammatory mediators + chemokines
Type I IFNs upregulate pro-apoptotic factors in epithelial cells
TNF alpha + chemokines recruit NK cells + PMNs that kill infected cells
Pneumonia
Inflammation of the alveoli in either or both lungs
Pneumonia Aetiology
Streptococcus pneumoniae most frequent causative agent
S. Pneumoniae antibiotic resistance
Penicillin 10%
Macrolides 15%
Pneumonia pathophysiology
Recognition of S. Pneumoniae by APC cells
Th1, Th2 + Th17
Activation of antibodies
Upper airway exposure- mainly IgA response
Th1
Activation of respiration macrophages
Th2
Production of specific antibodies
IgA
IgG
Th17
Neutrophilic infiltrate of lungs- essential components for protection against S. Pneumoniae
Loss of Barrier Function
Between alveoli and capillaries
May lead to spread of infection (sepsis) and systemic immune response
Pneumonia diagnosis
Physical exam Complete blood count Sputum culture Urine test PCR CT scan