13. Overview of viral, bacterial and fungal respiratory infections Flashcards
Symptoms of pneumonia
Fever (>38.0 °C)
Sweating/shivers
aches and pains
Pleural chest pain
Respiratory distress (tachypnoea, dyspnoea)
Diagnostic approach - Pneumonia
Oxygen sats
arterial blood gases
U+E
FBC
LFT
Microbiological examinations - Pneumonia
Urine antigen test
Sputum culture
Blood culture
Nucleic acid amplification test
Serological test
Pneumococcal pneumonia
Acute onset
Flu-like symptoms
Pleural chest pain
T ≥ 39 °C
CXR usually lobar or multilobar shadowing
Complications
Reactivation of latent infections (cold sore, shingles) Pleural effusion → empyema Pyo-pneumothorax Pericarditis Lung abscess Metastatic infections Endocarditis Meningitis, brain abscess Septicaemia
Cryptococcosis Treatment:
Amphotericin B and Flucytosine
Aspergilloma Treatment:
Itraconazole
ABPA Treatment:
steroids by aerosol or mouth
Invasive Aspergillosis Treatment:
Voriconazole
Transmission Diphtheria
Primary reservoir in humans
Acute, contagious disease
Nasopharyngeal secretions
usually affecting children
expelled in aerosol droplets and contact
Diphtheria Symptoms
greyish pseudomembrane on respiratory mucosa
Thick nasal discharge
fever and cough
Bull neck
cutaneous skin lesions
Diphtheria toxin
exotoxin released into the bloodstream
Bacteria remain in the upper respiratory tract
Toxin functions by ADP-ribosylation of translation elongation factor 2 (EF2)
EF2 is inactivated and host protein synthesis blocked
Diphtheria treatment
Antitoxin
Penicillin and erythromycin
Diphtheria Prevention
Immunisation with DTaP
Pertussis symptoms
breathing difficulties
Convulsions
cyanosis
Sporadic coughing
Pertussis toxin
ADP ribosylates a Giα1
causes a rise in host cell cAMP levels
Induces respiratory mucus secretions
Pertussis prevention
Immunisation with DTaP
Legionnaires’ Disease transmission
Environmental reservoir: no person-person transmission!
Legionnaires’ Disease symptoms
Acute pneumonia
Pericarditis
endocarditis
Pontiac Fever
Legionnaires’ Disease high susceptibility
1) Elderly people 2) Males 3) Immunocompromised
Legionnaires’ Disease treatment
Erythromycin
regular chlorination of water tanks
heat sterilisation of air-conditioning systems
INFLUENZA symptoms
fever myalgia headache pharyngitis
Influenza Source
reservoir is acute infection in other human beings
Influenza Spread
via aerial droplets and fomites
Influenza Incubation
Is short: 1-3 days
RSV source
Human beings
RSV spread
mainly as fomites
RSV Incubation
2-5 days
RSV symptoms
Intermittent fever
Pharyngitis
Coughing/sneezing
Labored breathing
Fast breathing
RSV treatment
Ribavirin aerosol oxygen therapy
Parainfluenza Source
reservoir is acute infection in other human beings
Parainfluenza Spread
aerial droplets and fomites
Parainfluenza Incubation
1-7 days
Parainfluenza Symptoms
hPIV-3 = bronchiolitis and pneumonia
HPIV-4 = Mild cold-like disease
PIV Treatment
infants nursed in plastic tents supplied with oxygen
anti-inflammatory drugs
Antibiotics
Reyes Syndrome
Abnormal accumulation of fat
in liver and brain
Reyes Syndrome factors that increase risk
1) Viral infection
2) Use of aspirin
