ICU · Infectious Diseases

Acute severe community-acquired pneumonia: post-influenza bacterial pneumonia

Also known as Post-influenza pneumonia · Bacterial superinfection · Staphylococcal pneumonia post-influenza

Post-influenza bacterial pneumonia is a devastating complication — influenza virus damages respiratory epithelium → secondary bacterial invasion. Most common organisms: Staphylococcus aureus (1, including MRSA and PVL-positive strains — causes necrotising pneumonia with high mortality), Streptococcus pneumoniae (2), Haemophilus influenzae. Presents as: initial viral illness (fever, myalgia, cough) → transient improvement → sudden deterioration (high fever, dyspnoea, septic shock, multilobar infiltrates, cavitation). Diagnosis: influenza PCR + sputum/blood cultures + urinary antigens. Treatment: antiviral (oseltamivir) + broad-spectrum antibiotics (cover MRSA — add vancomycin/linezolid) + supportive ICU care. Mortality: 20-40%.